采用Nd：YAG激光器对5052铝合金和镀层处理的ST07Z镀铜钢进行激光填缝焊接实验研究。研究了镀层对铝/钢搭接接头界面金属间化合物和强度的影响。采用光学显微镜、扫描电镜和拉伸试验机对熔-钎焊接头的显微结构、金属间化合物成分和断口进行了观察测试。结果表明, 对ST07Z钢做镀层处理, 显著提高焊接过程中铝液在钢表面的润湿铺展, 抑制铝铁原子的相互扩散, 减少Al-Fe金属间化合物的形成。接头界面处生成的金属间化合物主要有Fe2Al5、FeAl2和FeAl三种。采用镀层处理可有效提高焊接接头强度, 接头最大抗拉剪强度可达163 N/mm。

Melt-brazing experiments of 5052 aluminum alloy and copper plated steel by using the Nd：YAG laser with filler powder was investigated and the effect of coating on the interfacial intermetallic compounds and strength of aluminum/steel lap joints was analyzed respectively. Optical microscope, scanning electron microscope and tensile testing machine was used to observe the microstructure, composition and fracture surface of the fusion brazing joint. The results show that coating of ST07Z steel significantly improves molten aluminum wetting and spreading on steel surface of the welding process, inhibits the diffusion of aluminum and iron atoms and reduces the formation of Al-Fe intermetallic compounds. The intermetallic compounds formed at the interface of the joint mainly include Fe2Al5, FeAl2 and FeAl. Coating treatment can effectively improve the strength of welded joint, the maximum tensile shear strength of the joint can reaches 163 N/mm.