固溶时效对激光熔化沉积TC17钛合金显微组织的影响  

Effect of Solution and Aging Heat Treatment on Microstructure of Laser Melting Deposited TC17 Alloy

作　　者：孙晓敏[1] 刘栋[1] 汤海波[1] 王华明[1] 

机构地区：[1]北京航空航天大学材料学院,北京100191

出　　处：《热加工工艺》2012年第14期226-229,共4页Hot Working Technology

基　　金：国家973计划资助项目(2011CB606305)

摘　　要：研究了激光熔化沉积TC17钛合金原态及固溶时效后的显微组织,分析了一重固溶+时效和两重固溶+时效热处理对初生α相含量、长宽比的影响。结果表明,激光熔化沉积态TC17钛合金凝固组织为粗大的柱状β晶,显微组织为细密的片层α+β两相网篮组织。当固溶温度从800℃升高到835℃时,初生α相体积分数由53%减少到34%,宽0.4～0.5μm,长宽比约从9∶1减小到5∶1;时效后初生α相片层显著粗化,宽0.7～0.8μm,次生α相极其细密,均匀分布于初生α片层之间,含量随固溶温度升高逐渐增多。当进行两重固溶处理时,第一步固溶温度决定初生α相含量,而对初生α相的宽度及长宽比几乎没有影响,第二步固溶时间主要影响初生α相的长宽比,而对初生α相的含量及宽度几乎没有影响。The microstructure of laser melting deposited TC 17 alloy was investigated, and the influences of solution and aging treatment on the volume fraction and aspect ratio of primary a were studied. The results show that the microstructure of as-deposited TC17 alloy consists of coarse columnar β grains in which is fine lamellar a and β. With solution temperature increasing from 800 ℃ to 835 ℃, the volume fraction of primary a phase decreases obviously from 53% to 34%, the width maintains 0.4-0.5μm and the aspect ratio decreases from 9：1 to 5 ： 1. After aging treatment, the width of primary laths is much coarser, 0.7-0.8μm. The fine secondary a laths is homogeneous distribution, and the volume fraction increases with solution temperature increasing. After two multi solution and aging heat treatment, the volume fraction of primary a phase is decided by the first step solution temperature which hardly influences on the width and the aspect ratio. The second step solution time can greatly influence on the aspect ratio of primary a laths, but doesn＇t influence on the volume fraction and the width.

关 键 词：TC17钛合金 激光熔化沉积 热处理 显微组织 

分 类 号：TG156.92[金属学及工艺—热处理]