Optimisation of friction stir welding parameters using the Taguchi technique for dissimilar joining of AA5083 to copper

This work reports on the impact of process parameters on the intermetallic compound formation and the resultant mechanical properties of aluminium grade AA5083 to copper joints created by friction stir welding. The effect of welding speed (hence cooling rate), tool rotational speed, material placement, and tool design are considered in this analysis. The Taguchi design of experiments (DoE) was applied to identify the significant parameters that affect FSW joints’ mechanical strength and to reduce the number of experiments required to optimise joint efficiency. The aluminium to copper FSW joints exhibited diverse intermetallic compounds, such as Al2Cu, AlCu, and Al4Cu9, and their evolution was found to be controlled by the tool rotational and welding speed. The highest ultimate tensile strength of 194.5 MPa was achieved at 1500 rpm tool rotational speed, 100 mm/min traverse speed, and zero tool offset.