应变速率循环法构建TC21钛合金超塑性本构方程  

Study on superplastic constitutive relationship of TC21 titanium alloy based on strain rate circulation method

作　　者：甘雯晴 王高潮[1] 谭丽琴[1] 熊城 

机构地区：[1]南昌航空大学航空制造工程学院,南昌330063

出　　处：《塑性工程学报》2015年第2期56-61,共6页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51075196);江西省科技计划重点项目(20141BBE50011)

摘　　要：采用应变速率循环法在超塑拉伸机上对 T C21钛合金进行5组高温超塑性拉伸实验，变形温度范围860℃～940℃，应变速率循环范围10－5 s－1～10－3 s－1。通过对拉伸实验数据分析，计算出T C21钛合金动态再结晶激活能 Q ，利用Arrhenius模型构建TC21钛合金高温条件下的超塑性本构方程，并通过1stOpt软件进行非线性回归拟合进行修正，得到了更为精准的超塑性本构方程。实验结果表明，当变形温度不变时，流动应力随着应变速率的增大而增大，且高应变速率时，流动应力对应变速率的敏感性要大于低应变速率时，可判定 T C21钛合金属于正应变速率敏感材料。T C21钛合金在860℃附近时的超塑性较好，综合延伸率可达366.6％。The superplastic deformation behaviors of TC21 titanium alloy were performed on superplastic tensile testing machine in temperature range of 860℃ ~940℃ ,and strain rates range of 10-5 s-1 ~10-3 s-1 based on the strain rate circulation method .This paper obtained the dynamic recrystallization activation energy through analysis of the tensile experimental data ,established the constitutive relationship of the TC21 titanium alloy based on the Arrhenius model ,and obtained more accurate superplastic de‐formation constitutive equation by correcting the equation with the software of 1stopt .The results show that ,when the deforma‐tion temperature is constant ,the flow stress increases with increasing strain rate .And the flow stress sensitivity to the higher strain rate is greater than that to the low strain rate .So the study confirms that the TC21 titanium alloy is positive strain rate sen‐sitive material .The alloy superplasticity under around 860 ℃ is better and the comprehensive elongation is 366.6% .

关 键 词：TC21钛合金 应变速率循环 本构方程 超塑性变形 

分 类 号：TG14[一般工业技术—材料科学与工程]