分子动力学模拟纳米铜晶体中晶界对空穴扩展的影响

Molecular Dynamics Simulation of the Effect of Grain Boundary upon Vacancy Growth in Copper Nano-crystal

用分子动力学方法模拟了Σ9对称倾侧晶界铜双晶在拉伸变形过程中晶界对空穴扩展的影响。模拟结果表明:晶界对空穴沿界面的扩展起促进作用,但同时又阻碍空穴越过晶界向另一晶粒扩展;空穴离晶界较远时,晶体在变形过程中表现出比较明显的塑性;空穴的存在会降低晶体的强度,并且空穴离晶界越近晶体强度越低。

Molecular dynamics simulation is used to study the tension process of copper nano-bicrystal containing a E9 symmetric tilt grain boundary. What in discussion is the effect of grain boundary （GB） on the growth of vacancy in crystal. The results reveal that GB can promote the growth of vacancy along the interface, while obstruct it from growing into another grain through the interface. In addition, more plastic deformation is found when the initial vacancy runs away from the GB. The simulation also shows that the crystal is weakened by the vacancy in it in the way that the nearer the vacancy to the GB,the lower the strength.