Multi-response Optimization of Friction Stir Welded Reinforced Joints of Dissimilar Aluminum Alloys

In the present research, an attempt has been made to develop friction stir welded dissimilar reinforced joints of AA6061 and AA7075 using micro-sized Al2O3 particles. The influence of varying volume fractions of Al2O3 particles along with traverse and rotational speeds on microstructural evolution and mechanical behavior was investigated using response surface methodology. At a 95% confidence level, quadratic mathematical models were developed to predict the optimum value of output responses such as microhardness, tensile strength, and %elongation. According to the developed models, rotational speed was observed as the most influential variable, whereas traverse speed was observed as the least influential variable. The optimum values of rotational speed, traverse speed, and volume fraction of Al2O3 particles were found to be 971 rpm, 40 mm/min, and 10%, respectively. The optimum values of output responses, such as tensile strength, %elongation, and microhardness, were found to be 226.2 MPa, 17.4%, and 144.3 HV, respectively.