High efficiency and high quality welding of aluminum alloy by hybrid system combined Nd: YAG laser and diode laser

Recently the welding of aluminum alloy has been strongly required for the lightening the electronic products, the automobiles and so on. Then the hybrid laser system was newly developed in order to perform the high efficiency and high quality welding of aluminum alloy. The high electric-optical conversion efficiency was achieved by the new diode pumped pulsed Nd: YAG laser. The hybrid system is consisted of a newly developed pulsed Nd: YAG laser and a continuous diode laser, and it can deliver two lasers by one fiber. Higher absorption of laser energy into the aluminum alloy can be expected under the continuous irradiation of diode laser (λ= 808 nm), since the absorption into aluminum alloy shows the maximum at λ= 850 nm. The suitable bead width and depth could be obtained with better surface integrity when the pulse waveform took the highest peak at the first period. The bead width and depth increased with increasing the power of continuous diode laser, which leads to overlapping welding even under high speed condition. Moreover, the high efficiency and high quality welding of aluminum battery case could be accomplished by the newly developed hybrid system, in which the suitable pulse energy and the peak power could be given even under the high pulse repetition rate.