Bioceramic Coating Produced on AZ80 Magnesium Alloy by One-Step Microarc Oxidation Process
A self-sealing bioceramic coating was prepared on AZ80 magnesium alloy by one-step microarc oxidation (MAO) in an alkaline silicate solution in the presence of HA nanoparticles and K2TiF6. The influence of oxidation time on the microstructure and corrosion resistance was investigated. The surface and cross-sectional morphologies of the coatings were characterized by scanning electron microscopy, while their phase structure and chemical composition were obtained by x-ray diffraction analysis and energy-dispersive spectroscopy, respectively. The corrosion behavior of the coatings was evaluated by electrochemical measurements in a simulated body fluid. The results show that the self-sealing bioceramic coatings are mainly composed of MgO, MgF2, Ti3O5, Mg2SiO4, and HA phases, which effectively improve the corrosion resistance of the AZ80 magnesium alloy. The added K2TiF6 plays a key role in producing self-sealing coating, while the HA nanoparticles improve the bioactivity of the coating. Thus, the self-sealing bioceramic coating obtained by the one-step MAO process may develop into a suitable surface treatment technology for bone implants in clinical application.
Keywordscorrosion resistance hydroxyapatite magnesium alloy microarc oxidation self-sealing
The authors gratefully acknowledge the project sponsored by the support from National Natural Science Foundation of China (Nos. 51775502, 51275472).
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