Ti_3Al激光焊接接头组织与织构的EBSD分析  

EBSD analysis of microstructure and texture of Ti_3Al alloy laser welded joints

作　　者：王国庆[1,2] 宋志华[1] 吴爱萍[1] 赵一夫[1] 

机构地区：[1]清华大学机械工程系,北京100084 [2]中国运载火箭技术研究院,北京100076

出　　处：《焊接学报》2011年第4期63-66,116,共4页Transactions of The China Welding Institution

摘　　要：采用电子背散射衍射(EBSD)技术对Ti-23Al-17Nb合金CO2激光焊接接头的焊缝、热影响区和母材的组织组成、晶粒大小及形态、晶粒取向和取向差分布进行了研究.结果表明,焊接接头中焊缝和热影响区的组织是B2相,母材由B2相和少量的α2相组成.从母材、热影响区到焊缝,晶粒尺寸依次增大,母材为细小等轴晶,母材内B2相尺寸大于α2相.焊缝B2相的(001)[5-7 0]织构的强度最强,热影响区B2相和母材B2相的主要织构均为(001)[0-1 0],母材α2相的主要织构为(1 0-1 0)[-1 2-1 10].热影响区的小角度晶界居多,焊缝晶粒的取向与母材和热影响区晶粒的取向具有一定的关联性.The technique of electron backscatter diffraction(EBSD) was used to investigate the microstructure,grain size,grain shape,and texture of Ti-23Al-17Nb(at.%) alloy laser welded joints,which include weld,heat-affected zone(HAZ) and base material.The results indicated that the microstructure of the weld and HAZ consisted of B2 phase.The base material consisted primarily of B2 and a small quantity of α2 phase.The grain size became gradually larger from the base material to HAZ and weld.The base material was composed of fine equiaxial grains,and the grain size of B2 phase was larger than that of α2 phase.The B2 phase in the weld had the highest density of(001) texture component while it in base material and HAZ was dominated by(001) texture component.The α2 phase in the base material was dominated by(1 0-1 0) [-1 2-1 10] texture component.The HAZ had a high density of low angle boundaries.There were certain relations between the texture of weld and the texture of HAZ and base material.

关 键 词：Ti-23Al-17Nb 激光焊接 电子背散射衍射 微观组织 织构 

分 类 号：TG456.7[金属学及工艺—焊接]