Product Code: ICAL09_M403

High-Efficiency and High Quality Welding of Aluminum Alloy by Hybrid System Combined Nd:YAG Laser and Diode Laser
Authors:
Tomokazu Sakagawa, Kataoka Corporation; Yokohama-City Kanagawa Japan
Shin-Ichi Nakashiba, Kataoka Corporation; Yokohama, Kanagawa Japan
Shin Haraguchi, Okayama University; Okayama Japan
Yasuhiro Okamoto, Okayama University; Okayama Japan
Yoshiyuki Uno, Okayama University; Okayama Japan
Presented at ICALEO 2009

Recently, the welding of aluminum alloy has been strongly required for lightening the electronic products, automobiles and so on. Then hybrid laser system was newly developed in order to perform the high efficiency and high quality welding of aluminum alloy. 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. Numerical calculation made it clear that the surface temperature of aluminum alloy with diode laser could keep 300K higher than that without diode laser before next laser shot. Therefore, it could be expected that pulsed Nd:YAG laser would be absorbed more effectively because of higher surface temperature of aluminum alloy and high efficiency processing would be performed. 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.