(1. 广西大学 物理科学与工程技术学院，南宁 530004；
2. 广西大学 广西有色金属及特色材料加工重点实验室，南宁 530004；
3. 玉林师范学院 物理科学与工程技术学院，玉林 537000)
摘 要: 采用晶体相场模型模拟位向差为7.70°的对称倾侧晶界位错在外加应力作用下的运动形式和演化过程；计算位错分离的激活能，并从能量变化角度分析位错运动过程中发生的分解、湮没和合并机制；分析该对称倾侧晶界在外力作用下晶界湮没过程不同特征阶段的差异。结果表明，晶界的湮没存在不同的特征阶段，主要阶段如下：位错的攀移，位错的分解与滑移，位错湮没；位错的再攀移与位错再分解、再湮没，或者出现了若干短暂的新阶段，如滑移位错与晶界上其他位错发生合并而被晶界吸收，或者滑移位错与另一滑移位错在晶内发生合并形成新位错组，或者滑移位错与另一滑移位错发生湮没消失。晶界上全位错的分解实质是产生了一对新的符号相反的柏氏矢量；分位错在晶界上的湮没或合并实质是分位错与晶界上的全位错形成的一对符号相反的柏氏矢量发生抵消；分位错与分位错在晶粒内部的湮没消失，其实质是2个分位错之间的2对符号完全相反的位错柏氏矢量相互抵消。
关键字: 晶界；位错；湮没；分解；晶体相场模型
（1. College of Physics Science and Engineering, Guangxi University, Nanning 530004, China;
2. Guangxi Key Laboratory for Non-ferrous Metal and Featured Materials, Guangxi University, Nanning 530004, China;
3. Institute of Physics Science and Engineering Technology, Yulin Normal University, Yulin 537000, China）
Abstract:The movement and evolution of the dislocation for a low-angle grain boundary (GB) with orientation of 7.70° under stress were simulated by using the phase-field crystal model. The dislocation reaction of separation, annihilation and mergence and these mechanisms were analyzed from the energy point of view, and the activation energy of dislocation separation was calculated. The difference of feature stages for the annihilation process of dislocation under stress was shown through comparing two grain boundaries with different misorientations. The results show the obvious difference of typical stages of the annihilation process of GB. The main stages of GB annihilation include the dislocation climb, dislocation separation and dislocation slide, dislocation annihilation; again the dislocation climb and dislocation separation, dislocation annihilation, or instead of the dislocation climb, some new stages presented during the GB annihilation. For example, the sliding dislocation is merged by the dislocation inside the GB or absorbed by GB, or one sliding dislocation reacts with another sliding dislocation in the grain to merge into a new dislocation pairs, or the sliding dislocation reacts with another dislocation to present annihilation and disappear. The essence of dissociation of the full dislocation is that the new dislocation pairs with opposite Burgers vector are created, while that of annihilation or merge of dislocations is that the pair opposite Burgers vectors between the partial dislocation and the full dislocation on the grain boundary bring about to counteract. The annihilation of two dislocation pairs in the grain is produced by perfect counteracting of the two-opposite-pair Burgers vectors of these two dislocation pairs.
Key words: grain boundary; dislocation; annihilation; separation; phase-field crystal
