<p>Magnesium-rare earth (Mg-RE) alloys are promising candidates for sacrificial anodic applications; however, their high corrosion potential and rapid degradation limit their practical use. This study addresses this challenge by investigating the effects of friction stir processing (FSP) on the microstructural evolution and electrochemical performance of Mg-1Er-1Gd alloy. The scientific novelty is the utilization of FSP to refine the microstructure, enhance corrosion resistance, and improve sacrificial anodic efficiency of Mg-1Er-1Gd alloy. A detailed characterization of phase evolution, hardness, electrochemical behavior, and corrosion kinetics was conducted. The results indicate that FSP significantly enhances anodic performance, reducing the anodic consumption rate to 8.44 × 10⁻⁴ kg/Ah and increasing anodic efficiency to ~ 54%, which is 155% higher than the base alloy.</p> Graphical abstract <p></p>