Advances in microarc oxidation coated AZ31 Mg alloys for biomedical applications

• Influences of MAO parameters on properties of microarc oxidized AZ31 are reviewed.
• Influences of MAO parameters on the residual stress in oxide coatings are reviewed.
• Controlling AZ31 corrosion rate compatible with tissue healing rate is a challenge.

The AZ31 Mg alloy is highly corrodible in vivo. Microarc oxidation (MAO), among many other methods for producing a protective coating on AZ31, is effective and economic in reducing the corrosion rate. In this review, we aim to summarize the latest achievements and strategies for the MAO parameters as well as other factors that influence the corrosion properties of microarc oxidized AZ31. We also review the influence of the MAO parameters on the residual stress in the oxide coating on aluminum-containing Mg alloys. Finally, we outlook the existing issues and challenges in the biomedical applications of the microarc oxidized AZ31.