Influence of process parameters in blue laser welding of copper and aluminum thin sheets

The present study deals with using a blue laser to weld dissimilar thin sheets for applications in the e-mobility field. A 1.5 kW laser source, emitting at 450 nm, was exploited in the lap welding of 0.3 mm thick copper sheets over 0.4 mm thick aluminum 1050 ones. The relatively small spot (485 μm) exploited allowed smooth and narrow beads at a welding speed up to 120 mm/s, guaranteeing a good contact area suitable for achieving electrical and mechanical performance. Design of experiment approach was exploited to properly plan the number of trials constituting the experimental campaign. The welding results were characterized using metallographic analysis that pointed out the geometric features of the fused zone and the eventual presence of cracks and pores. The role of process parameters was also investigated in terms of influence on mechanical and electrical performances. The specimens were tested, in fact, through shear tensile and electrical resistance tests. Hence, assessing the general applicability of that kind of welding on a real potential application was possible.