Alloying addition of silicon to magnesium alloys, such as Mg2Si phases, has been observed to improve the creep response. However, being electrochemically noble compared to magnesium matrix, these phases can induce micro galvanic corrosion in magnesium alloys. To achieve an overall improvement in these trade-off properties, a noble solid-phase processing technique namely the friction extrusion has been used to process Mg-3wt%Si (Mg-3Si) alloy from the feed cast ingot. The cast Mg-3Si alloy, which was found to composed of α-Mg + Mg2Si eutectics and Mg2Si phase was observed to undergo grain refinement and fragmentation of Mg2Si phases by the friction extrusion process. Further, an increase in the cathodic kinetics and a decrease in polarization resistance of friction extrusion alloys were observed. Lastly, to understand underlying mechanism by deconvoluting the effect of grain size and second phase fragmentation, pH-dependent electrochemical studies were performed on Pure Mg and Mg2Si along with Mg-3Si samples.