Effect of Friction Stir Spot Welding with a Rotating Anvil on the Microstructure of Aluminum AA6061-T4 Alloy

Friction Stir Spot Welding (FSSW) has emerged as a promising alternative to traditional riveting in the automotive industry.In this study, we explore the application of doublesided FSSW, a solid-state joining method, as an innovative approach to overcome the limitations of conventional resistance spot welding.Our focus is on welding 2 mm thick sheets of aluminum alloy AA6061-T4.To improve the strength and quality of welded joints, we employed the double-sided FSSW technique, which utilizes a revolving anvil and a pin-less tool.This approach not only enhances the tensile strength of the connections but also mitigates potential defects such as keyholes.Intriguingly, our numerical analysis reveals the complexity of material flow between the rotating anvil and the pin-less tool during the welding process.This complexity underscores the suitability of using a rotating anvil and a pin-less tool in FSSW operations, particularly when welding larger sheets.In conclusion, our study underscores the potential of double-sided FSSW with a rotating anvil and pin-less tool for achieving robust weld connections in the context of aluminum alloy AA6061-T4.These findings contribute to the ongoing efforts to advance solid-state joining methods in the automotive industry, offering a more efficient and reliable alternative to traditional riveting.