Citations
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This panel provides information on past usage of this interatomic potential (IP) powered by the OpenKIM Deep Citation framework. The word cloud indicates typical applications of the potential. The bar chart shows citations per year of this IP (bars are divided into articles that used the IP (green) and those that did not (blue)). The complete list of articles that cited this IP is provided below along with the Deep Citation determination on usage. See the Deep Citation documentation for more information.
378 Citations (295 used)
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USED (definite) L. Zhang, Y. Shibuta, X. Huang, C. Lu, and M. Liu, “Grain boundary induced deformation mechanisms in nanocrystalline Al by molecular dynamics simulation: From interatomic potential perspective,” Computational Materials Science. 2019. link Times cited: 39 USED (definite) A. Prakash and E. Bitzek, “Idealized vs. Realistic Microstructures: An Atomistic Simulation Case Study on γ/γ′ Microstructures,” Materials. 2017. link Times cited: 15 Abstract: Single-crystal Ni-base superalloys, consisting of a two-phas… read moreAbstract: Single-crystal Ni-base superalloys, consisting of a two-phase γ/γ′ microstructure, retain high strengths at elevated temperatures and are key materials for high temperature applications, like, e.g., turbine blades of aircraft engines. The lattice misfit between the γ and γ′ phases results in internal stresses, which significantly influence the deformation and creep behavior of the material. Large-scale atomistic simulations that are often used to enhance our understanding of the deformation mechanisms in such materials must accurately account for such misfit stresses. In this work, we compare the internal stresses in both idealized and experimentally-informed, i.e., more realistic, γ/γ′ microstructures. The idealized samples are generated by assuming, as is frequently done, a periodic arrangement of cube-shaped γ′ particles with planar γ/γ′ interfaces. The experimentally-informed samples are generated from two different sources to produce three different samples—the scanning electron microscopy micrograph-informed quasi-2D atomistic sample and atom probe tomography-informed stoichiometric and non-stoichiometric atomistic samples. Additionally, we compare the stress state of an idealized embedded cube microstructure with finite element simulations incorporating 3D periodic boundary conditions. Subsequently, we study the influence of the resulting stress state on the evolution of dislocation loops in the different samples. The results show that the stresses in the atomistic and finite element simulations are almost identical. Furthermore, quasi-2D boundary conditions lead to a significantly different stress state and, consequently, different evolution of the dislocation loop, when compared to samples with fully 3D boundary conditions. read less USED (definite) Y. Wang, K. Tsuchiya, and L. Dai, “Size-dependent plastic deformation and failure mechanisms of nanotwinned Ni3Al: insights from an atomistic cracking model,” Materials Science and Engineering A-structural Materials Properties Microstructure and Processing. 2016. link Times cited: 17 USED (high confidence) I. Chesser, R. K. Koju, A. Vellore, and Y. Mishin, “Atomistic modeling of metal-nonmetal interphase boundary diffusion,” Acta Materialia. 2023. link Times cited: 0 USED (high confidence) B. A. Mohammed and R. S. Batbooti, “MD-based study on the deformation process of engineered Ni–Al core–shell nanowires: Toward an understanding underlying deformation mechanisms,” Curved and Layered Structures. 2023. link Times cited: 0 Abstract: Nowadays, core/shell structures due to very high thermal and… read moreAbstract: Nowadays, core/shell structures due to very high thermal and electrical conductivity are taken into account in the manufacture of many industrial sensors and catalysis. Ni–Al core/shell structures are known as one of the most practical materials due to their high chemical stabilities at elevated temperatures. Since the evaluation of the mechanical properties of the industrial core/shell catalysts is crucial, identification of the mechanism responsible for their plastic deformation has been a challenging issue. Accordingly, in this study, the mechanical properties and plastic deformation process of Ni–Al core/shell structures were investigated using the molecular dynamics method. The results showed that due to the high-stress concentration in the Ni/Al interface, the crystalline defects including dislocations and stacking faults nucleate from this region. It was also observed that with increasing temperature, yield strength and elastic modulus of the samples decrease. On the other hand, increasing the temperature promotes the heat-activated mechanisms, which reduces the density of dislocations and stacking faults in the material. Consequently, the obstacles in the slip path of the dislocations as well as dislocation locks are reduced, weakening the mechanical properties of the samples. read less USED (high confidence) T. Brink, L. Langenohl, H. Bishara, and G. Dehm, “Universality of grain boundary phases in fcc metals: Case study on high-angle [111] symmetric tilt grain boundaries,” Physical Review B. 2022. link Times cited: 6 Abstract: Grain boundaries often exhibit ordered atomic structures. In… read moreAbstract: Grain boundaries often exhibit ordered atomic structures. Increasing amounts of evidence have been provided by transmission electron microscopy and atomistic computer simulations that different stable and metastable grain boundary structures can occur. Meanwhile, theories to treat them thermodynamically as grain boundary phases have been developed. Whereas atomic structures were identified at particular grain boundaries for particular materials, it remains an open question if these structures and their thermodynamic excess properties are material specific or generalizable to, e.g., all fcc metals. In order to elucidate that question, we use atomistic simulations with classical interatomic potentials to investigate a range of high-angle [111] symmetric tilt grain boundaries in Ni, Cu, Pd, Ag, Au, Al, and Pb. We could indeed find two families of grain boundary phases in all of the investigated grain boundaries, which cover most of the standard fcc materials. Where possible, we compared the atomic structures to atomic-resolution electron microscopy images and found that the structures match. This poses the question if the grain boundary phases are simply the result of sphere-packing geometry or if material-specific bonding physics play a role. We tested this using simple model pair potentials and found that medium-ranged interactions are required to reproduce the atomic structures, while the more realistic material models mostly affect the grain boundary (free) energy. In addition to the structural investigation, we also report the thermodynamic excess properties of the grain boundaries, explore how they influence the thermodynamic stability of the grain boundary phases, and detail the commonalities and differences between the materials. read less USED (high confidence) Z. Zhang et al., “Simultaneously Achieving Strength and Ductility in Ni3Al Nanowires with Superlattice Intrinsic Stacking Faults,” International Journal of Mechanical Sciences. 2021. link Times cited: 7 USED (high confidence) Y. Nagatsuma, M. Ohno, T. Takaki, and Y. Shibuta, “Bayesian Data Assimilation of Temperature Dependence of Solid–Liquid Interfacial Properties of Nickel,” Nanomaterials. 2021. link Times cited: 8 Abstract: Temperature dependence of solid–liquid interfacial propertie… read moreAbstract: Temperature dependence of solid–liquid interfacial properties during crystal growth in nickel was investigated by ensemble Kalman filter (EnKF)-based data assimilation, in which the phase-field simulation was combined with atomic configurations of molecular dynamics (MD) simulation. Negative temperature dependence was found in the solid–liquid interfacial energy, the kinetic coefficient, and their anisotropy parameters from simultaneous estimation of four parameters. On the other hand, it is difficult to obtain a concrete value for the anisotropy parameter of solid–liquid interfacial energy since this factor is less influential for the MD simulation of crystal growth at high undercooling temperatures. The present study is significant in shedding light on the high potential of Bayesian data assimilation as a novel methodology of parameter estimation of practical materials an out of equilibrium condition. read less USED (high confidence) M. Prasad, A. Neogi, N. Vajragupta, R. Janisch, and A. Hartmaier, “Influence of Temperature on Void Collapse in Single Crystal Nickel under Hydrostatic Compression,” Materials. 2021. link Times cited: 3 Abstract: Employing atomistic simulations, we investigated the void co… read moreAbstract: Employing atomistic simulations, we investigated the void collapse mechanisms in single crystal Ni during hydrostatic compression and explored how the atomistic mechanisms of void collapse are influenced by temperature. Our results suggest that the emission and associated mutual interactions of dislocation loops around the void is the primary mechanism of void collapse, irrespective of the temperature. The rate of void collapse is almost insensitive to the temperature, and the process is not thermally activated until a high temperature (∼1200–1500 K) is reached. Our simulations reveal that, at elevated temperatures, dislocation motion is assisted by vacancy diffusion and consequently the void is observed to collapse continuously without showing appreciable strain hardening around it. In contrast, at low and ambient temperatures (1 and 300 K), void collapse is delayed after an initial stage of closure due to significant strain hardening around the void. Furthermore, we observe that the dislocation network produced during void collapse remains the sample even after complete void collapse, as was observed in a recent experiment of nickel-base superalloy after hot isostatic pressing. read less USED (high confidence) K. Ferasat, T. Swinburne, P. Saidi, M. Daymond, Z. Yao, and L. K. B’eland, “Interstitialcy-based reordering kinetics of Ni_3Al precipitates in irradiated Ni-based super alloys.” 2021. link Times cited: 0 USED (high confidence) A. A. Deshmukh and S. Pal, “Dynamic probing of structural evolution for Co50Ni50 metallic glass during pressurized cooling using atomistic simulation,” Journal of Molecular Modeling. 2020. link Times cited: 1 USED (high confidence) M. Zaenudin, M. N. Mohammed, and S. Al-Zubaidi, “Atomistic investigation on the effect of temperature on mechanical properties of diffusion-welded Aluminium-Nickel,” International Journal of Integrated Engineering. 2020. link Times cited: 1 Abstract: Joining two or more parts one of the industrial manufacturin… read moreAbstract: Joining two or more parts one of the industrial manufacturing processes required to satisfy the shape that either for functionality and appearance [1]. Several joining techniques have been proposed to satisfy these needs, and have shown very good performance for several applications, such as joining both similar and dissimilar metals [2]. By tracing the history of joining processes, at the first place, joining processes requires sort of fusion between the two, which in some cases will either reduce the performance of the material and sometimes also introducing several crack growth and embrittlement because it involves rapid solidification processes, thus heat treatment is necessary [3]. Furthermore, these techniques require other complex techniques to achieve an optimum parameter makes it economically not applicable [4]. Nowadays, solid-state welding in which the fusion of the materials during joining processes could be avoided is introduced. One of the methods of solid-state welding that is now widely used is diffusion-welding. Instead of only could be used for joining pure materials that are less complex, these techniques could also deal with the more complex materials ranging from alloys, compounds, several polymers, and so forth. Abstract: Atomistic investigation of diffusion welding between Aluminium and Nickel has been investigated, by means of Molecular Dynamics (MD) simulation. This study focuses on examining the effect of temperature on diffusion welding between Al-Ni for which it is still lacking. Employing several different temperatures, this study aims to examines the influence of temperature on the mechanical properties of diffusion-welded Al-Ni. The results have shown that the structural evolution significantly affected by the temperature. Better bonding structure is achieved as the temperature is increased which indicated by the wider interfacial region thickness on concentration profiles. However, as the temperature is increased lower ultimate tensile strength is obtained. Therefore, precisely estimates the temperature for particular materials in diffusion welding is a critical point. In this study, the optimum condition that fit on the diffusion welding process is when the temperature set on 500 K. read less USED (high confidence) R. Khusnutdinoff, R. Khairullina, A. Beltyukov, V. Lad’yanov, and A. Mokshin, “Viscous properties of nickel-containing binary metal melts,” Journal of Physics: Condensed Matter. 2020. link Times cited: 0 Abstract: The paper presents the results of molecular dynamics study o… read moreAbstract: The paper presents the results of molecular dynamics study of the viscosity of nickel-containing binary metal melts for a wide range of temperatures, including the region of the equilibrium liquid phase and supercooled melt. It is shown that the temperature dependencies of the viscosity of binary metal melts are described by the Kelton’s quasi-universal model. Based on the analysis of the viscosity coefficient of the binary melt composition within the framework of the Rosenfeld’s scale transformations, it has been established that to correctly describe the viscosity of binary/multicomponent metal melts within the framework of entropy models, it is necessary to use a more complex representation of the excess entropy S ex than in the approximation of pair correlation entropy S 2. read less USED (high confidence) A. Purohit, A. Schultz, and D. Kofke, “Implementation of harmonically mapped averaging in LAMMPS, and effect of potential truncation on anharmonic properties.,” The Journal of chemical physics. 2020. link Times cited: 3 Abstract: Implementation of the harmonically mapped averaging (HMA) fr… read moreAbstract: Implementation of the harmonically mapped averaging (HMA) framework in the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) is presented for on-the-fly computations of the energy, pressure, and heat capacity of crystalline systems during canonical molecular dynamics simulations. HMA has a low central processing unit and storage requirements and is straightforward to use. As a case study, the properties of the Lennard-Jones and embedded-atom model (parameterized for nickel) crystals are computed. The results demonstrate the higher efficiency of the new class compared to the inbuilt LAMMPS classes for calculating these properties. However, HMA loses its effectiveness in systems where diffusion occurs in the crystal, and an example is presented to allow this behavior to be recognized. In addition to its improved precision, HMA is less affected by small errors introduced by having a larger time step in molecular dynamics simulations. We also present an analysis of the effect of potential truncation on anharmonic properties, and show that artifacts of truncation on the HMA averages can be eliminated simply by shifting the potential energy to zero at the truncation radius. Full properties can be obtained by adding easily computed values for the lattice and harmonic properties using the untruncated potential. read less USED (high confidence) R. Voskoboinikov, “Simulation of Primary Radiation Damage in Nickel,” Physics of Metals and Metallography. 2020. link Times cited: 8 USED (high confidence) M. Shugaev and L. Zhigilei, “Thermodynamic analysis and atomistic modeling of subsurface cavitation in photomechanical spallation,” Computational Materials Science. 2019. link Times cited: 13 USED (high confidence) E. Schmidt, “Atomistic modelling of precipitation in Ni-base superalloys.” 2019. link Times cited: 0 Abstract: The presence of the ordered γ ′ phase (Ni3Al) in Ni-base sup… read moreAbstract: The presence of the ordered γ ′ phase (Ni3Al) in Ni-base superalloys is fundamental to the performance of engineering components such as turbine disks and blades which operate at high temperatures and loads. Hence for these alloys it is important to optimize their microstructure and phase composition. This is typically done by varying their chemistry and heat treatment to achieve an appropriate balance between γ ′ content and other constituents such as carbides, borides, oxides and topologically close packed phases. In this work we have set out to investigate the onset of γ ′ ordering in Ni-Al single crystals and in Ni-Al bicrystals containing coincidence site lattice grain boundaries (GBs) and we do this at high temperatures, which are representative of typical heat treatment schedules including quenching and annealing. For this we use the atomistic simulation methods of molecular dynamics (MD) and density functional theory (DFT). In the first part of this work we develop robust Bayesian classifiers to identify the γ ′ phase in large scale simulation boxes at high temperatures around 1500 K. We observe significant γ ′ ordering in the simulations in the form of clusters of γ ′-like ordered atoms embedded in a γ host solid solution and this happens within 100 ns. Single crystals are found to exhibit the expected homogeneous ordering with slight indications of chemical composition change and a positive correlation between the Al concentration and the concentration of γ ′ phase. In general, the ordering is found to take place faster in systems with GBs and preferentially adjacent to the GBs. The sole exception to this is the Σ3 (111) tilt GB, which is a coherent twin. An analysis of the ensemble and time lag average displacements of the GBs reveals mostly ‘anomalous diffusion’ behaviour. Increasing the Al content from pure Ni to Ni 20 at.% Al was found to either consistently increase or decrease the mobility of the GB as seen from the changing slope of the time lag displacement average. The movement of the GB can then be characterized as either ‘super’ or ‘sub-diffusive’ and is interpreted in terms of diffusion induced grain boundary migration, which is posited as a possible precursor to the appearance of serrated edge grain boundaries. In the second part of this work we develop a method for the training of empirical interatomic read less USED (high confidence) F. Bianchini, A. Glielmo, J. Kermode, and A. Vita, “Enabling QM-accurate simulation of dislocation motion in
γ−Ni
and
α−Fe
using a hybrid multiscale approach,” Physical Review Materials. 2019. link Times cited: 11 Abstract: We present an extension of the ‘learn on the fly’ method to … read moreAbstract: We present an extension of the ‘learn on the fly’ method to the study of the motion of dislocations in metallic systems, developed with the aim of producing information-efficient force models that can be systematically validated against reference QM calculations. Nye tensor analysis is used to dynamically track the quantum region centered at the core of a dislocation, thus enabling quantum mechanics/molecular mechanics simulations. The technique is used to study the motion of screw dislocations in Ni-Al systems, relevant to plastic deformation in Ni-based alloys, at a variety of temperature/strain conditions. These simulations reveal only a moderate spacing ( ∼ 5 A ) between Shockley partial dislocations, at variance with the predictions of traditional molecular dynamics (MD) simulation using interatomic potentials, which yields a much larger spacing in the high stress regime. The discrepancy can be rationalized in terms of the elastic properties of an hcp crystal, which influence the behavior of the stacking fault region between Shockley partial dislocations. The transferability of this technique to more challenging systems is addressed, focusing on the expected accuracy of such calculations. The bcc α − Fe phase is a prime example, as its magnetic properties at the open surfaces make it particularly challenging for embedding-based QM/MM techniques. Our tests reveal that high accuracy can still be obtained at the core of a dislocation, albeit at a significant computational cost for fully converged results. However, we find this cost can be reduced by using a machine learning approach to progressively reduce the rate of expensive QM calculations required during the dynamical simulations, as the size of the QM database increases. read less USED (high confidence) S. Hocker, H. Lipp, and S. Schmauder, “Precipitation, planar defects and dislocations in alloys: Simulations on Ni3Si and Ni3Al precipitates,” The European Physical Journal Special Topics. 2019. link Times cited: 5 USED (high confidence) S. Yuan, Z. Jiang, J. Liu, Y. Tang, and Y. Zhang, “Nano-twinning in a γ′ precipitate strengthened Ni-based superalloy,” Materials Research Letters. 2018. link Times cited: 19 Abstract: ABSTRACT Twinning has been found to be a dominate mechanism … read moreAbstract: ABSTRACT Twinning has been found to be a dominate mechanism in the γ′ precipitate strengthened Ni-based superalloys during service at intermediate temperatures. Here, high-resolution transmission electron microscopy and atomistic simulations have been combined to show that the twin nucleation process can be facilitated by Co replacing a fraction of Al in the γ′ precipitates, due to the negative binding energy of Co–Co atoms. The study further reveals that the presence of Co promotes a new twinning pathway featured with nucleation of one complex stacking fault (CSF) on the middle plane in between two separated CSFs. GRAPHICAL ABSTRACT IMPACT STATEMENT We demonstrate that Co in the γ′ precipitates promotes a new twinning pathway featured with nucleation of one CSF on the middle plane between two separated CSFs. read less USED (high confidence) C. Howells and Y. Mishin, “Angular-dependent interatomic potential for the binary Ni–Cr system,” Modelling and Simulation in Materials Science and Engineering. 2018. link Times cited: 26 Abstract: A new interatomic potential has been developed for the Ni–Cr… read moreAbstract: A new interatomic potential has been developed for the Ni–Cr system in the angular-dependent potential (ADP) format by fitting the potential parameters to a set of experimental and first-principles data. The ADP potential reproduces a wide range of properties of both elements as well as binary alloys with reasonable accuracy, including thermal and mechanical properties, defects, melting points of Ni and Cr, and the Ni–Cr phase diagram. The potential can be used for atomistic simulations of solidification, mechanical behavior and microstructure of the Ni-based and Cr-based phases as well as two-phase alloys. read less USED (high confidence) Z. D. McClure, S. Reeve, and A. Strachan, “Role of electronic thermal transport in amorphous metal recrystallization: A molecular dynamics study.,” The Journal of chemical physics. 2018. link Times cited: 2 Abstract: Recrystallization of glasses is important in a wide range of… read moreAbstract: Recrystallization of glasses is important in a wide range of applications including electronics and reactive materials. Molecular dynamics (MD) has been used to provide an atomic picture of this process, but prior work has neglected the thermal transport role of electrons, the dominant thermal carrier in metallic systems. We characterize the role of electronic thermal conductivity on the velocity of recrystallization in Ni using MD coupled to a continuum description of electronic thermal transport via a two-temperature model. Our simulations show that for strong enough coupling between electrons and ions, the increased thermal conductivity removes the heat from the exothermic recrystallization process more efficiently, leading to a lower effective temperature at the recrystallization front and, consequently, lower propagation velocity. We characterize how electron-phonon coupling strength and system size affect front propagation velocity. Interestingly, we find that initial recrystallization velocity increases with decreasing system size due to higher overall temperatures. Overall, we show that a more accurate description of thermal transport due to the incorporation of electrons results in better agreement with experiments. read less USED (high confidence) E. Y. Plotnikov et al., “A correlative four-dimensional study of phase-separation at the subnanoscale to nanoscale of a Ni Al alloy,” Acta Materialia. 2018. link Times cited: 30 USED (high confidence) B. Witbeck, J. Sink, and D. Spearot, “Influence of vacancy defect concentration on the combustion of reactive Ni/Al nanolaminates,” Journal of Applied Physics. 2018. link Times cited: 13 Abstract: Self-propagating reactions in Ni/Al nanolaminates have been … read moreAbstract: Self-propagating reactions in Ni/Al nanolaminates have been widely studied for their high combustion temperatures surpassing 1900 K and rapid combustion wave speeds exceeding 10 m/s. These combustion characteristics have motivated unique industrial applications, such as soldering of electrical components, and possible military applications. Unfortunately, there is a limited understanding of the effect of lattice defects on combustion characteristics. This work explores the effect of vacancy concentration on the combustion rate and peak temperature of reactive Ni/Al nanolaminates. Increasing vacancy concentration increases both reaction rates and peak reaction temperatures. For the reaction rate, vacancy concentration effects are shown to be interdependent with bilayer thickness, initial temperature, and hydrostatic pressure. The effects on reaction peak temperature are independent of these other system parameters. A new method for mapping vacancy and composition profiles is presented to demonstrate the formation and migration of vacancies during the self-propagating reaction.Self-propagating reactions in Ni/Al nanolaminates have been widely studied for their high combustion temperatures surpassing 1900 K and rapid combustion wave speeds exceeding 10 m/s. These combustion characteristics have motivated unique industrial applications, such as soldering of electrical components, and possible military applications. Unfortunately, there is a limited understanding of the effect of lattice defects on combustion characteristics. This work explores the effect of vacancy concentration on the combustion rate and peak temperature of reactive Ni/Al nanolaminates. Increasing vacancy concentration increases both reaction rates and peak reaction temperatures. For the reaction rate, vacancy concentration effects are shown to be interdependent with bilayer thickness, initial temperature, and hydrostatic pressure. The effects on reaction peak temperature are independent of these other system parameters. A new method for mapping vacancy and composition profiles is presented to demonstrate the fo... read less USED (high confidence) J. Liu, E. Tennessen, J. Miao, Y. Huang, J. Rondinelli, and H. Heinz, “Understanding Chemical Bonding in Alloys and the Representation in Atomistic Simulations,” The Journal of Physical Chemistry C. 2018. link Times cited: 29 Abstract: Alloys are widely used in catalysts and structural materials… read moreAbstract: Alloys are widely used in catalysts and structural materials. The nature of chemical bonding and the origin of alloy formation energies, defect energies, and interfacial properties have not been well understood to date but are critical to material performance. In this contribution, we explain the polar nature of chemical bonding and an implementation in classical and reactive atomistic simulations to understand such properties more quantitatively. Electronegativity differences between metal atoms lead to polar bonding, and exothermic alloy formation energies are related to charge transfer between the different elements. These differences can be quantified by atomic charges using pairwise charge increments, determined by matching the computed alloy formation energy to experimentally measured alloy formation energies using pair potentials for the pure metals. The polar character of alloys is comparable to organic molecules and partially ionic minerals, for example, AlNi and AlNi3 alloys assume significant a... read less USED (high confidence) C. Zhang, W. Hu, C. Liu, Y. Zhao, J. Shang, and Z. Wen, “Effects of low- to medium-angle grain boundaries on creep properties of superalloy,” Materials Science and Technology. 2018. link Times cited: 7 Abstract: The creep properties of Ni-based bicrystal specimens with lo… read moreAbstract: The creep properties of Ni-based bicrystal specimens with low- to medium-angle grain boundaries are investigated at 1100°C and 130 MPa with two misorientation angles prepared by double-seed solidification. Experimental results show that the angle of the grain boundary with respect to the stretching direction has a strong effect on creep life. Molecular dynamics simulations show that the effect of the grain boundary on the neighbouring dislocation density is related to the grain boundary angle. A creep constitutive model with the grain boundary angle and the initial damage rate can be adopted to describe the creep damage evolution. The model is then modified according to the molecular dynamics simulation and experimental results to give more accurate predictions of creep life. read less USED (high confidence) J. Zhang, X. Cheng, N. He, and G.-Q. Yan, “Lattice response to the relaxation of electronic pressure of ultrafast laser-irradiated copper and nickel nanofilms,” Journal of Physics: Condensed Matter. 2018. link Times cited: 3 Abstract: The impact of electronic pressure and electronic pressure gr… read moreAbstract: The impact of electronic pressure and electronic pressure gradient induced by laser excitation on the dynamic response of metals (Cu and Ni) has been numerically investigated using two complementary approaches. In the framework of DFPT, for electronic temperatures up to 6 eV, we demonstrate that electronic pressure results in a higher lattice stability. In other words, the electronic pressure has a negative influence on the phonon entropy and induces an increase in the shear modulus, which improves the melting temperature and lattice vibration frequency. Given the relaxation of electronic pressure during an extreme non-equilibrium state, we adopt a modified 2T-MD model to identify the contribution of the electronic pressure gradient to the atomic dynamics during fs laser excitation. Our results indicate the presence of rapid destabilization of the structure of Cu and Ni nano-films along the electronic pressure gradients. Specifically, the nucleation of the voids and heterogeneous nucleation occur at the surface layer, at a depth of several nanometers, for Cu and Ni, respectively. With the coexistence of a-thermal and thermal effects on scales, two different ultrafast destructuring processes of Cu and Ni both interrelate a hot electronic blast force and classical electron–ion dynamics. read less USED (high confidence) V. Turlo, F. Baras, and O. Politano, “Comparative study of embedded-atom methods applied to the reactivity in the Ni–Al system,” Modelling and Simulation in Materials Science and Engineering. 2017. link Times cited: 23 Abstract: Structural, thermodynamic, atomic and thermal transport prop… read moreAbstract: Structural, thermodynamic, atomic and thermal transport properties of solid and liquid phases of the Ni–Al system were studied by means of MD simulations using three embedded-atom method (EAM) potentials developed by Mishin and colleagues (Mishin et al 2002 Phys. Rev. B 65 224114; Mishin 2004 Acta Mater. 52 145167; Purja Pun and Mishin 2009 Phil. Mag. 89 32453267). The extracted properties (lattice parameter, enthalpy, heat capacity, mass diffusivity and thermal conductivity) were compared with experimental data. The limitations of EAM potentials for studying different aspects of reactivity were assessed for each potential separately. read less USED (high confidence) E. A. Schmidt and P. Bristowe, “Identifying early stage precipitation in large-scale atomistic simulations of superalloys,” Modelling and Simulation in Materials Science and Engineering. 