Abstract
Pulsed Nd:YAG laser and continuous diode laser were spatially superposed for higher absorption to aluminum alloy. 12-20% increase in bead width and 15-30% increase in weld depth could be obtained by superposition of continuous diode laser and pulsed Nd:YAG laser. Moreover, the unsteady thermal analysis with key-hole effect indicated that the temperature of specimen surface with continuous diode laser could be kept approximately 300K higher than that without continuous diode laser. Therefore, it was clarified that the bead width and depth would increase greatly due to higher absorption of Nd:YAG laser to aluminum alloy by superposition of diode laser.
