单晶γ-TiAl合金纳米切削过程的分子动力学模拟

Molecular dynamics simulations of nanometric cutting process of single crystal γ - TiAl alloy

摘要:

本文采用分子动力学方法研究了单晶γ-TiAl合金纳米切削过程，通过对单晶γ-TiAl合金建模、计算和分析，分析了不同切削深度和速度对切削过程的影响，研究结果发现：在切削过程中，随着切削深度增大，切屑体积逐渐增大，切屑中原子排列越来越紧密，位错密度也会随之增大；随着切削速度增大，位错密度反而会随之降低。在一定的切削深度和速度范围内，切削过程中刀具前方都会产生“V”型位错环，工件温度和势能也都会相应增大。特别是，切削速度为400m/s时，刀具前方的切削表面上未出现原子错排。

Abstract:

In this study, molecular dynamics simulations are employed to study the nanometric machining process of single crystal γ - TiAl alloy. The influences of different cutting speeds and depths on nanometric cutting process of single crystal γ - TiAl alloy are?studied by?molecular dynamics modeling, calculation and analysis.?The results show that the accumulated volume of chips increases with the cutting depth increases in nano-cutting process, at the same time the atoms in the chip stack are tighter and the dislocation density is increased; however the dislocation density decreased with the cutting speeds increases. In a certain cutting depth and speeds range, in front of the tool will produce "V"-type dislocation ring of the cutting process, temperature and potential energy of the workpiece will increased correspondingly. In particular, when the cutting speed is 400m/s, there is no atomic misalignment on the cutting surface in front of the tool.