Cu对铝/钢CMT熔钎焊接头界面区组织的影响研究

Research on Effect of Cu on Microstructure of Interface Area of Aluminum/Steel CMT Welding-brazing Joint

采用冷金属过渡方法,以AlSi5焊丝为填充金属,在5052铝合金和镀锌钢板之间添加铜箔片进行搭接熔钎焊,使用扫描电子显微镜结合能谱分析和拉伸试验机对接头的界面区组织与性能进行研究。结果表明,未加入铜箔时,界面区组织主要由FeAl_(3)金属间化合物组成;铜箔的加入使得界面区组织中新生成了CuAl_(2)金属间化合物,同时改善了Zn在界面区的分布。Zn固溶于Al中,一定程度上抑制了Fe-Al金属间化合物产生。加入铜箔后的试样断裂位置发生改变,接头的承载能力与未加入铜箔的相近。

The cold metal transfer method was used for lap fusion welding with AlSi5 welding wire as the filler metal and Cu foil added between 5052 aluminum alloy and galvanized steel plate.The interfacial microstructure and properties of the joint were studied by scanning electron microscope combined with energy spectrum analysis and tensile test machine.The results show that without copper foil addition,the microstructure of the interfacial zone is mainly composed of FeAl_(3) intermetallic compounds.The addition of copper foil makes the interfacial area generate CuAl_(2)intermetallic compounds,and improves the distribution of Zn in the interface area.Zn solid dissolves into Al,which inhibits the formation of Fe-Al intermetallic compounds.The fracture position changes after adding Cu foil,and the strength is similar to that without Cu foil.