Enhancement of Corrosion Resistance and Antibacterial Performance of Magnesium Alloys via a Superhydrophobic Cu‐MOFs/CuS Coating

Magnesium alloys are used in ultrahigh voltage (UHV) insulator connections due to their high specific strength, vibration damping, and shielding properties. However, their low electrochemical potential (−2.37 V) leads to porous oxide films in tidal flats, humid conditions, and salt spray environments, causing pitting and cracking. Subsequently, microorganisms attach to the surface, secreting metabolites that acidify the area in synergy with Cl − , forming biofilm‐corrosion coupling and accelerating failure. To address this, we developed a porous Cu‐MOFs/CuS composite coating on AZ31B magnesium alloy using a hydrothermal method (160°C, 10 h) and stearic acid modification, creating a superhydrophobic surface (contact angle of 162°). After 50 cycles of simulated sandpaper abrasion, the contact angle remained above 150°, demonstrating superior mechanical stability compared to pure Cu‐MOFs coatings. Immersion tests in acids, bases, and salts, as well as dynamic potentiodynamic polarization curves, proved that the Cu‐MOFs/CuS composite coating has superior acid–base‐salt stability and corrosion resistance compared to a pure MOFs coating. Moreover, the Cu 2+ released from the coating show high inhibitory and antibacterial effects on Escherichia coli and Staphylococcus epidermidis, significantly reducing the risk of microbially induced corrosion. This provides an innovative solution for the long‐term reliable service of magnesium alloys in UHV transmission and transformation equipment.