Robert T. Szymanski

Friction Stir Scribe Welding of Dissimilar Aluminum to Steel Lap Joints

The use of dissimilar material combinations such as aluminum to steel has been increasing in automobile and aerospace industries due to its potential for energy savings. Achieving an acceptable joint quality with fusion welding can be problematic due to the significant differences in physical and thermal properties between materials. One alternative to conventional fusion welding is friction stir scribe welding and because of the nature of the process, it can be a viable option for joining dissimilar metal combinations. The primary emphasis of this work is to investigate the feasibility of using FSS welding as a possible option for joining 1.0 mm thick 6022 aluminum to 0.7mm electro galvanized steel sheets in a dissimilar lap weld configuration. An H13 steel pin tool featuring a tungsten carbide scribe insert was used. An investigation on the optimum size of the scribe insert was conducted to evaluate the effects of microstructure and mechanical properties.