Ta对新β型γ-TiAl基合金板材组织与性能的影响  

Effect of Ta on Microstructure and Property of β Titanium Aluminide Sheet

作　　者：罗媛媛[1] 赵彬[1] 郭荻子[1] 张菁丽 杨帆[1] 吴金平[1] 毛小南[1] Luo Yuanyuan;Zhao Bin;Guo Dizi;Zhang Jingli;Yang Fan;Wu Jinping;Mao Xiaonan(Northwest Institute for Nonferrous Metal Research, Xi'an 710016,China)

机构地区：[1]西北有色金属研究院

出　　处：《稀有金属材料与工程》2019年第8期2677-2682,共6页Rare Metal Materials and Engineering

基　　金：陕西省科技统筹创新工程计划（2016KTCQ01-103)

摘　　要：以Ti-42.5Al-2Cr-0.2W与Ti-42.5Al-2Cr-0.2W-3Ta合金板材为研究对象,系统分析了Ta对合金不同状态下的显微组织及硬度的影响规律与内在的机制变化。结果表明:加工状态下,未含Ta的组织片层粗大且原始α晶粒较多;含Ta的组织片层细小均匀,再结晶晶粒数量多,原始α晶粒少。热处理状态下,含Ta的组织中片层球化趋势增加,B2相易分解为α2+γ。热处理时间延长,未含Ta的合金组织内的晶团长大速度更快。TEM组织中含Ta的合金板材组织中存在更多的β相以及少量的ω相,不含Ta的组织中β相少且无ω相。此外,硬度分析发现含有Ta的γ-TiAl合金板材硬度值低于不含Ta的合金板材,这与片层细小及β、ω相的数量有关。The effects of Ta on the microstructure and hardness of two kinds of β TiAl alloys, whose nominal composition is Ti-42.5 Al-2 Cr-0.2 W-3 Ta and Ti-42.5 Al-2 Cr-0.2 W(at%) were investigated. Both as-rolled and heat-treated alloys were examined by OM, SEM and TEM. The results show that the lamella is coarse and the α grains are enriched in Ti-42.5 Al-2 Cr-0.2 W alloy. Tantalum additions are effective in refining grains, enriching recrystallized grains and depleting the α grain. When the heat-treatment temperature increases, the globularization of the lamellar colonies tends to be more, and the metastable β phases decompose into α2+γ. As the time prolongs, the lamella grain and the γ grain grow rapidly in Ti-42.5 Al-2 Cr-0.2 W alloy. The microstructure of the sheet with Ta contains more β phases than the sheet without Ta. Meanwhile, the ω phase precipitates in the alloy with Ta. Besides, the hardness of the alloy with Ta is lower than that without Ta, which is relative to the refined lamella and the amount of β phases and ω phases.

关 键 词：TIAL基合金 微观组织 热处理 显微硬度 

分 类 号：TG146.23[一般工业技术—材料科学与工程]