基于逐步回归法的TB6钛合金本构关系研究

Study on Constitutive Relationship of TB6 Alloy Based on Stepwise Regression Method

在变形温度为800～1150℃、应变速率为0.001～10s-1时,采用THERMECMASTER-Z型热模拟试验机对TB6钛合金进行热压缩试验。通过真应力-真应变曲线,分析了流动应力随变形热力参数的变化规律,运用逐步回归法合理选择了影响流动应力的"最优"自变量子集,构建出铸态TB6钛合金的本构关系。误差分析表明,该本构方程有较好的精度,可以为TB6热加工工艺设计提供理论指导,且所建立的模型形式简单。

High temperature compression tests of titanium alloy TB6 were carried out at 800～1150 ℃and strain rate range of 0.001 ～10 s^ -1 using THERMECMASTER-Z hot working simulator. The influences of deformation thermal parameters on flow stress were revealed from true stress-true strain curve, and using stepwise regression method to select reasonably the ＂optimal＂ subset of variables which impacted on the flow stress, and the constitutive model of the alloy was established. Error analysis shows that the constitutive relationship of TB6 titanium can be applied in guiding the hot working process for its desired precision, and the established model is simple.