刀尖圆弧半径对单晶铜纳米切削过程影响的分子动力学分析

Molecular Dynamics Analysis for the Influence of Corner Radius on Single Crystal Copper Nano-cutting Process

采用分子动力学方法对不同刀尖圆弧半径时在纳米级尺度下切削加工单晶铜表面的过程进行分子动力学建模、计算与分析,研究不同刀尖圆弧半径对单晶铜纳米切削过程中微观接触区域原子状态和作用力变化的影响规律。研究结果发现:在单晶铜纳米切削过程中,切削作用力、位错及位错发射等缺陷随着切削厚度或刀尖圆弧半径的增大而增加;在相同切削厚度,相同切削距离下,刀尖圆弧半径越大,在刀具前方堆积的切屑体积越小。此外,在切削距离为1nm时,切削作用力发生突变;在切削距离1nm到2nm时,可以明显看到随切削距离的增加,刀尖圆弧半径越小,切削作用力上升幅度越大。在切削距离为3.5nm时,切削作用力基本保持稳定波动,其主要原因是位错等缺陷的产生引发作用力的波动。

Using molecular dynamics simulations to establish molecular dynamics modeling,calculation and analysis for different corner radius in nanometer-scale machining process of single crystal copper surface,the micro-contact area atomic states and forces change with different corner radius in cutting process of single crystal copper were studied.The results show that,in cutting process of single crystal copper,cutting forces,dislocations and defects such as dislocation emission increase with increasing cutting thickness or corner radius.In the same cutting thickness,cutting distance,the greater the corner radius,the smaller the accumulation at the front of a cutting tool chip.In addition,when cutting distance is 1nm,the cutting force mutates.When cutting distance is 1nm to 2nm,with the increase of cutting distance and the smaller corner radius is,the greater the cutting forces rise.When cutting distance is3.5nm,the cutting force remains stable fluctuations,mainly due to the force fluctuations caused by generation of dislocations and other defects.