Penetration and welding phenomena in YAG laser-mig hybrid welding of aluminum alloy

Abstract

Hybrid welding combining YAG laser and MIG arc was carried out on aluminum alloy, and the effects of various welding conditions were investigated. The optimum distances between the laser-focused point and the MIG wire target for deeper penetration were found to be about 2 to 4mm depending upon the MIG current of 60 to 240 A. Also porosity was reduced with an increase in the MIG current and sound weld beads were formed. These reasons were interpreted by observing keyhole behavior, bubbles formation, the droplets transfer from the filler wire and the molten pool geometry during hybrid welding with a high-speed video and X-ray real-time transmission observation method. It was revealed at high arc currents that bubbles were generated from the keyhole tip but that these bubbles disappearance from the concave molten pool surface were attributed to the suppression of porosity.Hybrid welding combining YAG laser and MIG arc was carried out on aluminum alloy, and the effects of various welding conditions were investigated. The optimum distances between the laser-focused point and the MIG wire target for deeper penetration were found to be about 2 to 4mm depending upon the MIG current of 60 to 240 A. Also porosity was reduced with an increase in the MIG current and sound weld beads were formed. These reasons were interpreted by observing keyhole behavior, bubbles formation, the droplets transfer from the filler wire and the molten pool geometry during hybrid welding with a high-speed video and X-ray real-time transmission observation method. It was revealed at high arc currents that bubbles were generated from the keyhole tip but that these bubbles disappearance from the concave molten pool surface were attributed to the suppression of porosity.