TC17钛合金高温变形行为研究

High Temperature Deformation Behaviour of TC17 Titanium Alloy

采用Gleeble 3500D热模拟试验机对TC17钛合金进行了高温压缩试验。其变形温度为973～1223 K,应变速率为0.001～10 s^(-1),应变0.9。结果表明:TC17钛合金高温流变应力对应变速率和变形温度非常敏感。在温度为1123,1183和1223 K,应变速率为10 s^(-1)时,TC17钛合金的流动应力出现了明显的应力不连续屈服现象。利用Zener-Holloman参数建立了TC17钛合金的高温本构方程,与试验结果对比表明:该方程可以准确地描述TC17钛合金的的高温流动行为。基于动态模型,建立了TC17钛合金的热加工图,并结合微观组织分析验证了加工图的准确性。

In order to investigate the hot deformation behavior of TC17 titanium alloy,isothermal compression tests by a Gleeble 3500 D simulator were carried out with a temperature range of 973～1223 K,a strain rate range of 0.001～10 s^-1 and strain of 0.9.The results indicate that the flow stress of the TC17 alloy at high temperature is sensitive to deformation temperature and strain rate.Meanwhile,a discontinuous yielding phenomenon is found at the strain rate of 10 s^-1 with temperature of 1123,1183 and 1223 K.Based on multiple regression,a constitutive model was put forward to describe the role of the flow stress as the Zener-Holloman parameter.Thereafter,the processing map on the basis of dynamic materials model was established,and the validity of the developed processing map was verified by the microstructure analyses of compressed TC17 titanium alloy.