以铝硅合金为过渡材料的Be激光焊接接头显微结构及剪切断口分析  

Analysis of Microstructure and Shear Fracture of Be Laser Welding Joint Using AlSi Alloy as Transition Material

作　　者：李玉斌[1] 蒙大桥[1] 刘柯钊[1] 谢志强[1] 何建军[1] 

机构地区：[1]中国工程物理研究院,四川绵阳621907

出　　处：《稀有金属材料与工程》2010年第5期878-882,共5页Rare Metal Materials and Engineering

基　　金：中国工程物理研究院重大基金(2005Z0302)

摘　　要：以AlSi合金为过渡材料,运用激光焊接技术实现Be与Be的连接。采用扫描电镜(SEM)、微控电子万能试验机和纳米压痕仪对焊接接头的显微组织及性能进行研究。结果表明:熔合区和焊缝区组织由Be与AlSi合金形成的复合相构成,熔合区宽度约10μm左右。焊接接头剪切强度～283MPa,剪切断裂形式属于准解理断裂,断裂部位多在焊缝区,具有以准解理为主并伴有塑性的混合型断口特征,分析认为熔合区附近热应力诱发的微裂纹、焊缝中形成的金属间化合物以及气孔是导致焊接接头失效的裂纹源。With AlSi alloy as transition material,beryllium and beryllium was welded by laser.The microstructure and performance of the welding joint was researched by means of scanning electron microscope（SEM）,electron probe microanalysis（EPMA） and nano-indentation apparatus.The results indicate that the microstructure of the fusion zone and the weld zone for the Be laser welding joint was composed of compound phase of Be and AlSi alloy,and the width of fusion zone was about 10 μm.The shear strength of the welding joint was ～283 MPa and the shear fracture mechanism is quasi-cleavage feature.The welding joint was ruptured mostly in the weld zone.The characteristic of shear fracture was quasi-cleavage with local ductile dimples.Brittle rupture for Be laser welding joint was attributed to micro-crack induced by welding thermal stress in fusion zone,intermetallic compound and gas porosity formed in the weld zone.

关 键 词：铍 AlSi合金 激光焊接 显微组织 剪切断口形貌 

分 类 号：TG407[金属学及工艺—焊接]