(中國科學院 金屬研究所， 沈陽 110016)
摘 要: 研究一種熱處理制度對細化鑄造Ti46Al8Nb合金晶粒所起的作用。 結(jié)果表明， 加熱至1 360 ℃于900 ℃熔融鹽淬火—退火—正火處理能夠有效地破壞合金穩(wěn)定、 粗大的鑄態(tài)組織， 鑄態(tài)晶粒尺寸由800 μm可細化至200 μm。 同時該熱處理還可顯著降低合金的淬火裂紋傾向性， 得到細小均勻的γ +α2全片層組織(FL)， 提高鑄造合金的室溫力學性能。
關鍵字: Ti46Al8Nb合金； 熱處理； 晶粒細化
（ 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
