Effect of heat input on the electrical resistivity of dissimilar friction stir welded joints of aluminium and copper

This paper reports the effect of heat input on the resulting electrical resistivities of joints between aluminium and copper produced with the friction stir welding process. Welds were produced using three different shoulder diameter tools, viz: 15, 18 and 25 mm by varying the rotational speed between 600 and 1200 rpm and the traverse speed between 50 and 300 mm/min in order to vary the heat input to the welds. The microstructures of the joint interfaces were characterized, and the electrical resistivities measured. The resulting microstructural characterization revealed that metallurgical bonding was achieved at the joint interfaces of the welds produced. It was also observed that the electrical resistivity of the joint increased as the heat input to the welds increases.