ABSTRACT Low-energy dislocation structure is one classical self-organised dislocation pattern, among which persistent slip band (PSB) ladders is the most representative. Periodically distributed PSB ladders consist of two phases: matrix phase and pattern phase. In the new two-phase model, the appearance of pattern phase results in the softening of PSBs with lower elastic constant. The formation of PSB ladders reflects two kinds of dynamic equilibriums: (i) bowing out and annihilation between unlike screw dislocations; (ii) multiplication and annihilation between unlike edge dislocations in the rung. Subsequently, in-situ annealing experiments indicate that most of the dislocations are annihilated and a few dislocations rearrange to result in the nucleation and growth of the twin. In a word, both the evolution of dislocation patterns and the transition from LEDS to twin structures are the process of energy redistribution. Controlling the stored energy per unit area will effectively improve the formation of distribution of defects, which will benefit to design the metallic materials based on the defect-engineering strategy.

中文翻译：

---

退火过程中疲劳铜单晶从 LEDS 到孪晶的结构转变的原位 TEM 研究

摘要 低能位错结构是一种经典的自组织位错模式，其中以持久滑移带（PSB）梯形结构最具代表性。周期性分布的 PSB 阶梯由两个阶段组成：矩阵阶段和模式阶段。在新的两相模型中，图案相的出现导致具有较低弹性常数的 PSB 软化。PSB阶梯的形成反映了两种动态平衡：(i)不同螺位错之间的弯曲和湮灭；(ii) 梯级中不同边缘位错之间的乘法和湮灭。随后，原位退火实验表明，大部分位错被湮灭，少数位错重新排列，导致孪晶的成核和生长。一句话，位错模式的演变和从 LEDS 到孪生结构的转变都是能量重新分配的过程。控制单位面积的储存能量将有效改善缺陷分布的形成，这将有利于基于缺陷工程策略的金属材料设计。