单晶SiC微切削机理分子动力学建模与仿真研究

单晶SiC硬度高、脆性大，加工困难，在塑性域加工时处于纳米尺度才可明显改善表面质量、获得高的精度。而单晶SiC的切削机理研究使用有限元和实验方法，无法获得时间尺度在飞秒或皮秒下材料发生的变化。为此，采用分子动力学模拟方法，对单晶3C-SiC切削过程进行了建模和仿真，分析了在不同切削速度、切削深度下切削力的变化。研究结果表明：切削速度为50 m/s、100 m/s和200 m/s时对应的平均切向切削力为737.34 nN、635.29 nN和587.09 nN，单晶SiC表面采用合适的切削速度能减小切削过程的切削力。

Modeling and Simulation of Micro-cutting Mechanism of Single Crystal SiC by Molecular Dynamics

Single crystal SiC has high hardness and brittleness, resulting in its processing difficulties. The surface quality and processing precision of single crystal SiC can be significantly improved only when it is processed in the nano-scale plastic range. At the nanoscale, however, the change of material at femtosecond/picosecond cannot be obtained using finite element and experimental methods. The molecular dynamics（MD） is used to model the cutting process of single crystal 3C-SiC. The cutting force is changed at different cutting speeds and depths. The results show that the average tangential cutting forces are 737.34 nN, 635.29 nN and 587.09 nN at the cutting speeds of 50 m/s, 100 m/s and 200 m/s, respectively, and an appropriate cutting speed is helpful to reduce the cutting force for the single crystal SiC.