纳米铜单晶及双晶静拉伸二维力学行为的原子模拟

Atomic Simulation of Two-dimentional Mechanical Behavior for Nano-single Crystal and Nano-bicrystal Copper under Static Tensile Loading

用分子动力学方法模拟了纳尺度铜单晶与铜双晶的 (111)面原子的静拉伸力学行为。模拟结果表明纳米铜晶体的静拉伸变形过程中 ,原子系统的排列结构在弹性阶段没有变化 ;在塑性阶段铜单晶出现两个方向的交错滑移 ,铜双晶的塑性变形机制远比铜单晶复杂从而导致两者应力应变曲线的差异。模拟还发现纳米铜晶体具有良好的塑性变形自组织能力。

The mechanical behavior of nano-single crystal and nano-bicrystal copper within (111) atomic layer under static tensile loading is studied with molecular dynamics. It can be found that the tension process of nano crystal copper consists of an elastic period and a plastic period. When deformation is elastic the structure of initial atomic system change little,while in plastic period change is obvious. For single crystal sliding occurs in two directions, and for bicrystal copper the mechanism of plastic deformation is far more sophisticated than single crystal from which the diffrence of their stress-strain curves results. Simulation also reveals that nano crystal copper has good ability of self-orgonization in plastic period.