Optimization of process parameters of friction stir spot welded aluminium 3102 and carbon steel 1010

A solid-state spot-welding technology called Friction Stir Spot Welding (FSSW) can be used as an alternative to Resistance Spot Welding (RSW). RSW has several constraints, including a high electrode wear rate, a high temperature, and a quick cooling rate, resulting in a brittle microstructure. Many industries, such as automotive and shipbuilding, require joints constructed of various metals such as aluminium and steel to reduce weight and enhance strength. Aluminium 3102 and carbon steel 1010 are friction stir spot welded (lap joint) in this project, with the aluminium at the top and the carbon steel at the bottom. The aluminium and carbon steel have 3mm thickness, 100mm length, and 30mm breadth, respectively, and are ready for welding. Consequently, the ideal set of parameters for FSSW of aluminium 3102 and carbon steel 1010 for each material must be identified. The process parameters considered in this welding are the Tool rotation speed (R), Dwell time (T), and Plunge depth (D), and the Tensile Shear Failure Load (TSFL) (in kN) of the weld is determined by a Tensile test. Each of these process variables directly influences the size of the stir zone and the mechanical properties of the weld. In this scenario, the experimental conditions for finishing the weld were developed using Central Composite Design (CCD). The microstructure and Vickers microhardness of the welded sample with the greatest TSFL is achieved, with hardness values of 147.8, 149.9, and 151.5 obtained in the Heat Affected Zone Thermo-Mechanically Affected Zone, and Stir Zone, respectively. A second-order linear regression equation must be created to establish a relationship between the process parameters. ANOVA was utilized to determine the most significant parameter and the sufficiency of the link, both of which were determined statistically. Dwell time (T) had the greatest effect on TSFL of any process component tested, with an F-value of 17.79 at the highest significance level.