MD Simulation Of Ultra-precision Cutting Of Single Crystal Silicon By Diamond Tools

At present,the inconsistency of the surface quality of single crystal silicon components severely restricts the further improvement of its use performance.In order to deeply study the formation mechanism of surface quality anisotropy of single crystal silicon processing and reduce the anisotropy of surface quality,it has become a scientific problem to be solved.In addition,in the nano-cutting process of single crystal silicon,the diamond tool is prone to severe wear in a short period of time,resulting in rapid deterioration of the surface quality of the machined surface.Therefore,this paper focuses on the novel processing method of nano-cutting single crystal silicon with the dynamic adjustment of the angle of the diamond tool.The molecular dynamics method is used to carry out the following research work:Firstly,in order to simulate the nano-cutting process,a new improved single crystal silicon nano-cutting model for the dynamic adjustment of the angle of the diamond tool was established.And choose the appropriate potential function,integration method and ensemble and other parameters.Second,simulations under the same cutting conditions were carried out using a tool swinging to six different rake angles of 0°,-7°,-15°,-21°,-30°,and-45°.Further analysis of the influence of different adjustment angles on the wear behavior of the tool by cutting force,friction coefficient,temperature,radial distribution function and wear rate.Through the simulation results,the adjustment angle with the largest degree of wear is obtained,and the reason for this phenomenon is further explained,which proves the correctness of the phenomenon.Thirdly,based on the nano-cutting inversion model of large-scale single crystal silicon workpieces,the influence of dynamic adjustment of tool angle on the nano-Cutting behavior of single crystal silicon is analyzed.Simulations under the same cutting conditions were carried out using a tool swinging to six different rake angles of-10°,-15°,-20°,-25°,-30°,-35° and-45°.Finally,the most different adjustment angles in the process of increasing negative rake angle are analyzed by coordination number(CN),von Mises stress,hydrostatic stress,system temperature,potential energy and cutting force,and the reasons are explained.This provides theoretical support for the dynamic adjustment of the tool rake angle.