Parametric study to investigate mechanical properties of welded dissimilar Al6063 and Al 7073 alloys through FSW process

Abstract

Aluminium alloys have been the most prominent materials that have applications in every industry due to their high strength-to-weight ratio. The low melting point and easy recyclability also attract the scientific community to apply such material in modern manufacturing. The revolution in aluminium alloys came after the invention of friction stir welding, which provided high-end welding results and catastrophically increased its application in aerospace industries. Still, many inconclusive studies need to be explored for its high-end application, especially for newly invented aluminium alloy composites. Hence, this study investigates the application of friction stir welding process for welding dissimilar Aluminium alloy compositions. The investigation starts by analysing the effect of rotational speed, feed rate, and force on temperature generation, hardness, and welding strength. Three levels of process parameters, i.e. rotational speed in the range of 1000–1200 rpm, force of 12–18 N and feed rate of 40–60 mm min−1, are selected to analyse the effect on hardness and strength of the weld. After analysis, the optimum conditions obtained were a rotational speed of 1200 rpm, a feed rate of 50 mm min−1, and an average load of 15 N for a maximum hardness of 93.16 BHN and welding strength of 228 MPa. The investigation’s findings indicated that several phenomena, including the effects of high blending activity, plastic disfigurement, the repercussions of grain structure, and frictional intensity, may influence the hardness and strength of the weld. The growth of uniform structure at the stirred area is caused by pin movement during welding, specifically from the retreating side to the advancing side.