Influence of surface condition in fiber laser welding of pure copper

In industry, pure copper is widely used in the applications requiring high electrical conductivity, rapid conduction of heat across or along a metal section as well as good corrosion resistance in fresh and salt water. So far, one of the challenges in laser welding of pure copper is the low welding efficiency resulting from its material properties of high reflectivity and thermal conductivity. In this study, the influence of surface condition in fiber laser welding of pure copper was investigated by varying processing parameters, including laser power and welding speed. Metallurgical observations were undertaken to evaluate the weld quality between four surface conditions (i.e. as-received, sandblasted, black-painted and nano-composite material added on the pure copper surface). The highest welding efficiency in laser welding of pure copper was obtained by applying the nano-composite material on the surface of pure copper coupons. The sandblast surface treatment and black-painted could also decrease the surface reflectivity from the laser beam and therefore enhanced the welding efficiency.