刀具几何参数对金属钛纳米切削影响的分子动力学研究（英文）

Molecular dynamics study of the effects of tool geometric parameters on titanium nanometric cutting

基于分子动力学的基本原理,构建了钛的纳米切削分子动力学仿真模型。工件原子间采用嵌入原子势EAM(Embedded atom method),工件原子与刀具原子间采用Morse势函数,研究了在不同刃口半径和刀具前角条件下,钛纳米切削过程中工件形态、系统势能、切削力以及工件温度等的变化规律。结果表明:随着刀具刃口半径增大,加工表面粗糙度增加,切削力和工件温度降低,切屑变薄;当刀具前角由负值增加到正值,钛工件承受的压应力逐渐变为剪应力,正前角刀具更有利于切削,同时在不同的刀具前角下,切向力和法向力的大小也有显著变化。

A nanometric cutting model of titanium was built based on the basic principles of molecular dynamics( MD) method. EAM( embedded atom method) and Morse potential function were used,respectively,to compute the interactions between atoms. Effects and variations of different cutting edge radius and tool rake angle on surface morphology,system potential energy,cutting force and temperature of titanium workpiece in nanometric cutting process were analyzed. Results show that: When cutting with a bigger cutting edge radius,roughness of machined surface gets increased and the size of cutting force,temperature of workpiece and volume of chips will be decreased. Titanium atoms are suffered by compressive stress and shear stress when cutting with negative and positive rake angle,respectively. Positive rake angle is more conducive to cutting,and the sizes of tangential force and normal force also have significant changes under different tool rake angle.