Abstract
A continuous diode laser was superposed on a pulsed Nd:YAG laser in aluminum welding because of its high efficient absorptivity to aluminum alloy, and effects of diode laser on the crack generation were investigated. The superposition of continuous diode laser would keep the specimen at the high temperature after the Nd:YAG laser pulse, and the temperature of irradiated area could be decreased gradually, which led to the gentle stress distribution. Therefore, it was clarified that cracks on the surface in a pulsed Nd:YAG laser welding of aluminum alloy could be decreased by the superposition of continuous diode laser.