2017. link Times cited: 2 Abstract: A method for identifying and classifying ordered phases in l… read moreAbstract: A method for identifying and classifying ordered phases in large chemically and thermally disordered atomistic models is presented. The method uses Steinhardt parameters to represent local atomic configurations and develops probability density functions to classify individual atoms using naïve Bayes. The method is applied to large molecular dynamics simulations of supersaturated Ni-20 at% Al solid solutions in order to identify the formation of embryonic γ′-Ni3Al. The composition and temperatures are chosen to promote precipitation, which is observed in the form of ordering and is found to occur more likely in regions with above average Al concentration producing ‘clusters’ of increasing size. The results are interpreted in terms of a precipitation mechanism in which the solid solution is unstable with respect to ordering and potentially followed by either spinodal decomposition or nucleation and growth. read less USED (high confidence) J. Huang et al., “Molecular dynamics simulation of persistent slip bands formation in nickel-base superalloys,” International Journal of Automation and Computing. 2017. link Times cited: 2 USED (high confidence) F. Tavazza, B. Kuhr, D. Farkas, and L. Levine, “Ni Nanoindentation at the Nanoscale: Atomic Rearrangements at the Ni–C Interface,” Journal of Physical Chemistry C. 2017. link Times cited: 6 Abstract: As mechanical testing proceeds toward ever-decreasing length… read moreAbstract: As mechanical testing proceeds toward ever-decreasing length scales, the ultimate limit is the atomic scale. Here, we investigate the atomic-scale interactions that occur at the diamond–nickel interface during the earliest stages of a Ni nanoindentation measurement. Using molecular dynamics with a custom-designed empirical potential, we found that, irrespectively of the Ni orientation, the same Ni–C interfacial structure always formed between the substrate and the diamond indenter. As the indenter digs deeper into the specimen, the location of the Ni–C interface changes, but its structure never does. In addition, the local formation of this structure produces longer-range disorder that may affect the local stresses and activation barriers to dislocation nucleation. As this process requires relatively large atomic displacements of the Ni atoms for some Ni orientations, we used density functional theory calculations to validate and understand the process. read less USED (high confidence) J. Huang et al., “Molecular dynamics simulation of persistent slip bands formation in nickel-base superalloys,” International Journal of Automation and Computing. 2016. link Times cited: 0 USED (high confidence) Y. Mishin and J. Cahn, “Thermodynamics of Cottrell atmospheres tested by atomistic simulations,” Acta Materialia. 2016. link Times cited: 27 USED (high confidence) E. Martínez, F. Soisson, A. Caro, and B. Uberuaga, “Atomistic modeling of the reordering process of γ′ disordered particles in Ni-Al alloys,” Journal of Nuclear Materials. 2016. link Times cited: 4 USED (high confidence) X. Sedao et al., “Growth Twinning and Generation of High-Frequency Surface Nanostructures in Ultrafast Laser-Induced Transient Melting and Resolidification.,” ACS nano. 2016. link Times cited: 76 Abstract: The structural changes generated in surface regions of singl… read moreAbstract: The structural changes generated in surface regions of single crystal Ni targets by femtosecond laser irradiation are investigated experimentally and computationally for laser fluences that, in the multipulse irradiation regime, produce sub-100 nm high spatial frequency surface structures. Detailed experimental characterization of the irradiated targets combining electron back scattered diffraction analysis with high-resolution transmission electron microscopy reveals the presence of multiple nanoscale twinned domains in the irradiated surface regions of single crystal targets with (111) surface orientation. Atomistic- and continuum-level simulations performed for experimental irradiation conditions reproduce the generation of twinned domains and establish the conditions leading to the formation of growth twin boundaries in the course of the fast transient melting and epitaxial regrowth of the surface regions of the irradiated targets. The observation of growth twins in the irradiated Ni(111) targets provides strong evidence of the role of surface melting and resolidification in the formation of high spatial frequency surface structures. This also suggests that the formation of twinned domains can be used as a sensitive measure of the levels of liquid undercooling achieved in short pulse laser processing of metals. read less USED (high confidence) G. Samolyuk, L. Béland, G. M. Stocks, and R. Stoller, “Electron–phonon coupling in Ni-based binary alloys with application to displacement cascade modeling,” Journal of Physics: Condensed Matter. 2016. link Times cited: 36 Abstract: Energy transfer between lattice atoms and electrons is an im… read moreAbstract: Energy transfer between lattice atoms and electrons is an important channel of energy dissipation during displacement cascade evolution in irradiated materials. On the assumption of small atomic displacements, the intensity of this transfer is controlled by the strength of electron–phonon (el–ph) coupling. The el–ph coupling in concentrated Ni-based alloys was calculated using electronic structure results obtained within the coherent potential approximation. It was found that Ni0.5Fe0.5, Ni0.5Co0.5 and Ni0.5Pd0.5 are ordered ferromagnetically, whereas Ni0.5Cr0.5 is nonmagnetic. Since the magnetism in these alloys has a Stoner-type origin, the magnetic ordering is accompanied by a decrease of electronic density of states at the Fermi level, which in turn reduces the el–ph coupling. Thus, the el–ph coupling values for all alloys are approximately 50% smaller in the magnetic state than for the same alloy in a nonmagnetic state. As the temperature increases, the calculated coupling initially increases. After passing the Curie temperature, the coupling decreases. The rate of decrease is controlled by the shape of the density of states above the Fermi level. Introducing a two-temperature model based on these parameters in 10 keV molecular dynamics cascade simulation increases defect production by 10–20% in the alloys under consideration. read less USED (high confidence) S. R. Yeratapally, M. Glavicic, M. Hardy, and M. Sangid, “Microstructure based fatigue life prediction framework for polycrystalline nickel-base superalloys with emphasis on the role played by twin boundaries in crack initiation,” Acta Materialia. 2016. link Times cited: 98 USED (high confidence) A. Prakash, M. Hummel, S. Schmauder, and E. Bitzek, “Nanosculpt: A methodology for generating complex realistic configurations for atomistic simulations,” MethodsX. 2016. link Times cited: 25 USED (high confidence) K. Manukyan et al., “Exothermic Self-Sustained Waves with Amorphous Nickel,” Journal of Physical Chemistry C. 2016. link Times cited: 22 Abstract: The synthesis of amorphous Ni (a-Ni) using a liquid-phase ch… read moreAbstract: The synthesis of amorphous Ni (a-Ni) using a liquid-phase chemical reduction approach is reported. Detailed structural analysis indicates that this method allows for efficient fabrication of high surface area (210 m2/g) amorphous Ni nanopowder with low impurity content. We investigated the self-propagating exothermic waves associated with crystallization of Ni from the amorphous precursor. Time-resolved X-ray diffraction indicates that amorphous nickel crystallizes in the temperature range 445–480 K. High-speed infrared imaging reveals that local preheating of compressed a-Ni nanopowder triggers a self-sustaining crystallization wave that propagates with velocity ∼0.3 mm/s. The maximum temperature of crystallization wave depends on the sample density and can be as high as 600 K. The Kissinger approach is used to determine the apparent activation energy (55.4 ± 4 kJ/mol) of crystallization. The self-diffusion activation energy of Ni atoms in a-Ni is ∼60 kJ/mol, determined through molecular dynamics (MD) si... read less USED (high confidence) S. Rao, D. Dimiduk, J. El-Awady, T. Parthasarathy, M. Uchic, and C. Woodward, “Screw dislocation cross slip at cross-slip plane jogs and screw dipole annihilation in FCC Cu and Ni investigated via atomistic simulations,” Acta Materialia. 2015. link Times cited: 24 USED (high confidence) C. Qiao et al., “Inhibition effect on the evolution of a twist grain boundary for an Al/Ni bimetal interface under torsion,” RSC Advances. 2015. link Times cited: 4 Abstract: By using a molecular dynamics method with EAM potential, we … read moreAbstract: By using a molecular dynamics method with EAM potential, we study the evolution phenomena of metal twist grain boundaries (GBs) in the [100], [111] and [110] orientations, together with their bimetal interface, under anticlockwise and clockwise torsions. Our results show that there are different evolution behaviors of the GB screw dislocations for single metals (Al and Ni) and their bimetal interface (Al/Ni) under torsion. Specifically, for the single metals in the [100] and [111] orientations, their GBs evolve toward lower or higher angle twist GBs depending on the twist direction. For Ni in the [110] orientation, the dislocations spread not only in the GB region but also in the grain interior. However, for the bimetal interface, the propagation of dislocations is not only reduced dramatically but also limited to the interface region, showing that there is an inhibition effect. Therefore, such an inhibition effect can enhance the stability of nanomaterials which is very useful for the further design of nanodevices. read less USED (high confidence) M. Caro, L. Béland, G. Samolyuk, R. Stoller, and A. Caro, “Lattice thermal conductivity of multi-component alloys,” Journal of Alloys and Compounds. 2015. link Times cited: 53 USED (high confidence) F. Niekiel, E. Spiecker, and E. Bitzek, “Influence of anisotropic elasticity on the mechanical properties of fivefold twinned nanowires,” Journal of The Mechanics and Physics of Solids. 2015. link Times cited: 36 USED (high confidence) A. Prakash et al., “Atom probe informed simulations of dislocation-precipitate interactions reveal the importance of local interface curvature,” Acta Materialia. 2015. link Times cited: 73 USED (high confidence) T. Lee, A. Caro, and M. Demkowicz, “Atomistic modeling of radiation-induced disordering and dissolution at a Ni/Ni_3Al interface,” Journal of Materials Research. 2015. link Times cited: 15 Abstract: L1_2-ordered γ′ precipitates embedded in a fcc γ matrix impa… read moreAbstract: L1_2-ordered γ′ precipitates embedded in a fcc γ matrix impart excellent mechanical properties to nickel-base superalloys. However, these enhanced mechanical properties are lost under irradiation, which causes the γ′ precipitates to disorder and dissolve. We conduct an atomic-level study of radiation-induced disordering and dissolution at a coherent (100) facet of an initially ordered γ′ Ni_3Al precipitate neighboring a pure Ni γ matrix. Using molecular dynamics, we simulate collision-induced events by sequentially introducing 10 keV primary knock-on atoms with random positions and directions. In the absence of thermally assisted recovery processes, the ordered Ni_3Al layer disorders rapidly within 0.1–0.2 dpa and then gradually dissolves into the adjacent Ni layer at higher doses. Both the disordering efficiency and mixing parameter calculated from the simulations lie within the range of values found by experiments carried out at room temperature, where thermally activated diffusion is insignificant. read less USED (high confidence) J. Amodeo, C. Begau, and E. Bitzek, “Atomistic Simulations of Compression Tests on Ni3Al Nanocubes,” Materials Research Letters. 2014. link Times cited: 33 Abstract: The deformation behaviour of nano-sized Ni3Al cubes with {10… read moreAbstract: The deformation behaviour of nano-sized Ni3Al cubes with {100} side surfaces is investigated under uniaxial compression using constant-temperature molecular dynamics simulations at 300 K. The simulations reproduce key features of recently performed nanocompression experiments, namely the lack of strain hardening, homogeneous deformation of the entire sample and overall high stress levels of the order of 3–5 GPa. According to the simulations, the critical initial step is the formation of a pseudo-twin structure, which then further deforms by Shockley partial dislocations. These deformation mechanisms differ significantly from bulk Ni3Al and are rationalized in terms of generalized stacking fault energies and resolved shear stresses. read less USED (high confidence) K. A. Bukreeva, A. Iskandarov, S. Dmitriev, Y. Umeno, and R. Mulyukov, “Theoretical shear strength of FCC and HCP metals,” Physics of the Solid State. 2014. link Times cited: 12 USED (high confidence) J.-ping Du, C.-yu Wang, and T. Yu, “The ternary Ni-Al-Co embedded-atom-method potential for gamma/gamma ’ Ni-based single-crystal superalloys: Construction and application,” Chinese Physics B. 2014. link Times cited: 11 Abstract: An Ni—Al—Co system embedded-atom-method potential is constru… read moreAbstract: An Ni—Al—Co system embedded-atom-method potential is constructed for the γ(Ni)/γ'(Ni3Al) superalloy based on experiments and first-principles calculations. The stacking fault energies (SFEs) of the Ni(Co, Al) random solid solutions are calculated as a function of the concentrations of Co and Al. The calculated SFEs decrease with increasing concentrations of Co and Al, which is consistent with the experimental results. The embedding energy term in the present potential has an important influence on the SFEs of the random solid solutions. The cross-slip processes of a screw dislocation in homogenous Ni(Co) solid solutions are simulated using the present potential and the nudged elastic band method. The cross-slip activation energies increase with increasing Co concentration, which implies that the creep resistance of γ(Ni) may be improved by the addition of Co. read less USED (high confidence) C. Becker et al., “Thermodynamic modelling of liquids: CALPHAD approaches and contributions from statistical physics,” physica status solidi (b). 2014. link Times cited: 32 Abstract: We describe current approaches to thermodynamic modelling of… read moreAbstract: We describe current approaches to thermodynamic modelling of liquids for the CALPHAD method, the use of available experimental methods and results in this type of modelling, and considerations in the use of atomic‐scale simulation methods to inform a CALPHAD approach. We begin with an overview of the formalism currently used in CALPHAD to describe the temperature dependence of the liquid Gibbs free energy and outline opportunities for improvement by reviewing the current physical understanding of the liquid. Brief descriptions of experimental methods for extracting high‐temperature data on liquids and the preparation of undercooled liquid samples are presented. Properties of a well‐determined substance, B2 O3, including the glass transition, are then discussed in detail to emphasize specific modelling requirements for the liquid. We then examine the two‐state model proposed for CALPHAD in detail and compare results with experiment and theory, where available. We further examine the contributions of atomic‐scale methods to the understanding of liquids and their potential for supplementing available data. We discuss molecular dynamics (MD) and Monte Carlo methods that employ atomic interactions from classical interatomic potentials, as well as contributions from ab initio MD. We conclude with a summary of our findings. read less USED (high confidence) S. Rao, D. Dimiduk, J. El-Awady, T. Parthasarathy, M. Uchic, and C. Woodward, “Spontaneous athermal cross-slip nucleation at screw dislocation intersections in FCC metals and L12 intermetallics investigated via atomistic simulations,” Philosophical Magazine. 2013. link Times cited: 23 Abstract: In this manuscript, we extend on our prior work to show that… read moreAbstract: In this manuscript, we extend on our prior work to show that under certain conditions cross-slip nucleation is athermal and spontaneous with zero activation energy in FCC elemental metals such as Ni and Cu, and L12 intermetallic compounds such as Ni3Al. Using atomistic simulations (molecular statics), we show that spontaneous cross-slip occurs at mildly repulsive intersections. Further, the local Shockley partial dislocation interactions at such repulsive intersections are found to be attractive leading to junction formation. The line orientation of the intersecting dislocation determines whether the spontaneous cross-slip nucleation occurs from either the glide plane to the cross-slip plane or vice versa. Collectively, these results suggest that cross-slip should be preferentially observed at selected screw dislocation intersections in FCC-derviative metals and alloys. read less USED (high confidence) R.-guang Xu, M. Falk, and T. Weihs, “Interdiffusion of Ni-Al multilayers: A continuum and molecular dynamics study,” Journal of Applied Physics. 2013. link Times cited: 46 Abstract: Molecular dynamics simulation of Al/Ni multilayer foils reve… read moreAbstract: Molecular dynamics simulation of Al/Ni multilayer foils reveals a range of different reaction pathways depending on the temperature of the reaction. At the highest temperatures, Fickian interdiffusion is the rate-limiting step in the intermixing process. At intermediate temperatures, Ni dissolution into the Al liquid becomes the rate-limiting mechanism for intermixing prior to formation of the B2 intermetallic phase. At lower temperatures, the B2 intermetallic forms early in the reaction process precluding both of these mechanisms. Interdiffusion and dissolution activation energies as well as diffusion prefactors are extracted from the simulations. read less USED (high confidence) S. Skirlo and M. Demkowicz, “The role of thermal spike compactness in radiation-induced disordering and Frenkel pair production in Ni3Al,” Scripta Materialia. 2012. link Times cited: 15 USED (high confidence) V. Vorontsov, R. Voskoboinikov, and C. Rae, “Shearing of γ′ precipitates in Ni-base superalloys: a phase field study incorporating the effective γ-surface,” Philosophical Magazine. 2012. link Times cited: 28 Abstract: An extended phase field model of dislocations in Ni-base sup… read moreAbstract: An extended phase field model of dislocations in Ni-base superalloys is presented. It incorporates the recently developed effective γ-surfaces for both matrix and precipitate phases, obtained from atomistic simulations. These novel γ-surfaces feature extrinsic stacking faults as additional local minima. Thus, they offer an increased number of available dislocation dissociation pathways within the phase field system. The new model has been used to simulate a variety of mechanisms for γ′ precipitate shearing proposed in literature. A critical assessment is made based on the modelling observations. read less USED (high confidence) C. Becker, F. Tavazza, and L. Levine, “Implications of the choice of interatomic potential on calculated planar faults and surface properties in nickel,” Philosophical Magazine. 2011. link Times cited: 15 Abstract: With the increasing use of molecular simulation to understan… read moreAbstract: With the increasing use of molecular simulation to understand deformation mechanisms in transition metals, it is important to assess how well the simulations reproduce physical behavior both near equilibrium and under more extreme conditions. In particular, it is important to examine whether simulations predict unusual deformation paths that are competitive with those experimentally observed. In this work we compare generalized planar fault energy landscapes and surface energies for various interatomic potentials with those from density functional theory calculations to examine how well these more complicated planar faults and surface energies are captured and whether any deformations are energetically competitive with the {111}⟨112⟩ slip observed in FCC crystals. To do this we examine not just the (111) fault orientation, but also the (100), (110), (210), (211), (311), and (331) orientations to test behavior outside of the fitting range of the interatomic potentials. We find that the shape of the (111)[11 ] stacking fault energy curve varies significantly with potential, with the ratio of unstable to stable stacking fault energies ranging from 1.22 to 14.07, and some deformation paths for non-(111) orientations give activation barriers less than 50% higher than the unstable stacking fault energies. These are important considerations when choosing an interatomic potential for deformation simulations. read less USED (high confidence) H. Xie, L. Bo, and T. Yu, “Molecular dynamics simulation of an edge dislocation slipping on a cubic plane of Ni3Al,” Modelling and Simulation in Materials Science and Engineering. 2011. link Times cited: 7 Abstract: The motion mechanism of an edge dislocation on a cubic plane… read moreAbstract: The motion mechanism of an edge dislocation on a cubic plane of Ni3Al is studied in periodic simulation cells subjected to applied shear stress. The simulation results show that the motion of the edge dislocation is controlled by the complex Lomer–Cottrell lock mechanism. Using this locking–unlocking mechanism, we have given a perfect explanation to the very jerky motion of the edge dislocation, which has been experimentally observed for about 20 years. read less USED (high confidence) V. Vorontsov, R. Voskoboinikov, and C. Rae, “Prediction of Mechanical Behaviour in Ni-Base Superalloys Using the Phase Field Model of Dislocations,” Advanced Materials Research. 2011. link Times cited: 5 Abstract: The “Phase-Field Model of Dislocations” (PFMD) was used to s… read moreAbstract: The “Phase-Field Model of Dislocations” (PFMD) was used to simulate shearing of gamma-prime precipitate arrays in single crystal turbine blade superalloys. The focus of the work has been on the cutting of the L12 ordered precipitates by a<112>{111} dislocation ribbons during Primary Creep. The Phase Field Model presented incorporates specially developed Generalised Stacking Fault Energy (–surface) data obtained from atomistic simulations. The topography of this surface determines the shearing mechanisms observed in the model. The merit of the new –surface, is that it accounts for the formation of extrinsic stacking faults, making the model more relevant to creep deformation of superalloys at elevated temperatures. read less USED (high confidence) M. Chandran and S. Sondhi, “First-principle calculation of APB energy in Ni-based binary and ternary alloys,” Modelling and Simulation in Materials Science and Engineering. 2011. link Times cited: 70 Abstract: An ab initio method based on density functional theory has b… read moreAbstract: An ab initio method based on density functional theory has been employed to compute the zero-temperature anti-phase boundary (APB) energies for Ni3Al1−xRx (R = Nb, Ta, Ti) system over a range of compositions. The computation is limited to the APB on the (1 1 1) plane for L12 crystal structure, allowing only the volume relaxation, appropriate for the γ′ precipitate in Ni-based superalloy. For the limiting case of the binary system Ni3Al, the APB energy has also been calculated for the (1 0 0) plane. We find that the APB energy for the (1 1 1) plane in Ni3Al is 181 mJ m−2, and substitution of Nb, Ta or Ti at the Al site increases the APB energy to over 600 mJ m−2, leading to higher strengths. While the peak APB energy values for all the ternary systems are quite similar, they are achieved over very different compositional ranges. Nb and Ta are found to have almost identical strengthening effect on Ni3Al. The selected compositional space is of direct relevance to the commercially important family of Ni-based superalloys, and our results provide important guidelines for alloy design strategies. read less USED (high confidence) C. Becker and Y. Mishin, “Temperature dependence of the pre-wetting transition at the (1 1 1) anti-phase boundary in Ni3Al: an atomistic study,” Modelling and Simulation in Materials Science and Engineering. 2010. link Times cited: 1 Abstract: Chemical composition and ordering at the (1 1 1) anti-phase … read moreAbstract: Chemical composition and ordering at the (1 1 1) anti-phase boundary (APB) in the Ni3Al-based γ′ phase have been studied by semi-grand canonical Monte Carlo simulations at temperatures from 700 to 1300 K. The atomic interactions are modeled with an embedded-atom potential reproducing the relevant part of the Ni–Al phase diagram. In a certain range of bulk compositions and temperatures within the γ′ phase stability domain, the APB undergoes a pre-wetting transformation by becoming a layer of disordered γ phase. The pre-wetting transformation line is mapped onto the bulk phase diagram allowing predictions of the APB state under various thermochemical conditions. read less USED (high confidence) A. Takahashi, M. Kawanabe, and N. Ghoniem, “γ-precipitate strengthening in nickel-based superalloys,” Philosophical Magazine. 2010. link Times cited: 12 Abstract: We describe here a computational method to study γ-precipita… read moreAbstract: We describe here a computational method to study γ-precipitate strengthening in nickel-based superalloys, and to specifically investigate the relative importance of stacking-fault energy and coherency strains. The method is a combination of the Parametric Dislocation Dynamics (PDD), an analytical solution to the spherical inclusion problem and the generalized Peierls–Nabarro (P-N) model. Earlier analytical solutions to stacking-fault strengthening predict a lower critical resolved shear stress (CRSS) in comparison with the results of the present model. This is attributed to shape changes of super-dislocations during their interaction with γ-precipitates. However, existing analytical solutions to coherency strengthening provide considerably larger values of the CRSS compared with the results of present simulations. The dislocation core is found to spread widely as it interacts with γ-precipitates, and is thus much softer than what has been considered in previous analytical solutions. This remarkable effect is a direct result of the core structure of dislocations interacting with precipitates. When this effect is accounted for, a new analytical solution is shown to give excellent agreement with present simulation results. We finally discuss the combined effects of the two strengthening mechanisms, when they operate simultaneously. read less USED (high confidence) B. Sonderegger and E. Kozeschnik, “Generalized Nearest-Neighbor Broken-Bond Analysis of Randomly Oriented Coherent Interfaces in Multicomponent Fcc and Bcc Structures,” Metallurgical and Materials Transactions A. 2009. link Times cited: 144 USED (high confidence) Y. Amouyal, Z. Mao, and D. Seidman, “Segregation of tungsten at γ′(L12)/γ(fcc) interfaces in a Ni-based superalloy: An atom-probe tomographic and first-principles study,” Applied Physics Letters. 2008. link Times cited: 47 Abstract: γ(fcc)/γ′(L12) heterophase interfaces in a Ni-based superall… read moreAbstract: γ(fcc)/γ′(L12) heterophase interfaces in a Ni-based superalloy are investigated using atom-probe tomography and first-principles calculations. Flat {100} interfaces exhibit a confined (nonmonotonic) Gibbsian interfacial excess of tungsten, ΓW=1.2±0.2 nm−2, corresponding to a 5 mJ m−2 decrease in interfacial free energy. Conversely, no measurable segregation of W is detected at curved interfaces. First-principles calculations for a Ni–Al–W system having a {100} interface indicate a decrease in the interfacial energy of 5 mJ m−2 due to W segregation. Similar calculations for {110} and {111} interfaces predict an increase of 1 and 9 mJ m−2 in their energies, respectively, and therefore no heterophase segregation. read less USED (high confidence) C. Becker, Y. Mishin, and W. Boettinger, “The pre-wetting transition at antiphase boundaries: an atomistic modeling study of Ni3Al,” Journal of Materials Science. 2008. link Times cited: 12 USED (high confidence) P. L. Williams, Y. Mishin, and J. C. Hamilton, “An embedded-atom potential for the Cu–Ag system,” Modelling and Simulation in Materials Science and Engineering. 2006. link Times cited: 430 Abstract: A new embedded-atom method (EAM) potential has been construc… read moreAbstract: A new embedded-atom method (EAM) potential has been constructed for Ag by fitting to experimental and first-principles data. The potential accurately reproduces the lattice parameter, cohesive energy, elastic constants, phonon frequencies, thermal expansion, lattice-defect energies, as well as energies of alternate structures of Ag. Combining this potential with an existing EAM potential for Cu, a binary potential set for the Cu–Ag system has been constructed by fitting the cross-interaction function to first-principles energies of imaginary Cu–Ag compounds. Although properties used in the fit refer to the 0 K temperature (except for thermal expansion factors of pure Cu and Ag) and do not include liquid configurations, the potentials demonstrate good transferability to high-temperature properties. In particular, the entire Cu–Ag phase diagram calculated with the new potentials in conjunction with Monte Carlo simulations is in satisfactory agreement with experiment. This agreement suggests that EAM potentials accurately fit to 0 K properties can be capable of correctly predicting simple phase diagrams. Possible applications of the new potential set are outlined. read less USED (high confidence) A. Suzuki and Y. Mishin, “Atomic mechanisms of grain boundary diffusion: Low versus high temperatures,” Journal of Materials Science. 2005. link Times cited: 128 USED (high confidence) C. Liu, F. Wang, P. Yuan, Z. Guo, J. Yu, and Y. Jia, “Atomistic view of thin Ni/Ni3Al (0 0 1) under uniaxial tension of twist grain boundaries,” RSC Advances. 2014. link Times cited: 9 Abstract: Atomic motion and the structure response of grain boundaries… read moreAbstract: Atomic motion and the structure response of grain boundaries (GBs) are essential to the plastic deformation of small-volume polycrystal systems, especially for thin materials that exhibit some dramatic characteristics. Here, the microstructure and properties of thin Ni/Ni3Al (0 0 1) with the uniaxial tension of twist GBs are investigated using molecular dynamics (MD) simulations with an embedded atom (EAM) potential. We find that low angle twist GB dislocations propagate mainly from the corners to the center of the interface, and for high angle twist GBs they originate from the edge of the interface but do not extend to the center. In the process of plastic deformation, both low angle and high angle twist GB fractures occur in the center of the interface, which is completely different from the situation of thick materials reported by other references. More interestingly, the fracture patterns between low angle and high angle twist GBs exhibit extremely different performance due to the different characteristics of the initial dislocation structures in the interfaces. read less USED (high confidence) S. Sonntag, “Computer simulations of laser ablation from simple metals to complex metallic alloys.” 2011. link Times cited: 10 Abstract: In this work, a method for computer simulations of laser abl… read moreAbstract: In this work, a method for computer simulations of laser ablation in metals is presented. The ambitious task to model the physical processes, that occur on different time and length scales, is overcome to some extent by the combination of two techniques: Molecular dynamics and finite differences. The former is needed to achieve atomistic resolution of the processes involved. Material failure like melting, vaporization or spallation occur on the atomic scale. Light absorption and electronic heat conduction, which plays the major role in metals, is described by a generalized heat conduction equation solved by the finite differences method. From the so-called Two-Temperature Model temperature, density and pressure evolution - both in time and space - can be derived. With this, various studies on laser heated metals were done. For reasons discussed in more detail later, aluminum was chosen as a model system for most simulations on isotropic materials. As a more complex structure, the metallic alloy Al13Co4 was used because of its special material properties. As an approximant to the decagonal phase of Al-Ni-Co, the alloy shows an anisotropy in its transport properties, e.g. an anisotropic heat conduction.
It will be shown, that the model is able to describe the physics in laser heated solids on time scales from 100 fs up to the ns-scale properly. Great insight was gained about the processes occuring during and shortly after the laser pulse. Many of the quantities interesting for experimentalists can be predicted by the theory. From the simulations relevant parameters like the electron-cooling time or the important ablation threshold were calculated. All values match their experimental counterpart very well.
