Experimental Investigation of Friction Stir Spot Welding of dissimilar AA5052-AA7075 Joints

Abstract

Friction Stir Spot Welding (FSSW) has emerged as a transformative solid-state joining method with wide-ranging applications in industries such as automotive, aerospace, and electronics. This study delves into the difficulties of FSSW for dissimilar aluminum alloys, specifically AA5052 and AA7075, which exhibit distinct material characteristics. To address the challenges posed by these dissimilar materials, a systematic Taguchi experimental design was employed to analyze the influence of three key welding parameters: rotational speed (RS), plunge rate (PR), and plunge depth (PD) on the maximum failure load (MFL) of the welds. The findings revealed notable trends in MFL in response to variations in these parameters. Notably, MFL consistently increased with higher RS and PR levels, while the impact of PD exhibited a more complex relationship, initially decreasing MFL until a critical point and then gradually increasing it. Through Signal-to-Noise ratio analysis, optimal welding conditions were pinpointed, indicating that the highest MFL was achieved at RS level 3 (1400 RPM), PR level 3 (8 mm/min), and PD level 1 (2.1 mm). Furthermore, a robust regression equation was formulated to predict MFL accurately based on the selected parameters. With a goodness-of-fit of 95.42%, the model demonstrates its reliability for navigating the design space effectively. This study contributes valuable insights into optimizing FSSW for dissimilar materials, facilitating its adoption and advancement in diverse industrial applications.