镁单晶变形行为的原子模拟  

Atomistic simulation of deformation behavior in magnesium single crystals

作　　者：亓宏刚[1] 郭雅芳[1] 

机构地区：[1]北京交通大学工程力学研究所,北京100044

出　　处：《计算力学学报》2008年第S1期72-76,共5页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(10672016)资助项目

摘　　要：应用分子动力学方法模拟镁单晶在单向拉伸作用下的力学性能和微观结构演化过程。不同应变和不同温度下的模拟结果中都观测到{1011}、{1012}型孪晶,表明这两种孪晶是镁单晶拉伸变形的主要机制。其中{1012}型孪晶的产生伴随新晶粒生成,并且随应变增加孪晶的数量增加。此外,随着温度的增加,原子热激活效应显著,镁单晶的最大弹性形变减小,最大应力值亦变小。The mechanical properties of Magnesium single crystals are sensitive to the twinning behavior.In this paper,molecular dynamics simulations are applied to investigate the deformation behavior in Magnesium single crystals.A tensile load is applied along the c-axis at different temperatures.We have found the formation of both the {1011} twin and the {1012}twin.It indicates that these two kinds of twin are the main deformation mechanism in Magnesium single crystals in tension.Moreover,new grain nucleation and growth are found accompanied with the {1012}twinning.The amount of twin increases with the load increasing.Furthermore,atoms movement is thermally activated with temperature increasing.Thus elastic strain energy and the stress decreases with the temperature increasing.

关 键 词：分子动力学 镁单晶 孪晶 应力-应变曲线 

分 类 号：TG146.22[一般工业技术—材料科学与工程]