Die vorliegende Arbeit beschaftigt sich mit der Laserablation in Metallen. Ziel ist es, mit Hilfe von numerischen Simulationen das Verhalten von Metallen nach der Bestrahlung mit intensiven Laserpulsen vorherzusagen. Die Arbeit ist inhaltlich in zwei Teile gegliedert. In der ersten Halfte werden theoretische Grundlagen, eine qualitative Beschreibung der Ablation und die Implementierung des Modells gegeben. Im zweiten Teil folgen Ergebnisse sowie, falls vorhanden, Vergleiche mit Experimenten. Die Arbeit schliest mit einer Zusammenfassung und einem Ausblick. read less USED (high confidence) X. Hongxian, W. Chong-yu, Y. Tao, and D. Jun-Ping, “Dislocation formation and twinning from the crack tip in Ni 3 Al: molecular dynamics simulations,” Chinese Physics B. 2009. link Times cited: 16 Abstract: The mechanism of low-temperature deformation in a fracture p… read moreAbstract: The mechanism of low-temperature deformation in a fracture process of L1(2) Ni(3)Al is studied by molecular dynamic simulations. Owing to the unstable stacking energy, the [0 (1) over bar1] superdislocation is dissociated into partial dislocations separated by a stacking fault. The simulation results show that when the crack speed is larger than a critical speed, the Shockley partial dislocations will break forth from both the crack tip and the vicinity of the crack tip; subsequently the super intrinsic stacking faults are formed in adjacent {111} planes, meanwhile the super extrinsic stacking faults and twinning also occur. Our simulation results suggest that at low temperatures the ductile fracture in L1(2) Ni(3)Al is accompanied by twinning, which is produced by super-intrinsic stacking faults formed in adjacent {111} planes. read less USED (high confidence) E. Bitzek and P. Gumbsch, “Atomistic Simulations of Dislocation — Crack Interaction,” Journal of Solid Mechanics and Materials Engineering. 2007. link Times cited: 13 Abstract: The interaction of dislocations with a static mode I crack i… read moreAbstract: The interaction of dislocations with a static mode I crack is studied by large scale molecular dynamics simulations. The model consists of a blunted [001](110) crack in nickel, to which after relaxation at K < K Ic the displacement field of a dislocation is added. The response of the system is monitored during its evolution in the micro-canonical ensemble. The three dimensional nature of the problem requires the simulation of many millions of atoms. The great demands on the computational resources and data storage can only be met by high performance computing platforms and by the development of appropriate simulation methods. The simulations allowed to identify different characteristic processes during the interaction of the impinging dislocation with the crack. In particular, stimulated dislocation emission and cross slip processes are observed to be important for the development of a plastic zone. read less USED (low confidence) S. Hayakawa and H. Xu, “Development of an interatomic potential for L12 precipitates in Fe–Ni–Al alloys,” Computational Materials Science. 2024. link Times cited: 0 USED (low confidence) P. Wang, F. Xu, Y. Wang, J. Song, and C. Chen, “Atomistic and continuum study of interactions between super-screw dislocations and coherent twin boundaries in L12-structured Ni3AI,” Mechanics of Materials. 2023. link Times cited: 1 USED (low confidence) Z. Zhu, L. Guo, R. Li, S. Chen, H. Deng, and H. Huang, “Micro/nano mechanical properties differences of shallow irradiation damage layer revealed by a combined experimental and MD study,” Materials Science and Engineering: A. 2023. link Times cited: 0 USED (low confidence) L. Li, J. Li, F. Liu, L. Tan, Q. Fang, and Y. Wei, “Influence of scandium addition on microstructure and mechanical properties in nickel-based superalloys: An integrated multiscale modeling and experimental approach,” International Journal of Plasticity. 2023. link Times cited: 1 USED (low confidence) L. Chalamet, D. Rodney, and Y. Shibuta, “Coarse-grained molecular dynamic model for metallic materials,” Computational Materials Science. 2023. link Times cited: 3 USED (low confidence) F. Vogel et al., “Tracking maze-like hierarchical phase separation behavior in a Fe-Si-V alloy,” Journal of Alloys and Compounds. 2023. link Times cited: 0 USED (low confidence) E. Galindo-Nava, R. Schlütter, O. Messé, C. Argyrakis, and C. Rae, “A model for dislocation creep in polycrystalline Ni-base superalloys at intermediate temperatures,” International Journal of Plasticity. 2023. link Times cited: 0 USED (low confidence) S. He, Q. Tan, X. Chen, Y. Liu, O. I. Gorbatov, and P. Peng, “First-principles study of Re-W interactions and their effects on the mechanical properties of γ/γ’ interface in Ni-based single-crystal alloys,” Materials Today Communications. 2023. link Times cited: 0 USED (low confidence) L. Yang, K. Sun, and H. Wu, “Effect of Void Defects on the Indentation Behavior of Ni/Ni3Al Crystal,” Nanomaterials. 2023. link Times cited: 0 Abstract: Inconel 718 (IN 718) superalloys are widely used as engineer… read moreAbstract: Inconel 718 (IN 718) superalloys are widely used as engineering materials owing to their superior mechanical performance. And voids are unavoidable defects in IN 718 superalloy preparation, which dramatically affect the mechanical properties of IN 718 superalloys. In this work, the effects of void radius, distance from the top of the void to the substrate surface, and substrate temperature on the mechanical properties of the Ni/Ni3Al crystal are systematically investigated. It is shown that voids affect the formation of stair-rod dislocations and Shockley dislocations in the substrate, which in turn determines the mechanical properties. Thus, with the increase in void radius, Young’s modulus and hardness gradually decrease. With the increase in void distance, Young’s modulus and hardness increase and finally tend to be stable. In addition, the increase in substrate temperature leads to the interphase boundary becoming irregular and increases the defects in the γ and γ″ phases. As a result, Young’s modulus and hardness of the substrate decrease. This work aims to provide a guideline for investigating the indentation properties of Ni-based superalloys using MD. read less USED (low confidence) M. P. Hazarika, A. Tripathi, and S. N. Chakraborty, “Two-temperature molecular dynamics simulation study of copper thin film irradiation with femtosecond and picosecond laser pulses,” Journal of Laser Applications. 2023. link Times cited: 0 Abstract: Metal targets irradiated with laser pulses have a wide range… read moreAbstract: Metal targets irradiated with laser pulses have a wide range of applications in thin film preparation, nanomaterial synthesis, bio-medical imaging, and metal ablation. Here, using two-temperature model based molecular dynamics simulation, we investigate laser mediated ablation in copper. Ablation of the film starts with the formation of voids within it. This void forming mechanism at low laser fluences ([Formula: see text] mJ/cm[Formula: see text]) is studied using both picosecond and femtosecond pulses. At the same fluence, shorter laser pulse transfers more energy to the atoms generating temperatures greater than the melting temperature of the crystal. This increases the kinetic energy of the atoms and they start vibrating with different velocities. If these vibrations cross a threshold of 5 Å per picosecond (500 m/s), voids and faults start appearing in the system. At the same fluence, higher concentration of voids are also created at a faster rate with the femtosecond pulse. read less USED (low confidence) M. Fullarton, G. Nandipati, D. Senor, A. Casella, and R. Devanathan, “Molecular Dynamics Study of Primary Damage in the Near-Surface Region in Nickel,” Journal of Nuclear Materials. 2023. link Times cited: 0 USED (low confidence) S. Chandra, A. Alankar, M. K. Samal, and V. Chavan, “Insights into fracture behavior of Ni-based superalloy single crystals: An atomistic investigation,” Journal of Alloys and Compounds. 2023. link Times cited: 3 USED (low confidence) P. Pandey et al., “On the faulting and twinning mediated strengthening and plasticity in a γʹ strengthened CoNi-based superalloy at room temperature,” Acta Materialia. 2023. link Times cited: 2 USED (low confidence) S. M. Estalaki, T. Luo, and K. Manukyan, “Bayesian optimization of metastable nickel formation during the spontaneous crystallization under extreme conditions,” Journal of Applied Physics. 2023. link Times cited: 0 Abstract: Spontaneous crystallization of metals under extreme conditio… read moreAbstract: Spontaneous crystallization of metals under extreme conditions is a unique phenomenon occurring under far-from-equilibrium conditions that could enable the development of revolutionary and disruptive metastable metals with unusual properties. In this work, the formation of the hexagonal close-packed nickel (hcp-Ni) metastable phase during spontaneous crystallization is studied using non-equilibrium molecular dynamics (MD) simulations, with the goal of maximizing the fraction of this metastable phase in the final state. We employ Bayesian optimization (BO) with the Gaussian processes (GPs) regression as the surrogate model to maximize the hcp-Ni phase fraction, where temperature and pressure are control variables. MD simulations provide data for training the GP model, which is then used with BO to predict the next simulation condition. Such BO-guided active learning leads to a maximum hcp-Ni fraction of 43.38% in the final crystallized phase within 40 iterations when a face-centered cubic crystallite serves as the seed for crystallization from the amorphous phase. When an hcp seed is used, the maximum hcp-Ni fraction in the final crystal increases to 58.25% with 13 iterations. This study shows the promise of using BO to identify the process conditions that can maximize the rare phases. This method can also be generally applicable to process optimization to achieve target material properties. read less USED (low confidence) E. Yousefi et al., “Dynamics of intermetallics formation in the Al/Ni reactive wetting system,” Materialia. 2023. link Times cited: 1 USED (low confidence) Z.-wei Zhang et al., “Theoretical model for yield strength of monocrystalline Ni3Al by simultaneously considering size and strain rate,” Transactions of Nonferrous Metals Society of China. 2023. link Times cited: 1 USED (low confidence) G. Teichert et al., “Bridging scales with Machine Learning: From first principles statistical mechanics to continuum phase field computations to study order disorder transitions in LixCoO2,” ArXiv. 2023. link Times cited: 0 Abstract: LixTMO2 (TM=Ni, Co, Mn) forms an important family of cathode… read moreAbstract: LixTMO2 (TM=Ni, Co, Mn) forms an important family of cathode materials for Li-ion batteries, whose performance is strongly governed by Li composition-dependent crystal structure and phase stability. Here, we use LixCoO2 (LCO) as a model system to benchmark a machine learning-enabled framework for bridging scales in materials physics. We focus on two scales: (a) assemblies of thousands of atoms described by density functional theory-informed statistical mechanics, and (b) continuum phase field models to study the dynamics of order-disorder transitions in LCO. Central to the scale bridging is the rigorous, quantitatively accurate, representation of the free energy density and chemical potentials of this material system by coarsegraining formation energies for specific atomic configurations. We develop active learning workflows to train recently developed integrable deep neural networks for such high-dimensional free energy density and chemical potential functions. The resulting, first principles-informed, machine learning-enabled, phase-field computations allow us to study LCO cathodes' phase evolution in terms of temperature, morphology, charge cycling and particle size. read less USED (low confidence) N. Tuchinda and C. Schuh, “Triple junction solute segregation in Al-based polycrystals,” Physical Review Materials. 2023. link Times cited: 3 USED (low confidence) B. Waters, D. S. Karls, I. Nikiforov, R. Elliott, E. Tadmor, and B. Runnels, “Automated determination of grain boundary energy and potential-dependence using the OpenKIM framework,” Computational Materials Science. 2022. link Times cited: 5 USED (low confidence) X. Wang et al., “Deformation Behavior of Cell Walls in an Additively Manufactured Hybrid Metallic Foam,” Additive Manufacturing. 2022. link Times cited: 0 USED (low confidence) R. Khusnutdinoff, R. R. Khairullina, A. L. Bel’tyukov, V. Lad’yanov, and A. Mokshin, “Viscoelastic and Quasi-Solid Properties of Ni-Containing Binary Metal Melts,” High Temperature. 2022. link Times cited: 0 USED (low confidence) X. Guo, J. Zhou, X. Zhang, P. Yang, J. Ren, and X. Lu, “Effect of alloying elements on the interface of fcc-Fe/Ni3Al by first principle calculations,” Computational Materials Science. 2022. link Times cited: 3 USED (low confidence) B. Dong, Y. Fu, H. Zhan, and C. Lü, “Thermal and Stress Impacts on Vacancy Diffusion through Atomistic Simulations,” International Journal of Mechanical Sciences. 2022. link Times cited: 2 USED (low confidence) Q. Bizot, O. Politano, V. Turlo, and F. Baras, “Molecular dynamics simulations of nanoscale solidification in the context of Ni additive manufacturing,” Materialia. 2022. link Times cited: 2 USED (low confidence) H. Zhang et al., “Experimental Study at the Phase Interface of a Single-Crystal Ni-Based Superalloy Using TEM,” Materials. 2022. link Times cited: 1 Abstract: The single-crystal Ni-based superalloys, which have excellen… read moreAbstract: The single-crystal Ni-based superalloys, which have excellent mechanical properties at high temperatures, are commonly used for turbine blades in a variety of aero engines and industrial gas turbines. Focusing on the phase interface of a second-generation single-crystal Ni-based superalloy, in-situ TEM observation was conducted at room temperature and high temperatures. Intensity ratio analysis was conducted for the measurement of two-phase interface width. The improved geometric phase analysis method, where the adaptive mask selection method is introduced, was used for the measurement of the strain field near the phase interface. The strained irregular transition region is consistent with the calculated interface width using intensity ratio analysis. An intensity ratio analysis and strain measurement near the interface can corroborate and complement each other, contributing to the interface structure evaluation. Using TEM in-situ heating and Fourier transform, the change of dislocation density in the γ phase near the two-phase interface of the single-crystal Ni-based superalloy was analyzed. The dislocation density decreases first with the increase in temperature, consistent with the characteristics of metal quenching, and increases sharply at 450 °C. The correlation between the variation of dislocation density at high temperatures and the intermediate temperature brittleness was also investigated. read less USED (low confidence) X. Bai et al., “Innovative strategy to optimize the temperature-dependent lattice misfit and coherency of iridium-based γ/γ’ interfaces,” Applied Surface Science. 2022. link Times cited: 0 USED (low confidence) J. Huang and C. Yang, “Parallel energy stable phase field simulations of Ni-based alloys system,” ArXiv. 2022. link Times cited: 1 Abstract: In this paper, we investigate numerical methods for solving … read moreAbstract: In this paper, we investigate numerical methods for solving Nickel-based phase field system related to free energy, including the elastic energy and logarithmic type functionals. To address the challenge posed by the particular free energy functional, we propose a semi-implicit scheme based on the discrete variational derivative method, which is unconditionally energy stable and maintains the energy dissipation law and the mass conservation law. Due to the good stability of the semi-implicit scheme, the adaptive time step strategy is adopted, which can flexibly control the time step according to the dynamic evolution of the problem. A domain decomposition based, parallel Newton--Krylov--Schwarz method is introduced to solve the nonlinear algebraic system constructed by the discretization at each time step. Numerical experiments show that the proposed algorithm is energy stable with large time steps, and highly scalable to six thousand processor cores. read less USED (low confidence) S. Verma, A. Pramanik, K. Jyothsna, K. Vamsi, and S. Karthikeyan, “Phase Transformation Temperatures, γ–γ′ Lattice Parameter Misfit, and γ′ Precipitate Morphology in Co–Ti–V Alloys,” Metallurgical and Materials Transactions A. 2022. link Times cited: 1 USED (low confidence) K.-R. Lee, Y. Park, and S. Han, “Ab initio
construction of full phase diagram of MgO-CaO eutectic system using neural network interatomic potentials,” Physical Review Materials. 2022. link Times cited: 3 Abstract: While several studies confirmed that machine-learned potenti… read moreAbstract: While several studies confirmed that machine-learned potentials (MLPs) can provide accurate free energies for determining phase stabilities, the abilities of MLPs for efficiently constructing a full phase diagram of multi-component systems are yet to be established. In this work, by employing neural network interatomic potentials (NNPs), we demonstrate construction of the MgO-CaO eutectic phase diagram with temperatures up to 3400 K, which includes liquid phases. The NNP is trained over trajectories of various solid and liquid phases at several compositions that are calculated within the density functional theory (DFT). For the exchange-correlation energy among electrons, we compare the PBE and SCAN functionals. The phase boundaries such as solidus, solvus, and liquidus are determined by free-energy calculations based on the thermodynamic integration or semigrand ensemble methods, and salient features in the phase diagram such as solubility limit and eutectic points are well reproduced. In particular, the phase diagram produced by the SCAN-NNP closely follows the experimental data, exhibiting both eutectic composition and temperature within the measurements. On a rough estimate, the whole procedure is more than 1,000 times faster than pure-DFT based approaches. We believe that this work paves the way to fully $\textit{ab initio}$ calculation of phase diagrams. read less USED (low confidence) M. Zakaryan et al., “Spontaneous Crystallization for Tailoring Polymorphic Nanoscale Nickel with Superior Hardness,” The Journal of Physical Chemistry C. 2022. link Times cited: 2 USED (low confidence) S. Yang, J. Zhong, J. Wang, J. Gao, Q. Li, and L. Zhang, “A novel computational model for isotropic interfacial energies in multicomponent alloys and its coupling with phase-field model with finite interface dissipation,” Journal of Materials Science & Technology. 2022. link Times cited: 8 USED (low confidence) L. Xu, Z. Huang, Q. Shen, and F. Chen, “Atomistic Simulations of Plasticity Heterogeneity in Gradient Nano-grained FCC Metals,” Materials & Design. 2022. link Times cited: 10 USED (low confidence) T. Zhao et al., “Revealing sulfur- and phosphorus-induced embrittlement and local structural phase transformation of superlattice intrinsic stacking faults in L12-Ni3Al,” Journal of Materials Science. 2022. link Times cited: 3 USED (low confidence) M. Cheng, M. Liang, and H. Liao, “First principles study of Ni3Al/Ni6Ta2 interface and electronic properties,” Vacuum. 2022. link Times cited: 3 USED (low confidence) B. Xie, X. Wang, Y. Fan, and R. Li, “Atomistic Investigation on the Strengthening Mechanism of Single Crystal Ni-Based Superalloy under Complex Stress States,” Metals. 2022. link Times cited: 2 Abstract: Single crystal Ni-based superalloy, with excellent mechanica… read moreAbstract: Single crystal Ni-based superalloy, with excellent mechanical properties in high temperature, always works under complex stress states, including multiaxial tension and compression, which results in various strengthening mechanisms. In this paper, the atomistic simulation is applied to investigate the microstructure evolution under complex mechanical loading conditions, including uniaxial, equibiaxial, and non-equibiaxial tensile–compressive loadings. By comparison of the strain–stress curves and analysis of dislocation motion, it is believed that the tension promotes the bowing out of dislocations into the channel at loading direction, while compression limits it. Moreover, the dislocation analysis shows that the initial dislocation network, comprised of Lomer dislocations, will dissociate to form Lomer–Cottrell lock upon loading, which acts as a barrier to the further glide of dislocations. The mechanism of dislocation evolution is analyzed in detail by combining Schmid factor analysis and the comparison of energy density difference between γ and γ′ phases. read less USED (low confidence) J. Hao et al., “Molecular dynamics simulations on shock induced plasticity and stacking fault of coherent 001 Ni/Ni3Al Laminate Composite,” Journal of Materials Research and Technology. 2022. link Times cited: 4 USED (low confidence) Z. Bai, A. Misra, and Y. Fan, “Universal Trend in the dynamic relaxations of tilted metastable grain boundaries during ultrafast thermal cycle,” Materials Research Letters. 2022. link Times cited: 4 Abstract: Nonequilibrium relaxations in a multiplicity of tilted grain… read moreAbstract: Nonequilibrium relaxations in a multiplicity of tilted grain boundaries (GBs) subjected to ultrafast thermal driving forces are investigated by atomistic modeling. By scrutinizing the intermediate metastable microstates and their assessable activation barriers in the underlying energy landscape, we demonstrate the energetics and atomic diffusions in tilted metastable GBs are disorder-driven rather than free volume-driven. A critical transition temperature is identified, separating the nonequilibrium GBs’ evolution into a fast-varying stage, and a tuning-ineffective stage, respectively. We further discover a universal correlation between such critical temperature and GBs’ inherent structure energy, which enables predicting the tunability of metastable GBs’ kinetic and mechanical properties. GRAPHICAL ABSTRACT IMPACT STATEMENT We report a universal correlation between tilted GBs’ metastable microstates and kinetic properties during extreme thermal processing, suggesting a new strategy of manipulating interface-rich materials’ performance without changing their macroscopic textures. read less USED (low confidence) C. Chen and J.-Y. Song, “A Combined Atomistic-Continuum Study on the Unfaulting of Single and Multi-layer Interstitial Dislocation Loops in Irradiated FCC and HCP Metals,” International Journal of Plasticity. 2022. link Times cited: 4 USED (low confidence) R. Li, B. Xie, X. G. Yang, Y. S. Fan, Y. T. Sun, and D. Shi, “Multi-scale modelling of rafting behaviour under complex stress states for Ni3Al superalloys,” International Journal of Plasticity. 2022. link Times cited: 11 USED (low confidence) J. Wang, J. Liang, Z. Wen, Z. Yue, and Y. Peng, “Unveiling the local deformation behavior of typical microstructures of nickel-based single crystals under nanoindentation,” Mechanics of Materials. 2022. link Times cited: 4 USED (low confidence) S. Nasiri and M. Zaiser, “Effects of elasticity and dislocation core structure on the interaction of dislocations with embedded CNTs in Aluminium: An atomistic simulation study.,” Materialia. 2022. link Times cited: 8 USED (low confidence) C. Cui, X. Gong, L. Chen, W. Xu, and L. Chen, “Atomic-scale Investigations on Dislocation-Precipitate Interactions Influenced by Voids in Ni-based Superalloys,” International Journal of Mechanical Sciences. 2021. link Times cited: 5 USED (low confidence) J. Zhang et al., “On the tungsten segregation at γ/γ′ interface in a Ni-based single-crystal superalloy,” Vacuum. 2021. link Times cited: 8 USED (low confidence) J. Zhou, Y. He, J. Shen, F. Essa, and J. Yu, “Ni/Ni3Al interface-dominated nanoindentation deformation and pop-in events,” Nanotechnology. 2021. link Times cited: 26 Abstract: Nickel-based single crystal alloys have excellent mechanical… read moreAbstract: Nickel-based single crystal alloys have excellent mechanical properties due to its unique two-phase structure and interface. Therefore, molecular dynamics methods were used to simulate nanoindentation and microstructural evolution. We found the indenter reaction force and hardness of the Ni3Al phase is the largest. The pop-in event in Ni3Al phase is more obvious than that in the Ni phase and Ni/Ni3Al phase. Because lots of dislocations in the Ni3Al phase break through the barrier of the interface and cut into the Ni phase, while dislocations in the Ni phase only slip inside the Ni phase. Moreover, we found that the position of the starting point of the adhesion force recovery is mainly related to the elastic recovery of the material. The stronger the elastic recovery of the phase, the smaller the depth value corresponding to the starting point of the recovery. We further studied the variation of potential energy with indentation depth and found that the change of wave trough of the load–displacement (P–h) curve is related to stacking fault energy. This study has important theoretical guiding significance for the in-depth understanding and engineering application of the mechanical properties of nickel-based single crystal alloys. read less USED (low confidence) L. Wang and J. Hoyt, “Layering misalignment and negative temperature dependence of interfacial free energy of B2-liquid interfaces in a glass forming system,” Acta Materialia. 2021. link Times cited: 8 USED (low confidence) Z. Zhang et al., “Interaction between the edge dislocation dipole pair and interfacial misfit dislocation network in Ni-based single crystal superalloys,” International Journal of Solids and Structures. 2021. link Times cited: 10 USED (low confidence) M. Wagih and C. Schuh, “Thermodynamics and design of nanocrystalline alloys using grain boundary segregation spectra,” Acta Materialia. 2021. link Times cited: 20 USED (low confidence) J. Gabriel et al., “Bayesian Automated Weighting of Aggregated DFT, MD, and Experimental Data for Candidate Thermodynamic Models of Aluminum with Uncertainty Quantification,” Materialia. 2021. link Times cited: 2 USED (low confidence) H. Song and M. Mendelev, “Molecular Dynamics Study of Mechanism of Solid–Liquid Interface Migration and Defect Formation in Al3Sm Alloy,” JOM. 2021. link Times cited: 2 USED (low confidence) P. Chen, A. Chesetti, and M. Demkowicz, “Healing of nanocracks by collision cascades in nickel,” Journal of Nuclear Materials. 2021. link Times cited: 5 USED (low confidence) Z. Zhang et al., “Atomistic modeling for the extremely low and high temperature-dependent yield strength in a Ni-based single crystal superalloy,” Materials Today Communications. 2021. link Times cited: 6 USED (low confidence) T. Mann, M. Fahrmann, and M. Titus, “Ab Initio Investigation of Planar Defects in Immm-Ni2(Cr,Mo,W) Strengthened HAYNES 244 Alloy,” Metallurgical and Materials Transactions A. 2021. link Times cited: 1 USED (low confidence) K. Vamsi and S. Karthikeyan, “Modeling APB energies in multicomponent Ni-base superalloys,” Intermetallics. 2021. link Times cited: 13 USED (low confidence) Z. Zhang et al., “Interactions between butterfly-like prismatic dislocation loop pairs and planar defects in Ni3Al.,” Physical chemistry chemical physics : PCCP. 2021. link Times cited: 7 Abstract: Understanding the interactions between planar defects and co… read moreAbstract: Understanding the interactions between planar defects and complex dislocation structures in a material is of great significance to simplify its design. In this paper, we show that, from an atomistic perspective, by using molecular dynamics simulations on nanoindentations, a prismatic dislocation loop in Ni3Al appears in pairs with a butterfly-like shape. The planar defects in Ni3Al can effectively block the movement of the prismatic dislocation loop pairs and play a hardening role. Among the impediment factors, twinning boundaries are the strongest and antiphase boundaries are the weakest. Superlattice intrinsic and complex stacking faults have basically the same blocking effect. Furthermore, we systematically elucidate the hardening effects and interaction mechanisms between the prismatic dislocation loop pairs and planar defects. These findings provide novel insights into the nanostructured design of materials with excellent mechanical properties. read less USED (low confidence) C. Chen, J. Zhang, and J. Song, “Comprehensive study of vacancy frank loop unfaulting: atomistic simulations and predictive model,” Acta Materialia. 2021. link Times cited: 7 USED (low confidence) M. Dodaran, S. Guo, M. Khonsari, N. Shamsaei, and S. Shao, “A theoretical calculation of stacking fault energy of Ni alloys: The effects of temperature and composition,” Computational Materials Science. 2021. link Times cited: 15 USED (low confidence) J. F. Hickman, Y. Mishin, V. Ozoliņš, and A. Ardell, “Coarsening of solid
β
-Sn particles in liquid Pb-Sn alloys: Reinterpretation of experimental data in the framework of trans-interface-diffusion-controlled coarsening,” Physical Review Materials. 2021. link Times cited: 3 Abstract: James F. Hickman,1 Yuri Mishin ,2 Vidvuds Ozoliņš ,3 and Ala… read moreAbstract: James F. Hickman,1 Yuri Mishin ,2 Vidvuds Ozoliņš ,3 and Alan J. Ardell 4,* 1Materials Science and Engineering Division, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899-8910, USA 2Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030-4444, USA 3Department of Applied Physics, Energy Sciences Institute, Yale University, New Haven, Connecticut 06511, USA 4Department of Materials Science and Engineering, UCLA Samueli School of Engineering, Los Angeles, California 90095-1595, USA read less USED (low confidence) Z. Zhang, Q. Fu, J. Wang, P. Xiao, F. Ke, and C. Lu, “Hardening Ni3Al via complex stacking faults and twinning boundary,” Computational Materials Science. 2021. link Times cited: 15 USED (low confidence) S. Moeini-Ardakani, S. M. Taheri-Mousavi, and J. Li, “Highly efficient parallel grand canonical simulations of interstitial-driven diffusion-deformation processes,” Modelling and Simulation in Materials Science and Engineering. 2021. link Times cited: 1 Abstract: Absorption of interstitial alloying elements like H, O, C, a… read moreAbstract: Absorption of interstitial alloying elements like H, O, C, and N in metals and their continuous relocation and interactions with various microstructural features such as vacancies, dislocations, and grain boundaries have crucial influences on metals’ properties. However, besides limitations in experimental tools in capturing these mechanisms, the inefficiency of numerical tools also inhibits modeling efforts. Here, we present an efficient framework to perform hybrid grand canonical Monte Carlo and molecular dynamics simulations that allow for parallel insertion/deletion of Monte Carlo moves. A new methodology for calculation of the energy difference at trial moves that can be applied to many-body potentials as well as pair ones is a primary feature of our implementation. We study H diffusion in Fe (ferrite phase) and Ni polycrystalline samples to demonstrate the efficiency and scalability of the algorithm and its application. The computational cost of using our framework for half a million atoms is a factor of 250 less than the cost of using existing libraries. read less USED (low confidence) R. Wu, Y. Zhao, Q. Yin, J. Wang, X. Ai, and Z. Wen, “Atomistic simulation studies of Ni-based superalloys,” Journal of Alloys and Compounds. 2021. link Times cited: 23 USED (low confidence) L.-F. Zhu, J. Janssen, S. Ishibashi, F. Körmann, B. Grabowski, and J. Neugebauer, “A fully automated approach to calculate the melting temperature of elemental crystals,” Computational Materials Science. 2021. link Times cited: 17 USED (low confidence) M. He, E. T. Karim, M. Shugaev, and L. Zhigilei, “Atomistic simulation of the generation of vacancies in rapid crystallization of metals,” Acta Materialia. 2021. link Times cited: 7 USED (low confidence) J. Huo, H. Yang, J. Wang, and C. He, “Computational simulation of al-based alloy surface structure dislocation: the first-principles calculation and atomic pair-potential lattice dynamics calculation,” Modern Physics Letters B. 2021. link Times cited: 2 Abstract: In this paper, the first-principles calculation methods are … read moreAbstract: In this paper, the first-principles calculation methods are used to obtain the generalized stacking fault (GSF) energy of Al and Al alloy surface structures. At the same time, after obtaining the a... read less USED (low confidence) C. Hu, Z. Zhang, H. Chen, J. He, and H. Guo, “Reactive elements dependence of elastic properties and stacking fault energies of γ-Ni, γ′-Ni3Al and β-NiAl,” Journal of Alloys and Compounds. 2020. link Times cited: 16 USED (low confidence) S. Zhao, D. Chen, G. Yeli, and J. Kai, “Atomistic insight into the effects of order, disorder and their interface on defect evolution,” Journal of Alloys and Compounds. 2020. link Times cited: 8 USED (low confidence) J. Li, H.-W. Chen, Q. Fang, C. Jiang, Y. Liu, and P. Liaw, “Unraveling the dislocation–precipitate interactions in high-entropy alloys,” International Journal of Plasticity. 2020. link Times cited: 68 USED (low confidence) R. Voskoboinikov, “MD study of surface collision cascades in nickel,” Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms. 2020. link Times cited: 2 USED (low confidence) R. Voskoboinikov, “Optimal sampling of MD simulations of primary damage formation in collision cascades,” Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms. 2020. link Times cited: 5 USED (low confidence) Y. Ouyang et al., “Molecular dynamics simulation of diffusion for Ni–Zr interface,” International Journal of Modern Physics B. 2020. link Times cited: 3 Abstract: The molecular dynamics simulation has been performed to stud… read moreAbstract: The molecular dynamics simulation has been performed to study the effects of temperature on interdiffusion of Ni–Zr system. The simulated results indicate that the thickness of Ni/Zr diffusion layer increased with increasing diffusion time, and interdiffusion results in disordered or amorphization in the diffusion zone. During the diffusion process, Ni atoms diffuse crossing the interface more easily and deeply into Zr side than Zr atoms into Ni side. The activation energies of Ni and Zr are 1.25 and 1.28 eV for Ni(100)//Zr(0001) interface, 1.33 and 1.42 eV for Ni(110)//Zr(0001) interface at the temperature range of 950–1100 K, respectively. The microscopic diffusion mechanisms for Ni atoms in Zr lattice have been studied, and the results show that the most possible diffusion mechanism is the interstitial hopping mechanism, while for Zr diffusing in Ni, the vacancy diffusion mechanism is favored. The interdiffusion for case of Ni(110)//Zr(0001) interface is more easy than that of Ni(100)//Zr(0001) interface due to the lower surface energy for the former. In the diffusion zone of Ni–Zr, some typical clusters have been identified, which are similar to those extracted from the Ni–Zr intermetallic compounds, and which are generally consistent with the experimental observations in diffusion couples. read less USED (low confidence) R. Voskoboinikov, “Statistics of primary radiation defects in pure nickel,” Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms. 2020. link Times cited: 6 USED (low confidence) S. Rao, M. Dupraz, C. Woodward, and T. Parthasarathy, “Response surface for screw dislocation: Twin boundary interactions in FCC metals,” Acta Materialia. 2020. link Times cited: 3 USED (low confidence) S. Nag and W. Curtin, “Effect of solute-solute interactions on strengthening of random alloys from dilute to high entropy alloys,” Acta Materialia. 2020. link Times cited: 28 USED (low confidence) G. Kaptay, “A coherent set of model equations for various surface and interface energies in systems with liquid and solid metals and alloys.,” Advances in colloid and interface science. 2020. link Times cited: 42 USED (low confidence) M. Shi, N. Admal, and E. Tadmor, “Noise filtering in atomistic stress calculations for crystalline materials,” Journal of The Mechanics and Physics of Solids. 2020. link Times cited: 2 USED (low confidence) П. А. Иванович et al., “Structural and Energy Characteristics of NiAl Alloys with Deviations from Stoichiometric Composition. General Provisions. Part 1,” Izvestiya of Altai State University. 2020. link Times cited: 0 Abstract: The research results are presented in two parts. The first p… read moreAbstract: The research results are presented in two parts. The first part presents data describing the general state of the problem of low-stability pre-transitional structural phase states in intermetallides of the Ni-Al system. Physical interpretations of low-stability structural phase states in condensed systems are described along with the applied physical-mathematical model based on a calculated block of 32x32x32 elementary cells (65536 atoms) of an ordered BCC structure (superstructure B2, Pearson symbol cP2). The study is carried out by Monte Carlo methods using the Metropolis algorithm for an intermetallic NiAl sample of stoichiometric composition (used as an example). It is found out that a kind of hysteresis is observed during thermal cycling. The presence of such hysteresis indicates the irreversibility of the occurring processes. This implies a difference in the structural phase states at the heating and cooling stages.
