Enhancing Corrosion Resistance and Antibacterial Properties of ZK60 Magnesium Alloy Using Micro-Arc Oxidation Coating Containing Nano-Zinc Oxide

Abstract

Nano-zinc oxides (ZnO) demonstrate remarkable antibacterial properties. To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation (MAO) coatings, this study investigates the preparation of ZnO-containing micro-arc oxidation coatings with dual functionality by incorporating nano-ZnO into MAO electrolyte. The influence of varying ZnO concentrations on the microstructure, corrosion resistance, and antibacterial properties of the coating was examined through microstructure analysis, immersion tests, electrochemical experiments, and antibacterial assays. The findings revealed that the addition of nano-ZnO significantly enhanced the corrosion resistance of the MAO-coated alloy. Specifically, when the ZnO concentration in the electrolyte was 5 g/L, the corrosion rate was more than ten times lower compared to the MAO coatings without ZnO. Moreover, the antibacterial efficacy of ZnO + MAO coating, prepared with a ZnO concentration of 5 g/L, surpassed 95% after 24 h of co-culturing with Staphylococcus aureus (S. aureus). The nano-ZnO + MAO-coated alloy exhibited exceptional degradation resistance, corrosion resistance, and antibacterial effectiveness.