发表机构
RWTH Aachen University; Ruhr University Bochum; Max Planck Institute for Sustainable Materials; Fuyao University of Science and Technology; Université de Lorraine; Helmholtz-Zentrum Berlin für Materialien und Energie（亚琛工业大学; 波鸿鲁尔大学; 马普可持续材料研究所; 福耀科技大学; 洛林大学; 柏林亥姆霍兹材料与能源中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过原子模拟和实验，发现Laves相中存在耦合同步剪切滑移机制，涉及相邻滑移面上两个同步Shockley不全位错的同步滑移，形成外禀层错，并揭示其在相变和孪生中的关键作用。
AI 中文摘要
同步剪切是Laves相在高温下的主要塑性变形机制，由同步Shockley不全位错（即分区位错）介导，这些位错通过局部事件（如扭结对形核和扩展）进行运动。通过原子模拟，我们在Laves相中发现了一种新的滑移机制，即耦合同步剪切滑移，涉及两个同步Shockley不全位错在相邻滑移面上的同步滑移，导致外禀层错的形成。高分辨扫描透射电子显微镜揭示了与C15 NbCr2中由外禀层错包围的耦合同步Shockley不全位错一致的扩展芯结构，以及它们参与孪生的过程。这些结果强调了耦合同步剪切滑移在实现Laves多型体之间相变和调控孪生行为中的关键作用，为拓扑密堆金属间相塑性的动力学本质提供了新的原子尺度见解。
英文摘要
Synchro-shear is the primary plastic deformation mechanism in Laves phases at elevated temperatures, mediated by synchro-Shockley partial dislocations-zonal dislocations that proceed via localized events such as kink-pair nucleation and propagation. Using atomistic simulations, we identified a novel slip mechanism in Laves phases, namely coupled synchro-shear slip, involving the synchronized glide of two synchro-Shockley partial dislocations on adjacent slip planes, leading to the formation of extrinsic stacking faults. High-resolution scanning transmission electron microscopy revealed the extended core structures consistent with coupled synchro-Shockley partial dislocations bounded by extrinsic stacking faults in C15 NbCr2 and their involvement in twinning. These results highlight the critical role of coupled synchro-shear slip in enabling phase transformations between Laves polytypes and in governing twinning behavior, providing new atomistic insight into the kinetic nature of plasticity in topologically close-packed intermetallic phases.
