Preparation of multifunctional composite coating on magnesium alloys with corrosion resistance, conductivity and antibacterial properties

In order to solve the problem of poor electrical conductivity of conventional magnesium alloy MAO coatings and to further enhance the multifunctionality of magnesium alloy coatings, this study examines the enhancement of EW75 through the development of composite coatings designed to improve its corrosion resistance, electrical conductivity, hydrophobicity, and antibacterial properties. MAO was employed as a base treatment, followed by application of organic composite coatings containing conductive graphite powder, silver-copper alloy powder, or a combination of both. Coatings were comprehensively characterized to evaluate their microstructure, corrosion resistance, electrical conductivity, hydrophobicity, and mold resistance. Results indicated that composite coatings significantly enhanced corrosion resistance compared to pure MAO coatings, with MAO-AgCu composite coating exhibiting the best performance. Furthermore, coatings demonstrated improved electrical conductivity, with MAO-AgCu coating displaying the lowest surface resistivity. Hydrophobicity was significantly improved in MAO–C-AgCu coating, and all coatings exhibited robust antibacterial effects, particularly against mold growth. This study enhances magnesium alloys’ functionality, with potential applications in corrosion protection, electrical properties, and antimicrobial resistance.