Effect of tool rotational speed on the mechanical and electrochemical properties of friction stir welded 5083 Al-Mg alloy

While friction stir welding (FSW) is a sustainable method for joining aluminum alloys, the effect of rotational speed on the combined microstructural, mechanical, and corrosion behavior of 5083 Al-Mg alloy is not well established. Most studies treat these properties separately, creating a gap in understanding their interdependence. Closing this gap is essential for optimizing FSW parameters for durable marine applications. Therefore, this study investigates the impact of varying rotational speeds (600, 700, and 800 RPM) on the metallurgical evolution, mechanical performance, and electrochemical behavior of friction stir welded 5083 Al-Mg alloy. Welds were produced using a butt joint configuration with a fixed tool traverse speed of 180 mm/min. Comprehensive analyses were conducted, encompassing X-ray diffraction analysis, mechanical testing, and electrochemical corrosion evaluations. The findings reveal that a rotational speed of 800 RPM delivers the most optimal weld characteristics compared to 600 RPM and 700 RPM. Specifically, the weld fabricated at this speed exhibited the highest tensile strength (342.48 MPa), minimal residual stresses, a highly uniform phase formation, and exceptional corrosion resistance, evidenced by an impressively low corrosion rate of 0.01 mpy.