【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800μm可细化至200μm。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。更多还原

【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.更多还原