基于三维分子动力学的单晶硅斜向切削机理研究

摘要

在已有分子动力学仿真理论和对实际单点金刚石刀具刃口半径测量的基础上，建立了与刀具更相符的三维分子动力学仿真模型。对单晶硅进行了斜向切削的分子动力学仿真，得到脆性材料去除方式存在2个阶段，即弹性变形，塑性去除；并得到单晶硅脆塑转变的临界切深为0.314nm。进行实际的斜向切削实验，由白光干涉仪测量切削区域，得到与仿真结果一致的临界切削厚；通过 TEM 观察切削厚度为40nm 时切屑晶格状态为单晶与非晶态同时存在，得到非晶层变形厚度小于40nm。%　　Two occurred moments which are elastic deformation and both elastic deformation and plastic removing in the process of taper cutting were presented. The both status critical value is 0.314nm gained by the results of MD simulation. There are two modes of elastic deformation and plastic removing at the same time. The 3D model is verified by comparing with results obtained by other studies. When the undeformed chip thickness is 40nm, the chip is amorphous and monocrystalline by the TEM observation. It can be gained that the lattice deformation is less than 40nm in the nanocutting process.