钛合金切削中切屑形态与残余应力的仿真与实验研究

Simulation and Experimental Study on Chip Morphology and Residual Stress in Cutting of Titanium Alloy

钛合金作为航空工业的常用材料,其加工后的残余应力会严重影响到零件的使用寿命。本文针对钛合金加工建立了基于CEL方法的仿真模型,并搭建正交实验平台测量切屑形态和残余应力来验证模型的有效性。将所提模型与传统的拉格朗日方法和ALE方法进行比较,结果表明CEL方法虽然耗时较长但是预测结果更加准确并且不产生网格畸变,综合性能最优。最后基于所提方法探究不同进给量和刃口半径影响下的切屑形态和加工表面残余应力。结果表明,随着进给量和刃口半径的增大,切屑锯齿化程度和等效切屑厚度增大,表面残余应力随着进给量和刃口半径的增大变得更压。

As a common material in the aviation industry,the residual stresses of titanium alloy after machining can seriously affect the service life of the components.In this study,a finite element model based on the Coupled Eulerian-Lagrangian(CEL)method in the machining of titanium alloy was established,and the orthogonal experimental platform was used to obtain the chip morphology and residual stresses to verify the validity of the model.The present model was compared with the traditional Lagrangian and Arbitrary Lagrange-Eulerian(ALE)methods,the results show that although the CEL method takes a long time,the prediction results are more accurate without mesh distortion and have the best comprehensive performance.Finally,the present method was used to investigate the chip morphology and residual stresses on the machined surface under the different feeds and edge radius.The results show that the degree of chip serration and equivalent chip thickness increase with the increasing of feed and edge radius,and the residual stresses of surface become more compressive.