锻造态纯钽压缩过程中的变形行为研究

Research on Deformation Behavior of Pure Tantalum in Forging State during Compression Process

使用Gleeble-3800热模拟试验机研究了锻造态纯钽在室温至350℃温度范围、0.1~10 s^(-1)应变速率范围、最大变形量为60%下的变形特性。根据实验所得的真应力-应变曲线,可观察到在达到峰值应力之前,变形抗力随着变形温度的降低和应变速率的增加而增加;在达到峰值应力之后,存在以动态回复为主导的变形机制。根据材料的流动应力应变曲线,进一步计算得到了材料的变形激活能Q和应力指数n,分别为36.52 kJ/mol和25.92,并以此构建了描述流变行为的本构方程。

The deformation characteristics of forged pure tantalum were studied using a Gleeble-3800 thermal simulation testing machine in the temperature range of room temperature to 350℃,strain rate range of 0.1~10 s^(-1),and maximum deformation of 60%.According to the true stress-strain curve obtained from the experiment,it can be observed that the deformation resistance increases with the decrease of deformation temperature and the increase of strain rate before reaching the peak stress.After reaching the peak stress,there exists a deformation mechanism dominated by dynamic recovery.Based on the flow stress-strain curve of the material,the deformation activation energy Q and stress index n of the material were further calculated to be 36.52 kJ/mol and 25.92,respectively,and a constitutive equation was constructed to describe the rheological behavior.