物理学报Issue(21)：370-377,8.DOI:10.7498/aps.62.218101
不同对称性下晶界结构演化及微观机理的晶体相场法研究
Phase field crystal study on grain boundary evolution and its micro-mechanism under various symmetry
摘要
Abstract
Phase field crystal method is used to investigate the deformation process and mechanism of twined structure of a trigonal phase under uniaxial tensile deformation, and the evolution and corresponding micro-mechanism of low-angle symmetric and asymmetric grain boundaries (GB) as well as high-angle symmetric and asymmetric GB during deformation process are analyzed in detail. The deformation is performed under the condition that the direction of applied stress is parallel to that of initial GB. Results show that low-angle symmetric GB is composed of two kinds of edge dislocations with the angle made by Burgers vectors being around 60◦During deformation, two kinds of dislocations in low-angle symmetric GB move along two opposite directions, then meet with the same kind of dislocation emitted from another GB leading to the annihilation of partial dislocations. As to the low-angle asymmetric GB, its only one kind of dislocation first climbs and moves along the horizontal direction of the applied stress, then each dislocation will break down into two dislocations with their Burgers vectors making an angle about 120◦, finally a perfect single crystal is formed via the movement and annihilation of dislocations. High-angle GBs first keep horizontal shape under the applied stress, then become serrated, and the dislocations are emitted from the cusps in GBs. Finally, the high-angle asymmetric GB will decompose with the movement and annihilation of dislocation, while the shape of high-angle symmetric GB becomes horizontal again. It can be seen that the high-angle symmetric GB is more stable than the high-angle asymmetric GB;this is in agreement with the results of experiments and molecular dynamics.关键词
晶体相场/双晶/晶界/对称性Key words
phase field crystal/twin crystal/grain boundary/symmetry引用本文复制引用
龙建,王诏玉,赵宇龙,龙清华,杨涛,陈铮..不同对称性下晶界结构演化及微观机理的晶体相场法研究[J].物理学报,2013,(21):370-377,8.基金项目
国家自然科学基金(批准号:51274167,51174168)和西北工业大学基础研究基金(批准号:NPU-FFR-JC20120222)资助的课题.@@@@Project supported by the National Natural Science Foundation of China (Grant Nos.51274167,51174168), and the NPU Foundation for Fundamental Research (Grant No. NPU-FFR-JC20120222) （批准号:51274167,51174168）
