送丝位置对铝/镀锌板CMT搭接接头组织与性能的影响

采用CMT搭接方法研究不同送丝位置对6082铝合金/镀锌板搭接接头质量的影响. 使用金相显微镜、扫描电镜(SEM)、能谱仪(EDS)分析焊接接头的形貌，微观组织及元素分布；通过拉伸试验检测接头的力学性能. 结果表明，1和2位置时，焊缝成形不饱满，锌层蒸发严重，界面处形成FeAl₂，FeAl及FeAl₃的金属间化合物，承载力达到6 kN；当3，4和5位置时送丝位置指向铝板，焊缝成形饱满，界面处形成Fe_6.6Al₃Zn_0.2和Fe₂Al₃Si_0.3，厚度约为2 μm，承载力达到7.5 kN，综上所述，CMT焊接铝合金/镀锌板时送丝位置应偏向铝板，可得到综合性能更好的焊接接头.

Effect of wire feeding positions on microstructure and properties of CMT lap welding joint between aluminum and galvanized steel

Effect of wire feeding positions on the weld joint quality of 6082 aluminum/ galvanized steel was studied by CMT lap welding method. The surface morphology and microstructure were observed by metallographic microscope and SEM, respectively, and element distribution was measured by EDS. The mechanical properties of the weld joint were measured by tensile test. The results show that the shape of weld joints was not plump, when the wire feeding was at 1 and 2 position and the zinc layer of galvanized steel evaporated seriously. The intermetallic compounds of FeAl₂, FeAl and FeAl₃ formed at the interface. The tensile strength of weld joint was 6 kN. The better shape of weld joints was prepared when the wire feeding was pointed to the aluminum plate. Fe_6.6Al₃Zn_0.2 and Fe₂Al₃Si_0.3 were founded at the interface with about 2 μm in thickness. The tensile strength of weld joint was 7.5 kN. In summary, the wire feeding direction should be pointed to aluminum alloy during CMT lap welding for a good performance of weld joints.