Laser roll welding of dissimilar metal joint of low carbon steel to aluminum alloy using 2kW fiber laser

Recently, lightening, speed-up and decreasing vibration of the transport vehicles have been discussed tor improving of environmental problems. As one of the solution, the material hybrid concept using aluminum alloys and high strength steels has been proposed. Therefore, new welding processes by which these dissimilar materials can be joined in high reliability and productivity are demanded. Laser Roll Welding was developed for joining of dissimilar metals by M. Kutsuna, M. Rathod and A. Tsuboi in 2002. Up to now, a CO2 laser has been used as a heat source. In the present work, Laser Roll Welding of low carbon steel and aluminum alloy using a 2kW fiber laser was investigated to improve the joint properties due to the effective heating characteristics. Effects of the process parameters were studied. Otherwise, the influences of process parameters on the weldability, the formation of intermetallic compound layer and the mechanical properties have been investigated. As a result, various types of intermetallic compound layer were confirmed at the Laser Roll Welded joint interfaces. When intermetallic compound layer thickness was less than 10μm, specimen was failure in the base metal of low carbon steel in the tensile shear test.