Atomistic and data-driven insights into the local slip resistances in random refractory multi-principal element alloys
South China University of Technology（华南理工大学）；University of Oklahoma（俄克拉荷马大学）；Stanford University（斯坦福大学）；University of California, Santa Barbara（加利福尼亚大学圣塔芭芭拉分校）
Wu-Rong Jian, Arjun S. Kulathuvayal, Hanfeng Zhai, Anshu Raj, Xiaohu Yao, Yanqing Su, Shuozhi Xu, Irene J. Beyerlein
Refractory multi-principal element alloys (RMPEAs) have attracted growing interest for their exceptional high-temperature strength, yet their complex compositions hinder a mechanistic understanding of plastic deformation. Here, we perform atomistic simulations to determine local slip resistances (LSRs) of edge and screw dislocations on primary BCC slip planes in 12 equal-molar RMPEAs. Machine learning is employed to uncover relationships between LSR and underlying material properties, enabling systematic assessment of compositional effects on dislocation behavior. Based on these insights, we develop a thermally activated, dislocation-based model to predict macroscopic yield stress. We find that increasing the fraction of hexagonal close-packed elements above 50% significantly reduces unstable stacking fault energy, ideal shear strength, and screw LSR across all slip planes. Higher elastic anisotropy further lowers these quantities, while lattice distortion modifies relative slip resistances between dislocation characters and slip systems. By combining an autoencoder with a random forest model, we identify elastic constants and lattice distortion as the dominant factors controlling LSR. The resulting framework accurately predicts tensile yield stress in BCC RMPEAs and provides guidance for alloy design.
Short-range order and compositional phase stability in refractory high-entropy alloys via first principles theory and atomistic modelling: NbMoTa, NbMoTaW and VNbMoTaW
Emergent B2 chemical orderings in the AlTiVNb and AlTiCrMo refractory high-entropy superalloys studied via first-principles theory and atomistic modelling
结合从头算电子结构理论与原子尺度蒙特卡罗模拟，研究了 AlTiVNb 和 AlTiCrMo 难熔高熵高温合金的相稳定性，揭示了高温下由 Al 和 Ti 驱动的 B2 化学有序及其对电子结构和电阻率的影响。
Multiscale modeling of plastic deformation of molybdenum and tungsten: I. Atomistic studies of the core structure and glide of 1/2<111> screw dislocations at 0 K
Zonal dislocations in Laves phases: A coupled synchro-shear slip mechanism
RWTH Aachen University（亚琛工业大学）；Ruhr University Bochum（波鸿鲁尔大学）；Max Planck Institute for Sustainable Materials（马普可持续材料研究所）；Fuyao University of Science and Technology（福耀科技大学）；Université de Lorraine（洛林大学）；Helmholtz-Zentrum Berlin für Materialien und Energie（柏林亥姆霍兹材料与能源中心）
Pseudoelastic deformation in Mo-based refractory multi-principal element alloys
由密度泛函理论方法支持的相图对于设计作为多主元素$-$合金的子集的高熵合金是至关重要的。我们提出了五元（MoW）$_{x}$ Zr $_{y}$（TaTi）$_{1-x-y}$耐火高熵合金的相和性能分析相结合的计算相图（CALPHAD）和密度泛函理论的结果，辅以分子动力学模拟。通过计算和密度泛函理论相稳定性分析表明，该五元体的富钼钨区具有稳定的单相体心立方结构。我们报道了具有伪弹性行为的Mo $-$ W $-$ Ta $-$ Ti $-$ Zr合金族的第一个五元组成，即，应力滞后$-$应变。我们的分析表明，只有Mo $-$ W $-$富含Mo $-$ W $-$ Ta $-$ Ti $-$ Zr的成分，即，Mo $+$ W $\ge$ 85原子%，显示出在应力-应变中可再现的滞后现象，这是伪弹性行为的原因。基于温度依赖性相图分析和分子动力学模拟预测的弹性行为（其揭示了孪生辅助的伪弹性行为），对（MoW）$_{85}$ Zr $_{7.5}$（TaTi）$_{7.5}$进行下选择。虽然在体心立方晶体中大多未被探索，但孪生是晶体固体中与位错滑移竞争的基本变形机制。该合金在单轴$\lt$ 100 $\gt$加载期间显示出相同的循环变形特征，即，伪弹性在加载方向上是各向同性的。此外，从77到1500 K的温度升高增强了加载-卸载循环中的弹性应变恢复，提供了可能的控制来调整伪弹性行为。
Dislocation-mediated plasticity in the Al$_{2}$Cu θ-phase
The deformation behaviour of the intermetallic Al $_{2}$ Cu-phase was investigated using atomistic simulations and micropillar compression, where slip on the unexpected {211} and {022} slip planes was revealed. Additionally, all possible slip systems for the intermetallic phases were further evaluated and a preference for the activation of slip systems based on their effective interplanar distances as well as the effective Burgers vector is proposed. The effective interplanar distance corresponds to the manually determined interplanar distance, whereas the effective Burgers vector takes a pote…
Cracking the case: fluctuations enhance ductility in refractory alloys
École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；Laboratory of materials design and simulation (MADES), Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院材料研究所材料设计与模拟实验室）；National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院新型材料计算设计与发现国家中心）；EMPA - Swiss Federal Laboratories for Materials Science and Technology（瑞士联邦材料科学与技术研究院）；Laboratory for Multiscale Modeling in Mechanics (LAMMM), Institute of Mechanical Engineering, École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院机械工程学院多尺度力学建模实验室）；School of Engineering, Brown University, Providence, RI 02906 USA（布朗大学工程学院）
Multiscale modeling of plastic deformation of molybdenum and tungsten: II. Yield criterion for single crystals based on atomistic studies of glide of 1/2<111> screw dislocations
Nanoindentation induced plasticity in equiatomic MoTaW alloys by experimentally guided machine learning molecular dynamics simulations
National Centre for Nuclear Research, NOMATEN CoE（国家核研究中心，NOMATEN卓越中心）；Institute for Technology of Nuclear and Other Mineral Raw Materials（核及其他矿物原料技术研究所）
Misfit-dislocation hierarchy governs sliding of asymmetric non-CSL grain boundaries
Woodruff School of Mechanical Engineering, Georgia Institute of Technology（佐治亚理工学院机械工程学院）；School of Mechanics and Engineering Science, Peking University（北京大学力学与工程科学学院）；Institute of Microstructure and Property of Advanced Materials, Beijing Key Lab of Microstructure and Property of Advanced Materials, Beijing University of Technology（北京工业大学先进材料微结构及性能研究所）
Influence of Manganese Content on Plastic Deformation Mechanisms in Polycrystalline α-Ti-Mn Alloys
Institute for Technology of Nuclear and Other Mineral Raw Materials（核与其他矿物原材料技术研究所）；National Centre for Nuclear Research, NOMATEN CoE（国家核研究中心，NOMATEN卓越中心）
