基于摩擦修正的TC6钛合金低应变速率大变形本构模型建立

Low Strain Rate and Large Deformation Constitutive Model of TC6 Titanium Alloy Based on Friction Correction

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0.0001~0.1 s^(-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。

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 0.0001-0.1 s^(-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 correction has higher linear correlation,smaller mean absolute error and higher prediction accuracy.