纯铝中间层厚度对铝/钢点焊接头性能的影响

Effect of pure aluminum insert thickness on the performance of resistance spot welded aluminum alloy/steel joints

采用纯铝作为中间层对铝合金与低碳钢进行了电阻点焊,分析中间夹层厚度对界面反应层厚度和接头抗拉强度的影响。在钢/中间夹层界面观察到有界面反应层生成,其主要由靠近钢侧的Fe2Al5和靠近中间夹层铝侧的FeAl3两种金属间化合物组成。与不加中间夹层相比,利用纯铝作为中间夹层点焊的铝合金与低碳钢的接头具有较薄的界面反应层和较高的接合强度。随着中间夹层厚度的增加,界面反应层厚度逐渐减小,而接头抗拉强度则呈增大趋势。结果表明,采用纯铝作为中间夹层点焊铝合金与钢具有一定的有效性。

Aluminum alloy and mild steel was welded using resistance spot welding with a pure aluminum insert.The effect of insert thickness on the strength and the interracial reaction layer thickness of the joint was investigated.A reaction layer consisting of Fe2AI5 adjacent to steel and FeAI3 adjacent to aluminum formed in the welding interface.The thinner reaction layer was observed and the cross tensile strength was obtained for the joint between aluminum alloy and mild steel welded by resistance spot welding with a pure aluminum insert,in comparison with that of the joint welded using conventional resistance spot welding method.With the increasing of insert thickness,the interfacial reaction layer thickness decreased,while the cross tensile strength of the joint showed a rising trend.The reushs reveal that it is feasible to weld aluminum alloy and mild steel sheets via a resistance spot welding method using a pure aluminum insert.