【摘要】 用风冷（ＧＦＣ）／回火再加在１０００～１２００℃之间的循环热处理的方法对Ｔｉ４６Ａｌ８．５Ｎｂ０．２Ｗ 合金的铸态合金的组织细化进行了研究。结果表明：风冷（ＧＦＣ）／回火处理能快速地破碎Ｔｉ４６Ａｌ８．５Ｎｂ０．２Ｗ 合金的铸态组织，得到双态组织（ＤＭ），并且组织比较均匀。循环热处理是在１０００～１２００℃之间进行，循环热处理能有效地阻止已经存在的γ晶粒的异常长大，并且能使空冷形成的亚稳层片迅速均匀地等轴化成ＮＧ组织。更多还原

【Abstract】 The gas fan cooling/tempering and subsequent(1000℃1200℃)×4 cycles heat treatment,instead of the conventional forging process,was investigated to refine the microstructure of cast Ti46Al 8.5 Nb0.2W alloy.By tempering the gas fan cooled metastable structure at temperature above α transus,the cast microstrucure can be destroyed rapidly and the fine and homogeneous duplex microstructure was developed in cast Ti46Al8.5Nb0.2W alloy.It has been found that the duplex microstructure can be transformed into the fine and homogeneous NG microstructure by the (1000℃1200℃)×4 cycles heat treatment.The mechanisms involve preventing the existent γ grains from growing anomalously and globularizing the metastable lamellar structure produced during air cooling from 1250℃ into NG microstructure.更多还原