物理学报2009，Vol.58Issue(11)：7934-7946,13.
有限温度下位错环的脱体现象
Separating of dislocation ring at finite temperature
摘要
Abstract
We constructed a partial dislocation ring with Burgers vector b = [112]/6 in the glide plane (111) of copper crystal, and studied its self-contraction process in the temperature range, from 0 to 350 K by using molecular dynamics simulations. The resuhs reveal that, at zero temperature the dislocation ring cannot pass the Peierls-Nabarro potential barrier, so its migrating velocity is zero; below 50 K, the screw part and the edge part of the dislocation have nearly the same migrating velocity. With the increasing of temperature, the edge dislocation migrates more quickly than the screw dislocation. At a higher temperature, the dislocation core becomes wider, consequently, it may contain more complex internal structures and becomes easier for separating. At the same time, local stress gradient within the mixed dislocation zone becomes steeper and results in the generation of four partial dislocation rings. The four new dislocation rings first grow with time under the influence of original dislocation ring. When the original ring finally disappears, the newly created rings begin to shrink and finally disappear. This is a new dislocation source, different from the Frank-Read, L or double cross-slip type.关键词
单晶铜/位错环/分子动力学/位错源Key words
FCC-Cu/dislocation loop/molecular dynamics/dislocation source分类
化学化工引用本文复制引用
卢果,方步青,张广财,许爱国..有限温度下位错环的脱体现象[J].物理学报,2009,58(11):7934-7946,13.基金项目
国家自然科学基金(批准号:10702010和10775018),中国工程物理研究院发展基金和实验室基金资助的课题.Project supported by the National Natural Science Foundation of China(Grant Nos. 10702010,10775018) and the Science Foundation of LCP and CAEP. （批准号:10702010和10775018）
