激光深熔钎焊车用铝/钢异种金属试验研究

Experimental investigation of laser deep penetration welding-brazing of automotive aluminum /steel galvanized metal

为了实现车用铝/钢异种金属良好连接,采用光纤激光对车用铝合金与镀锌钢对接接头进行了激光深熔填丝钎焊工艺试验,并对焊缝接头的成形、界面金属间化合物层,以及力学性能进行了分析。结果表明,铝合金一侧是激光深熔焊接接头,而镀锌钢一侧是钎焊接头;在镀锌钢与钎焊缝中间界面存在金属间化合物层,厚度小于10μm;金属间化合物主要为Al7.2Fe2Si和(Al,Si)13Fe4;拉伸试样主要断裂于铝合金热影响区处,平均抗拉强度为145MPa;接头的断裂方式主要是韧窝断裂。

In order to achieve good automotive joining of aluminum /steel dissimilar metals , the experiments of butt joining aluminum alloy to galvanized steel were carried out by laser deep penetration welding -brazing with a fiber laser .The seam appearance , the intermetallic composition layer as well as the mechanical properties of the joints were analyzed .The results show that a typical deep penetration welding seam is formed on the aluminum alloy side , while a brazed seam is generated on the solid galvanized steel side .There is a thin layer of the intermetallic composition on the interface between the galvanized steel and the brazed seam , which is less than 10μm.The main intermetallic compositions were Al 7.2 Fe2 Si and （ Al,Si） 13 Fe4 .The tensile samples were fractured at the heat affected zone of the aluminum alloy .The average tensile strength of the joint is 145MPa.The fracture mode of the joint is ductile fracture .