摘要
采用晶体相场模型模拟了对称倾侧亚晶界结构及其在应力作用下的湮没机制,并从位错运动和能量角度对湮没机制进行分析,此外还分别讨论了温度、位向差和应力方向对亚晶界湮没的影响.研究表明,亚晶界是由呈一定角度的双位错组垂直分布组成的;亚晶界的湮没过程包括4个阶段:位错的攀移,位错的分离与攀滑移,位错的再次攀移和再次分离、攀滑移;温度的降低阻碍亚晶界的湮没;位向差小的亚晶界先于位向差大的亚晶界湮没,且湮没速度较快;亚晶界上应力方向的改变会引起湮没过程中位错运动方向发生改变,从而影响亚晶界的湮没,压应力有利于亚晶界的湮没.
The structure of symmetric tilt sub-grain boundary （SGB） and its annihilation mechanism under stress were modeled with the phase field crystal approach, including the analysis from two aspects of dislocation movement and system energy. In addition, the effects of temperature, misorien- tation and stress direction on SGB annihilation were also discussed. Simulated results show that the SGB is composed of double-array dislocations with a vertical distribution. The annihilation process generally contains four stages： dislocation climb, dislocation separation, another dislocation climb and separation again. The reduction of temperature hinders the process of annihilation. The SGB with a small misorientation annihilates earlier and faster than the one with a large misorientation. The annihilation differs under different stress conditions, and the compressive stress is favorable to the annihilation.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第10期1301-1306,共6页
Acta Metallurgica Sinica
基金
国家自然科学基金项目51075335
10902086和50875217
西北工业大学基础研究基金项目NPU-FFR-JC201005
西北工业大学博士论文创新基金项目CX201103资助~~
关键词
晶体相场模型
亚晶界
双位错组
应力诱发淹没
phase field crystal model, sub-grain boundary, double-array dislocation, stressinduced annihilation
