Weld penetration and welding phenomena of aluminum alloy with high-power fiber laser

Abstract

Fiber laser bead-on-plate welding was performed on aluminum alloy A5083 using 10 kW apparatus to investigate the effects of various welding conditions on penetration and defect formation. Especially, the effects of power density (from 10 kW/mm2 to 1.5 MW/mm2) and welding speed (from 0.6 m/min to 20 m/min) on weldability were examined. Consequently, it was found that the weld beads were narrower and deeper with an increase in laser power density. For example, fully penetrated weld beads were produced in 10 mm thick plates at 640 kW/mm2 laser power density at the welding speed of 10 m/min. However, convex-concave bead surfaces were obtained. Moreover, in the case of the high power density, no pore and many pores were present at high and low welding speeds, respectively. On the other hand, in the case of the ultra-high power density, few pores were generated in high speed welding. These reasons were interpreted by observing keyhole behavior, bubbles formation and the molten pool geometry during high power fiber laser welding with a high-speed video camera and X-ray real-time transmission observation method.Fiber laser bead-on-plate welding was performed on aluminum alloy A5083 using 10 kW apparatus to investigate the effects of various welding conditions on penetration and defect formation. Especially, the effects of power density (from 10 kW/mm2 to 1.5 MW/mm2) and welding speed (from 0.6 m/min to 20 m/min) on weldability were examined. Consequently, it was found that the weld beads were narrower and deeper with an increase in laser power density. For example, fully penetrated weld beads were produced in 10 mm thick plates at 640 kW/mm2 laser power density at the welding speed of 10 m/min. However, convex-concave bead surfaces were obtained. Moreover, in the case of the high power density, no pore and many pores were present at high and low welding speeds, respectively. On the other hand, in the case of the ultra-high power density, few pores were generated in high speed welding. These reasons were interpreted by observing keyhole behavior, bubbles formation and the molten pool geometry during high power fi...