5A90铝锂合金激光填丝焊焊缝金属组织特征分析  

Analyses on microstructure of fusion zone in 5A90 aluminum-lithium alloy joint welded by laser welding with filler wire

作　　者：崔丽[1] 李晓延[1] 贺定勇[1] 陈俐[2] 

机构地区：[1]北京工业大学材料科学与工程学院,100124 [2]北京航空制造工程研究所,100024

出　　处：《焊接》2009年第11期24-27,共4页Welding & Joining

基　　金：航空科学基金项目(20085475003);重点实验室基金资助项目(9140C4051030802)

摘　　要：采用激光填丝焊进行了5A90铝锂合金薄板的焊接试验,对填丝焊及激光焊接头的表面形貌、横断面、显微组织和硬度进行了研究,并通过透射电镜(TEM)分析了焊缝的析出相。结果表明,激光填丝焊可以改善激光焊焊缝表面的凹陷,有效改善焊缝成形;填丝焊与激光焊焊缝的显微组织差别不大,主要的析出相为δ′相(Li_3Al),析出相种类一致,仅尺寸和数量不同;填丝焊与激光焊的接头硬度低于母材,但填丝焊的平均硬度值高于激光焊。5A90 Aluminum-Lithium alloy thin sheets were welded by laser welding with filler wire.The weld appearance,microstructure and microhardness of the welded joints were studied.The structure and phase composition of 5A90 Aluminum-Lithium alloy obtained by laser welding with filler wire technique were studied by means of transmission electron microscope(TEM) and microhardness measurement was conducted across the base metal,heat affect zone and welded joints.It was revealed that the weld appearance and cross section of the welds were improved by laser welding with filler wire.The solidification structure was not changed by laser welding with filler wire.The presence ofδ' precipitates occurred in both the welds and the differences in precipitates are the size and quantity of theδ' precipitates.Compared with joints welded by laser welding,the microhardness of the welded joint with filler wire is enhanced.

关 键 词：铝锂合金 激光焊 填丝焊 显微组织 

分 类 号：TG456.7[金属学及工艺—焊接]