关键词: 钛合金, 弯曲成形, 变弹性模量, 五点弯曲, 回弹预测

Abstract: Larger springback might be produced in the bending processes of the Ti-6Al-4V titanium alloys, and the elastic modulus has a greater impact on the springback, but previous studies did not considered the changes of elastic modulus during the plastic strain changes of the materials. The uniaxial tensile tests and cyclic loading-unloading tests of Ti-6Al-4V titanium alloys were carried out to determine the anisotropy parameters and the change rule of elastic modulus with plastic strains herein. Then, a mathematical model of variable elastic modulus of Ti-6Al-4V titanium alloys was established. Based on two different constitutive models of YLD2000-2D yield criterion with variable elastic modulus and Mises isotropy, the five-point bending processes of Ti-6Al-4V titanium alloy sheets were numerically simulated at room temperature. In order to verify the results of the numerical simulation,the five-point bending experiments of the Ti-6Al-4V sheets were carried out at room temperature. The results show that the former significantly improves the springback prediction accuracy of Ti-6Al-4V titanium alloys, which is an increase of 31.18% compared with the latter.

Key words: titanium alloy, bending forming, variable modulus of elasticity, five point bending, rebound prediction