(哈尔滨工业大学 材料科学与工程学院，哈尔滨 150001)
摘 要: 采用Gleeble−1500 热压缩模拟试验机进行压缩实验，在变形温度为1 100~1 250 ℃、应变速率为10−2~ 1 s−1的范围内，研究Ti-46Al-2Cr-4Nb-Y合金的高温变形行为，并基于动态材料模型，建立Ti-46Al-2Cr-4Nb-Y合金的加工图。结果表明：Ti-46Al-2Cr-4Nb-Y合金的高温变形流变应力对温度及应变速率敏感；流变应力随应变速率的增大而增大，随温度的升高而减小；动态再结晶是导致流变软化及稳态流变的主要原因；Ti-46Al-2Cr-4Nb-Y合金的安全热加工区域为温度1 200~1 230 ℃，应变速率10−2~10−1 s−1。
关键字: TiAl合金；高温变形；动态再结晶；加工图
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:The hot deformation behavior of Ti-46Al-2Cr-4Nb-Y alloy was investigated by hot compressive tests on Gleeble−1500 thermal simulation test machine in the temperatures range of 1 100~1 250 ℃ and strain rate range of 0.01~1 s−1. Based on dynamic materials model, the processing map for the Ti-46Al-2Cr-4Nb-Y alloy was obtained. The results show that the flow stress is sensitive to temperature and strain rate. And the flow stress increases with increasing the strain rate and decreases with increasing the deformation, the smaller the flow stress. Dynamic recrystallization is the main reason for flow softening and stable flow. The hot deformation of Ti-46Al-2Cr-4Nb-0.2Y alloy can be carried out safely in the region with a strain rate range of around 10−2−10−1 s−1 and temperature range of around 1 200−1 230 ℃.
Key words: TiAl alloy; hot deformation; dynamic recrystallization; processing map
