Enhanced Corrosion Resistance in High-Strength Biodegradable Mg-Zn-Ca-Si Glassy Alloy Composite via Preparation of a Self-Sealing Plasma Electrolytic Oxidation Layer

In this study, a dendrites reinforced Mg_85.9Zn₁₂Ca₂Si_0.1 glassy alloy composite was fabricated through rapid solidification. After self-sealing plasma electrolytic oxidation (PEO) treatment, the glassy alloy composite maintained desirable mechanical properties, showing a large plastic strain of 8.0% and a high fracture strength of 652 MPa. The adhesion strength of the PEO layer was around 51 MPa that met the requirement of implant materials. For the PEO-treated composite, the corrosion current density in the stimulated body fluid solution reduced by four orders of magnitude in comparison with bare substrate, from 2.45 × 10⁻⁴ to 8.74 × 10⁻⁸ A/cm². Furthermore, the PEO layer exhibited an excellent bioactivity which could elicit the spontaneous generation of apatite on the coating. This work offers a promising method for the development of advanced biodegradable alloys.