Weld fusion property of lotus-type porous copper by laser beam irradiation

Welding of lotus root like porous metals with long cylindrical pores aligned in one direction is important for new applications of porous metals. In this study, an effect of the pore growth direction on the shape of weld fusion zone of lotus-type porous copper by laser beam welding was investigated at a first attempt of the welding of lotus-type porous metals in the welding speed and laser power range of 1.67-16.7 mm s^-1 and 2.0-3.2 kW, respectively. Significant anisotropy in the shape of weld fusion zone was observed when lotus-type copper melted in the perpendicular and parallel pore growth directions to the surface of work piece, on which the laser beam was irradiated. In the perpendicular direction, smooth weld head was obtained, but in the parallel direction, only a groove was formed instead of the weld head even at the same welding conditions of 3.33 mm s^-1 in welding speed and 3.2 kW in laser power.