Preparation and Characterization of Permanganate Conversion Coating for Biodegradable AZ31B Magnesium Alloy

A permanganate conversion coating was prepared on biodegradable AZ31B magnesium alloy to improve its anti-corrosion property. Morphology, composition and corrosion resistance of the coating were studied in this paper. The SEM research showed that the coating was approximately 10-12μm in thickness with net-like microcracks. The XRD analysis indicated that the coating was mainly composed of MgO, MnO and Mn 2 O 3 . Electrochemical test showed manganese conversion treatment could significant improve the corrosion resistance of AZ31B.