硬铝合金超精密车削残余应力的仿真及试验

为满足超精密车削加工零件低表面应力的使用性能要求,采用有限元和试验相结合的方法,对硬铝合金进行微米级的超精密车削仿真和试验.分析切削过程的切削力和切削温度,研究已加工表面残余应力产生的原因及残余应力的性质,得到切削深度和切削速度对已加工表面残余应力的影响规律.仿真结果表明:金刚石刀具车削硬铝合金,切削温度低,切削力小,但是单位切削力大.切削力是已加工表面形成残余压应力的主导因素.表层残余应力随着切削深度的增加而变大,随着切削速度的增大反而有减小的趋势.在微米级硬铝合金的超精密切削过程中,切削深度对已加工表面残余应力的影响更为显著.进行微米级的超精密车削试验,采用XRD对表层残余应力进行测量,对有限元仿真结果进行了验证,为硬铝合金超精密车削表面残余应力的控制打下理论基础.

Simulation and experiments of residual stresses on ultra-precision turning of hard aluminum alloy

To meet the requirements of low surface residual stresses on the parts made by ultra-precision turning, by finite element analysis and tests, the micron level ultra-precision turning and simulation of aluminum alloy were done. The cutting force and temperature were analyzed, the cause and nature of machined surface residual stresses were studied, and the influence laws of the cutting depth and cutting speed on residual stresses were gotten. Simulation results show that in the cutting process the cutting force was small and the cutting temperature was low, but the unit cutting force was high. The cutting force was the leading factor in forming the compressive stress on the machined surface. The machined surface residual stresses increased with the increase of cutting depth and decreased with the increase of cutting speed. The cutting depth obviously influenced the residual stresses. The experiments of ultra-precision turning in micron level were done and the machined surface residual stresses were measured by XRD. The results of simulation were verified.