In Situ Cerium‐Doped Micro‐Arc Oxidation Coatings on Titanium Alloys for Corrosion Resistance and Biocompatibility

A cerium‐doped micro‐arc oxidation (MAO) strategy was developed to construct multifunctional ceramic coatings on selective‐laser‐melted Ag@GNSs/TC26 substrates using a phytic‐acid‐based electrolyte with Ce(NO 3 ) 3 concentrations (0.1–0.3 g/L). The coatings were characterized by XRD, SEM/EDS, and XPS, and evaluated for corrosion resistance in simulated body fluid (SBF), apatite‐forming ability, and cytocompatibility. The MAO layers exhibited volcano‐like microporous morphology, comprising anatase and rutile TiO 2 , with Ce incorporated as CeO 2 and CePO 4 (Ce 3+ /Ce 4+ mixed states). Electrochemical tests showed Ce‐dependent protection: corrosion potential shifted positively (−0.051 to 0.027 V vs. SCE), with optimal performance at 0.3 g/L Ce(NO 3 ) 3 (corrosion current density: 9.09 × 10 −8 A·cm −2 ; coating capacitance: 2.94 × 10 −7 F). SBF immersion revealed hydroxyapatite formation (MAO‐3 > MAO‐2 > MAO‐1). CCK‐8 assays demonstrated acceptable cytocompatibility (viability ≥ 70%), with MAO‐1/MAO‐2 showing higher viability and MAO‐3 exhibiting mild time‐dependent decrease. Ce incorporation enhanced corrosion resistance and bioactivity simultaneously, requiring optimized levels to balance protection and cellular response.