(1.中南工业大学粉冶所，长沙410083；
2.中科院北京电镜室，北京100080)
摘 要: 研究了热加工和热处理对TiAl基合金显微组织的影响。试验发现，三向压应力能显著地提高合金的热变形塑性，实现无破损大应变速率热变形。分析表明，常规热变形工艺下试样中仍存在粗大层片状晶团，且不能由随后热处理消除，而复合热机械处理新工艺能在整个试样上得到细小、均匀的显微组织。
关键字: TiAl基合金 热变形 显微组织
（Powder Metallurgy Research Institute，Central South University of Technology，Changsha 410083）
Abstract:The effects of hot working and heat treatment on microstructure of TiAI-based alloys were investi-gated. The test results indicated that three-dimension stress state could promote hot deforming plasticity of TiAl based alloys efficiently, and large press ratio forging of samples without surface crack under a high strain rate could be obtained. The coarse lamellar grains were retained in samples which experienced normal hot deformation and could not be removed by following heat treatment，while homogeneous and refined microstructure could be ob-tamed throughout the whole samples under a new process of multi-thermal-mechanical treatment.
Key words: TiAl-based alloy hot deformation microstructure
