Influence of heat treatment on microstructure of a newβ-solidifyingγ-TiAl alloy  

作　　者：Li Quan Xiao-bing Li Peng Xue Jun-jie Hao Kun Qian Bo Chen Jian-zhong Li Kui Liu 

机构地区：[1]School of Metallurgy,Northeastern University,Shenyang,110819,Liaoning,China [2]Department of Materials Science and Technology,Ji Hua Laboratory,Foshan,528200,Guangdong,China

出　　处：《Journal of Iron and Steel Research International》2025年第1期239-248,共10页钢铁研究学报(英文版)

基　　金：the Jihua Laboratory Scientific Research Project(No.X210291TL210);the National Natural Science Foundation of China(No.51971215).

摘　　要：The high strength and stability of the full-lamellar structure guarantee the industrial application of theβ-solidifyingγ-TiAl alloys.However,it is a huge challenge to design an alloy with good hot-deformability as well as the full-lamellar structure.The low-cost Ti-42.5Al-2Mn-0.4Mo-0.1B-0.1C(at.%)alloy was designed,which undergoes bothβandαsingle-phase region during the solidification.It is found that the full-lamellar structure can be obtained by the solution heat treatment at 1230℃ for 20 min and then aging treatment at 800℃ for 3 h.Interestingly,a new microstructure,namely,the pearlitic-like microstructure(PM)induced by theα_(2)/γ→βo+γcellular reaction was observed when the aging temperature is increased to above 800℃.The volume fraction of the PM is gradually increased from 0%to 25.5%,65%,and 94%according to elevated aging temperature from 800 to 900,1000,and 1050℃,respectively.The mechanism of the reducedα_(2)/γlamellae and PM formation was discussed regarding the heterogeneous distribution ofβstabilizing elements and the interface energy stored inα_(2)/γlamellae.

关 键 词：β-γ-TiAl Alloy design Two-step heat treatment Full-lamellar structure Cellular reaction 

分 类 号：TG156[金属学及工艺—热处理] TG146.23[金属学及工艺—金属学]