Microstructure and electrical resistivity properties of copper and aluminium friction stir spot welds

Dissimilar metal joining methods are essential for the manufacturing of a various structures and parts in the industries. Friction stir spot welding process was performed on 3 mm thick AA1060 and C11000. This paper presents the results on the microstructure, chemical analysis and electrical resistivities of the produced joints. The microstructure showed a contrast between the two different materials namely copper and aluminium and the presence of a copper ring (hook) in all the produced spot welds. The presence of copper particles in the aluminium matrix was observed in most of the welds. The conducted energy dispersive spectroscopy (EDS) analysis confirmed the presence intermetallic compounds. It was observed that, the spot weld produced using 800 rpm and 1 mm shoulder plunge depth exhibited a low electrical resistivity value of 0.009 μΩ, which shows an appreciation of 0.011 μΩ (55 %), compared to the average of the parent materials (0.020 μΩ). This could be an attractive option for electrical applications.