【摘要】 研究了淬火/回火热处理中淬火温度和回火时间对Ti-48Al-2Cr-0.5Mo合金晶粒细化的影响。研究表明:一定的淬火/回火热处理能将大小约为1000μm的铸态组织细化成为18～30μm的均匀双态组织;TiAl基合金的细化效果严重依赖淬火阶段的加热温度,温度升高,得到的块状组织较细,羽毛状组织体积分数减少,在两相区回火时,高温淬火组织的回火组织较细,而时间的延长,晶粒长大,但不明显。更多还原

【Abstract】 By tempering the quenching samples in the α+γ phase region, a very fine duplex microstructure(18-30μm) was obtained in the as cast Ti-48Al-2Cr-0. 5Mo (at %) alloys with an initial grain size of about 1000μm . The refining effect was found to be greatly dependent on the quenched microstructure which is controlled by prior heating temperature. With increasing the quenched temperature, the quenched microstructures become fine and the volume fraction of feather microstructure decreases. During tempering, larger grain was produced with time increasing. The 18μm microstructure in tempering for 3h was obtained in the sample quenched at 1400℃. The mechanism of grain refinement in TiAl base alloy was also discussed theoretically in present work.更多还原