纳米切削工艺中刀具原子尺度磨损机理的分子动力学分析

INVESTIGATION ATOMIC LEVEL MICROMECHANISM ABOUT TOOL WEAR IN THE CASE OF NANOMETRIC CUTTING USING MOLECULAR DYNAMICS METHOD

为研究刀具磨损的微观机理,以单晶铝为例,采用分子动力学方法对纳米切削中刀具失效的原子级物理本质进行研究。模拟结果显示,随着切削深度的增加,能够形成化学键的配对原子数也急剧增加,导致刀具的扩散磨损加剧;晶体的各向异性对刀具扩散磨损影响很小,说明扩散磨损主要是一种化学过程;扩散磨损生成的积屑瘤代替刀具进行切削,使得超精密加工的表面质量恶化,切削区域温度上升,进一步加剧扩散磨损过程。

In order to investigate the micro-mechanism of tool wear, nanometric cutting single crystal aluminum with diamond tool is analized by using molecular dynamics simulation method. The simulation results show that the number of chemical bond increases with increasing of depth of cut and intensify tool diffusion wear, while crystal orientation has little effect upon tool wear, the build-up edge induced by diffusion wear acts as cutting tool, degrades the machined surface quality and raises temperature which intensify tool wear inversely.