Phase selection and solidification path transition of Ti-48Al-xNb alloys with different cooling rates  

作　　者：Tan He Rui Hu Jie-Ren Yang Heng-Zhi Fu 

机构地区：[1]The State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an,710072,China

出　　处：《Rare Metals》2023年第1期288-295,共8页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No.51401168);the 111 Project (the Discipline Innovative Engineering Plan) of Northwestern Polytechnical University (No.B08040)。

摘　　要：Ti-48Al-xNb alloys were solidified by containerless electromagnetic levitation with quenching system of the conical copper mold.The influence of cooling rates on phase selection of T1-48Al-xNb alloys was investigated.In near-equilibrium solidification condition,the dendrite βphase is observed as the leading phase.No other metastable phase(e.g.,α phase) is observed.In contrast,in rapid solidification condition,the metastable α phase is observed in as-quenched Ti-48Al-2Nb alloy.Furthermore,the metastable α phase is replaced by the primary β phase with Nb addition increasing.For Ti-48Al-(x=4,6,8)Nb alloys,increasing cooling rate results in a solidification path transition.The peritectic reaction(L+β→α) is therefore significantly suppressed.The relationships between primary dendrite arm spacing(λ_(1)) and cooling rate(τ) can be described.

关 键 词：TiAl alloy Cooling rate MICROSTRUCTURE Phase selection 

分 类 号：TG146[一般工业技术—材料科学与工程]