基于摩擦修正的TC6钛合金低应变速率变形本构模型建立

Low strain rate deformation constitutive model of TC6 titanium alloy based on friction correction

摘要:

采用Thermecmastor-Z100kn热模拟试验机对TC6钛合金进行了低应变速率大变形热压缩试验，获得了变形温度范围为900～945℃、应变速率范围为0.0001～0.1s-1、变形程度为70%时的真应力-真应变曲线。分别使用传统摩擦修正模型与改进摩擦修正模型对真应力-真应变曲线进行修正，并建立了基于摩擦修正的应变补偿型Arrhenius模型。结果表明：改进摩擦修正模型能更好地表征材料在大变形状态下的真应力-真应变动态响应。经摩擦模型修正的应变补偿型Arrhenius模型相线性相关度较高，平均绝对误差较小，预测值精度较高。

Abstract:

The thermal compression test of TC6 titanium alloy under low strain rate and large deformation was carried out by Thermecmastor Z100kn thermal simulation machine. The true stress-strain curves were obtained when the deformation temperature was 900 ~ 945℃, the strain rate was 0.0001 ~ 0.1s-1 and the deformation degree was 70%.The traditional friction correction model and the improved friction correction model were used to correct the true stress-strain curve, and the strain-compensated Arrhenius model based on the friction correction was established. The results show that the modified friction correction model can better characterize the true stress-strain dynamic response of materials under large deformation. The strain-compensated Arrhenius model modified by friction model has higher linear correlation, smaller mean absolute error and higher prediction accuracy.