论文标题
晶型拓扑相变
Grain-Boundary Topological Phase Transitions
论文作者
论文摘要
断开连接的形成和迁移（线缺陷约束晶粒边界（GB）平面具有脱位和步骤字符）控制了GBS的许多动力学和动力学特性以及它们是中心成分的多晶材料。我们证明GBS经历了Kosterlitz-Thouless（KT）类型的有限温度拓扑相变。该相变向对应于（和解开）断开连接之间的远程相互作用的筛选。这种相转换导致GB迁移，GB滑动和粗糙的行为的突然变化。我们通过平均场理论，重新归一化的群体理论和动力学蒙特卡洛模拟分析了这种KT转变，并研究了这种转变如何影响微观结构尺度现象，例如晶粒生长停滞，异常谷物生长和倍增性。
The formation and migration of disconnections (line defects constrained to the grain boundary (GB) plane with both dislocation and step character) control many of the kinetic and dynamical properties of GBs and the polycrystalline materials of which they are central constituents. We demonstrate that GBs undergo a finite-temperature topological phase transition of the Kosterlitz-Thouless (KT) type. This phase transition corresponds to the screening of long-range interactions between (and unbinding of) disconnections. This phase transition leads to abrupt change in the behavior of GB migration, GB sliding, and roughening. We analyze this KT transition through mean-field theory, renormalization group theory, and kinetic Monte Carlo simulations, and examine how this transition affects microstructure-scale phenomena such as grain growth stagnation, abnormal grain growth and superplasticity.
