A comparative analysis of friction stir and tungsten inert gas dissimilar AA5082-AA7075 butt welds

The aluminium alloys AA5082 and AA7075 were welded using friction stir welding (FSW) and tungsten inert gas (TIG) welding. The effect of these two (FSW and TIG) welding processes on the tensile and fatigue properties of dissimilar AA5082-AA7075 butt welded joints were studied. The S-N curve for both, FSW and TIG, joints were established. The results exhibited that the tensile and fatigue properties of dissimilar FSW welded butt joints are better than those of dissimilar TIG welded butt joints. The fatigue strength for FSWed and TIG welded joint is determined as 40 MPa for 106 cycles and 30 MPa for 105 cycles of fatigue life, respectively. The micro-hardness of the joints is also studied for both joints. The hardness for TIG joint is lower than the FSWed joint in the welded zone.