Effects of Processing Parameters on Temperature Distributions, Tensile Behaviour and Microstructure of Friction Stir Welding of Dissimilar Aluminium Alloys

Research has shown that there is a correlation between process parameters, temperature variations, tensile strength, microstructures and the durability of the welds obtained in friction stir welding (FSW). The need to institute this correlation is crucial in order to achieve a weld free of defects and having sound mechanical behaviours for industrial applications. This work examines process parameters effects on variations of weld temperature, tensile strength and microstructures in dissimilar FSW of 6101-T6 and 7075-T651 aluminium alloys with a plate thickness of 6 mm. The welding was done with rotational speeds of 1250, 1550 and 1850 rpm and traverse speeds of 50 and 110 mm/min. The results obtained indicate that processing parameters significantly affect the temperature distributions in the weld. Increase in rotational speed increases the temperature but cause a decrease in tensile strength. While the increase in travel speed cause a reduction in temperature which results to increase in the tensile strength. Highest tensile strength of 143 MPa was obtained at 1250 rpm and 50 mm/min but better mixing of both materials was achieved at 1550 rpm and 50 mm/min.