纳米铜薄膜塑性变形中空位型缺陷形核与演化的分子动力学研究  

Generation and evolution of vacancy-type defects in nano-Cu films during plastic deformation by means molecular dynamics

作　　者：徐爽[1] 郭雅芳[1] 

机构地区：[1]北京交通大学土木建筑工程学院力学系,北京100044

出　　处：《物理学报》2013年第19期388-394,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11072026)资助的课题~~

摘　　要：本文采用分子动力学方法模拟了纳米单晶铜薄膜在单向拉伸载荷作用下的塑性变形过程,重点分析了空位型缺陷的形核过程和演化机理.在模拟过程中,采用镶嵌原子势描述原子间的相互作用.模拟结果表明纳米铜薄膜中塑性变形起源于位错的表面形核,而空位型缺陷的形核及演化都与晶体内部的位错运动密切相关.空位型缺陷通常从位错割阶及层错交截处开始形核,以单空位、层错四面体和不规则空位团等形式存在.Molecular dynamics simulations were performed to study the plastic deformation of Cu films under uniaxial tension. The genera-tion and evolution mechanisms of vacancy-type defects were carefully studied. In the simulations, embedded atom method （EAM） was selected as the interatomic potential function. Simulation results indicate that the plastic deformation is due to the dislocation nucle-ation near free surfaces. Both the generation and evolution of vacancy-type defects are related to dislocation activities. Vacancy-type defects prefer to nucleate at the position of dislocation jogs and the intersection of stacking faults initially, and finally exist in the form of single vacancy, vacancy clusters and stacking-fault tetrahedrons.

关 键 词：纳米薄膜 塑性变形 空位 层错四面体 

分 类 号：O484.1[理学—固体物理]