Laser Beam Welding of Automobile Materials for Lightweight Car Body
This paper presents laser beam welding (LBW) of an age-hardened aluminum alloy and a bake-hardening (BH) steel, which are promising materials for lightweight car body, compared with conventional arc welding. The LBW of the aluminum alloy had a significantly narrower fusion zone and heat affected zone (HAZ) than the arc weld and the hardness of the softened zones was almost completely recovered to the base metal hardness after a post weld aging treatment. This advantage of LBW is due to a low overall heat input resulting from its high energy density. This is also beneficial for welding of the BH steel. In the LBW of the pre-strained BH steel, both the fusion zone and HAZ were bake-hardened after a heat-treatment and the fracture occurred in the base metal in the tensile test. In contrast to this, the arc weld had a large softened zone in the HAZ and fractures in this region.
Masaaki Naka and Toshimi Yamane
A. Hirose and K. F. Kobayashi, "Laser Beam Welding of Automobile Materials for Lightweight Car Body ", Materials Science Forum, Vol. 502, pp. 487-492, 2005