铝合金与不锈钢异种金属铝硅药芯焊丝TIG熔钎焊接头组织及性能  

Microstructure and properties of dissimilar metals TIG welding-brazing joint of aluminum alloy to stainless steel using Al-Si flux-cored wire

作　　者：林三宝[1] 宋建岭[1] 马广超[1] 杨春利[1] 

机构地区：[1]哈尔滨工业大学现代焊接生产技术国家重点实验室,哈尔滨150001

出　　处：《焊接学报》2009年第7期9-12,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(50874033)

摘　　要：采用铝硅药芯焊丝进行了铝合金与不锈钢异种金属无镀层TIG熔钎焊试验,运用OM,SEM,EDS及XRD分析了接头微观组织,研究了界面层及焊缝中金属间化合物种类,分析了药芯钎剂的作用,并测试了接头力学性能.结果表明,药芯钎剂能够促进铝硅钎料在不锈钢表面润湿铺展,获得的润湿角小于30°,钎剂挥发不完全,在接头中产生许多气孔;接头中钢侧界面层由[Al,Fe,Si]相和Fe4Al13构成,焊缝由α-Al基体、汉字状α铁相(Fe2SiAl8)以及细长板条状混合相(β铁相FeSiAl5及少量Al-Si共晶相)构成;剪切试验中接头均断裂在钢侧界面层,接头抗剪强度仅为55MPa,断裂面由[Al,Fe,Si]相、FeAl以及少量的FeSi,AlCr相构成.Dissimilar metals of aluminum alloy to stainless steel by non-coated TIG welding-brazing was investigated using Al-Si flux-cored wire. The joint was characterized in order to determine the phases and the brittle intermetallic compound (IMC) in the interfacial layer by OM,SEM,EDS and XRD,and the effect of the flux was analyzed during the process and the mechanical properties were also tested. The results show that the flux of the wire can improve the wettability and spreadability of Al-Si filler metal on the surface of the steel and the wetting angle is less than 30°. The non-complete volatilizing of the flux causes mass of voids in the welded beam. The interfacial layer in steel side comprises [Al,Fe,Si] phase and Fe4Al13,and the welded beam comprises α-Al matrix,'Chinese script' α-phase (Fe2SiAl8) and needle-plate mixed phase (β-phase FeSiAl5 and Al-Si eutectic phases). During the shearing test,the fracture occurs at the interfacial layer in steel side and the shear strength is only 55 MPa. The fracture surface comprises [Al,Fe,Si] phase,Fe4Al13 and little of Fe2Si and Al5Cr phases.

关 键 词：钨极氩弧熔钎焊 铝合金 不锈钢 铝硅药芯焊丝 金属间化合物 

分 类 号：TG457.1[金属学及工艺—焊接]