KDP晶体塑性域超精密切削加工过程仿真

Simulation of ultra-precision cutting process of KDP crystal in ductile mode

提出了压痕实验与有限元仿真结合的方法。它采用压痕深度与有限元仿真深度进行对比,可求解出KDP晶体的塑性特性参数。建立了KDP晶体塑性域切削的有限元模型,并用该模型仿真研究了切削参数对KDP晶体表面形成过程的影响。结果表明,在刀具前角为-40°左右时,工件表面质量可达到最佳值。研究还发现,当刀具刃口半径为80nm时,其能够产生切屑的最小切削厚度在10nm-30nm之间,此时法向切削力与主切削力之比为0.96,该结论对KDP晶体超光滑表面的获取有着重要指导意义。

A method combining indentation test with finite element simulation is proposed to obtain the ductile parameters of KDP crystal by comparing indentation depth with finite element simulation depth. A finite element model for cutting KDP crystal in ductile mode is established. The effect of rake angle and cutting depth on cutting process of KDP crystal is simulated by the model. The simulation result shows that when the front rake of the tool is about -40° the surface quality of the workpiece will be optimum. The study also discovers that when the radius of tool edge is 80 nm the minimum thickness of cutting is within a range of 10 nm-30 nm with a ratio of 0.96. between normal cutting force and main cutting force. The conclusion is very important for keeping an ultra-smooth KDP crystal surface.