The improved performance of micro-arc oxidation coating on Mg surface via the in-situ incorporation of Ta2O5 by pre-sputtering Ta layer

To further enhance the corrosion resistance of micro-arc oxidation (MAO) coatings on magnesium alloys, this study proposes a novel approach for in situ incorporating tantalum oxide into MAO coating by pre-sputtering pure tantalum layer on magnesium surface. The results show that the uniformly distributed tantalum oxide enhances the chemical stability of the MAO coating. Compared to the normal MAO coating, the tantalum oxide-containing MAO coating exhibits superior corrosion resistance, inhibiting localized corrosion of the substrate. Additionally, tantalum oxide-containing MAO coating also improved the hydrophilicity of magnesium alloy in simulated body fluid. This innovative method contributes to the long-term service reliability of magnesium alloys, highlighting its potential applications as orthopedic implants. •A novel approach is proposed to fabricate the Ta2O5-containing MAO coating on Mg alloy.•The structural integrity and adhesion of the coating are enhanced.•The coating improves the corrosion resistance and reduces the localized corrosion tendency of Mg alloy.