基于SPH法微切削单晶锗动态过程模拟研究

Simulation of Dynamic Process of Micro-Cutting Single Crystal Germanium Based on SPH Method

单晶锗飞切加工时,观察切屑形成较为困难。针对该问题,文中采用了一种无网格仿真方法(SPH法),通过建立单晶锗(111)晶面微切削仿真模型,研究塑性去除时,切削深度、切削速度对切削力及切屑形成的影响。结果表明,在切削速度为4μm·μs^(-1),切削深度分别为0.5μm、1μm、2μm、5μm时,切向力及法向力都出现逐渐增大然后减小至趋于平缓的波动的趋势。该结果表明切削深度越大,切削力稳定波动值越大,且在该切削条件下产生切屑的临界切削深度为0.5~1μm。在单晶锗切削深度为1μm,切削速度为2μm·μs^(-1)、4μm·μs^(-1)、6μm·μs^(-1)、8μm·μs^(-1)时,切向力及法向力值受切削速度的影响不大,且在该切削条件下产生切屑的临界切削速度为2~4μm·μs^(-1)。

In view of the difficulty of observing chip formation in flying cutting of single crystal germanium,a meshless simulation method(SPH method)is adopted in this study.The influence of cutting depth and cutting speed on cutting force and chip formation during plastic removal is studied by establishing a micro-cutting simulation model of single crystal germanium(111).The results show that when the cutting speed is 4μm·μs^(-1) and the cutting depth is 0.5μm,1μm,2μm and 5μm,the tangential force and normal force gradually increase and then decrease to a gentle fluctuation trend.It is concluded that the larger the cutting depth is,the greater the stable fluctuation value of cutting force is,and the critical cutting depth for chip generation is between 0.5μm and 1μm.When the cutting depth of single crystal germanium is 1μm and the cutting speed is 2μm·μs^(-1),4μm·μs^(-1),6μm·μs^(-1) and 8μm·μs^(-1),it is found that the tangential force and normal force are not affected by the cutting speed,and the critical cutting speed for chip formation is between 2μm·μs^(-1) and 4μm·μs^(-1).