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采用Gleeble-1500热模拟实验机及光学显微镜和透射电子显微镜研究了Ti-47Al-2Cr-0.2Mo(原子分数,%)合金在2.5 s-1,1050～1150℃,道次保温时间分别为1 min、5 min、10 min条件下的多道次热压缩变形行为及其组织演化规律。结果表明,增大道次变形量,合金软化率增大;随着道次间保温时间的延长,合金软化率逐渐增大;变形及保温温度升高,合金软化率提高。动态和亚动态再结晶是合金发生软化的主要原因。再结晶优先发生于层片晶团边界处。随着变形温度升高,γ晶粒内的孪生增多。经过热压缩变形后,组织被细化和均匀化。位错和孪生是主要的变形机制。
The heat preservation time of Ti-47Al-2Cr-0.2Mo (atomic fraction,%) alloy at 2.5 s-1 and 1050-1150 ℃ was studied by using Gleeble-1500 thermal simulator, optical microscope and transmission electron microscope. min, 5 min, 10 min, the multi-pass hot compression deformation behavior and its microstructure evolution. The results show that increasing the amount of deformation of the pass increases the softening ratio of the alloy; the softening ratio of the alloy gradually increases with the increase of the holding time between passes; the deformation and holding temperature increase and the softening ratio of the alloy increases. Dynamic and sub-dynamic recrystallization is the main reason for the softening of the alloy. Recrystallization preferentially occurs at the boundaries of the lamellae. As the deformation temperature increases, the twin in the γ grains increases. After hot compression deformation, the tissue is refined and homogenized. Dislocations and twins are the major deformation mechanisms.