The second part of the paper will demonstrate the results of a computer simulation of changes in structural phase states. The focus will be made on the low-stability pre-transitional structural phase states and energy characteristics of intermetallides образом with deviations from the stoichiometric composition of Ni45Al55 and Ni55Al45. read less USED (low confidence) Y. Lin et al., “Enhanced Radiation Tolerance of the Ni-Co-Cr-Fe High-Entropy Alloy as Revealed from Primary Damage,” MatSciRN: Other Mechanical Properties & Deformation of Materials (Topic). 2020. link Times cited: 93 Abstract: High-entropy alloys (HEAs) have received much attention for … read moreAbstract: High-entropy alloys (HEAs) have received much attention for the development of nuclear materials because of their excellent irradiation tolerance. In the present study, the generation and evolution of irradiation-induced defects in the NiCoCrFe HEA were investigated by molecular dynamics (MD) simulations to understand the mechanisms of its irradiation tolerance compared with bulk Ni. The displacement cascades were simulated for the energies of primary knock-on atoms (PKA) ranging from 10 to 50 keV to understand the irradiation resistance in HEAs. In general, there are more displaced atoms produced in the thermal spike phase, but fewer defects survived at the end of the cascades in the NiCoCrFe alloy than in Ni. Both interstitial and vacancy clusters increase in size or number with increasing PKA energy in both materials, but they do so more slowly in the NiCoCrFe HEA. The delayed damage accumulations in the NiCoCrFe HEA are attributed to the high defect recombination caused by the following two mechanisms. First, the enhanced thermal spike and the low thermal conductivity of HEAs for heat dissipation result in the higher efficiency of defect recombination. Furthermore, the substantially small binding energies of interstitial loops in the NiCoCrFe HEA, as compared with those in Ni, are responsible for the delayed interstitial clustering in the NiCoCrFe HEA. read less USED (low confidence) H. Yang, L. Zhu, R. Zhang, J. Zhou, and Z. Sun, “Influence of high stacking-fault energy on the dissociation mechanisms of misfit dislocations at semi-coherent interfaces,” International Journal of Plasticity. 2020. link Times cited: 9 USED (low confidence) P. Saidi et al., “Effect of He on the Order-Disorder Transition in Ni_3Al under Irradiation.,” Physical review letters. 2020. link Times cited: 9 Abstract: The order-disorder transition in Ni-Al alloys under irradiat… read moreAbstract: The order-disorder transition in Ni-Al alloys under irradiation represents an interplay between various reordering processes and disordering due to thermal spikes generated by incident high energy particles. Typically, ordering is enabled by diffusion of thermally generated vacancies, and can only take place at temperatures where they are mobile and in sufficiently high concentration. Here, in situ transmission electron micrographs reveal that the presence of He-usually considered to be a deleterious immiscible atom in this material-promotes reordering in Ni_{3}Al at temperatures where vacancies are not effective ordering agents. A rate-theory model is presented, that quantitatively explains this behavior, based on parameters extracted from atomistic simulations. These calculations show that the V_{2}He complex is an effective agent through its high stability and mobility. It is surmised that immiscible atoms may stabilize reordering agents in other materials undergoing driven processes, and preserve ordered phases at temperature where the driven processes would otherwise lead to disorder. read less USED (low confidence) M. Zaenudin, M. N. Mohammed, A. Sunardi, S. Al-Zubaidi, and H. Wijaya, “Atomistic investigation on the failure of diffusion-bonded Aluminium-Nickel,” Journal of Physics: Conference Series. 2020. link Times cited: 0 Abstract: This study presents an investigation on the role of temperat… read moreAbstract: This study presents an investigation on the role of temperature on the failure of diffusion-bonded Aluminium and Nickel. During diffusion bonding processes, where the bulk materials is subjected to join at the temperature of 300 K, 500 K, and 700 K with pressure of 10 MPa for 200 ps, the applied temperature is significantly influencing the final result of diffusion-bonded Al-Ni both in term of qualitative analysis (diffusion behaviour) and quantitative calculation (concentration distribution). In this case, as the temperature increased, the thickness of the interfacial region/diffusion zone is increased. However, when it is subjected to tensile test, the applied temperature is only has a significant impact to the ultimate tensile strength, that as the temperature is increased the ultimate tensile strength is decreased, but the applied temperature during diffusion welding is not influencing both time and strain value of the sample when it starts to failure. read less USED (low confidence) M. Dodaran et al., “Effect of alloying elements on the γ’ antiphase boundary energy in Ni-base superalloys,” Intermetallics. 2020. link Times cited: 42 USED (low confidence) H. Yang, L. Zhu, R. Zhang, J. Zhou, and Z. Sun, “Shearing dominated by the coupling of the interfacial misfit and atomic bonding at the FCC (111) semi-coherent interfaces,” Materials & Design. 2020. link Times cited: 6 USED (low confidence) R. Voskoboinikov, “An MD study of primary damage formation in aluminium,” Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms. 2019. link Times cited: 7 USED (low confidence) L. Qi, M. Xiong, F. Liu, X. Yue, and Y. Yaoyong, “Analysis of Boron on microstructure and composition of IC10 superalloy,” IOP Conference Series: Earth and Environmental Science. 2019. link Times cited: 1 Abstract: The microstructure and composition of IC10 superalloy contai… read moreAbstract: The microstructure and composition of IC10 superalloy containing B (0 wt% 1.1 wt%) were studied in this paper. DSC and microstructure analysis were used to compare the formation process of the microstructure and composition of the IC10 alloy with or without boron content. Precipitation temperatures and sequence of initial phases of IC10 alloys with or without B content were researched. The results shows that the exothermal peaks of formation for γ, MC carbide, (γ+γ’) eutectic and secondary γ’ phase reveal on DSC cooling curves. The alloys with 1.1% B have amephase component and the formation sequence of six phasesis γ, MC, (γ+γ’) eutectic, secondary γ’, M3B2 and Ni5Hf in turn. The boron content enhances the volume fraction of M3B2 and (γ+γ’) eutectic, decreases the temperature of liquids and solidus and also delays the formation of MC and (γ+γ’) eutectic obviously. read less USED (low confidence) Q. Li, F. Liu, X. Yue, M. Xiong, and H. Qin, “Effect of interlayer material on microstructure and mechanical properties of diffusion brazd IC10 superalloy,” IOP Conference Series: Materials Science and Engineering. 2019. link Times cited: 2 Abstract: The diffusion brazd test of IC10 superalloy was carried out … read moreAbstract: The diffusion brazd test of IC10 superalloy was carried out by using Russia solder M3 interlayer powder. The wetting quality of the high-temperature alloy was evaluated by the contact angle of wetting at various temperatures. The mechanical properties of the joints were determined at operating temperatures. The result shows that at the temperature of 1250°C, the contact angles of interlayer powder M3 alloy do not exceed 4∼5°, it has high wettability and spread ability over the surface of the IC10 alloy. The average test time before failure at the temperature of 900° and the stress of 320 MPa was 38 hours, and at the stress of 350 MPa was 9.6 hours, all both higher than 80% of the base material under the same experimental conditions. The structure of the joints has a smooth transition from the base metal to the soldered joint. In the structure of the joint, the γ’- phase with a large volume concentration in the base metal. IC10 superalloy has excellent high temperature properties when the M3 interlayer was used. read less USED (low confidence) F. Fischer, G. Schmitz, and S. Eich, “A systematic study of grain boundary segregation and grain boundary formation energy using a new copper–nickel embedded-atom potential,” Acta Materialia. 2019. link Times cited: 32 USED (low confidence) D. Nguyen-Trong, K. Pham-Huu, and P. Nguyen-Tri, “Simulation on the Factors Affecting the Crystallization Process of FeNi Alloy by Molecular Dynamics,” ACS Omega. 2019. link Times cited: 24 Abstract: This paper investigates the crystallization process of FeNi … read moreAbstract: This paper investigates the crystallization process of FeNi alloys with different impurity concentrations of Ni(x) [x = 10% (Fe90Ni10), 20% (Fe80Ni20), 30% (Fe70Ni30), 40% (Fe60Ni40), and 50% (Fe50Ni50)] at temperature (T) = 300 K and Fe70Ni30 at heating rates of 4 × 1012, 4 × 1013, and 4 × 1014 K/s at different temperatures, T = 300, 400, 500, 600, 700, 900, 1100, and 1300 K. Molecular dynamics models with the Sutton–Chen embedded interaction potential and recirculating boundary conditions are used to calculate the molecular parameters of alloys, such as radial distribution function, total energy of the system (Etot), size (l), and crystallization temperature (through the relationship between Etot and T). The common neighborhood analysis method is used to confirm the theoretical results of crystallization for Fe–Fe, Fe–Ni, and Ni–Ni. The annealing process did not have an effect on the crystallization process of FeNi alloys. The effect of Ni content, heating rate, and annealing time on structural unit numbers, such as face-centered cubic, hexagonal close-packed, blocked cubic center, and amorphous, and the crystallization process of FeNi alloys is also investigated. read less USED (low confidence) R. Voskoboinikov, “MD simulations of primary damage formation in L12 Ni3Al intermetallics,” Journal of Nuclear Materials. 2019. link Times cited: 12 USED (low confidence) X. Lu, P. Yang, J. Luo, J. Ren, H. Xue, and Y. Ding, “Tensile mechanical performance of Ni–Co alloy nanowires by molecular dynamics simulation,” RSC Advances. 2019. link Times cited: 17 Abstract: In this present contribution, tensile mechanical properties … read moreAbstract: In this present contribution, tensile mechanical properties of Ni–Co alloy nanowires with Co content from 0 to 20% were studied by molecular dynamics. The simulation results show the alloy nanowire with the Co content of 5% has the highest yield value of 9.72 GPa. In addition, more Frank dislocations were generated during the loading process to improve the performance of the alloy nanowire. The Young's modulus increases little by little from 105.68 to 179.78 GPa with the increase of Co content. Secondly, with the increase of temperature, the yield strength gradually decreases to 2.13 GPa. Young's modulus tends to decrease linearly from 170.7 GPa to 48.21 GPa. At the temperatures of 500 K and 700 K, it is easier to form Frank dislocation and Hirth dislocation, respectively, in the loading process. The peak value of the radial distribution function decreases and the number of peaks decreases, indicating the disappearance of the ordered structure. Finally, after the introduction of the surface and inner void, the yield strength of the nanowire drops about to 8.97 and 6.6 GPa, respectively, and the yield strains drop to 0.056 and 0.043. In the case of the existence of internal void, perfect dislocation and Hirth dislocation can be observed in the structure. read less USED (low confidence) J. Wang, Z. Wen, J. Liang, and Z. Yue, “Typical characteristics for creep fracture cleavage plane of nickel-based single crystal,” Materials Science and Engineering: A. 2019. link Times cited: 9 USED (low confidence) R. L. Morrison, S. Fensin, and J. L. W. Carter, “Exploration of the sliding behavior of a Σ11 grain boundary with precipitates in Ni–Al system using molecular dynamics,” Materialia. 2019. link Times cited: 5 USED (low confidence) F. Fischer, G. Schmitz, and S. Eich, “A Systematic Study of Grain Boundary Segregation and Grain Boundary Formation Energy Using a New Copper-Nickel Embedded-Atom Potential,” Computational Materials Science eJournal. 2019. link Times cited: 0 Abstract: In this atomistic study on the copper–nickel system, a new e… read moreAbstract: In this atomistic study on the copper–nickel system, a new embedded-atom alloy potential between copper and nickel is fitted to experimental data on the mixing enthalpy, taking available potentials for the pure components from literature. The resulting phase boundaries of the new potential are in very good agreement with a recent CALPHAD prediction. Using this new potential, a high angle symmetrical tiltΣ5 and a coherent Σ3 twin grain boundary (GB) are chosen for a systematic investigation of equilibriumGB segregation in the semi-grandcanonical ensemble at temperatures from 400 K to 800 K. Applying thermodynamically accurate integration techniques, the GB formation energies are calculated exactly and as an absolute value for every temperature and composition, which also enables the evaluation of GB excess entropies. The thorough thermodynamic model of GBs developed by Frolov and Mishin is excellently confirmed by the simulations quantitatively, if the impact of both segregation and GB tension on the change in GB formation energy is accounted for. In the case of the Σ3 coherent GB, it turns out that the change in GB formation energy at low temperatures is for the most part attributed to the GB tension, while segregation only has a small influence. This demonstrated effect of GB tensions should also be taken into account in the interpretation of experiments. read less USED (low confidence) J. Wang, J. Liang, Z. Wen, and Z. Yue, “Atomic simulation of void location effect on the void growth in nickel-based single crystal,” Computational Materials Science. 2019. link Times cited: 17 USED (low confidence) E. Antillon, C. Woodward, S. Rao, B. Akdim, and T. Parthasarathy, “A molecular dynamics technique for determining energy landscapes as a dislocation percolates through a field of solutes,” Acta Materialia. 2019. link Times cited: 25 USED (low confidence) Z. Mao, C. Booth-Morrison, C. Sudbrack, R. Noebe, and D. Seidman, “Interfacial free energies, nucleation, and precipitate morphologies in Ni-Al-Cr alloys: Calculations and atom-probe tomographic experiments,” Acta Materialia. 2019. link Times cited: 18 USED (low confidence) S. Rao et al., “Large-scale dislocation dynamics simulations of strain hardening of Ni microcrystals under tensile loading,” Acta Materialia. 2019. link Times cited: 21 USED (low confidence) M. He, C. Wu, M. Shugaev, G. Samolyuk, and L. Zhigilei, “Computational Study of Short-Pulse Laser-Induced Generation of Crystal Defects in Ni-Based Single-Phase Binary Solid–Solution Alloys,” The Journal of Physical Chemistry C. 2019. link Times cited: 20 Abstract: Single-phase concentrated solid–solution alloys exhibit enha… read moreAbstract: Single-phase concentrated solid–solution alloys exhibit enhanced mechanical characteristics and radiation damage resistance, making them promising candidate materials for applications involving an exposure to rapid localized energy deposition. In this paper, we use large-scale atomistic modeling to investigate the mechanisms of the generation of vacancies, dislocations, stacking faults, and twin boundaries in Ni, Ni50Fe50, Ni80Fe20, and Ni80Cr20 targets irradiated by short laser pulses in the regime of melting and resolidification. The decrease in the thermal conductivity and strengthening of the electron–phonon coupling due to the intrinsic chemical disorder in the solid-solution alloys are found to have important implications on localization of the energy deposition and generation of thermoelastic stresses. The interaction of the laser-induced stress waves with the melting front is found to play a key role in roughening of the crystal–liquid interface and generation of dislocations upon the solidificati... read less USED (low confidence) X. Zhang et al., “Temperature dependence of the stacking-fault Gibbs energy for Al, Cu, and Ni,” Physical Review B. 2018. link Times cited: 55 Abstract: The temperature-dependent intrinsic stacking fault Gibbs ene… read moreAbstract: The temperature-dependent intrinsic stacking fault Gibbs energy is computed based on highly converged density-functional-theory (DFT) calculations for the three prototype face-centered cubic metals ... read less USED (low confidence) G. Wang and Y. Xu, “Embedded-atom potential for Ni-Al alloy,” IOP Conference Series: Materials Science and Engineering. 2018. link Times cited: 1 Abstract: We construct a new embedded-atom potential for Ni-Al system.… read moreAbstract: We construct a new embedded-atom potential for Ni-Al system. The lattice constants, cohesive energies, elastic constants, vacancy formation energies, stacking fault energies and equations of state of Ni and Al are included in the fitting process of potentials for pure Ni and pure Al. The cross-interaction potential is fitted to the lattice constants, cohesive energies, elastic constants of Ni3Al and NiAl and the energies of (100) APB and (111) SISF of Ni3Al. The potential accurately reproduces the various physical properties of Ni, Al, Ni3Al and NiAl phases. The results of the new embedded-atom potential and other embedded-atom potentials are compared and discussed in detail. read less USED (low confidence) H. Kondo, M. Wakeda, and I. Watanabe, “Atomic study on the interaction between superlattice screw dislocation and γ-Ni precipitate in γ′-Ni3Al intermetallics,” Intermetallics. 2018. link Times cited: 10 USED (low confidence) H. N. Pishkenari, F. S. Yousefi, and A. Taghibakhshi, “Determination of surface properties and elastic constants of FCC metals: a comparison among different EAM potentials in thin film and bulk scale,” Materials Research Express. 2018. link Times cited: 22 Abstract: Three independent elastic constants C11, C12, and C44 were c… read moreAbstract: Three independent elastic constants C11, C12, and C44 were calculated and compared using available potentials of eight different metals with FCC crystal structure; Gold, Silver, Copper, Nickel, Platinum, Palladium, Aluminum and Lead. In order to calculate the elastic constants, the second derivative of the energy density of each system was calculated with respect to different directions of strains. Each set of the elastic constants of the metals in bulk scale was compared with experimental results, and the average relative error was for each was calculated and compared with other available potentials. Then, using the Voigt-Reuss-Hill method, approximated values for Young and shear moduli and Poisson’s ratio of the FCC metals in the bulk scale were found for each potential. Furthermore, to observe the surface effects on the metals in nanoscale, surface elastic constants of the thin films of the metals have been calculated. In the study of the thin films of materials in nanoscale, the number of surface atoms is considerable compared to all atoms of the object. This leads to an increase in the surface effects, which influence the elastic properties. By considering this fact and employing related definitions and equations, the properties of the thin films of the metals were calculated, and the surface effects for different crystallographic directions were compared. Subsequently, in some cases, comparisons among characteristics of the metals in the thin film and bulk material were made. read less USED (low confidence) A. Sharma, J. Hickman, N. Gazit, E. Rabkin, and Y. Mishin, “Nickel nanoparticles set a new record of strength,” Nature Communications. 2018. link Times cited: 71 USED (low confidence) K. Kumar, R. Sankarasubramanian, and U. Waghmare, “Influence of dilute solute substitutions in Ni on its generalized stacking fault energies and ductility,” Computational Materials Science. 2018. link Times cited: 15 USED (low confidence) N. Dũng, “Influence of impurity concentration, atomic number, temperature and tempering time on microstructure and phase transformation of Ni1−xFex (x = 0.1, 0.3, 0.5) nanoparticles,” Modern Physics Letters B. 2018. link Times cited: 17 Abstract: The influence of the concentration of impurity Fe in nanopar… read moreAbstract: The influence of the concentration of impurity Fe in nanoparticles Ni1−xFex with x = 0.1, 0.3 and 0.5 at T = 300 K; 4000 atoms, 5324 atoms, 6912 atoms and 8788 atoms at T = 300 K; 6912 atoms at T =... read less USED (low confidence) N. T. Dung, “Influence of impurity concentration, atomic number, temperature and tempering time on microstructure and phase transformation of Ni1−xFex (x = 0.1, 0.3, 0.5) nanoparticles,” Modern Physics Letters B. 2018. link Times cited: 8 Abstract: The influence of the concentration of impurity Fe in nanopar… read moreAbstract: The influence of the concentration of impurity Fe in nanoparticles Ni[Formula: see text]Fe[Formula: see text] with x = 0.1, 0.3 and 0.5 at T = 300 K; 4000 atoms, 5324 atoms, 6912 atoms and 8788 atoms at T = 300 K; 6912 atoms at T = 1500 K, 1300 K, 1100 K, 900 K, 700 K, 600 K, 500 K and 300 K and tempering time t = 500 ps at 6912 atoms on microstructure, phase transition temperature of Ni[Formula: see text]Fe[Formula: see text] nanoparticles is studied by molecular dynamics method with the Sutton–Chen embedded interaction potential and liberal boundary conditions. The structural properties are analyzed through the radial distribution function, the energy, the size, the phase transition temperature (determined by the relationship between total energy and temperature) and combined with the common neighbor analysis (CNA) method. The obtained first peak positions of the radial distribution function for the lengths of atomic pair Fe–Fe, Fe–Ni and Ni–Ni are consistent with the experimental data. In Ni[Formula: see text]Fe[Formula: see text] nanoparticles always exist in three types of structures (FCC, HCP, Amor) and phase transition temperatures range from 500 K to 700 K. When the concentration of impurity Fe in Ni[Formula: see text]Fe[Formula: see text] nanoparticles increases, then nanoparticles move from crystalline to amorphous state. When Ni[Formula: see text]Fe[Formula: see text] nanoparticles are at amorphous state, then the influence of factors such as the atomic number, the temperature and the tempering time on structure and transition temperature is negligible. read less USED (low confidence) E. Schmidt, A. T. Fowler, J. Elliott, and P. Bristowe, “Learning models for electron densities with Bayesian regression,” Computational Materials Science. 2018. link Times cited: 12 USED (low confidence) Z. Wen, J. Wang, Y. W. Wu, K. Zhou, and Z. Yue, “Atomistic simulation analysis of the effects of void interaction on void growth and coalescence in a metallic system,” Current Applied Physics. 2018. link Times cited: 13 USED (low confidence) J. Shang, F. Yang, C. Li, N. Wei, and X. Tan, “Size effect on the plastic deformation of pre-void Ni/Ni3Al interface under uniaxial tension: A molecular dynamics simulation,” Computational Materials Science. 2018. link Times cited: 25 USED (low confidence) Y. Ru et al., “New type of γ′ phase in Ni based single crystal superalloys: Its formation mechanism and strengthening effect,” Materials & Design. 2018. link Times cited: 13 USED (low confidence) S. Trady, M. Mazroui, A. Hasnaoui, and K. Saadouni, “Microstructural evolutions and fractal characteristics in medium range level in AlxNi100-x alloys during rapid solidification process,” Journal of Alloys and Compounds. 2018. link Times cited: 13 USED (low confidence) K. Choudhary, A. Biacchi, S. Ghosh, L. Hale, A. Walker, and F. Tavazza, “High-throughput assessment of vacancy formation and surface energies of materials using classical force-fields,” Journal of Physics: Condensed Matter. 2018. link Times cited: 16 Abstract: In this work, we present an open access database for surface… read moreAbstract: In this work, we present an open access database for surface and vacancy-formation energies using classical force-fields (FFs). These quantities are essential in understanding diffusion behavior, nanoparticle formation and catalytic activities. FFs are often designed for a specific application, hence, this database allows the user to understand whether a FF is suitable for investigating particular defect and surface-related material properties. The FF results are compared to density functional theory and experimental data whenever applicable for validation. At present, we have 17 506 surface energies and 1000 vacancy formation energies calculation in our database and the database is still growing. All the data generated, and the computational tools used, are shared publicly at the following websites: www.ctcms.nist.gov/~knc6/periodic.html, https://jarvis.nist.gov and https://github.com/usnistgov/jarvis. Approximations used during the high-throughput calculations are clearly mentioned. Using some of the example cases, we show how our data can be used to directly compare different FFs for a material and to interpret experimental findings such as using Wulff construction for predicting equilibrium shape of nanoparticles. Similarly, the vacancy formation energies data can be useful in understanding diffusion related properties. read less USED (low confidence) Y. Ru et al., “Improved 1200 °C stress rupture property of single crystal superalloys by γ′-forming elements addition,” Scripta Materialia. 2018. link Times cited: 25 USED (low confidence) S. Soltani, N. Abdolrahim, and P. Sepehrband, “Mechanism of intrinsic diffusion in the core of screw dislocations in FCC metals – A molecular dynamics study,” Computational Materials Science. 2018. link Times cited: 6 USED (low confidence) X. Chen, S. Lu, Z. Yang, T. Fu, C. Huang, and X. Peng, “Molecular dynamic simulation on nano-indentation of NiTi SMA,” Materials Science and Engineering A-structural Materials Properties Microstructure and Processing. 2018. link Times cited: 41 USED (low confidence) L. Lin, S. Hui, G. Lu, S. Wang, X.-dong Wang, and D.-J. Lee, “Molecular dynamics study of high temperature wetting kinetics for Al/NiAl and Al/Ni3Al systems: Effects of grain boundaries,” Chemical Engineering Science. 2017. link Times cited: 12 USED (low confidence) B. Xing, S. Yan, W. Jiang, and Q.-H. Qin, “Effect of Inclination Angle on Mechanical Behaviour and Deformation Asymmetry in Aluminium Bicrystal,” J. Integr. Des. Process. Sci. 2017. link Times cited: 1 Abstract: The influence of inclination angle of the grain boundary (GB… read moreAbstract: The influence of inclination angle of the grain boundary (GB) and the stress sign (negative or positive) on the mechanical performance of Σ13 aluminium (Al) bicrystals are investigated via molecular dynamic (MD) simulations of the deformation process. The mechanical response of the slanted GB ranging from 0° to 60° shows that (i) the peak yield needed for dislocation nucleation is inversely proportional to the magnitude of the angle; (ii) compression favors greater yield stresses of the slanted bicrystals than tension. Corresponding Schmid factors give an insight on how the inclination angle tends to compromise the elasticity of the bicrystal. Moreover, a considerable discrepancy in plasticity is also identified by dynamic monitoring of the atomic configuration and HCP atoms. This study provides a prediction of the impact of inclination angle on mechanical behaviour of bicrystal metals. read less USED (low confidence) X. Liu, S. Shang, Y.-J. Hu, Y. Wang, Y. Du, and Z.-kui Liu, “Insight into γ-Ni/γ′-Ni3Al interfacial energy affected by alloying elements,” Materials & Design. 2017. link Times cited: 34 USED (low confidence) A. Hassani, A. Makan, K. Sbiaai, A. Tabyaoui, and A. Hasnaoui, “Incidence energy effect and impact assessment during homoepitaxial growth of nickel on (001), (111) and (110) surfaces,” Thin Solid Films. 2017. link Times cited: 21 USED (low confidence) L. Béland et al., “Accurate classical short-range forces for the study of collision cascades in Fe-Ni-Cr,” Comput. Phys. Commun. 2017. link Times cited: 34 USED (low confidence) S. Trady, A. Hasnaoui, and M. Mazroui, “Atomic packing and medium-range order in Ni 3 Al metallic glass,” Journal of Non-crystalline Solids. 2017. link Times cited: 41 USED (low confidence) S. Soltani, N. Abdolrahim, and P. Sepehrband, “Molecular dynamics study of self-diffusion in the core of a screw dislocation in face centered cubic crystals,” Scripta Materialia. 2017. link Times cited: 11 USED (low confidence) J. Wang, Z. Yue, Z. Wen, D. Zhang, and C. Liu, “Orientation effects on the tensile properties of single crystal nickel with nanovoid: Atomistic simulation,” Computational Materials Science. 2017. link Times cited: 20 USED (low confidence) B. Wang, G. Kang, Q. Kan, K. Zhou, and C. Yu, “Molecular dynamics simulations to the pseudo-elasticity of NiTi shape memory alloy nano-pillar subjected to cyclic compression,” Computational Materials Science. 2017. link Times cited: 24 USED (low confidence) G. Demange, L. Lunéville, V. Pontikis, and D. Simeone, “Prediction of irradiation induced microstructures using a multiscale method coupling atomistic and phase field modeling: Application to the AgCu model alloy,” Journal of Applied Physics. 2017. link Times cited: 18 Abstract: Microstructure patterning using the ion beam mixing process … read moreAbstract: Microstructure patterning using the ion beam mixing process results from the competition between thermal diffusion and ballistic disordering induced by impinging ions. Although microstructure patterning under irradiation is now qualitatively understood, so far, no study could quantitatively estimate irradiation conditions leading to patterning. In this work, a new multiscale approach based on phase field was developed to simulate the microstructure evolution, and the occurrence of patterning due to ion irradiation in a silver-copper alloy, from atomic to microstructural scale. For that purpose, an efficient numerical scheme was developed to simulate the microstructure dynamics, within the framework of phase field. Equilibrium parameters of AgCu were computed using a mixed Monte Carlo-molecular dynamics approach. Ballistic effects induced by krypton ion irradiation, and point defect recreation leading to irradiation enhanced diffusion, were estimated using the binary collision approximation framework. As a... read less USED (low confidence) L. Gorelik and D. Mordehai, “Atomically Informed Continuum Models for the Elastic Contact Properties of Hollow and Coated Rigid Cylinders at the Nanoscale,” Journal of Applied Mechanics. 