Analysis of copper sheets welded by fiber laser with beam oscillation

Laser welding of Copper is a challenge due to its high thermal conductivity, low absorptivity of laser light and facility to dissolve oxygen favoring the formation of oxides. However, recent developments suggest that these problems can be overcome by power spatial modulation of the laser beam. This paper presents results on laser welding with beam oscillation (wobbling effect) performed on Copper plates. The effect of the major welding parameters on the weld surface aspect and bead profile are discussed, as well as the microstructure evolution. An interesting feature was observed in the microstructure of the fusion zone in the form of circular shaped bands which result from the solidification front of the weld metal as the laser oscillates and travels continuously. No defects were seen in the welds suggesting this variant of laser welding has potential for industrial applications where high thermal and/or electrical conductivities are required.