Co‐Doping With Nanoparticles to Enhance the Corrosion Resistance, Wear Resistance, and Biocompatibility of Micro‐Arc Oxidation Coatings on Magnesium Alloys

A nano‐TiO 2 /ZnO co‐doped micro‐arc oxidation coating (M‐Ti/Zn) was fabricated on AZ91D magnesium alloy to address rapid corrosion, poor biocompatibility, and infection risk of biodegradable implants. The M‐Ti/Zn coating exhibited the densest structure (porosity 4.866%), highest nanoparticle content (Ti 2.3%, Zn 3.1%), and superior corrosion resistance (electrochemical impedance 1.3 × 10 5 Ω·cm 2 , stable pH 7.5–8.0 over 90 days). It achieved 99.99% antibacterial rate against E. coli and S. aureus , a hemolysis rate of 4.3% (ISO10993‐4 compliant), and 110.3% osteoblast viability. Additionally, it showed the highest hardness and best wear resistance. This multifunctional coating offers excellent corrosion resistance, antibacterial property, biocompatibility, and mechanical integrity, showing great promise for biodegradable medical implants.