2017. link Times cited: 3 USED (low confidence) R. Dikken, B. Thijsse, and L. Nicola, “Impingement of edge dislocations on atomically rough contacts,” Computational Materials Science. 2017. link Times cited: 5 USED (low confidence) G. Bonny, A. Bakaev, P. Olsson, C. Domain, E. Zhurkin, and M. Posselt, “Interatomic potential to study the formation of NiCr clusters in high Cr ferritic steels,” Journal of Nuclear Materials. 2017. link Times cited: 17 USED (low confidence) A. Hassani, A. Makan, K. Sbiaai, A. Tabyaoui, and A. Hasnaoui, “THE INFLUENCE OF THE SURFACE ORIENTATION ON THE MORPHOLOGY DURING HOMOEPITAXIAL GROWTH OF NICKEL BY MOLECULAR DYNAMICS SIMULATION,” Surface Review and Letters. 2017. link Times cited: 17 Abstract: Homoepitaxial growth film for (001), (110) and (111) Ni subs… read moreAbstract: Homoepitaxial growth film for (001), (110) and (111) Ni substrates is investigated by means of molecular dynamics (MD) simulation. Embedded atom method (EAM) is considered to represent the interaction potential between nickel atoms. The simulation is performed at 300K using an incident energy of 0.06eV. In this study, the deposition process is performed periodically and the period, n, is relative to a perfect layer filling. The coverage rate of the actual expected level, L(n), can be considered a determinant for thin-film growth of nickel. The L(n) level is the most filled level during the deposition on (001) substrate, while it is the less filled one in the case of (111) substrate. Moreover, the upper level is the one which is responsible for the surface roughness and the appearance time of an upper layer may also be a factor influencing the surface roughness. The deposition on (111) substrate induces the most rigorous surface with a rapid appearance time of the upper layers. The L(n−1) layers are almost completely filled for all substrates. The L(n−2) and lower layers are completely filled for (001) and (110) substrates while for (111) substrate the completely filled layers are L(n−3) and lower ones. read less USED (low confidence) Y. Zhang, R. Ashcraft, M. Mendelev, C. Wang, and K. Kelton, “Experimental and molecular dynamics simulation study of structure of liquid and amorphous Ni62Nb38 alloy.,” The Journal of chemical physics. 2016. link Times cited: 67 Abstract: The state-of-the-art experimental and atomistic simulation t… read moreAbstract: The state-of-the-art experimental and atomistic simulation techniques were utilized to study the structure of the liquid and amorphous Ni62Nb38 alloy. First, the ab initio molecular dynamics (AIMD) simulation was performed at rather high temperature where the time limitations of the AIMD do not prevent to reach the equilibrium liquid structure. A semi-empirical potential of the Finnis-Sinclair (FS) type was developed to almost exactly reproduce the AIMD partial pair correlation functions (PPCFs) in a classical molecular dynamics simulation. This simulation also showed that the FS potential well reproduces the bond angle distributions. The FS potential was then employed to elongate the AIMD PPCFs and determine the total structure factor (TSF) which was found to be in excellent agreement with X-ray TSF obtained within the present study demonstrating the reliability of the AIMD for the simulation of the structure of the liquid Ni-Nb alloys as well as the reliability of the developed FS potential. The glass structure obtained with the developed potential was also found to be in excellent agreement with the X-ray data. The analysis of the structure revealed that a network of the icosahedra clusters centered on Ni atoms is forming during cooling the liquid alloy down to Tg and the Nb Z14, Z15, and Z16 clusters are attached to this network. This network is the main feature of the Ni62Nb38 alloy and further investigations of the properties of this alloy should be based on study of the behavior of this network. read less USED (low confidence) S. Meher, G. Viswanathan, S. Nag, H. Fraser, and R. Banerjee, “Determination of the gamma prime/gamma interface width in a Co–Al–W alloy via coupled aberration-corrected scanning transmission electron microscopy and atom probe tomography,” Scripta Materialia. 2016. link Times cited: 9 USED (low confidence) S. Trady, M. Mazroui, A. Hasnaoui, and K. Saadouni, “Molecular dynamics study of atomic-level structure in monatomic metallic glass,” Journal of Non-crystalline Solids. 2016. link Times cited: 46 USED (low confidence) M. D. Reyes, R. Voskoboinikov, M. Kirk, H. Huang, G. Lumpkin, and D. Bhattacharyya, “Defect evolution in a NiMoCrFe alloy subjected to high-dose Kr ion irradiation at elevated temperature,” Journal of Nuclear Materials. 2016. link Times cited: 7 USED (low confidence) Z. Hou, P. Hedström, Q. Chen, Y. Xu, D. Wu, and J. Odqvist, “Quantitative modeling and experimental verification of carbide precipitation in a martensitic Fe–0.16 wt%C–4.0 wt%Cr alloy,” Calphad-computer Coupling of Phase Diagrams and Thermochemistry. 2016. link Times cited: 26 USED (low confidence) S. M. Rassoulinejad-Mousavi, Y. Mao, and Y. Zhang, “Evaluation of Copper, Aluminum and Nickel Interatomic Potentials on Predicting the Elastic Properties,” arXiv: Computational Physics. 2016. link Times cited: 63 Abstract: Choice of appropriate force field is one of the main concern… read moreAbstract: Choice of appropriate force field is one of the main concerns of any atomistic simulation that needs to be seriously considered in order to yield reliable results. Since, investigations on mechanical behavior of materials at micro/nanoscale has been becoming much more widespread, it is necessary to determine an adequate potential which accurately models the interaction of the atoms for desired applications. In this framework, reliability of multiple embedded atom method based interatomic potentials for predicting the elastic properties was investigated. Assessments were carried out for different copper, aluminum and nickel interatomic potentials at room temperature which is considered as the most applicable case. Examined force fields for the three species were taken from online repositories of National Institute of Standards and Technology (NIST), as well as the Sandia National Laboratories, the LAMMPS database. Using molecular dynamic simulations, the three independent elastic constants, C11, C12 and C44 were found for Cu, Al and Ni cubic single crystals. Voigt-Reuss-Hill approximation was then implemented to convert elastic constants of the single crystals into isotropic polycrystalline elastic moduli including Bulk, Shear and Young's modulus as well as Poisson's ratio. Simulation results from massive molecular dynamic were compared with available experimental data in the literature to justify the robustness of each potential for each species. Eventually, accurate interatomic potentials have been recommended for finding each of the elastic properties of the pure species. Exactitude of the elastic properties was found to be sensitive to the choice of the force fields. Those potentials were fitted for a specific compound may not necessarily work accurately for all the existing pure species. read less USED (low confidence) S. Hocker, M. Hummel, P. Binkele, H. Lipp, and S. Schmauder, “Molecular dynamics simulations of tensile tests of Ni-, Cu-, Mg- and Ti-alloyed aluminium nanopolycrystals,” Computational Materials Science. 2016. link Times cited: 12 USED (low confidence) B. Zheng and H. Du, “Study of the Mechanical Deformation of Transforming Nanowires Constrained in Metal Matrix,” Materials Science Forum. 2016. link Times cited: 0 Abstract: We report the results of a simulation study of the mechanica… read moreAbstract: We report the results of a simulation study of the mechanical deformation of NiAl nanowires constrained in Al metal matrix. The constrained nanowires showed high elastic yield stress and nonelastic stretching via a transition from the B2 to BCT phase. The phase transformation mechanism was that of atomic shuffling, via the appearance, spreading, and aggregation of isolated defect atoms, instead of dislocation movement. Because of geometry constraints, the interphase energy between the new and parent phases is not readily released, which results in strain hardening. read less USED (low confidence) K. Xiong, H. Lu, and J. Gu, “Atomistic simulations of the nanoindentation-induced incipient plasticity in Ni3Al crystal,” Computational Materials Science. 2016. link Times cited: 38 USED (low confidence) L. Béland et al., “Features of primary damage by high energy displacement cascades in concentrated Ni-based alloys,” Journal of Applied Physics. 2016. link Times cited: 53 Abstract: Alloying of Ni with Fe or Co has been shown to reduce primar… read moreAbstract: Alloying of Ni with Fe or Co has been shown to reduce primary damage production under ion irradiation. Similar results have been obtained from classical molecular dynamics simulations of 1, 10, 20, and 40 keV collision cascades in Ni, NiFe, and NiCo. In all cases, a mix of imperfect stacking fault tetrahedra, faulted loops with a 1/3⟨111⟩ Burgers vector, and glissile interstitial loops with a 1/2⟨110⟩ Burgers vector were formed, along with small sessile point defect complexes and clusters. Primary damage reduction occurs by three mechanisms. First, Ni-Co, Ni-Fe, Co-Co, and Fe-Fe short-distance repulsive interactions are stiffer than Ni-Ni interactions, which lead to a decrease in damage formation during the transition from the supersonic ballistic regime to the sonic regime. This largely controls final defect production. Second, alloying decreases thermal conductivity, leading to a longer thermal spike lifetime. The associated annealing reduces final damage production. These two mechanisms are especially ... read less USED (low confidence) Y. Feruz and D. Mordehai, “Towards a universal size-dependent strength of face-centered cubic nanoparticles,” Acta Materialia. 2016. link Times cited: 37 USED (low confidence) P. Chowdhury, G. Ren, and H. Sehitoglu, “NiTi superelasticity via atomistic simulations,” Philosophical Magazine Letters. 2015. link Times cited: 41 Abstract: The NiTi shape memory alloys (SMAs) are promising candidates… read moreAbstract: The NiTi shape memory alloys (SMAs) are promising candidates for the next-generation multifunctional materials. These materials are superelastic i.e. they can fully recover their original shape even after fairly large inelastic deformations once the mechanical forces are removed. The superelasticity reportedly stems from atomic scale crystal transformations. However, very few computer simulations have emerged, elucidating the transformation mechanisms at the discrete lattice level, which underlie the extraordinary strain recoverability. Here, we conduct breakthrough molecular dynamics modelling on the superelastic behaviour of the NiTi single crystals, and unravel the atomistic genesis thereof. The deformation recovery is clearly traced to the reversible transformation between austenite and martensite crystals through simulations. We examine the mechanistic origin of the tension–compression asymmetries and the effects of pressure/temperature/strain rate variation isolatedly. Hence, this work essentially brings a new dimension to probing the NiTi performance based on the mesoscale physics under more complicated thermo-mechanical loading scenarios. read less USED (low confidence) S.-L. Liu, C.-yu Wang, and T. Yu, “Effect of Re and W upon brittle fracture in Ni3Al cracks by atomic simulation,” Computational Materials Science. 2015. link Times cited: 4 USED (low confidence) B.-H. Wu, J. Zhou, C. Xue, and H. Liu, “Molecular dynamics simulation of the deposition and annealing of NiAl film on Ni substrate,” Applied Surface Science. 2015. link Times cited: 32 USED (low confidence) A. Hassani, A. Makan, K. Sbiaai, A. Tabyaoui, and A. Hasnaoui, “Molecular dynamics study of growth and interface structure during aluminum deposition on Ni(1 0 0) substrate,” Applied Surface Science. 2015. link Times cited: 29 USED (low confidence) S. Kalidindi, J. A. Gomberg, Z. Trautt, and C. Becker, “Application of data science tools to quantify and distinguish between structures and models in molecular dynamics datasets,” Nanotechnology. 2015. link Times cited: 39 Abstract: Structure quantification is key to successful mining and ext… read moreAbstract: Structure quantification is key to successful mining and extraction of core materials knowledge from both multiscale simulations as well as multiscale experiments. The main challenge stems from the need to transform the inherently high dimensional representations demanded by the rich hierarchical material structure into useful, high value, low dimensional representations. In this paper, we develop and demonstrate the merits of a data-driven approach for addressing this challenge at the atomic scale. The approach presented here is built on prior successes demonstrated for mesoscale representations of material internal structure, and involves three main steps: (i) digital representation of the material structure, (ii) extraction of a comprehensive set of structure measures using the framework of n-point spatial correlations, and (iii) identification of data-driven low dimensional measures using principal component analyses. These novel protocols, applied on an ensemble of structure datasets output from molecular dynamics (MD) simulations, have successfully classified the datasets based on several model input parameters such as the interatomic potential and the temperature used in the MD simulations. read less USED (low confidence) S. Ma, N. Ren, and J. Zhang, “Observation of morphology and stress distribution around dislocation in Ni3Al on the atomic scale,” Solid State Communications. 2015. link Times cited: 6 USED (low confidence) S. Schweizer, R. Chaudret, J. Low, and L. Subramanian, “Molecular modeling and simulation of Raney Nickel: From alloy precursor to the final porous catalyst,” Computational Materials Science. 2015. link Times cited: 8 USED (low confidence) Y. Shen, Y. Gan, W. Qi, Y. Shen, and Z. Chen, “Effect of the hot electron blast force on ultrafast laser ablation of nickel thin film,” Applied Optics. 2015. link Times cited: 5 Abstract: The hot electron blast effect on the femtosecond laser-induc… read moreAbstract: The hot electron blast effect on the femtosecond laser-induced response of a nickel nanofilm is numerically studied by a coupled continuum-atomistic method. It is found that the hot electron blast force significantly affects the laser-induced stress waves in the nickel film, whereas the lattice temperature is much less influenced by the blast force. The simulation results for the laser ablation of the nickel film reveal that the neglect of the hot electron blast effect could significantly underestimate the ablation depth and overpredict the ablation threshold. It is also shown that the increase of ablation depth with the increasing laser fluence in the photomechanical ablation of nickel thin film mainly results from the thermal melting of the deeper material. read less USED (low confidence) S.-L. Liu, C.-yu Wang, T. Yu, and Z.-G. Liu, “Effect of Re on lattice trapping in γ′-Ni3Al cracks by atomistic simulation,” Computational Materials Science. 2015. link Times cited: 10 USED (low confidence) K. Kumar, R. Sankarasubramanian, and U. Waghmare, “The effect of gamma-gamma ‘ interface on the tensile and shear strengths of nickel-based superalloys: A first-principles study,” Computational Materials Science. 2015. link Times cited: 6 USED (low confidence) X. Ye, C.-S. Liu, W. Zhong, and Y. Du, “Precipitate size dependence of Ni/Ni3Al interface energy,” Physics Letters A. 2015. link Times cited: 19 USED (low confidence) Y. Chen et al., “Measurement of size-dependent composition variations for gamma prime (γ’) precipitates in an advanced nickel-based superalloy.,” Ultramicroscopy. 2014. link Times cited: 48 USED (low confidence) D. Crudden, A. Mottura, N. Warnken, B. Raeisinia, and R. Reed, “Modelling of the influence of alloy composition on flow stress in high-strength nickel-based superalloys,” Acta Materialia. 2014. link Times cited: 122 USED (low confidence) X. Zhang, H. Deng, S. Xiao, J.-feng Tang, L. Deng, and W. Hu, “Effect of Re content on the γ/γ′ interface: A Monte Carlo simulation,” Computational Materials Science. 2014. link Times cited: 5 USED (low confidence) Z. Wen, Y.-hong Zhao, H. Hou, N. Wang, L. Fu, and P. Han, “A first-principles study on interfacial properties of Ni(001)/Ni3Nb(001),” Transactions of Nonferrous Metals Society of China. 2014. link Times cited: 15 USED (low confidence) X.-yuan Yang and W. Hu, “The alloying element dependence of the local lattice deformation and the elastic properties of Ni3Al: A molecular dynamics simulation,” Journal of Applied Physics. 2014. link Times cited: 18 Abstract: Molecular dynamics (MD) together with the modified analytica… read moreAbstract: Molecular dynamics (MD) together with the modified analytical embedded atom method (MAEAM) is employed to study the alloying elements (Re, Ru, Co, and Ta) dependence of the elastic properties of L12-Ni3Al. The investigations indicate that the calculated elastic properties of Ni3Al are in reasonable agreement with the previous results. The substituting formation energies of the alloying elements in Ni3Al are calculated to determine the site preference. It is found out that Re, Ru, and Ta atoms prefer to occupy the Al sites, and the Co atom prefers to occupy the Ni site. Based on Re, Ru, and Ta substituting the 1st, 2nd, 3rd, and 4th nearest-neighbor atoms, we ascertain that the substituting manners of these alloying elements have a decisive effect on the bulk modulus and the local crystal lattice of Ni3Al. Moreover, for Re, the bonding interaction plays a predominant role in the improvement in the bulk modulus of Ni3Al, whereas the size effect of Ru and Ta on the improvement in the bulk modulus is more obv... read less USED (low confidence) A. Ardell, “Trans-interface-diffusion-controlled coarsening in ternary alloys,” Acta Materialia. 2013. link Times cited: 28 USED (low confidence) A. Ardell, “Trans-interface-diffusion-controlled coarsening of γ′ precipitates in ternary Ni–Al–Cr alloys,” Acta Materialia. 2013. link Times cited: 42 USED (low confidence) J. Zhang, Z. Chen, Y. Wang, and Y. Tao, “The temporal evolution of microstructures during structural transition of D022 and L12 involved with transient phases,” Superlattices and Microstructures. 2013. link Times cited: 3 USED (low confidence) Z. Wen et al., “First-principle study of interfacial properties of Ni–Ni3Si composite,” Computational Materials Science. 2013. link Times cited: 16 USED (low confidence) L. Sandoval, G. Campbell, and J. Marian, “Thermodynamic interpretation of reactive processes in Ni–Al nanolayers from atomistic simulations,” Modelling and Simulation in Materials Science and Engineering. 2013. link Times cited: 13 Abstract: Metals that can form intermetallic compounds by exothermic r… read moreAbstract: Metals that can form intermetallic compounds by exothermic reactions constitute a class of reactive materials with multiple applications. Ni–Al laminates of thin alternating layers are being considered as model nanometric metallic multilayers for studying various reaction processes. However, the reaction kinetics at short timescales after mixing are not entirely understood. In this work, we calculate the free energies of Ni–Al alloys as a function of composition and temperature for different solid phases using thermodynamic integration based on state-of-the-art interatomic potentials. We use this information to interpret molecular dynamics (MD) simulations of bilayer systems at 800 K and zero pressure, both in isothermal and isenthalpic conditions. We find that a disordered phase always forms upon mixing as a precursor to a more stable nano crystalline B2 phase. We construe the reactions observed in terms of thermodynamic trajectories governed by the state variables computed. Simulated times of up to 30 ns were achieved, which provides a window to phenomena not previously observed in MD simulations. Our results provide insight into the early experimental reaction timescales and suggest that the path (segregated reactants) → (disordered phase) → (B2 structure) is always realized irrespective of the imposed boundary conditions. read less USED (low confidence) M. Chaudhari, J. Tiley, R. Banerjee, and J. Du, “Site preference and interaction energies of Co and Cr in gamma prime Ni3Al: a first-principles study,” Modelling and Simulation in Materials Science and Engineering. 2013. link Times cited: 19 Abstract: Nickel-based superalloys are critical for aerospace and powe… read moreAbstract: Nickel-based superalloys are critical for aerospace and power applications due to excellent high-temperature properties. These high-temperature properties are attributed to the coherently precipitated gamma prime phase in the gamma matrix. The segregation of alloying elements between the matrix and the gamma prime phase drives precipitate misfit strains and impacts material strength. This study aims at understanding the site preference of Co and Cr within the ordered gamma prime phase. The study also calculates the interaction energy between alloying additions within the ternary systems Ni–Al–Cr and Ni–Al–Co, and the quaternary system Ni–Al–Cr–Co. It is found that Co has mixed substitution behavior between the Al and Ni sites in the gamma prime phase. The results from the Ni–Al–Cr ternary system show that two Cr atoms prefer being close to each other, with the most stable configuration of the first nearest neighbors of the Al–Al site. The interaction energies calculated from the Ni–Al–Co system show that the initial distance between two Co atoms will decide whether the two Co atoms prefer Ni–Ni or Ni–Al configuration. The study on the quaternary system Ni–Al–Cr–Co reveals that the initial configuration of Cr and Co atoms will affect the final most stable configuration. The results are found to be consistent with our previous findings. read less USED (low confidence) Z. A. Tooq and S. Kenny, “Modelling radiation damage at grain boundaries in fcc nickel and Ni-based alloy using long time scale dynamics techniques,” Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms. 2013. link Times cited: 9 USED (low confidence) Y. Zhu, Z. Li, and M. Huang, “Atomistic modeling of the interaction between matrix dislocation and interfacial misfit dislocation networks in Ni-based single crystal superalloy,” Computational Materials Science. 2013. link Times cited: 62 USED (low confidence) S. Rao, D. Dimiduk, T. Parthasarathy, M. Uchic, and C. Woodward, “Atomistic simulations of surface cross-slip nucleation in face-centered cubic nickel and copper,” Acta Materialia. 2013. link Times cited: 28 USED (low confidence) L. Alawieh, T. Weihs, and O. Knio, “A generalized reduced model of uniform and self-propagating reactions in reactive nanolaminates,” Combustion and Flame. 2013. link Times cited: 49 USED (low confidence) B. Lü, G. Chen, S. Qu, H. Su, and W. Zhou, “First-principle calculation of yield stress anomaly of Ni3Al-based alloys,” Materials Science and Engineering A-structural Materials Properties Microstructure and Processing. 2013. link Times cited: 11 USED (low confidence) C. Peng, Y. Zhong, Y. Lu, S. Narayanan, T. Zhu, and J. Lou, “Strain rate dependent mechanical properties in single crystal nickel nanowires,” Applied Physics Letters. 2013. link Times cited: 49 Abstract: We measure the strain rate dependence of 0.2% offset yield s… read moreAbstract: We measure the strain rate dependence of 0.2% offset yield stress in single-crystal nickel nanowires with diameters ranging from 80 to 300 nm. In situ tensile experiments with strain rates from 10−4 s−1 to 10−2 s−1 were conducted, and the small activation volume (∼10b3, where b is the Burgers vector length) and high strain-rate sensitivity (∼0.1) were obtained. These results agreed with atomistic simulations. Our work provides insights into the strength-limiting and rate-controlling mechanism of plasticity at the nanoscale. read less USED (low confidence) Y. Wang, G. Gao, and S. Ogata, “Size-dependent transition of deformation mechanism, and nonlinear elasticity in Ni3Al nanowires,” Applied Physics Letters. 2013. link Times cited: 17 Abstract: A size-dependent transition of deformation mechanism is reve… read moreAbstract: A size-dependent transition of deformation mechanism is revealed in Ni3Al nanowire under atomistic uniaxial tension. Deformation twinning is replaced by phase transformation when the diameter of Ni3Al nanowire reduces to a critical value near 4 nm. Enhanced size-dependent nonlinear elasticity is observed in the nanowires, in comparison to their bulk counterpart which is benchmarked by combined density functional and atomistic study. This study provide fundamental understanding on the size-dependent deformation mechanisms of nanostructured alloys. read less USED (low confidence) G. Kaptay, “On the interfacial energy of coherent interfaces,” Acta Materialia. 2012. link Times cited: 49 USED (low confidence) K. Vamsi and S. Karthikeyan, “Effect of Off‐Stoichiometry and Ternary Additions on Planar Fault Energies in Ni3Al,” Superalloys. 2012. link Times cited: 23 Abstract: First principles calculations were done to evaluate the latt… read moreAbstract: First principles calculations were done to evaluate the lattice parameter, cohesive energy and stacking fault energies of ordered gamma' (Ll(2)) precipitates in superalloys as a function of composition. It was found that addition of Ti and Ta lead to an increase in lattice parameter and decrease in cohesive energy, while Ni antisites had the opposite effect. Ta and Ti addition to stoichiometric Ni3Al resulted in an initial increase in the energies of APB((111)), CSF(111), APB((001)) and SISF(111). However, at higher concentrations, the fault energies decreased. Addition of Ni antisites decreased the energy of all four faults monotonically. A model based on nearest neighbor bonding was used for Ni-3(Al, Ta), Ni-3(Al, Ti) and Ni-3(Al, Ni) pseudo-binary systems and extended to pseudo- ternary Ni-3(Al, Ta, Ni) and Ni-3(Al, Ti, Ni) systems. Recipes were developed for predicting lattice parameters, cohesive energies and fault energies in pseudo- ternary systems on the basis of coefficients derived from simpler pseudobinary systems. The model predictions were found to be in good agreement with first principles calculations for lattice parameters, cohesive energies, and energies of APB((111)) and CSF(111). read less USED (low confidence) J. Zhang, Z. Chen, X.-juan Du, C. Chen, and T. Yang, “Characterization of lattice defects for L12–Ni3Al involving the ordering process via the microscopic phase field method,” Superlattices and Microstructures. 2012. link Times cited: 4 USED (low confidence) B. Ge, Y.-shi Luo, J.-rong Li, J. Zhu, D. Tang, and Z. Gui, “Study of γ/γ′ interfacial width in a nickel-based superalloy by scanning transmission electron microscopy,” Philosophical Magazine Letters. 2012. link Times cited: 13 Abstract: The γ/γ′ interfaces are thought to play an important role in… read moreAbstract: The γ/γ′ interfaces are thought to play an important role in determining the mechanical properties in single-crystal nickel-based superalloys. In this article, interfacial width in DD6, one second-generation single-crystal superalloy containing 2 wt% Re, has been studied by means of scanning transmission electron microscopy. From an atomic resolution high angle annular dark field image, both compositional interfaces and order–disorder interfaces are studied, and it is first found that the interfacial width of chemical composition is same with that between the ordered and disordered phases. read less USED (low confidence) P. Gopal and S. G. Srinivasan, “First-principles study of self- and solute diffusion mechanisms inγ′-Ni3Al,” Physical Review B. 2012. link Times cited: 28 USED (low confidence) T. Kelly and D. Larson, “Atom Probe Tomography 2012,” Annual Review of Materials Research. 2012. link Times cited: 225 Abstract: In the world of tomographic imaging, atom probe tomography (… read moreAbstract: In the world of tomographic imaging, atom probe tomography (APT) occupies the high-spatial-resolution end of the spectrum. It is highly complementary to electron tomography and is applicable to a wide range of materials. The current state of APT is reviewed. Emphasis is placed on applications and data analysis as they apply to many fields of research and development including metals, semiconductors, ceramics, and organic materials. We also provide a brief review of the history and the instrumentation associated with APT and an assessment of the existing challenges in the field. read less USED (low confidence) V. Vorontsov, L. Kovarik, M. Mills, and C. Rae, “High-resolution electron microscopy of dislocation ribbons in a CMSX-4 superalloy single crystal,” Acta Materialia. 2012. link Times cited: 101 USED (low confidence) M. Horstemeyer, “Case Study: Conducting a Structural Scale Metal Forming Finite Element Analysis Starting from Electronics Structures Calculations Using ICME Tools.” 2012. link Times cited: 0 USED (low confidence) A. Ardell, “Gradient energy, interfacial energy and interface width,” Scripta Materialia. 2012. link Times cited: 53 USED (low confidence) D. Terentyev, E. Zhurkin, and G. Bonny, “Emission of full and partial dislocations from a crack in BCC and FCC metals: An atomistic study,” Computational Materials Science. 2012. link Times cited: 18 USED (low confidence) S. Rao, D. Dimiduk, T. Parthasarathy, M. Uchic, and C. Woodward, “Atomistic simulations of intersection cross-slip nucleation in L12 Ni3Al,” Scripta Materialia. 2012. link Times cited: 15 USED (low confidence) Q. Wu and S. Li, “Alloying element additions to Ni3Al: Site preferences and effects on elastic properties from first-principles calculations,” Computational Materials Science. 2012. link Times cited: 123 USED (low confidence) K. Zhao, “Chemical and Structural Characterization of γ/γ′ Interfaces,” Advanced Materials Research. 