Influence of a Stationary Shoulder Friction Stir Welding Tool on the Mechanical and Corrosion Properties of AA2024 Aluminum Alloy Joints at Different Parameter Values

Abstract

Sound weld joints of similar AA2024 aluminum alloy plates of 6 mm were achieved unprecedentedly at different rotational (386-1216 rpm) and traverse speeds (13-90 mm/min) using an indigenously developed stationary shoulder friction stir welding (SSFSW) tool. Results indicate a smooth and bowl-shaped symmetrical nugget zone (NZ) with fine equiaxed grains. The grains as well as the nugget zone width vary with the speed variation. A change of 16% in the width of NZ is observed with an increase in traverse speed from 13 to 90 mm/min. The SSFSW tool reduces the width of the weakest region of the weld joint, known as the heat-affected zone, by almost 50%. The SSFSW joint produced at 931-90 mm/min shows the highest value (101 HV) of the minimum hardness region as compared to other parameters. The SSFSW tool shifts the weakest region toward the NZ, as substantiated by the fracture location of the tensile samples. In addition, SSFSW joints show higher corrosion resistance in NZ due to recrystallized fine grains as compared to HAZ. The SSFSW tool reduces the width of the most severely corrosion-affected region and, hence, improves the corrosion resistance of the joint.