TC21钛合金超塑性拉伸变形流变行为  

Superplastic Tensile Deformation Behavior of TC21Titanium Alloy

作　　者：朱深亮 董洪波[1] 张贵华[1] 刘诚[1] 余新平[1] 

机构地区：[1]南昌航空大学航空制造工程学院

出　　处：《特种铸造及有色合金》2014年第11期1217-1221,共5页Special Casting & Nonferrous Alloys

基　　金：航空科学基金资助项目(2010ZE56016);国家自然科学基金资助项目(51164029)

摘　　要：通过恒应变速率超塑性拉伸试验,研究了TC21钛合金在变形温度为1 153~1 193K,应变速率为3.3×10-4~3.3×10-2 s-1条件下的拉伸流变应力行为。计算了TC21钛合金超塑性拉伸变形激活能和相应的应力指数,建立了TC21钛合金应力-应变本构模型,并通过1stopt软件对其进行修正。研究表明,在同一应变速率下,TC21钛合金流变应力随变形温度的升高而减小;在同一变形温度下,流变应力随着应变速率的增大而增大。当应变速率较高,变形温度较低时,动态再结晶为主要软化机制;当应变速率较低,变形温度较高时,加工硬化与软化达到动态平衡,软化机制以动态回复为主;当变形温度为1 153K,应变速率为3.3×10-4 s-1时,TC21钛合金具有较好的超塑性（408.60%）;超塑性拉伸变形激活能和应力指数分别为329.20kJ/mol、2.367 7。Superplastic tensile test was carried out to understand the deformation of TC21 titanium alloys at 1 153~1 193 K and strain rate of 0. 033~0. 000 33 s-1. The superplastic tensile deformation activation energy and corresponding stress exponent were calculated. Based on the calculation results, the consti- tutive equations of strain rate and flow stress was deduced, and it was modified by the software of lstopt. The results show that the flow stress is decreased with the increase of deformation temperature at a constant strain rate, and it is increased with the increase of strain rate at a constant temperature. With a higher strain rate and a lower deformation temperature, the main softening mechanism of TC21 titanium alloys is characterized by dynamic recrystallization, on the contrary, the main softening mecha- nism is characterized by dynamic （408.60%） at 1 153 K and 0. 000 33s.The superplastic deformation activation energy and the corre-sponding stress exponent are 329.20 kJ/mol and 2. 3677, respectively.

关 键 词：TC21合金 本构方程 超塑性变形 流变应力 

分 类 号：TG146.23[一般工业技术—材料科学与工程]