2012. link Times cited: 0 Abstract: More attention has been paid to the interfaces since mechani… read moreAbstract: More attention has been paid to the interfaces since mechanical properties of nickel-base superalloys are determined to some degree by them. The compositional transition across γ/γ′ interfaces and atomic structure of the interfaces was investigated using three-dimensional atom probe tomography and scanning transmission electron microscope equipped with high-resolution Energy Dispersive X-ray Spectrometry. Results show that no obvious segregation to the interfaces or ledges of the precipitates in the present experimental alloys has been observed. Also, adsorption of a solute to the interface was not observed. The interfaces are not flat as usually thought at an atomic scale. The interfacial thickness is about two atomic layers, i.e. 0.7 nm. read less USED (low confidence) Z. Jiao, C. Song, L. Tiesong, and P. He, “Molecular dynamics simulation of the effect of surface roughness and pore on linear friction welding between Ni and Al,” Computational Materials Science. 2011. link Times cited: 33 USED (low confidence) E. Tadmor and R. E. Miller, “Modeling Materials: Continuum, Atomistic and Multiscale Techniques.” 2011. link Times cited: 395 Abstract: 1. Introduction Part I. Continuum Mechanics and Thermodynami… read moreAbstract: 1. Introduction Part I. Continuum Mechanics and Thermodynamics: 2. Essential continuum mechanics and thermodynamics Part II. Atomistics: 3. Lattices and crystal structures 4. Quantum mechanics of materials 5. Empirical atomistic models of materials 6. Molecular statics Part III. Atomistic Foundations of Continuum Concepts: 7. Classical equilibrium statistical mechanics 8. Microscopic expressions for continuum fields 9. Molecular dynamics Part IV. Multiscale Methods: 10. What is multiscale modeling? 11. Atomistic constitutive relations for multilattice crystals 12. Atomistic/continuum coupling: static methods 13. Atomistic/continuum coupling: finite temperature and dynamics Appendix References Index. read less USED (low confidence) S. Rao, D. Dimiduk, T. Parthasarathy, J. El-Awady, C. Woodward, and M. Uchic, “Calculations of intersection cross-slip activation energies in fcc metals using nudged elastic band method,” Acta Materialia. 2011. link Times cited: 52 USED (low confidence) M. Chaudhari, J. Du, J. Tiley, and R. Banerjee, “Density Functional Theory Based Calculations of Site Occupancy in the Gamma Prime Ni3al Phase of Nickel Based Super Alloys.” 2011. link Times cited: 1 USED (low confidence) L. Trandinh, Y.-M. Ryu, and S. Cheon, “Nanoindentation on the Layered Ag/Cu for Investigating Slip of Misfit Dislocation.” 2011. link Times cited: 0 Abstract: The EAM simulation of nanoindentation was performed to inves… read moreAbstract: The EAM simulation of nanoindentation was performed to investigate misfit dislocation slip in the Ag/Cu. The film layer, whose thickness in the range of 2-5nm, was indented by a spherical indenter with the Nse-Hoover thermostat condition. The simulation shows that the indentation position relative to misfit dislocation (MFD) has the effect on the dislocation, glide up or cross slip, for Ag film layer thickness less than 4 nm. Elastic energy variation during MFDs slip was revealed to be a key factor for the softening of Ag/Cu. The critical film layer thickness was evaluated for each case of Ag/Cu according to the spline extrapolation technique. read less USED (low confidence) C. Hin, J. Lépinoux, J. Neaton, and M. Dresselhaus, “From the interface energy to the solubility limit of aluminium in nickel from first-principles and Kinetic Monte Carlo calculations,” Materials Science and Engineering B-advanced Functional Solid-state Materials. 2011. link Times cited: 6 USED (low confidence) Y. Amouyal and D. Seidman, “The role of hafnium in the formation of misoriented defects in Ni-based superalloys: An atom-probe tomographic study,” Acta Materialia. 2011. link Times cited: 45 USED (low confidence) M.-yi Zhang, K. Yang, and Z. Chen, “Kinetics of Order-Disorder Transition of Antiphase Domain Boundary Formed between DO22 Phases: Microscopic Phase-Field Study,” Advanced Materials Research. 2010. link Times cited: 0 Abstract: Based on the microscopic phase-field model, the precipitatio… read moreAbstract: Based on the microscopic phase-field model, the precipitation process of Ni75Al4.3V20.7 alloy at 1190K is simulated, and the kinetics of order-disorder transition at antiphase domain boundary (APDB) formed between DO22 (Ni3V) phases is investigated. After the ordered APDB formed by the impingement of growing DO22 (Ni3V) domains, the order-disorder transition at APDB is happened. Accompanied with the enrichment of Ni and Al at the APDB, the ordered APDB transforms into a thin disordered phase layer. The second phase L12 nucleates at the order-disorder interface between DO22 and disordered phases, and grows along the disorder phase layer quickly. The order-disorder transition at the ordered APDB accelerates the nucleation and growth of L12 phase at the APDB. The disordered phase caused by the order-disordered transition can be considered the transient phase during the precipitation process of L12 phase. read less USED (low confidence) L. Proville and B. Bakó, “Dislocation depinning from ordered nanophases in a model fcc crystal: From cutting mechanism to Orowan looping,” Acta Materialia. 2010. link Times cited: 69 USED (low confidence) D. Bachurin, D. Weygand, and P. Gumbsch, “Dislocation―grain boundary interaction in 〈111〉 textured thin metal films,” Acta Materialia. 2010. link Times cited: 95 USED (low confidence) A. Ardell, “Quantitative predictions of the trans-interface diffusion-controlled theory of particle coarsening,” Acta Materialia. 2010. link Times cited: 43 USED (low confidence) C. Colinet and J. Tedenac, “Point defects and chemical potentials in D88–Sn3Ti5,” Intermetallics. 2010. link Times cited: 9 USED (low confidence) Y. Mishin, M. Asta, and J. Li, “Atomistic modeling of interfaces and their impact on microstructure and properties,” Acta Materialia. 2010. link Times cited: 418 USED (low confidence) R. Voskoboinikov and C. Rae, “A new ?-surface in 111 plane in L12 Ni3Al.” 2009. link Times cited: 10 Abstract: The well-known ?-surface concept originally proposed by V.Vi… read moreAbstract: The well-known ?-surface concept originally proposed by V.Vitek [1] has been extended to the case of the shift of one part of the crystal with respect to another in two adjacent {111} planes of the stacking fault. The proposed approach has been applied for evaluation of the effective ?-surface in {111} crystallographic plane in L12 Ni3Al. Five stable planar stacking faults has been found, in particular, superlattice intrinsic stacking fault (SISF), superlattice extrinsic stacking fault (SESF), complex stacking fault (CSF), antiphase boundary (APB) and complex extrinsic stacking fault (CESF). The last planar fault configuration has neither been observed experimentally nor predicted analytically in L12 Ni3Al before. read less USED (low confidence) Z. Jing, C. Zheng, L. Yanli, W. YongXin, and Z. Yan, “Antisite Defects of the L1 2 Structure Determined by the Phase Field Microelasticity Model,” Chinese Physics Letters. 2009. link Times cited: 1 Abstract: A phase field microelasticity simulation is performed to exa… read moreAbstract: A phase field microelasticity simulation is performed to examine the antisite defect of L12-Ni3Al in Ni75 Al5.3 V19.7 ternary alloy. Combinimg strain energy with the phase field model leads to an atom configuration change as time proceeds. For the Ni sublattice, the antisite defect AlNi, the equilibrium occupancy probability (OP) of which declines, precedes NiNi and VNi in reaching equilibrium; subsequently, NiNi and VNi present a phenomenon of symmetrical rise and decline individually. Similarly, for the Al sublattice, the antisite defect NiAl, the OP of which eventually rises, takes fewer time steps than AlAi and VAl to attain equilibrium. Thereafter, AlAl rises while VAl declines symmetrically at the axes of the NiAlMAI curve. Furthermore, the OP for the Al sublattice is much more sensitive to strain energy than that for the Ni sublattice. read less USED (low confidence) C. Colinet and J. Tedenac, “Constitutional and thermal defects in B82–SnTi2,” Intermetallics. 2009. link Times cited: 12 USED (low confidence) J. Tiley, G. Viswanathan, R. Srinivasan, R. Banerjee, D. Dimiduk, and H. Fraser, “Coarsening kinetics of γ′ precipitates in the commercial nickel base Superalloy René 88 DT,” Acta Materialia. 2009. link Times cited: 150 USED (low confidence) C. Wang and C.-yu Wang, “Density functional theory study of Ni/Ni3Al interface alloying with Re and Ru,” Surface Science. 2008. link Times cited: 29 USED (low confidence) C. Colinet, J. Tedenac, and S. Fries, “Constitutional and thermal defects in D019-SnTi3,” Intermetallics. 2008. link Times cited: 15 USED (low confidence) H. Xie, C.-yu Wang, and T. Yu, “Atomistic simulation of fracture in Ni_3Al,” Journal of Materials Research. 2008. link Times cited: 14 Abstract: The molecular dynamics method has been used to simulate mode… read moreAbstract: The molecular dynamics method has been used to simulate mode I cracking in Ni_3Al. Close attention has been paid to the process of atomic configuration evolution of the cracks. The simulation results show that at low temperature, the Shockley partial dislocations are emitted before the initiation of the crack propagation, subsequently forming the pseudo-twins on (111) planes in crack-tip zone, and then the crack cleavage occurs. The emitting of the Shockley partial dislocations accompanies the crack cleavage during the simulation process. At the higher temperature, the blunting at the crack tip is caused by the [110] superdislocations emitted on (100) plane. The present work also shows that the dipole dislocations on (111) planes in the 1/2[110] dislocation core can be formed. read less USED (low confidence) W. K. Liu, E. Karpov, and H. S. Park, “Classical Molecular Dynamics.” 2006. link Times cited: 0 USED (low confidence) C. Jiang, D. Sordelet, and B. Gleeson, “Site preference of ternary alloying elements in Ni3Al: A first-principles study,” Acta Materialia. 2006. link Times cited: 123 USED (low confidence) Y. Mishin, “Atomistic Computer Modeling of Intermetallic Alloys,” Materials Science Forum. 2005. link Times cited: 3 Abstract: The paper gives a brief overview of our recent work on atomi… read moreAbstract: The paper gives a brief overview of our recent work on atomistic computer modeling of ordered intermetallic compounds of the Ni-Al and Ti-Al systems. Atomic interactions in these systems are modeled by semi-empirical potentials fit to experimental and first-principles data. The methodology includes a large variety of techniques ranging from harmonic lattice dynamics to molecular dynamics and Monte Carlo simulations. The properties studied include lattice characteristics (elastic constants, phonons, thermal expansion), point-defect properties, atomic diffusion, generalized stacking faults, dislocations, surfaces, grain boundaries, interphase boundaries, and phase diagrams. We especially emphasize the recent progress in the understanding of diffusion mechanisms in NiAl and TiAl, calculation of stacking fault energies in Ni3Al in relation to dislocation behavior, and calculations of / 0 interface boundaries in Ni-Al alloys. read less USED (low confidence) A. Ardell and V. Ozoliņš, “Trans-interface diffusion-controlled coarsening,” Nature Materials. 2005. link Times cited: 219 USED (low confidence) J. Buršík, “Effect of Ordering on the Elastic Parameters of Multicomponent Ni-Based Systems,” Materials Science Forum. 2005. link Times cited: 0 Abstract: Ordering in Ni-based superalloys is the crucial process cont… read moreAbstract: Ordering in Ni-based superalloys is the crucial process controlling the development of the characteristic two-phase microstructure and subsequently the mechanical properties. Disordered systems containing up to six alloying elements typical of advanced Ni-based superalloys were modelled in this work. Their ordering at elevated temperatures was simulated using a Monte Carlo approach with phenomenological Lennard-Jones pair potentials. Selected atomic configurations differing in the degree of order were subject to further studies of elastic parameters. Hydrostatic deformation and uniaxial deformation along high symmetry directions of model crystals were simulated. Molecular dynamics was used to relax local atomic positions in deformed crystals. Changes of elastic parameters due to ordering in face centred cubic lattice are discussed. read less USED (low confidence) A. Khoei, M. Youzi, and G. T. Eshlaghi, “Mechanical Properties And γ/γ’ Interfacial Misfit Network Evolution: A Study Towards the Creep Behavior of Ni-Based Single Crystal Superalloys,” MatSciRN: Other Mechanical Properties & Deformation of Materials (Topic). 2021. link Times cited: 0 Abstract: The aim of this study is to investigate the role of the temp… read moreAbstract: The aim of this study is to investigate the role of the temperature, stress, strain rate, and rhenium (Re) on the γ/γ' interfacial misfit dislocation network and mechanical response of Ni-based single crystal superalloys. Due to the mismatch between the two phases, a dislocation network forms after aging at high temperatures to alleviate the stress field. The (100), (110), and (111) phase interface models are generated to further study the properties of the superalloy by applying molecular dynamics simulations. It is noted that the strength and stability of the network are diminished as the thermal condition intensifies owing to the dispersed atomic potential energy at the interface. By applying a constant strain rate of 2x108 (s-1) at 0 K, the (100) and (111) phase interface models lose the co-coordinating role of maintaining the dynamic equilibrium. Hence, dislocations pile-up in the damaged area, and the network is no longer able to fortify the interface. For the (110) phase interface model, the dominant deformational mechanism is precipitate shearing. As temperature increases, the elastic modulus, initial mismatch stress, and yield strength decrease. Moreover, the yield strength of material increases as the strain rate increases. The pinning effect of Re atoms is surveyed by replacing 3.293at%, and 5at% of matrix Ni atoms with Re at 1600 K. The dislocation hampering property of Re is more perceptible when enough dislocations in the γ phase are moving at elevated temperatures. In addition, Re manages to soothe the stress field at the interface and does not affect the network morphology. Finally, an investigation of the creep behavior of the superalloy is provided. It is observed that the escalated damage to the interfacial network due to the increased temperature leads to the domination of the softening mechanisms (cross-slip and dislocation climb) on the deformation and shortens the steady-state creep. Moreover, Re atoms act as an extra hardening factor to improve the tertiary creep. read less USED (low confidence) M. Shugaev et al., “Laser-Induced Thermal Processes: Heat Transfer, Generation of Stresses, Melting and Solidification, Vaporization, and Phase Explosion,” Handbook of Laser Micro- and Nano-Engineering. 2020. link Times cited: 16 USED (low confidence) “References,” Welding the Inconel 718 Superalloy. 2019. link Times cited: 0 USED (low confidence) C. Becquart, A. Backer, and C. Domain, “Atomistic Modeling of Radiation Damage in Metallic Alloys.” 2018. link Times cited: 11 USED (low confidence) K. Kumar, R. Sankarasubramanian, and U. Waghmare, “Tuning planar fault energies of Ni3Al with substitutional alloying: First-principles description for guiding rational alloy design,” Scripta Materialia. 2018. link Times cited: 22 USED (low confidence) A. Matsushita, S. Takamoto, A. Hatano, and S. Izumi, “Development of Hybrid Method Using Ab initio and Classical Molecular Dynamics for Calculating the Thermal Expansion Coefficient of Alloys at High Temperature,” Journal of The Society of Materials Science, Japan. 2018. link Times cited: 0 Abstract: In order to predict the thermal expansion coefficient (TEC),… read moreAbstract: In order to predict the thermal expansion coefficient (TEC), quasiharmonic approximation based on the ab initio electronic structure calculation is an effective and conventional scheme. However, it is known that the deviation due to anharmonic effect arises at high temperature. Although Molecular Dynamics (MD) naturally includes the anharmonic effect, classical MD is lacking in accuracy because of its empirical interatomic potential and ab initio MD is not applicable because of its high computational cost. In this paper, we have proposed a new hybrid method using ab initio electronic structure calculation and classical molecular dynamics for calculating TEC of alloys at high temperature. Our method is non-empirical, highly accurate and computationally inexpensive. The method consists of three steps. Firstly, various snapshots of the atomic coordination at a certain temperature are sampled by classical MD. Secondly, physical properties of each snapshot are calculated by ab initio electronic structure calculation. Finally, by analyzing them statistically, the equilibrium volume is computed. TEC is obtained by repeating these steps at different temperatures. We have calculated the TECs of Al, Ni3Al, and NiAl. Results show good agreements with experimental results. Our method enables us to improve the conventional quasiharmonic approximation and obtain accurate TEC at high temperature through the incorporation of anharmonic effect. read less USED (low confidence) J. Kristensen, I. Bilionis, and N. Zabaras, “Adaptive Simulation Selection for the Discovery of the Ground State Line of Binary Alloys with a Limited Computational Budget.” 2017. link Times cited: 11 USED (low confidence) G. Anand and P. Chattopadhyay, “Computational Design of Microstructure: An Overview.” 2016. link Times cited: 0 Abstract: During the last couple of decades, treatment of microstructu… read moreAbstract: During the last couple of decades, treatment of microstructure in materials science has been shifted from the diagnostic to design paradigm. Design of microstructure is inherently complex problems due to non linear spatial and temporal interaction of composition and parameters leading to the target properties. In most of the cases, different properties are reciprocally correlated i.e., improvement of one lead to the degradation of other. Also, the design of microstructure is a multiscale problem, as the knowledge of phenomena at range of scales from electronic to mesoscale is required for precise compositionmicrostructure-property determination. In the view of above, present chapter provides the introduction to computationally driven microstructure engineering in the framework of constitutive length scale in microstructure design. The important issues pertaining to design such as phase stability and interfaces has been explained. Additionally, the bird-eye view of various computational techniques in order of length scale has been introduced, with an aim to present the picture of combination of various techniques for solving microstructural design problems under various scenarios. read less USED (low confidence) S. Schweizer, R. Chaudret, T. Spyriouni, J. Low, and L. Subramanian, “Influence of the Precursor Composition and Reaction Conditions on Raney-Nickel Catalytic System,” Foundations of Molecular Modeling and Simulation. 2015. link Times cited: 2 USED (low confidence) Q.-N. Fan, C.-yu Wang, T. Yu, and J.-ping Du, “A ternary Ni–Al–W EAM potential for Ni-based single crystal superalloys,” Physica B-condensed Matter. 2015. link Times cited: 11 USED (low confidence) N. Hiroshi, “Defects in Metals.” 2014. link Times cited: 1 USED (low confidence) E. Y. Plotnikov, Z. Mao, R. Noebe, and D. Seidman, “Temporal evolution of the γ(fcc)/γ′(L12) interfacial width in binary Ni–Al alloys,” Scripta Materialia. 2014. link Times cited: 40 USED (low confidence) T. Weihs, “Fabrication and characterization of reactive multilayer films and foils.” 2014. link Times cited: 71 Abstract: Abstract: This chapter explores exothermic, self-propagating… read moreAbstract: Abstract: This chapter explores exothermic, self-propagating formation reactions within multilayer films and foils, and it describes how the average chemistries and microstructures of the materials impact their measured reaction heats, ignition thresholds and reaction velocities. The chapter also reviews recent attempts to identify the very rapid phase transformations that occur within the layered materials, as well as the unsteady propagation of reactions at slower velocities. Lastly, commercial applications are described. read less USED (low confidence) R. Reed and C. Rae, “Physical Metallurgy of the Nickel-Based Superalloys.” 2014. link Times cited: 64 USED (low confidence) D. Larson, T. Prosa, R. Ulfig, B. Geiser, and T. Kelly, “Applications of the Local Electrode Atom Probe.” 2013. link Times cited: 1 USED (low confidence) X.-yuan Yang, W. Hu, and X. Zhang, “Atomistic simulation for the γ′-phase volume fraction dependence of the interfacial behavior of Ni-base superalloy,” Applied Surface Science. 2013. link Times cited: 10 USED (low confidence) L. Thuinet and R. Besson, “Ab initio study of competitive hydride formation in zirconium alloys,” Intermetallics. 2012. link Times cited: 43 USED (low confidence) A. Takahashi and M. Kawanabe, “Numerical Analysis of Precipitation Strengthening by γ-Precipitates in Nickel-Based Superalloy,” Transactions of the Japan Society of Mechanical Engineers. A. 2009. link Times cited: 1 USED (low confidence) C. Wang and C. Wang, “Ni/Ni(3)Al interface: A density functional theory study.” 2009. link Times cited: 45 USED (low confidence) Y. Gornostyrev, O. Kontsevoi, K. Khromov, M. Katsnelson, and A. Freeman, “The role of thermal expansion and composition changes in the temperature dependence of the lattice misfit in two-phase γ/γ′ superalloys,” Scripta Materialia. 2007. link Times cited: 30 USED (low confidence) W. Cao, J. Zhu, F. Zhang, W. A. Oates, M. Asta, and Y. Chang, “Application of the cluster/site approximation to the calculation of coherent interphase boundary energies,” Acta Materialia. 2006. link Times cited: 11 USED (low confidence) Y. Mishin, “Interatomic Potentials for Metals.” 2005. link Times cited: 41 NOT USED (low confidence) X. Chen et al., “Machine learning enhanced empirical potentials for metals and alloys,” Comput. Phys. Commun. 2021. link Times cited: 5 NOT USED (low confidence) G. Teichert, A. Natarajan, A. V. der Ven, and K. Garikipati, “Scale bridging materials physics: Active learning workflows and integrable deep neural networks for free energy function representations in alloys,” Computer Methods in Applied Mechanics and Engineering. 2020. link Times cited: 19 NOT USED (low confidence) Z. Trautt, F. Tavazza, and C. Becker, “Facilitating the selection and creation of accurate interatomic potentials with robust tools and characterization,” Modelling and Simulation in Materials Science and Engineering. 2015. link Times cited: 14 Abstract: The Materials Genome Initiative seeks to significantly decre… read moreAbstract: The Materials Genome Initiative seeks to significantly decrease the cost and time of development and integration of new materials. Within the domain of atomistic simulations, several roadblocks stand in the way of reaching this goal. While the NIST Interatomic Potentials Repository hosts numerous interatomic potentials (force fields), researchers cannot immediately determine the best choice(s) for their use case. Researchers developing new potentials, specifically those in restricted environments, lack a comprehensive portfolio of efficient tools capable of calculating and archiving the properties of their potentials. This paper elucidates one solution to these problems, which uses Python-based scripts that are suitable for rapid property evaluation and human knowledge transfer. Calculation results are visible on the repository website, which reduces the time required to select an interatomic potential for a specific use case. Furthermore, property evaluation scripts are being integrated with modern platforms to improve discoverability and access of materials property data. To demonstrate these scripts and features, we will discuss the automation of stacking fault energy calculations and their application to additional elements. While the calculation methodology was developed previously, we are using it here as a case study in simulation automation and property calculations. We demonstrate how the use of Python scripts allows for rapid calculation in a more easily managed way where the calculations can be modified, and the results presented in user-friendly and concise ways. Additionally, the methods can be incorporated into other efforts, such as openKIM. read less NOT USED (high confidence) H. Juárez et al., “Modeling of surface phenomena of liquid Al–Ni alloys using molecular dynamics,” Scientific Reports. 2023. link Times cited: 0 NOT USED (high confidence) E. Chen, A. Tamm, T. Wang, M. Epler, M. Asta, and T. Frolov, “Modeling antiphase boundary energies of Ni3Al-based alloys using automated density functional theory and machine learning,” npj Computational Materials. 2022. link Times cited: 15 NOT USED (high confidence) J. Guénolé, V. Taupin, M. Vallet, W. Yu, and A. Guitton, “Features of a nano-twist phase in the nanolayered Ti3AlC2 MAX phase,” Scripta Materialia. 2022. link Times cited: 0 NOT USED (high confidence) T. Hammerschmidt, J. Rogal, E. Bitzek, and R. Drautz, “Atomic-scale modeling of superalloys,” Nickel Base Single Crystals Across Length Scales. 2021. link Times cited: 1 NOT USED (high confidence) S. Nasiri, K. Wang, M. Yang, J. Gu’enol’e, Q. Li, and M. Zaiser, “Atomistic Aspects of Load Transfer and Fracture in CNT-Reinforced Aluminium,” SSRN Electronic Journal. 2021. link Times cited: 6 Abstract: This paper describes atomistic simulations of deformation an… read moreAbstract: This paper describes atomistic simulations of deformation and fracture of Al reinforced with carbon nanotubes (CNTs). We use density functional theory (DFT) to understand the energetics of Al-graphene interfaces and gain reference data for the parameterization of Al-C empirical potentials. We then investigate the load transfer between CNTs and Al and its effect on composite strengthening. To this end, we perform uniaxial tensile simulations of an Al crystal reinforced with CNTs of various volume fractions. We also study the interaction of the embedded CNTs with a crack. We show that the interaction between CNTs and Al is weak such that, under tensile loading, CNTs can easily slide inside the Al matrix and get pulled out from the cracked surface. This effect is almost independent of CNT length and volume fraction. Little load transfer and consequently no crack bridging are observed during the simulation of pristine CNTs threading the crack surfaces. CNTs that are geometrically fixated inside Al, on the other hand, can increase the fracture stress and enhance plastic dissipation in the matrix. CNTs located in front of a growing crack blunt the crack and induce plastic deformation of the Al matrix. Depending on the CNT orientation, these processes can either increase or decrease the failure stress of the composite. read less NOT USED (high confidence) A. Roy and M. Gururajan, “Phase Field Modelling of Morphologies Driven by Tetragonal Interfacial Energy Anisotropy,” Crystal Growth & Design. 2021. link Times cited: 5 Abstract: A wide range of morphologies, such as dipyramids, rods, plat… read moreAbstract: A wide range of morphologies, such as dipyramids, rods, plates, and their truncated variants with more than one type of facet, are experimentally observed in tetragonal systems. In many cases, the ... read less NOT USED (high confidence) D. Farkas and A. Caro, “Model interatomic potentials for Fe–Ni–Cr–Co–Al high-entropy alloys,” Journal of Materials Research. 2020. link Times cited: 76 Abstract: A set of embedded atom model (EAM) interatomic potentials wa… read moreAbstract: A set of embedded atom model (EAM) interatomic potentials was developed to represent highly idealized face-centered cubic (FCC) mixtures of Fe–Ni–Cr–Co–Al at near-equiatomic compositions. Potential functions for the transition metals and their crossed interactions are taken from our previous work for Fe–Ni–Cr–Co–Cu [D. Farkas and A. Caro: J. Mater. Res. 33 (19), 3218–3225, 2018], while cross-pair interactions involving Al were developed using a mix of the component pair functions fitted to known intermetallic properties. The resulting heats of mixing of all binary equiatomic random FCC mixtures not containing Al is low, but significant short-range ordering appears in those containing Al, driven by a large atomic size difference. The potentials are utilized to predict the relative stability of FCC quinary mixtures, as well as ordered L1_2 and B2 phases as a function of Al content. These predictions are in qualitative agreement with experiments. This interatomic potential set is developed to resemble but not model precisely the properties of this complex system, aiming at providing a tool to explore the consequences of the addition of a large size-misfit component into a high entropy mixture that develops multiphase microstructures. read less NOT USED (high confidence) J. Amodeo, F. Pietrucci, and J. Lam, “Out-of-Equilibrium Polymorph Selection in Nanoparticle Freezing.,” The journal of physical chemistry letters. 