Dual layer inorganic coating on magnesium for delaying the biodegradation for bone fixation implants

In this study, a dual layer inorganic coating was formed on a pure magnesium metal using electrochemical methods to delay the biodegradation of the metal for potential bone fixation implant applications. Firstly, a layer of silicate-based coating was formed on the base metal using the plasma electrolytic oxidation (PEO) method. A second layer of calcium phosphate (CaP) was formed on the PEO coating using the electrodeposition method. in vitro electrochemical degradation testings showed that the double layer coating (PEO-CaP) has significantly improved the initial degradation resistance of the metal. Localized degradation was not evident on the PEO-CaP coated metal even after 72 h exposure to simulated body fluid (SBF).