基于应变速率循环法的TA15钛合金超塑性本构方程  

Superplastic Constitutive Relationship of TA15 Titanium Alloy Based on Strain Rate Circulation Method

作　　者：谭丽琴[1] 王高潮[1] 甘雯晴 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：《航空材料学报》2014年第6期21-27,共7页Journal of Aeronautical Materials

基　　金：江西省科技计划重点项目(20141BBE50011)

摘　　要：采用应变速率循环法对TA15钛合金进行三组高温超塑性拉伸试验,变形温度区间为850 ～ 950℃,应变速率循环区间为5×10^-6～5×10^-4 s^-1.分析拉伸试验数据后,计算出TA15钛合金动态再结晶激活能Q,结合金相组织分析得出其热变形过程中发生了动态再结晶的结论;并利用Arrhenius模型构建超塑性本构方程,应用origin数据处理软件进行数据分析,求得TA15钛合金高温条件下的超塑性本构方程.运用1 stopt软件修正了该本构方程,使其精度达到99.3％.结果表明,TA15钛合金的流动应力对变形温度较为敏感,随着温度的升高,流变应力逐渐减小,软化机制愈发明显,且在900℃附近的超塑性较好,伸长率达到了846％.The superplastic deformation behavior of TA15 titanium alloy was performed based on the strain rate circulation using superplastic tensile testing machine in the temperature range 850-900℃,and the strain rates range 5 × 10^-6-5 × 10^-4 s^-1.The dynamic recrystallization activation energy was obtained through the analysis of the tensile experimental data,and the conclusion about dynamic recrystallization occuring during the thermal deformation was given by combining microstructure analysis.The constitutive relationship of the TA15 titanium alloy based on the Arrhenius model was established,the data was analysed using origin data processing software,then the constitutive equations about TA15 titanium alloy under high temperature conditions was obtained.1 stopt software was used to fix the constitutive equations,and an accuracy of 99.3% was obtained.The results show that the flow stress of TA15 titanium alloy is sensitive to the deformation temperature.With the increase of temperature,flow stress decreases and softening mechanism increases.The titanium alloy superplasticity is the best at around 900℃ with the elongation reaching 846%.

关 键 词：TA15钛合金 应变速率循环 本构方程 超塑性变形 

分 类 号：TG311[金属学及工艺—金属压力加工] V261.32[航空宇航科学与技术—航空宇航制造工程]