Optimization of process parameters in friction stir welding of AA5451

Abstract Friction stir welding is one of the primary fabrication techniques for making different engineering components, especially aluminum alloys. The welded joint with the friction stir process greatly depends on the process parameters, i.e., feed rate, rotational speed, and pin profile of the tool. In the current study, plates of AA5451 were joined by the friction stir welding technique, and the Taguchi method was used to find the process parameters at an optimal level. It was concluded that for tensile strength, tool rotation speed of 1400, threaded tool pin profile and feed rate of 18 mm/min were optimum parameters. At the same time, the optimum parameters for hardness were tool rotation speed of 1200, threaded tool pin profile and feed rate of 18 mm/min. Overall, the tool pin profile was the major parameter for improving the welded joint’s tensile strength and hardness. In addition, the contribution in terms of percentage of each input parameter was found by the Analysis of Variance (ANOVA). The ANOVA results also revealed that the pin profile of tool has the maximum contribution on the results of tensile strength and hardness. The study also investigated the joint efficiency of friction stir welded joint, hardness at weld zone, and metallography on friction stir welding samples at the optimized level.