摘要
在Gleeble-1500D热模拟机上对等离子烧结态TC4钛合金开展单向热压缩实验,研究该合金在应变速率为10-3~5 s-1、变形温度为850~1050℃条件下的热变形行为。根据Arrheniu方程构建符合等离子烧结态TC4钛合金高温塑性变形的本构方程。结果表明:在初始变形阶段,由于加工硬化的作用,等离子烧结态TC4钛合金流变应力值随应变的增加迅速达到峰值应力,而后应力值开始减小并趋于稳定,表明该合金变形行为符合稳态流变特征;采用所建立的等离子烧结态TC4钛合金的Arrhenius双曲正弦本构方程能够较好地预测TC4钛合金的峰值应力,且预测值与实测值之间的平均相对误差为6.73%。在950℃和0.1 s-1以及1050℃和5 s-1条件下,模型平均相对误差绝对值分别为2.03%和4.67%。等离子烧结态TC4钛合金的平均变形激活能为411 k J·mol-1,平均应变速率敏感指数为0.21。
Uniaxial hot compression experiments of SPSed TC4 titanium alloy were carried out on Gleeble-1500D thermal simulator,the hot deformation behaviors of the alloy at strain rate of 10-3-5 s-1 and deformation temperature of 850-1050℃were studied.The constitutive equation of plastic deformation of SPSed TC4 titanium alloy at high temperature was established according to Arrhenius equation.The results show that in the initial deformation stage,the flow stress of SPSed TC4 titanium alloy rapidly reaches the peak stress with the increase of strain,and then starts to decrease and tends to be stable due to the effect of work hardening,which shows that the deformation behavior of the alloy conforms to the steady flow characteristics.The Arrhenius hyperbolic sine constitutive equation of SPSed TC4 titanium alloy can be used to mell predict the peak stress of TC4 titanium alloy,and the average relative error between the predicted value and the measured value is 6.73%.The absolute value of the average relative error of the model is 2.03%and 4.67%,respectively,under the conditions of 950℃and 0.1 s-1,1050℃and 5 s-1.The average deformation activation energy and the average strain rate sensitive index of TC4 titanium alloy are 411 kJ·mol-1 and 0.21,respectively.
作者
刘海军
张治民
徐健
吴耀金
李旭斌
薛勇
LIU Hai-jun;ZHANG Zhi-min;XU Jian;WU Yao-jin;LI Xu-bin;XUE Yong(College of Materials Science and Engineering,North University of China,Taiyuan 030051,China;College of Mechatronics Engineering,North University of China,Taiyuan 030051,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第6期263-270,共8页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51675492)
关键词
等离子烧结
TC4钛合金
热压缩
本构模型
spark plasma sintering(SPS)
TC4 titanium alloy
hot compression
constitutive model
