Corrosion behaviour of friction stir welded dissimilar magnesium alloys ZE41 and AZ31

This study investigates the influence of tool rotational speed and feed rate on the corrosion behaviour of ZE41‐AZ31 friction stir welded (FSW) dissimilar joints using immersion testing, open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) analysis. Results show that higher rotational speeds, particularly 1200 min −1 combined with lower feed rates (20 mm·min −1 ‐ 30 mm·min −1 ), significantly enhance corrosion resistance. The optimal condition of 1200 min −1 and 20 mm·min −1 yielded the lowest corrosion rate (2.097 mm·yr −1 ), highest open circuit potential (~ ‐1.575 V), largest Nyquist semicircle diameter, and lowest I corr , indicating improved passive film formation and charge transfer resistance. In contrast, lower speeds and higher feed rates (800 min −1 , 40 mm·min −1 ) resulted in poor corrosion performance due to insufficient heat input and weld defects. Overall, a high rotational speed with a low to moderate feed rate optimizes electrochemical stability and corrosion resistance in ZE41‐AZ31 friction stir welding joints.