2020. link Times cited: 7 Abstract: The ability to design synthesis processes that are out of eq… read moreAbstract: The ability to design synthesis processes that are out of equilibrium has opened the possibility of creating nanomaterials with remarkable physico-chemical properties, choosing from a much richer palette of possible atomic architectures compared to equilibrium processes in extended systems. In this work, we employ atomistic simulations to demonstrate how to control polymorph selection via cooling rate during nanoparticle freezing in the case of Ni$_3$Al, a material with a rich structural landscape. State-of-the-art free-energy calculations allow to rationalize the complex nucleation process, discovering a switch between two kinetic pathways, yielding the equilibrium structure at room temperature and an alternative metastable one at higher temperature. Our findings address the key challenge in the synthesis of nano-alloys for technological applications, i.e., rationally exploiting the competition between kinetics and thermodynamics by designing a treatment history that forces the system into desirable metastable states. read less NOT USED (high confidence) A. Ardell, “Trans-interface-diffusion-controlled coarsening of γ′ particles in Ni–Al alloys: commentaries and analyses of recent data,” Journal of Materials Science. 2020. link Times cited: 11 NOT USED (high confidence) S. O. Kart, H. H. Kart, and T. Çagin, “Atomic-scale insights into structural and thermodynamic stability of spherical Al@Ni and Ni@Al core–shell nanoparticles,” Journal of Nanoparticle Research. 2020. link Times cited: 6 NOT USED (high confidence) V. Atrazhev et al., “The Mechanism of Grain Boundary Serration and Fan-Type Structure Formation in Ni-Based Superalloys,” Metallurgical and Materials Transactions A. 2020. link Times cited: 8 NOT USED (high confidence) E. Antillon and M. Ghazisaeidi, “Efficient determination of solid-state phase equilibrium with the multicell Monte Carlo method.,” Physical review. E. 2020. link Times cited: 5 Abstract: Building on our previously introduced multicell Monte Carlo … read moreAbstract: Building on our previously introduced multicell Monte Carlo (MC)^{2} method for modeling phase coexistence, this paper provides important improvements for efficient determination of phase equilibria in solids. The (MC)^{2} method uses multiple cells, representing possible phases. Mass transfer between cells is modeled virtually by solving the mass balance equation after the composition of each cell is changed arbitrarily. However, searching for the minimum free energy during this process poses a practical problem. The solution to the mass balance equation is not unique away from equilibrium, and consequently the algorithm is in risk of getting trapped in nonequilibrium solutions. Therefore, a proper stopping condition for (MC)^{2} is currently lacking. In this work, we introduce a consistency check via a predictor-corrector algorithm to penalize solutions that do not satisfy a necessary condition for equivalence of chemical potentials and steer the system toward finding equilibrium. The most general acceptance criteria for (MC)^{2} is derived starting from the isothermal-isobaric Gibbs ensemble for mixtures. Using this ensemble, translational MC moves are added to include vibrational excitations as well as volume MC moves to ensure the condition of constant pressure and temperature entirely with a MC approach, without relying on any other method for relaxation of these degrees of freedom. As a proof of concept the method is applied to two binary alloys with miscibility gaps and a model quaternary alloy, using classical interatomic potentials. read less NOT USED (high confidence) R. Voskoboinikov, “Molecular Dynamics Simulations of Surface Collision Cascades in Nickel,” Physics of Metals and Metallography. 2020. link Times cited: 2 NOT USED (high confidence) S. Nasiri, K. Wang, M. Yang, Q. Li, and M. Zaiser, “Nickel coated carbon nanotubes in aluminum matrix composites: a multiscale simulation study,” The European Physical Journal B. 2019. link Times cited: 14 NOT USED (high confidence) S. Yang, J. Zhong, J. Wang, L. Zhang, and G. Kaptay, “OpenIEC: an open-source code for interfacial energy calculation in alloys,” Journal of Materials Science. 2019. link Times cited: 12 NOT USED (high confidence) L. Lang et al., “Development of a Ni–Mo interatomic potential for irradiation simulation,” Modelling and Simulation in Materials Science and Engineering. 2019. link Times cited: 5 Abstract: An interatomic potential for the Ni–Mo binary alloy focusing… read moreAbstract: An interatomic potential for the Ni–Mo binary alloy focusing on irradiation has been constructed with the modified analysis embedded atom method. The newly developed interatomic (Ni–Ni and Mo–Mo) potentials and the Ni–Mo cross-interactions are fitted to the ab initio results and experimental data, including defect energies, formation energies of three stable phases. The properties used for fitting are accurately reproduced by the present potentials for both pure elements and alloy systems. Those properties beyond the fitting ranges are also well predicted, demonstrating its excellent transferability. The advantages and certain weaknesses of the new potential are also discussed in detail compared with other existing potentials. The potential is expected to be especially suitable for irradiation simulations of Ni–Mo alloys. read less NOT USED (high confidence) A. M. Tan, C. Woodward, and D. Trinkle, “Dislocation core structures in Ni-based superalloys computed using a density functional theory based flexible boundary condition approach,” Physical Review Materials. 2019. link Times cited: 16 Abstract: Anne Marie Z. Tan,1,2 Christopher Woodward,3,* and Dallas R.… read moreAbstract: Anne Marie Z. Tan,1,2 Christopher Woodward,3,* and Dallas R. Trinkle1,† 1Department of Materials Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, USA 2Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA 3Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson Air Force Base, Dayton, Ohio 45433-7817, USA read less NOT USED (high confidence) A. Goryaeva, C. Fusco, M. Bugnet, and J. Amodeo, “Influence of an amorphous surface layer on the mechanical properties of metallic nanoparticles under compression,” Physical Review Materials. 2019. link Times cited: 9 Abstract: This study aims to investigate the role of amorphous surface… read moreAbstract: This study aims to investigate the role of amorphous surface layers on the mechanical response of metallic nanoparticles under compression using molecular dynamics simulations. For this purpose, the transferability of three embedded-atom-method (EAM) potentials to model monoatomic Ni glass and amorphous-crystalline structures is examined. Particular attention is paid to the crystallisation rate of the amorphous shell surrounding the crystalline inner structure. Relying on the most appropriate model, the influence of the amorphous layer on the mechanical response of crystalline-amorphous Ni nanoparticles is further investigated. Regardless of its thickness, the amorphous surface layer significantly changes both the effective elastic modulus of the nanoparticle and the flow stress. Besides stress, dislocation nucleation processes as well as the final shape of the compressed particles are influenced by the presence of the amorphous shell. These results bring new insights on the influence of surface state on the mechanics of metallic nano-objects. read less NOT USED (high confidence) F. Forghani et al., “On the control of structural/compositional ratio of coherent order-disorder interfaces,” Journal of Alloys and Compounds. 2019. link Times cited: 6 NOT USED (high confidence) L. Wei, S. Wang, Q. Yang, Y.-W. Cheng, and S. Tan, “Investigation on precipitation phenomena and mechanical properties of Ni–25Cr–20Co alloys aged at high temperature,” Journal of Materials Research. 2018. link Times cited: 3 Abstract: The evolution of carbides and the coarsening behavior of L1_… read moreAbstract: The evolution of carbides and the coarsening behavior of L1_2 ordered γ′ phase in Ni–25Cr–20Co alloys aged for varying time from 1000 to 5000 h at 700 and 750 °C were discussed in this paper. The mechanical properties of the alloys after aging were also discussed. Due to the changing of predominated resistance factor, a few of the γ′ precipitates’ shape changed from spherical to cuboidal after aging at 750 °C for 3000 h. The sizes and volume fraction of the γ′ precipitates were measured after aging at both temperatures. The experimentally determined temporal exponent of the γ′ coarsening indicated that the coarsening kinetics is in accordance with both models: the classical matrix diffusion LSW model and the trans-interface diffusion-controlled model. Additionally, the coarsening rate of the γ′ precipitates is dominated by the diffusion coefficients of Nb based on the classical LSW model. Furthermore, the yield strength curves of the alloys aged at 700 °C showed different trends at both test temperatures which is related to the influence of γ′ coarsening on the critical resolved shear stress. read less NOT USED (high confidence) F. Baras, V. Turlo, O. Politano, S. Vadchenko, A. Rogachev, and A. Mukasyan, “SHS in Ni/Al Nanofoils: A Review of Experiments and Molecular Dynamics Simulations,” Advanced Engineering Materials. 2018. link Times cited: 38 Abstract: Non‐isothermal processes in nanometric metallic multilayers … read moreAbstract: Non‐isothermal processes in nanometric metallic multilayers are reviewed, both experimentally and theoretically. The Ni/Al nanofoil is considered as a model system. On the one hand, the experimental methods of elaboration and analysis are presented and, on the other hand, the modeling approach at the macroscopic and atomic scale. The basic experimental features are reported together with recent achievements. Molecular dynamics investigation of the reactivity of Ni/Al systems is reported for bulk systems and nanosystems including nanoparticles, nanowires, nanofilms, and multilayers. The focus is on atomic‐scale modeling versus experiments. Molecular dynamics approaches allow us to elucidate the mechanisms of non‐isothermal processes occurring in nanoscale systems, such as phase transformations and self‐propagation reactions. read less NOT USED (high confidence) A. Goodfellow, “Strengthening mechanisms in polycrystalline nickel-based superalloys,” Materials Science and Technology. 2018. link Times cited: 50 Abstract: ABSTRACT Nickel-based superalloys are currently the material… read moreAbstract: ABSTRACT Nickel-based superalloys are currently the material of choice for use in high-temperature applications due to their excellent high-temperature strength. It is understood that many mechanisms contribute to this property, but debate exists regarding how to model these mechanisms and predict the overall strength. This review covers the different strengthening mechanisms occurring in polycrystalline Ni-based superalloys and how these may be modelled, with the aim of revealing the gaps in the literature. It is found that models for precipitation and coherency strengthening are particularly controversial, and a unified model for the yield strength of superalloys is missing from the literature. This is of commercial importance for the design of new alloys with superior mechanical properties to those currently available. This review was submitted as part of the 2018 Materials Literature Review Prize of the Institute of Materials, Minerals and Mining run by the Editorial Board of MST. Sponsorship of the prize by TWI Ltd is gratefully acknowledged. read less NOT USED (high confidence) L. Hale, “Comparing Modeling Predictions of Aluminum Edge Dislocations: Semidiscrete Variational Peierls–Nabarro Versus Atomistics,” JOM. 2018. link Times cited: 7 NOT USED (high confidence) A. Glielmo, C. Zeni, and A. Vita, “Efficient nonparametric n -body force fields from machine learning,” Physical Review B. 2018. link Times cited: 92 Abstract: The authors present a scheme to construct classical $n$-body… read moreAbstract: The authors present a scheme to construct classical $n$-body force fields using Gaussian Process (GP) Regression, appropriately mapped over explicit n-body functions (M-FFs). The procedure is possible, and will yield accurate forces, whenever prior knowledge allows to restrict the interactions to a finite order $n$, so that the ``universal approximator'' resolving power of standard GPs or Neural Networks is not needed. Under these conditions, the proposed construction preserves flexibility of training, systematically improvable accuracy, and a clear framework for validation of the underlying machine learning technique. Moreover, the M-FFs are as fast as classical parametrized potentials, since they avoid lengthy summations over database entries or weight parameters. read less NOT USED (high confidence) M. Chandran, S. C. Lee, and J. Shim, “Machine learning assisted first-principles calculation of multicomponent solid solutions: estimation of interface energy in Ni-based superalloys,” Modelling and Simulation in Materials Science and Engineering. 2017. link Times cited: 5 Abstract: A disordered configuration of atoms in a multicomponent soli… read moreAbstract: A disordered configuration of atoms in a multicomponent solid solution presents a computational challenge for first-principles calculations using density functional theory (DFT). The challenge is in identifying the few probable (low energy) configurations from a large configurational space before DFT calculation can be performed. The search for these probable configurations is possible if the configurational energy E ( σ ) can be calculated accurately and rapidly (with a negligibly small computational cost). In this paper, we demonstrate such a possibility by constructing a machine learning (ML) model for E ( σ ) trained with DFT-calculated energies. The feature vector for the ML model is formed by concatenating histograms of pair and triplet (only equilateral triangle) correlation functions, g ( 2 ) ( r ) and g ( 3 ) ( r , r , r ) , respectively. These functions are a quantitative ‘fingerprint’ of the spatial arrangement of atoms, familiar in the field of amorphous materials and liquids. The ML model is used to generate an accurate distribution P ( E ( σ ) ) by rapidly spanning a large number of configurations. The P ( E ) contains full configurational information of the solid solution and can be selectively sampled to choose a few configurations for targeted DFT calculations. This new framework is employed to estimate (100) interface energy ( σ IE ) between γ and γ ′ at 700 °C in Alloy 617, a Ni-based superalloy, with composition reduced to five components. The estimated σ IE ≈ 25.95 mJ m−2 is in good agreement with the value inferred by the precipitation model fit to experimental data. The proposed new ML-based ab initio framework can be applied to calculate the parameters and properties of alloys with any number of components, thus widening the reach of first-principles calculation to realistic compositions of industrially relevant materials and alloys. read less NOT USED (high confidence) J. Amodeo and K. Lizoul, “Mechanical properties and dislocation nucleation in nanocrystals with blunt edges,” Materials & Design. 2017. link Times cited: 36 NOT USED (high confidence) S. Alkan and H. Sehitoglu, “Dislocation core effects on slip response of NiTi- a key to understanding shape memory,” International Journal of Plasticity. 2017. link Times cited: 32 NOT USED (high confidence) M. Kbirou, S. Trady, A. Hasnaoui, and M. Mazroui, “Cooling rate dependence and local structure in aluminum monatomic metallic glass,” Philosophical Magazine. 2017. link Times cited: 39 Abstract: The local atomic structure in aluminium monatomic metallic g… read moreAbstract: The local atomic structure in aluminium monatomic metallic glass is studied using molecular dynamics simulations combined with the embedded atom method (EAM). We have used a variety of analytical methods to characterise the atomic configurations of our system: the Pair Distribution Function (PDF), the Common Neighbour Analysis (CNA) and the Voronoi Tessellation Analysis. CNA was used to investigate the order change from liquid to amorphous phases, recognising that the amount of icosahedral clusters increases with the decrease of temperature. The Voronoi analysis revealed that the icosahedral-like polyhedral are the predominant ones. It has been observed that the PDF function shows a splitting in the second peak, which cannot be attributed to the only ideal icosahedral polyhedron 〈0, 0, 12, 0〉, but also to the formation of other Voronoi polyhedra 〈0, 1, 10, 2〉 . Further, the PDFs were then integrated giving the cumulative coordination number in order to compute the fractal dimension (df). read less NOT USED (high confidence) N. T. Brown, E. Martínez, and J. Qu, “Interfacial free energy and stiffness of aluminum during rapid solidification,” Acta Materialia. 2017. link Times cited: 12 NOT USED (high confidence) R. Dikken, B. Thijsse, and L. Nicola, “Friction of atomically stepped surfaces,” Physical Review B. 2017. link Times cited: 5 Abstract: The friction behavior of atomically stepped metal surfaces u… read moreAbstract: The friction behavior of atomically stepped metal surfaces under contact loading is studied using molecular dynamics simulations. While real rough metal surfaces involve roughness at multiple length scales, the focus of this paper is on understanding friction of the smallest scale of roughness: atomic steps. To this end, periodic stepped Al surfaces with different step geometry are brought into contact and sheared at room temperature. Contact stress that continuously tries to build up during loading, is released with fluctuating stress drops during sliding, according to the typical stick-slip behavior. Stress release occurs not only through local slip, but also by means of step motion. The steps move along the contact, concurrently resulting in normal migration of the contact. The direction of migration depends on the sign of the step, i.e., its orientation with respect to the shearing direction. If the steps are of equal sign, there is a net migration of the entire contact accompanied by significant vacancy generation at room temperature. The stick-slip behavior of the stepped contacts is found to have all the characteristic of a self-organized critical state, with statistics dictated by step density. For the studied step geometries, frictional sliding is found to involve significant atomic rearrangement through which the contact roughness is drastically changed. This leads for certain step configurations to a marked transition from jerky sliding motion to smooth sliding, making the final friction stress approximately similar to that of a flat contact. read less NOT USED (high confidence) A. Glielmo, P. Sollich, and A. Vita, “Accurate interatomic force fields via machine learning with covariant kernels,” Physical Review B. 2016. link Times cited: 147 Abstract: We present a novel scheme to accurately predict atomic force… read moreAbstract: We present a novel scheme to accurately predict atomic forces as vector quantities, rather than sets of scalar components, by Gaussian process (GP) regression. This is based on matrix-valued kernel functions, on which we impose the requirements that the predicted force rotates with the target configuration and is independent of any rotations applied to the configuration database entries. We show that such covariant GP kernels can be obtained by integration over the elements of the rotation group $\mathit{SO}(d)$ for the relevant dimensionality $d$. Remarkably, in specific cases the integration can be carried out analytically and yields a conservative force field that can be recast into a pair interaction form. Finally, we show that restricting the integration to a summation over the elements of a finite point group relevant to the target system is sufficient to recover an accurate GP. The accuracy of our kernels in predicting quantum-mechanical forces in real materials is investigated by tests on pure and defective Ni, Fe, and Si crystalline systems. read less NOT USED (high confidence) M. D. Grapes and T. Weihs, “Exploring the reaction mechanism in self-propagating Al/Ni multilayers by adding inert material,” Combustion and Flame. 2016. link Times cited: 31 NOT USED (high confidence) G. Ren and H. Sehitoglu, “Interatomic potential for the NiTi alloy and its application,” Computational Materials Science. 2016. link Times cited: 45 NOT USED (high confidence) A. Nassour, “Embedded atom approach for gold–silicon system from ab initio molecular dynamics simulations using the force matching method,” Bulletin of Materials Science. 2016. link Times cited: 2 NOT USED (high confidence) L. Béland, Y. Osetsky, and R. Stoller, “Atomistic material behavior at extreme pressures.” 2016. link Times cited: 26 NOT USED (high confidence) P. Chowdhury, L. Patriarca, G. Ren, and H. Sehitoglu, “Molecular dynamics modeling of NiTi superelasticity in presence of nanoprecipitates,” International Journal of Plasticity. 2016. link Times cited: 74 NOT USED (high confidence) M. Sun and C.-yu Wang, “First principles study of the diffusional phenomena across the clean and Re-doped γ-Ni/γ’-Ni 3 Al interface of Ni-based single crystal superalloy,” Chinese Physics B. 2016. link Times cited: 6 Abstract: Density functional theory calculations in conjunction with t… read moreAbstract: Density functional theory calculations in conjunction with the climbing images nudged elastic band method are conducted to study the diffusion phenomena of the Ni-based single crystal superalloys. We focus our attention on the diffusion processes of the Ni and Al atoms in the γ and γ' phases along the direction perpendicular to the interface. The diffusion mechanisms and the expressions of the diffusion coefficients are presented. The vacancy formation energies, the migration energies, and the activation energies for the diffusing Ni and Al atoms are estimated, and these quantities display the expected and clear transition zones in the vicinity of the interface of about 3–7 (002) layers. The local density-of-states profiles of atoms in each (002) layer in the γ and γ' phases and the partial density-of-states curves of Re and some of its nearest-neighbor atoms are also presented to explore the electronic effect of the diffusion behavior. read less NOT USED (high confidence) A. Ardell, “Non-integer temporal exponents in trans-interface diffusion-controlled coarsening,” Journal of Materials Science. 2016. link Times cited: 13 NOT USED (high confidence) V. Yamakov et al., “Multiscale modeling of sensory properties of Co–Ni–Al shape memory particles embedded in an Al metal matrix,” Journal of Materials Science. 2016. link Times cited: 24 NOT USED (high confidence) G. P. P. Pun, K. Darling, L. Kecskes, and Y. Mishin, “Angular-dependent interatomic potential for the Cu–Ta system and its application to structural stability of nano-crystalline alloys,” Acta Materialia. 2015. link Times cited: 92 NOT USED (high confidence) K. Shreiber and D. Mordehai, “Dislocation-nucleation-controlled deformation of Ni3Al nanocubes in molecular dynamics simulations,” Modelling and Simulation in Materials Science and Engineering. 2015. link Times cited: 20 Abstract: The strength of Ni3Al nanocubes under compression, as well a… read moreAbstract: The strength of Ni3Al nanocubes under compression, as well as the underlying dislocation mechanisms, are analysed in molecular dynamics simulations. For this purpose, the bond-order parameters analysis is extended to multi-atomic systems in order to identify the intrinsic planar defects in Ni3Al. We benchmarked different interatomic potentials and compared the results with experimental ones. The different potentials resulted in different elastic responses under compression but all yielded abruptly at a compressive stress of about 7–8 GPa, followed by a large strain burst. The nanocubes yielded by nucleating Shockley partial dislocations at the vertices on {1 1 1} ?> planes, leaving a structure of faulted planes. The mechanical response was found to be size independent, which we attribute to the cubical shape of the nanoparticle and the lack of stress gradients at its vertices. read less NOT USED (high confidence) G. P. P. Pun, V. Yamakov, and Y. Mishin, “Interatomic potential for the ternary Ni–Al–Co system and application to atomistic modeling of the B2–L10 martensitic transformation,” Modelling and Simulation in Materials Science and Engineering. 2015. link Times cited: 80 Abstract: Ni–Al–Co is a promising system for ferromagnetic shape memor… read moreAbstract: Ni–Al–Co is a promising system for ferromagnetic shape memory applications. This paper reports on the development of a ternary embedded-atom potential for this system by fitting to experimental and first-principles data. Reasonably good agreement is achieved for physical properties between values predicted by the potential and values known from experiment and/or first-principles calculations. The potential reproduces basic features of the martensitic phase transformation from the B2-ordered high-temperature phase to a tetragonal CuAu-ordered low-temperature phase. The compositional and temperature ranges of this transformation and the martensite microstructure predicted by the potential compare well with existing experimental data. These results indicate that the proposed potential can be used for simulations of the shape memory effect in the Ni–Al–Co system. read less NOT USED (high confidence) S.-L. Liu, C.-yu Wang, and T. Yu, “Influence of the alloying elements Re, Co and W on the propagation of the Ni/Ni3Al interface crack,” RSC Advances. 2015. link Times cited: 15 Abstract: The influence of the alloying elements Re, Co and W on the p… read moreAbstract: The influence of the alloying elements Re, Co and W on the propagation of the (010)[101] Ni/Ni3Al interface crack has been investigated by molecular dynamics simulations and the discrete-variational method. The simulation results show that the interface crack propagates in a brittle manner at low temperature (5 K), but in a ductile manner at high temperature (1273 K), both with and without the addition of alloying elements. Owing to the scientific and technological importance of superalloys, the effects of the chemical bonding behavior between the alloying element X (X = Re, Co, or W) and Ni atoms on the crack shape, crack propagation velocity, and dislocation emission were investigated. At low temperature, the alloying elements Re and W inhibit the propagation of the Ni/Ni3Al interface crack, while at high temperature Re, Co and W can improve the ductility of Ni-based single-crystal superalloys. Furthermore, the adhesion work of the interface, surface energy, and unstable stacking energy were calculated to understand the propagation mechanism of the Ni/Ni3Al interface crack because of alloying element addition. The results of this study may provide useful information for the design of Ni-based superalloys. read less NOT USED (high confidence) F. Tavazza, T. Senftle, C. Zou, C. Becker, and A. Duin, “Molecular Dynamics Investigation of the Effects of Tip–Substrate Interactions during Nanoindentation,” Journal of Physical Chemistry C. 2015. link Times cited: 52 Abstract: Nanoindentation in molecular dynamics (MD) simulations typic… read moreAbstract: Nanoindentation in molecular dynamics (MD) simulations typically uses highly idealized indenter tip models. Such tips usually consist of either a single sphere or a collection of atoms, both of which are purely repulsive in their interactions with the substrate. It is also assumed that there is no environmental or substrate contamination, nor is there a surface oxide layer. In this work we examine the effects of these assumptions by comparing detailed MD simulations utilizing varying interaction potentials against both experimental atomic force microscopy observations and calculations using density functional theory. Specifically, we examine the effect of a tip–substrate interaction on the indenter under clean, hydrogenated, and oxidized conditions. We find that under clean or oxidized conditions (where we include oxygen on the nickel surface to mimic a passivating NiO layer) there is a substantial material transfer from the substrate to the tip. This material (Ni atoms) remains adsorbed on the tip upon r... read less NOT USED (high confidence) C. Sun et al., “Thermally Induced Interdiffusion and Precipitation in a Ni/Ni3Al System,” Materials Research Letters. 2015. link Times cited: 5 Abstract: Ordered Ni3Al intermetallic precipitates constitute the main… read moreAbstract: Ordered Ni3Al intermetallic precipitates constitute the main hardening sources of Ni-based superalloys. Here, we report the interdiffusion and precipitation behavior in a Ni/Ni3Al model system. The deposition of Ni3Al on a pure Ni layer at 500°C generated L12-structured γ′ (Ni3Al) precipitates, preferentially at the interface. After annealing at 800°C for 1 h, interdiffusion between Ni and Ni3Al layers occurred, and the γ′ precipitates that grew near the parent Ni/Ni3Al interface are ∼2.8 times larger in size than those formed in the matrix. Monte Carlo simulations indicate that vacancies preferentially diffuse along the Ni/Ni3Al interface, increasing the probability of precipitation. read less NOT USED (high confidence) Y. Chen, E. Francis, J. Robson, M. Preuss, and S. Haigh, “Compositional variations for small-scale gamma prime (γ′) precipitates formed at different cooling rates in an advanced Ni-based superalloy,” Acta Materialia. 2015. link Times cited: 84 NOT USED (high confidence) P. Schelling, J. Ernotte, L. Shokeen, J. W. Halley, and W. Tucker, “Molecular-dynamics calculation of the vacancy heat of transport,” Journal of Applied Physics. 2014. link Times cited: 2 Abstract: We apply the recently developed constrained-dynamics method … read moreAbstract: We apply the recently developed constrained-dynamics method to elucidate the thermodiffusion of vacancies in a single-component material. The derivation and assumptions used in the method are clearly explained. Next, the method is applied to compute the reduced heat of transport Qv*−hfv for vacancies in a single-component material. Results from simulations using three different Morse potentials, with one providing an approximate description of Au, and an embedded-atom model potential for Ni are presented. It is found that the reduced heat of transport Qv*−hfv may take either positive or negative values depending on the potential parameters and exhibits some dependence on temperature. It is also found that Qv*−hfv may be correlated with the activation entropy. The results are discussed in comparison with experimental and previous simulation results. read less NOT USED (high confidence) J. Yu, Q.-xin Zhang, and Z. Yue, “Tensile mechanical properties of Ni3Al nanowires at intermediate temperature,” RSC Advances. 