奥氏体不锈钢小孔钻削仿真及试验研究

Simulation and Experimental Investigation of Minipore Drilling of Austenitic Stainless Steel

基于有限变形理论、虚功原理、更新的拉格朗日公式及热弹塑性本构方程,建立了金属小孔钻削加工的热力耦合有限元模型;针对难加工材料1Cr18N i9Ti进行了小孔钻削加工过程的模拟与试验研究;对切削加工有限元模拟中的关键技术,如材料模型、工件与切屑的分离、断裂准则以及动态网格自适应技术等进行了探讨,动态模拟了麻花钻钻孔中切屑的成形过程,其中工件采用刚塑性材料模型,刀具采用考虑了温度变化的刚性材料模型.仿真结果与试验数据吻合,表明所建立的有限元模型是正确的,可用来对钻削力、扭矩及钻削温度随进给量的变化进行有效的预测.

Based on the finite deformation theory, the virtual work theory, the updated Lagrange formula and the thermo-elastic-plastic constitutive equation, a coupled thermo-mechanical finite element model of metal minipore drilling process was established. Then, the minipore drilling process of a hard-to-cut material 1Cr18NigTi was simulated and experimentally studied. Some key techniques in the finite element simulation of metal cutting process, such as the material model, the chip separation, the damage criterion, and the dynamic mesh self-adaptive technology, were also discussed. Moreover, the chip formation in the twist drilling process was simulated by using the rigid plastic material model for workpieces and the thermal rigid model for tools. It is found that the simulated results accord well with the experimental ones, thus showing that the proposed finite element model is not only correct but also feasible in the prediction of the variations of drilling force, torque, and temperature with the feed.