激光沉积Ti60A高温钛合金显微组织及固态相变  

Microstructure and phase transformations of laser deposited high temperature titanium alloy Ti60A

作　　者：马陶然[1] 方艳丽[1] 王华明[1] 

机构地区：[1]北京航空航天大学大型整体金属构件激光直接制造教育部工程研究中心,北京100191

出　　处：《材料热处理学报》2012年第10期101-106,共6页Transactions of Materials and Heat Treatment

基　　金：教育部长江学者和创新团队发展计划(IRT0805);国家重点基础研究发展计划(2011CB606305)

摘　　要：采用激光熔化逐层沉积隔行扫描方式成形了近α高温钛合金Ti60A厚壁板材,获得了具有定向生长特征的柱状晶组织,晶粒直径大小不均匀,晶内为细长α片层。在α+β两相区上部进行固溶时效及双重退火热处理,研究了激光沉积Ti60A合金的固态相变行为。结果表明,合金经固溶处理得到了规则的杆块状初生α相和针状六方马氏体α';经过时效处理后,α'分解成连续且极细小的α/β片层组织。合金经过双重退火热处理后,获得了具有"蟹爪"状初生α相和细长片层状β转变组织的"特殊双态组织"。Laser melting deposition with line interlaced scanning mode was utilized to shape the near-alpha high temperature titanium alloy Ti60A thick plate. Microstructure of the titanium alloy featured by slender a lamellae consists of columnar grains with orientated growth characteristics and the grain diameter is not uniform. Solid solution and aging treatments as well as double-annealing treatment were applied in upper α＋β phase field of the alloy to study its phase transformation behavior. The results show that regular rod-like α phase and needle-like hexagonal martensite α＇ could be produced after solution treatment, then α＇ is decomposed into continuous and ultra-fine α ＋ 13 lamellae after aging. Double annealing for the alloy would lead to a unique and stable bi-model microstructure consisting of crab- claw-like primary α phase and slight lamellar transformed β phase.

关 键 词：高温钛合金 激光熔化沉积 显微组织 固态相变 

分 类 号：TG132.3[一般工业技术—材料科学与工程]