2014. link Times cited: 8 Abstract: Molecular dynamics (MD) methods are employed to study the me… read moreAbstract: Molecular dynamics (MD) methods are employed to study the mechanical properties of Ni3Al nanowires (NWs) along the [001], [110] and [111] crystal orientations under tensile loading at intermediate temperatures. The stress–strain responses, Young's modulus, elongations and crystal defects of NWs are compared at different temperatures and different crystal orientations. The simulation results indicate that the yield stress decreases linearly with an increase in temperature, which is the same as the trend for Young's modulus. In addition, tensile tests exhibit that Ni3Al NWs have an obvious intermediate temperature brittleness (ITB) behavior at about 900–1100 K. The crystal structure is less stable at intermediate temperatures. Furthermore, we find that the different crystal defects formed are mainly point dislocations and stacking faults. The higher the stacking fault energy (SFE) of Ni3Al NWs, the easier are the dislocation slips. The glide dislocation expands within the {111} glide plane. In general, studying the relation between the incipient plastic deformation and the temperature of Ni3Al NWs at different crystal orientations can help us further understand the mechanical properties accurately and completely. read less NOT USED (high confidence) A. Ruban, V. A. Popov, V. K. Portnoi, and V. Bogdanov, “First-principles study of point defects in Ni3Al,” Philosophical Magazine. 2014. link Times cited: 25 Abstract: The energetics and structural properties of native, substitu… read moreAbstract: The energetics and structural properties of native, substitutional and interstitial defects in NiAl have been investigated by first-principles methods. In particular, we have determined the formation energies of composition conserving defects and established that the so-called penta defect, which consists of four vacancies on Ni sublattice and Ni antisite on the Al sublattice, is the main source of vacancies in NiAl. We show that this is due to the strong Ni-site preference of vacancies in NiAl. We have also calculated the site substitution behaviour of Cu, Pd, Pt, Si, Ti, Cr, V, Nb, Ta and Mo and their effect on the concentration expansion coefficient. We show the latter information can used for an indirect estimate of the site substitution behaviour of the alloying elements. The solution energy of carbon and its effect on the lattice constant of NiAl have been obtained in the dilute limit in the first-principles calculations. We have also determined the chemical and strain-induced carbon–carbon interactions in the interstitial positions of NiAl. These interactions have been subsequently used in the statistical thermodynamic simulations of carbon ordering in NiAl. read less NOT USED (high confidence) X.-yuan Yang, S. Xiao, and W. Hu, “Atomistic simulation for the size effect on the mechanical properties of Ni/Ni 3 Al nanowire,” Journal of Applied Physics. 2013. link Times cited: 11 Abstract: The size dependence of the mechanical properties of Ni/Ni3Al… read moreAbstract: The size dependence of the mechanical properties of Ni/Ni3Al nanowires (NWs) was investigated with molecular dynamics (MD) simulations. The results indicated that the surface energy σ increased, and bulk modulus B and B/G ratio decreased with increasing the inverse of the nanowire perimeter of the NWs. The extrapolated values of surface energy σ0 were 2.100 J/m2 and 1.956 J/m2 for the samples with surface atoms of pure Ni atoms and mixture of Ni and Al atoms, respectively. The size dependence of the bulk modulus was in good agreement with the prediction of the Birch-Murnaghan equation and the surface shell softening the bulk modulus. Finally, the B/G ratio indicated that the ductility/brittleness behaviors of the NWs depended mainly on the energy distributions of the surface shell, and the mechanisms of the ductility/brittleness of the NWs were studied in detail. read less NOT USED (high confidence) Y. Mishin, “Calculation of the γ/γ′ interface free energy in the Ni–Al system by the capillary fluctuation method,” Modelling and Simulation in Materials Science and Engineering. 2013. link Times cited: 41 Abstract: Monte Carlo computer simulations with an embedded-atom poten… read moreAbstract: Monte Carlo computer simulations with an embedded-atom potential are applied to study coherent γ/γ′ interfaces in the Ni–Al system. The (1 0 0) interface free energy has been extracted from the power spectrum of equilibrium shape fluctuations (capillary waves) and found to decrease with temperature from about 20 mJ m−2 at 550 K to about 10 mJ m−2 at 1200 K. These numbers are in reasonable agreement with existing experimental data. Strengths and weaknesses of the capillary wave method are discussed. read less NOT USED (high confidence) R. Voskoboinikov, “Effective γ-surfaces in 111 plane in FCC Ni and L12 Ni3Al intermetallic compound,” The Physics of Metals and Metallography. 2013. link Times cited: 14 NOT USED (high confidence) A. Walle et al., “Ab initiocalculation of anisotropic interfacial excess free energies,” Physical Review B. 2013. link Times cited: 8 Abstract: We describe a simple method to determine, from ab initio cal… read moreAbstract: We describe a simple method to determine, from ab initio calculations, the complete orientation-dependence of interfacial free energies in solid-state crystalline systems. We illustrate the method with an application to precipitates in the Al-Ti alloy system. The method combines the cluster expansion formalism in its most general form (to model the system's energetics) with the inversion of the well-known Wulff construction (to recover interfacial energies from equilibrium precipitate shapes). Although the inverse Wulff construction only provides the relative magnitude of the various interfacial free energies, absolute free energies can be recovered from a calculation of a single, conveniently chosen, planar interface. The method is able to account for essentially all sources of entropy (arising from phonons, bulk point defects, as well as interface roughness) and is thus able to transparently handle both atomically smooth and rough interfaces. The approach expresses the resulting orientation-dependence of the interfacial properties using symmetry-adapted bases for general orientation-dependent quantities. As a by-product, this paper thus provides a simple and general method to generate such basis functions, which prove useful in a variety of other applications, for instance to represent the anisotropy of the so-called constituent strain elastic energy. read less NOT USED (high confidence) M. Mendelev, M. Kramer, S. Hao, K. Ho, and C. Z. Wang, “Development of interatomic potentials appropriate for simulation of liquid and glass properties of NiZr2 alloy,” Philosophical Magazine. 2012. link Times cited: 116 Abstract: A new interatomic potential for the Ni–Zr system is presente… read moreAbstract: A new interatomic potential for the Ni–Zr system is presented. This potential was developed specifically to match experimental scattering data from Ni, Zr and NiZr2 liquids. Both ab initio and published thermodynamic data were used to optimise the potential to study the liquid and amorphous structure of the NiZr2 alloy. This potential has the C 16 phase, being more stable than C 11b phase in the NiZr2 alloy, consistent with experiments. The potential leads to the correct glass structure in the molecular dynamics simulation and, therefore, can be used to study the liquid–glass transformation in the NiZr2 alloy. read less NOT USED (high confidence) M. Chaudhari et al., “Site occupancy of chromium in the γ′-Ni3Al phase of nickel-based superalloys: a combined 3D atom probe and first-principles study,” Philosophical Magazine Letters. 2012. link Times cited: 22 Abstract: Transition-metal dopants play a critical role in the high-te… read moreAbstract: Transition-metal dopants play a critical role in the high-temperature mechanical strength and corrosion resistance of nickel-based superalloys. In this article, the site occupancy behavior of chromium in γ′-Ni3Al has been investigated by combining three-dimensional (3D) atom probe and high-resolution transmission electron microscopy characterizations with ab initio density functional theory (DFT) calculations. The 3D atom probe data show a clear preference of chromium on the aluminum sublattice over the nickel sublattice in Rene88 super alloys. First-principles DFT total-energy calculations were performed to understand the site occupancy of chromium in the L12 structured γ-Ni3Al. The obtained chromium site preference energies have been compared using the anti-site and vacancy-based substitution formation mechanism, as well as using the standard defect formation formalism. It was found that chromium prefers aluminum site, consistent with the 3D atom probe result. In addition, interaction energies between two chromium atoms have also been determined from first-principles calculations. Our results show that chromium atoms prefer to be close by on either nickel or aluminum sublattices or on a nickel–aluminum mixed lattice, suggesting a potential tendency of chromium segregation in the γ′ phase. read less NOT USED (high confidence) H. Xie, L. Bo, and T. Yu, “Atomistic simulation of microtwinning at the crack tip in L12 Ni3Al,” Philosophical Magazine. 2012. link Times cited: 15 Abstract: The mechanisms of deformation at the crack tip in L12 Ni3Al … read moreAbstract: The mechanisms of deformation at the crack tip in L12 Ni3Al have been studied by molecular dynamics simulations. The stress-induced microtwinning is found to occur at the crack tip when a sufficiently high stress concentration exists. The formation mechanism of the microtwinning is discussed. It is found to be achieved by the emission of Shockley partial dislocations from the crack tip and then slip of the Shockley partial dislocations on adjacent {111} planes. Furthermore, the mechanism of the microtwinning is also discussed from the standpoint of stress. read less NOT USED (high confidence) Z. Mao, C. Booth-Morrison, E. Y. Plotnikov, and D. Seidman, “Effects of temperature and ferromagnetism on the γ-Ni/γ′-Ni3Al interfacial free energy from first principles calculations,” Journal of Materials Science. 2012. link Times cited: 28 NOT USED (high confidence) N. S. Weingarten and B. Rice, “A molecular dynamics study of the role of relative melting temperatures in reactive Ni/Al nanolaminates,” Journal of Physics: Condensed Matter. 2011. link Times cited: 38 Abstract: Molecular dynamics (MD) simulations using a recently develop… read moreAbstract: Molecular dynamics (MD) simulations using a recently developed first-principles-based embedded-atom-method (EAM) potential are used to simulate the exothermic alloying reactions of a Ni/Al bilayer initially equilibrated at 1200 K. Simulations are performed in the isobaric–isoenthalpic (NPH) ensemble, which provides insight into the influence of pressure on atomic mixing and the subsequent alloying reaction. For pressures lower than 8 GPa, the mechanism of mixing is the same: as mixing and reaction occur at the interface, the heat generated first melts the Al layer, and subsequent mixing leads to further heat generation after which the Ni layer melts, leading to additional mixing until the alloying reactions are completed. However, for simulations at pressures higher than 8 GPa, the reaction does not occur within the time interval of the simulation. The results will be compared with our previous simulations of a Ni/Al bilayer using a different interatomic potential, which predicts substantially different pressure-dependent melting behavior of the pure components. This comparative study suggests that pressure-dependent melting behavior of components of reactive materials can be used to influence reaction rates and mechanisms. read less NOT USED (high confidence) M.-yi Zhang, Y. Kun, C. Zhen, Y. Wang, and X. L. Fan, “Microscopic phase-field study on order-disorder transition of the antiphase domain boundary formed between L1 2 phases,” Science China-technological Sciences. 2011. link Times cited: 1 NOT USED (high confidence) M. Chandran and S. Sondhi, “First-principle calculation of stacking fault energies in Ni and Ni-Co alloy,” Journal of Applied Physics. 2011. link Times cited: 70 Abstract: The (111) intrinsic stacking fault energy γISF in Ni and Ni-… read moreAbstract: The (111) intrinsic stacking fault energy γISF in Ni and Ni-Co alloy was calculated and compared using two different ab initio methods, viz., the supercell approach and the axial interaction model (AIM), based on density functional theory. The supercell approach uses energies of crystal structure in slab geometry with and without the stacking fault. In the AIM approach, the problem is mapped to a 1D spin-model and the interaction parameters are obtained using energies for ordered structures, thus obviating the need to handle faulted structure. For elemental Ni, the calculated values of γISF from AIM and supercell approaches differ by not more than by 2%, and compares well with experimental value. For Ni-Co alloy, AIM predicts a slightly faster decrease in γISF with increasing Co concentration compared to supercell approach and experimental data. Overall, there is good agreement between the two approaches. read less NOT USED (high confidence) A. Ardell, “A1-L12 interfacial free energies from data on coarsening in five binary Ni alloys, informed by thermodynamic phase diagram assessments,” Journal of Materials Science. 2011. link Times cited: 57 NOT USED (high confidence) F. Rizzi et al., “Bayesian Inference of Atomic Diffusivity in a Binary Ni/Al System Based on Molecular Dynamics,” Multiscale Model. Simul. 2011. link Times cited: 27 Abstract: This work focuses on characterizing the integral features of… read moreAbstract: This work focuses on characterizing the integral features of atomic diffusion in Ni/Al nanolaminates based on molecular dynamics (MD) computations. Attention is focused on the simplified problem of extracting the diffusivity, D, in an isothermal system at high temperature. To this end, a mixing measure theory is developed that relies on analyzing the moments of the cumulative distribution functions (CDFs) of the constituents. The mixing measures obtained from replica simulations are exploited in a Bayesian inference framework, based on contrasting these measures with corresponding moments of a dimensionless concentration evolving according to a Fickian process. The noise inherent in the MD simulations is described as a Gaussian process, and this hypothesis is verified both a priori and using a posterior predictive check. Computed values of D for an initially unmixed system rapidly heated to 1500 K are found to be consistent with experimental correlation for diffusion of Ni into molten Al. On the contrary,... read less NOT USED (high confidence) R. Srinivasan et al., “The use of advanced characterization to study transitions across solid state interfaces,” JOM. 2010. link Times cited: 8 NOT USED (high confidence) J. Zhang, Z. Chen, Y. Lu, M.-yi Zhang, and Y. Wang, “Microscopic phase field study of the antisite defect of Ni3Al in binary Ni-Al alloys,” Science China Physics, Mechanics and Astronomy. 2010. link Times cited: 1 NOT USED (high confidence) B. Sadigh, P. Erhart, A. Stukowski, and A. Caro, “Composition-dependent interatomic potentials: A systematic approach to modelling multicomponent alloys,” Philosophical Magazine. 2009. link Times cited: 16 Abstract: We propose a simple scheme to construct composition-dependen… read moreAbstract: We propose a simple scheme to construct composition-dependent interatomic potentials for multicomponent systems that, when superposed onto the potentials for the pure elements, can reproduce not only the heat of mixing of the solid solution in the entire concentration range but also the energetics of a wider range of configurations including intermetallic phases. We show that an expansion in cluster interactions provides a way to systematically increase the accuracy of the model, and that it is straightforward to generalise this procedure to multicomponent systems. Concentration-dependent interatomic potentials can be built upon almost any type of potential for the pure elements including embedded atom method (EAM), modified EAM, bond-order, and Stillinger–Weber type potentials. In general, composition-dependent N-body terms in the total energy lead to explicit (N + 1)-body forces, which potentially render them computationally expensive. We present an algorithm that overcomes this problem and that can speed up the calculation of the forces for composition-dependent pair potentials in such a way as to make them computationally comparable in efficiency and scaling behaviour to standard EAM potentials. We also discuss the implementation in Monte Carlo simulations. Finally, we exemplarily review the composition-dependent EAM model for the Fe–Cr system. read less NOT USED (high confidence) G. P. P. Pun and Y. Mishin, “Development of an interatomic potential for the Ni-Al system,” Philosophical Magazine. 2009. link Times cited: 341 Abstract: We construct an interatomic potential for the Ni-Al system w… read moreAbstract: We construct an interatomic potential for the Ni-Al system within the embedded-atom method formalism. The potential is based on previously developed accurate potentials for pure Ni and Al. The cross-interactions are fitted to experimental cohesive energy, lattice parameter and elastic constants of B2-NiAl, as well as to ab initio formation energies of several real or imaginary intermetallic compounds with different crystal structures and chemical compositions. The potential accurately reproduces a variety of physical properties of the NiAl and Ni3Al phases, and shows reasonable agreement with experimental and ab initio data for phase stability across the Ni-Al phase diagram. Most of the properties reproduced by the new potential were not involved in the fitting process, which demonstrates its excellent transferability. Advantages and certain weaknesses of the new potential in comparison with other existing potentials are discussed in detail. The potential is expected to be especially suitable for simulations of heterophase interfaces and mechanical behavior of Ni-Al alloys. read less NOT USED (high confidence) X. Song, Z. Gan, S. Liu, H. Yan, and Q. Lv, “Computational study of thermocompression bonding of carbon nanotubes to metallic substrates,” Journal of Applied Physics. 2009. link Times cited: 17 Abstract: Thermocompression bonding of carbon nanotubes (CNTs) to meta… read moreAbstract: Thermocompression bonding of carbon nanotubes (CNTs) to metallic substrates is studied using molecular dynamics. The interaction of the CNT and the metal cluster at high temperature is investigated first. For the diffusion bonding process, the effects of temperature and external pressure are examined. In addition, we apply the tensile loading to examine the mechanical properties and the failure modes during the debonding process. The results show that formation of coalescence structure between the CNT and the metal cluster provides a nanoscale metal surface to facilitate diffusion bonding. Both high temperature and high pressure will enhance the bonding. In addition, the debonding position of the samples under the tensile loading depends on the competition of CNT-metal and metal-metal interface strength. For samples bonded under high temperature and high pressure, the debonding first occurs at the CNT-metal interface. While for samples bonded under low temperature and low pressure, the interdiffusion is n... read less NOT USED (high confidence) C. Wang and C.-yu Wang, “Effects of alloying Re and Ru in the edge-dislocation core of the Ni/Ni 3 Al interface,” Chinese Physics B. 2009. link Times cited: 6 Abstract: Investigations of alloying Re and Ru in the [110](001) dislo… read moreAbstract: Investigations of alloying Re and Ru in the [110](001) dislocation core of the Ni/Ni(3)Al interface were conducted within the framework of density functional theory. The energetic calculations show that both elements can stabilize the [110](001) dislocation core. In the dislocation core region, Re and Ru prefer to substitute for Ni on the site in the gamma-phase. Re is easier to segregate into the dislocation core region as compared with Ru; it especially prefers to substitute for Ni on the gamma-(Ni)1 site. read less NOT USED (high confidence) L. Kovarik et al., “Microtwinning and other shearing mechanisms at intermediate temperatures in Ni-based superalloys,” Progress in Materials Science. 2009. link Times cited: 288 NOT USED (high confidence) J. Zhang, Z. Chen, M.-yi Zhang, Q. Lai, Y. Lu, and Y. Wang, “Antisite defect types and temporal evolution characteristics of D022-Ni3V structure: Studied by the microscopic phase field,” Science in China Series G: Physics, Mechanics and Astronomy. 2009. link Times cited: 3 NOT USED (high confidence) R. Srinivasan et al., “Atomic scale structure and chemical composition across order-disorder interfaces.,” Physical review letters. 2009. link Times cited: 99 Abstract: Through a combination of aberration-corrected high-resolutio… read moreAbstract: Through a combination of aberration-corrected high-resolution scanning transmission electron microscopy and three-dimensional atom probe tomography, the true atomic-scale structure and change in chemical composition across the complex order-disorder interface in a metallic alloy has been determined. The study reveals the presence of two interfacial widths, one corresponding to an order-disorder transition, and the other to the compositional transition across the interface, raising fundamental questions regarding the definition of the interfacial width in such systems. read less NOT USED (high confidence) N. Vinogradova, N. Kazantseva, N. Stepanova, E. Romanov, and A. Pirogov, “Twinning and phase transformations in refractory alloy ÉP-800 after dynamic loading,” Metal Science and Heat Treatment. 2008. link Times cited: 3 NOT USED (high confidence) Y. Mishin and A. Lozovoi, “Angular-dependent interatomic potential for tantalum,” Acta Materialia. 2006. link Times cited: 70 NOT USED (high confidence) Y. Mishin, M. Mehl, D. Papaconstantopoulos, and D. Papaconstantopoulos, “Phase stability in the Fe–Ni system: Investigation by first-principles calculations and atomistic simulations,” Acta Materialia. 2005. link Times cited: 261 NOT USED (high confidence) S. Meher, P. Nandwana, T. Rojhirunsakool, J. Tiley, and R. Banerjee, “Probing the crystallography of ordered Phases by coupling of orientation microscopy with atom probe tomography.,” Ultramicroscopy. 2015. link Times cited: 17 NOT USED (high confidence) K. Vamsi and S. Karthikeyan, “Modelling ternary effects on antiphase boundary energy of Ni3Al.” 2014. link Times cited: 14 Abstract: The shearing of ordered γ′ precipitates by matrix dislocatio… read moreAbstract: The shearing of ordered γ′ precipitates by matrix dislocations results in the formation of antiphase boundaries (APB) in Ni-base superalloys. The APB energy is an important source of order-strengthening in disk and blade alloys where Ti and Ta substitute for Al in γ′. While the importance of APB energy is well-acknowledged, the effect of alloying on APB energy is not fully understood. In the present study, the effect of Ti and Ta additions on the {111} and {010} APB energies was probed via electronic structure calculations. Results suggest that at low levels of Ti/Ta, APB energies on either plane increases with alloying. However, at higher Ti/Ta levels, the APB energies decrease with alloying. These trends understood by accounting for nearest neighbour violations about the APB and additionally, invoking the effect of precipitate composition on the energy penalty of the violations. We propose an Environment Dependent Nearest Neighbour Bond (EDNNB) model that predicts APB energies that are in close agreement to calculated values. read less NOT USED (high confidence) J.-ping Du, C.-yu Wang, C.-yu Wang, and T. Yu, “Construction and application of multi-element EAM potential (Ni–Al–Re) in γ/γ′ Ni-based single crystal superalloys,” Modelling and Simulation in Materials Science and Engineering. 2012. link Times cited: 44 Abstract: Based on experiments and first-principles calculations, a Ni… read moreAbstract: Based on experiments and first-principles calculations, a Ni–Al–Re system embedded atom method (EAM) potential is constructed for the γ(Ni)/γ′(Ni3Al) superalloy. The contribution of the inner elastic constants is considered in the fitting of Re with a hexagonal close-packed structure. Using this potential, point defects, planar defects and lattice misfit of γ(Ni) and γ′(Ni3Al) are investigated. The interaction between Re and the misfit dislocation of the γ(Ni)/γ′(Ni3Al) system is also calculated. We conclude that the embedding energy has an important effect on the properties of the alloys, such as the planar fault energies of Ni3Al, by considering the relationship between the charge transfer calculated from first-principles, the elastic constants of Ni3Al and the host electron density of the EAM potential. The multi-element potential predicts that Re does not form clusters in γ(Ni), which is consistent with recent experiments and first-principles calculations. read less NOT USED (high confidence) M. Sangid, H. Maier, and H. Sehitoglu, “A physically based fatigue model for prediction of crack initiation from persistent slip bands in polycrystals,” Acta Materialia. 2011. link Times cited: 170 NOT USED (high confidence) P. Brommer, “Development and test of interaction potentials for complex metallic alloys.” 2008. link Times cited: 8 Abstract: Complex metallic alloys and quasicrystals show extraordinary… read moreAbstract: Complex metallic alloys and quasicrystals show extraordinary physical properties relevant for technological applications, for example hardness at low density. In the study of these systems, atomistic simulation with classical interaction potentials is a very promising tool. Such simulations require classical effective potentials describing the cohesive energy as a function of the atomic coordinates. The quality of the simulation depends crucially on the accuracy with which this potential describes the real interactions. One way to generate physically relevant potentials is the force matching method, where the parameters of a potential are adjusted to optimally reproduce the forces on individual atoms determined from quantum-mechanical calculation. The programme package potfit developed as part of this thesis implements the force matching method efficiently. Potentials are generated for a number of complex metallic alloy systems. A potential for the decagonal basic Ni-rich Al-Co-Ni quasicrystal is used to simulate diffusion processes and melting. In the CaCd6 system built from multishelled clusters, the shape and orientation of the innermost cluster shell is studied. Finally, phonon dispersion in the Mg-Zn system is determined and compared to experiment. The programme potfit is shown to be an effective tool for generating physically justified effective potentials. Potentials created with potfit can greatly improve the understanding of complex metallic alloys through atomistic simulations.
Komplexe intermetallische Verbindungen und Quasikristalle zeigen ausergewohnliche physikalische Eigenschaften, wie z.B. Harte bei geringer Dichte. Bei der Untersuchung dieser Systeme sind atomistische Simulationen mit klassischen Wechselwirkungspotenzialen ein wichtiges Werkzeug. Fur solche Simulationen benotigt man klassische effektive Potenziale, die die Bindungsenergie als eine Funktion der Atomkoordinaten beschreiben. Die Qualitat der Simulation hangt entscheidend von der Genauigkeit ab, mit der diese Potenziale die echten Wechselwirkungen wiedergeben. Eine Moglichkeit, physikalisch relevante Potenziale zu erzeugen, ist die Force-Matching-Methode. Dabei werden die Parameter eines Potenzials so angepasst, dass die mit quantenmechanischen Methoden bestimmten Krafte auf die einzelnen Atome bestmoglich reproduziert werden. Das als Teil dieser Arbeit entwickelte Programmpaket potfit implementiert die Force-Matching-Methode effizient. Fur einige komplexe intermetallische Verbindungen werden Potenziale bestimmt. In dekagonalen Al-Co-Ni-Quasikristallen werden mit Hilfe eines Potenzials Diffusionsprozesse und Schmelzvorgange simuliert. In der aus mehrschaligen Clustern bestehenden CaCd6-Verbindung wird die Struktur der innersten Clusterschale untersucht. Schlieslich wird die Phononendispersion im Mg-Zn-System bestimmt und mit experimentellen Ergebnissen verglichen. Es wird gezeigt, dass das Programm potfit ein effektives Werkzeug zur Erzeugung physikalisch gerechtfertigter Wechselwirkungen ist. Potenziale, die mit potfit erzeugt werden, konnen zum Verstandnis komplexer metallischer Verbindungen durch atomistische Simulationen viel beitragen. read less NOT USED (definite) L. Tagliaferri et al., “Aluminizing via Ionic Liquid Electrodeposition and Pack Cementation: A Comparative Study with Inconel 738 and a CoNiCrAlY,” THE Coatings. 2017. link Times cited: 6 Abstract: A novel aluminizing process based upon room temperature Al-e… read moreAbstract: A novel aluminizing process based upon room temperature Al-electrodeposition from Ionic Liquids followed by diffusion heat treatment was applied on bare- and CoNiCrAlY-coated Inconel 738 (IN738). The aluminized samples were tested by isothermal oxidation at 1000 °C in air. The microstructural and chemical evolution of the samples were determined as function of oxidation time and compared with the currently applied coatings obtained via pack cementation. The newly proposed method is suitable for the CoNiCrAlY coating, but not for the bare IN738. In the latter, the formed Al-enriched layer is much thinner and the anticorrosion properties resulted in being reduced. This is probably due to the presence of precipitates, which slow down the aluminum inward diffusion impairing the formation of a well-developed interdiffusion zone (IDZ). Traces of the electrolyte, embedded during the Al-electrodeposition process, can be seen as the origin of these precipitates. read less |
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