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High-power Nd:YAG laser welding of aluminum alloys for car body
Published September 25, 2000 by ISATA - Dusseldorf Trade Fair in United Kingdom
Event: ISATA 2000
Vehicle manufacturers are strongly interested in aluminum car bodies because of their high potential for lightening vehicles. High-power Nd:YAG lasers are expected to provide high-speed welding of aluminum alloys thanks to their high energy beam. However, a single beam spot is apt to provide unstable welding because of violent interaction between an aluminum alloy and the beam. In this research, dual focus beam welding of aluminum alloys was investigated from the viewpoint of obtaining a stable weld bead and higher welding speed than what is possible with MIG and spot welding.
Two- and three-kW lasers were combined. The distance and configuration of the dual focus beam spots significantly influence weld bead quality. With a narrower distance between spots, the weld bead surface is irregular and blowholes are apt to appear, although deep penetration is obtained. With a wider distance, the bead is more stable, but penetration is shallower, Under the optimum conditions, stable and high-speed welding is possible.
The results of a welding experiment conducted on a component consisting of structural profiles and a sheet panel show that comparable tensile strength of the joint is obtained at a speed ten times faster than with MIG welding and with only one-fifth of the distortion.