(中国科学院 金属研究所， 沈阳 110016)
摘 要: 研究一种热处理制度对细化铸造Ti46Al8Nb合金晶粒所起的作用。 结果表明， 加热至1 360 ℃于900 ℃熔融盐淬火—退火—正火处理能够有效地破坏合金稳定、 粗大的铸态组织， 铸态晶粒尺寸由800 μm可细化至200 μm。 同时该热处理还可显著降低合金的淬火裂纹倾向性， 得到细小均匀的γ +α2全片层组织(FL)， 提高铸造合金的室温力学性能。
关键字: Ti46Al8Nb合金； 热处理； 晶粒细化
（ Institute of Metal Research, Chinese Academy of Sciences,
Shenyang 110016, China）
Abstract: A new heat treatment was developed to investigate the grain refinement of as-cast Ti46Al8Nb alloy. The results indicate that the original coarse grain of 800 μm and stable as-cast grains can be effectively refined to 200 μm by heating to 1 360 ℃ and then quenching into 900 ℃ molten salt, followed by the annealing and normalizing treatment. Such heat-treatment leads to the formation of a fully lamellar microstructure with refined grain size consisted of the γ and α2 phases. Besides, quenching into 900 ℃ salt bath reduces the tendency of cracking and mechanical properties at room temperature can be improved.
Key words: Ti46Al8Nb alloy; heat treatment; grain refinement
