Abstract:
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 FeAl
2, FeAl and FeAl
3 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
6.6Al
3Zn
0.2 and Fe
2Al
3Si
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.