连续加热时γ-TiAl激光快凝组织及其性能的变化  

Structure and Hardness Changes of Laser Melted TiAl AlloySurface During Continuous Heating

作　　者：吴国清[1] 黄正[1] 林建国[2] 杨金海[2] 

机构地区：[1]北京航空航天大学材料科学与工程系 [2]湘潭大学物理系

出　　处：《北京航空航天大学学报》2003年第3期241-243,共3页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金资助项目 (5 99710 0 4) ;航空基础科学基金资助项目 (0 1H5 10 0 4)

摘　　要：为认识超塑扩散连接机理 ,研究了γ TiAl基合金表层激光快速熔凝组织在连续加热过程中的相转变规律及硬度变化 .结果表明 ,在以 1 0℃ /min连续加热时 ,γ TiAl激光表面快速熔凝组织在 75 0℃左右发生α2 →γ相转变 ,在 860℃左右其组织由枝晶组织转变为细小的等轴晶组织 ,硬度值也出现了相应变化 .Structural transformation and hardness variation in the laser melted TiAl intermetallic alloy surface during continuous heating were studied. The results indicate that, during continuous heating from 50 to 1000°C with a heating rate of 10°C/min, α2&rarrγ phase transformation takes place at about 750°C, and the dendritic structure is transformed into fine-grained structure at about 860°C. Variations in the hardness of the laser melted TiAl intermetallic alloy surface were also measured. The fine grain structure is considered to be a good basis of superplastic/diffusion bonding.

关 键 词：显微组织 硬度 热处理 激光表面处理 TIAL基合金 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG457.19[金属学及工艺—金属材料]