Ti-6Al-4V钛合金等通道转角挤压的有限元模拟

Finite Element Simulation of Equal Channel Angular Pressing of Ti-6Al-4V Alloy

运用有限元方法对Ti-6Al-4V钛合金等温等通道转角挤压过程进行了模拟,获得了摩擦因子、挤压角、过渡角等挤压参数对材料变形区的应变分布和挤压载荷的影响规律。结果表明:摩擦因子的增大引起局部应变集中,摩擦因子为0.5时,最大挤压载荷比零摩擦条件时提高了2.37倍;增大挤压角有利于获得均匀等效应变,减小挤压载荷,但同时减小了单次变形的应变量;减小过渡角可以扩大均匀应变区域,但过渡角过小会引起通道转角处的严重应变集中。

With the help of finite element method, the distribution of equivalent strain, extrusion load during the isothermal equal channel angular pressing（ECAP） of Ti-6Al-4V alloy under different shear factor of friction, channel and corner angle were studied. The results showed that the increasing factor of friction caused the strain concentration, since the maximum load was improved 2.37 times than that of no friction, when the shear factor of friction was 0.5. Increasing channel angle was beneficial for decreasing load and deformation homogeneousness, but reducing equivalent strain in each pass. In addition, decreasing corner angle was beneficial for increasing the extent of the homogeneous deformation, but exhibited severe strain concentration near the corner angle.