An investigation of friction stir welding parameters on the weld strength of dissimilar alloys

Weld quality and efficiency are always under increasing demand, in many industrial sectors. Although traditional welding methods accomplish the task, issues such as solidification shrinkage, hot cracking, residual strains, and the release of hazardous gases during the welding process persist as significant concerns. To address these limitations and promote more environmental affinity, the friction stir welding (FSW) method is employed. This study examines the joining of two dissimilar aluminum alloys, AA 5083 and AA 8011, focusing on process characteristics such as tool speeds, feed rates, metal orientation, and tool dimensions. Tensile test’s results indicate that the highest ultimate tensile strength is achieved at a rotational speed (Rs) of 1200 rpm, a feed rate (Fr) of 40 mm/min, and a tool offset (To) of 1 mm on AA 5083. Visual inspection techniques, including scanning electron microscopy and VMM, are employed to evaluate the quality of the weld surface. The microstructural examination revealed a homogeneous distribution of grains, which is consistent with the improved tensile properties. Vickers microhardness tests are conducted to assess the hardness of the weld across the joints. Among the experimental conditions investigated, a rotational speed of 1200 rpm and a feed rate of 40 mm/min produced the highest tensile strength and the most favorable weld characteristics.