Abstract:

One methodology was proposed to indirectly compare molecular dynamics simulations of probe-based echanical nanomscratching on single crystalline copper with experiments. The quantitative comparison of elastic modulus of workpiece, the quantitative comparison of mechanical property of workpiece via nanoindentation, and the qualitative comparison of machined surface morphology were conducted sequentially. Molecular dynamics simulations of compression, shear, tension, and nanoindentation on single crystalline Cu show that the calculated elastic modulus of simulated workpiece are in good agreement with experimental data, and the symmetry of surface pile up after nanoindentation matches well with experimental observation. The comparison results demonstrate that the utilized potential of embedded-atom method accurately describes atomic interactions between copper atoms, which supplies high accuracy for consequent molecular dynamics simulations. It is shown that the experimental results of mechanical nanomachining can be well predicted by molecular dynamics simulations.

Key words: mechanical nanomachining, single crystalline copper, molecular dynamics, surface morphology

摘要：

以单晶铜微探针纳米刻划加工为例，提出了一种分子动力学模拟与实验的间接对比方法,依次开展了工件材料的弹性常量的定量对比、工件材料机械性能的纳米压痕测量的定量对比、已加工表面形貌的定性对比。单晶铜工件压缩、剪切、拉伸和纳米压痕的分子动力学模拟显示,分子动力学模拟体系的弹性模量与实验测得值相同，压痕后工件表面材料堆积的对称特性与实验结果相符。研究结果表明，所使用的嵌入原子势能函数可以精确地描述单晶铜工件中铜原子之间的相互作用，纳米机械加工的分子动力学模拟具有较高的精度，并且可以很好地预测纳米机械加工的实验结果。

关键词: 纳米机械加工, 单晶铜, 分子动力学, 表面形貌