Effects of operating parameters on surface quality for the pulsed laser welding of zinc-coated steel

This paper presents an analysis of the influences of dominant processing parameters of pulsed laser seam welding on weld surface quality. The parameters are the average peak power density (APPD), the average output power, the welding speed, the pulse energy and the pulse duration. Only one temporal pulse type, a 'rectangular' power pulse without a characteristic leading-edge power spike, is used in this study. Laser seam welds are produced in 0.7 mm thick electro-galvanised steel sheets. A surface study of acceptable welds reveals that various operating parameters are influential to different degrees on the surface finish and the presence of slumps in the welds. It is found that proper control of the above-mentioned processing parameters can produce the desired top surface quality of lap welds in the laser seam welding process.