工业纯钛TA2热变形过程的流变行为本构方程

利用Gleeble-3800热模拟实验机研究了工业纯钛TA2的热变形行为.变形温度为750～1000℃,步长50℃,应变速率分别为0.01、0.1、1和10 s-1.实验结果表明,TA2在热压缩变形过程中发生了加工硬化以及动态回复、动态再结晶.随着变形温度的降低和应变速率的增加,流变应力逐渐增加.为了准确预测TA2的高温流变行为,基于实验数据和双曲正弦Arrhe-nius模型构建了考虑应变影响的本构方程,本构方程中材料常数α、n、Q、lnA与应变之间存在6阶多项式关系.本文所提出考虑应变影响的本构方程可以用于研究工业纯钛TA2的高温流变行为.

Constitutive equation for flow behavior of commercially pure titanium TA2 during hot deformation

The hot deformation behavior of TA2, which is commercially pure titanium, was investigated using a Gleeble-3800 simulator over temperature and strain ranges of 750-1000℃ and 0. 01-10 s-1 , respectively. The results show that during hot compres-sive deformation, work hardening, dynamic recovery, and dynamic recrystallization occur. The flow stress increases as temperature de-creases and strain rate increases. To accurately predict the flow behavior for the alloy, constitutive equations considering the effect of strain were derived based on the obtained experimental data and a hyperbolic sine Arrhenius-type model. The material constantsα, n, Q, and lnA were found to be functions of strain and could be fitted by employing a sixth-order polynomial. Subsequently, the developed constitutive model can be employed to describe the deformation behavior of commercially pure titanium TA2.