Improving in vitro corrosion resistance of biomimetic calcium phosphate coatings for Mg substrates using calcium hydroxide layer

Abstract

Biomimetic calcium phosphate coatings have been studied to improve the corrosion resistance of biodegradable magnesium alloys. The corrosion resistance of these coatings is often limited by defects during creation. A method for improving the corrosion response of these coatings is therefore needed if biomimetic coatings are to be used for corrosion protection. In this study, a calcium hydroxide underlayer was applied to improve the properties of these biomimetic coatings. The in vitro corrosion response was studied using hydrogen evolution and electrochemical techniques. It was found that the calcium hydroxide layer increased the corrosion resistance of the coatings. The coatings created had fewer defects than the unmodified biomimetic coatings. Over time, the calcium hydroxide layer also prevented the defects in the coating from growing, leading to longer lasting protection. The results of this study suggest that calcium hydroxide coatings can significantly improve the corrosion protection of a biomimetic coating.