Preparation and properties of composite MAO/ECD coatings on magnesium alloy

► A porous biocoating was fabricated on magnesium alloy substrate via Micro-arc Oxidation (MAO). ► We first discovered a new electrolyte of MAO which can introduce Ca and P into MAO coatings. ► HA coatings were prepared by electrochemical deposition (ECD) on the MAO coatings. ► We combined MAO and ECD and prepared biodegradable coatings containing Ca/P. ► MAO/ECD coatings have the dual function of anticorrosion and potential bioactivity.