Effect of Tin (Sn) Addition on the Corrosion Behavior of Hydroxyapatite (HAP) Coated Mg/MgSn Alloys using Different Coating Methods

Abstract

This study investigates the effect of tin (Sn) addition on the corrosion behavior of hydroxyapatite (HAP) coated Magnesium (Mg) /MgSn alloys by using two different coating methods. Mg/Mg alloys have gained significant attention in recent years due to their lightweight, high strength, and potential for use in a wide range of industrial applications. However, their corrosion properties during cathodic reactions with abundant hydrogen evolution have limited their widespread use, particularly in biomedical applications. In this study, pure Mg, Mg2Sn, Mg3Sn, Mg4Sn, and Mg5Sn alloys were prepared by powder metallurgy method. Then samples were coated by two different methods, dip-coating and electro-deposition. Potentiodynamic polarization and hydrogen evolution reaction analysis were performed to evaluate the corrosion rate and the hydrogen volume released from the alloys. The results indicate that the addition of Sn does not significantly increase the corrosion resistance of MgSn alloys. However, the current density and hydrogen evolution of the alloys are apparently improved after the coating process. The better corrosion resistance was observed for the Mg with higher composition, which are Mg4Sn and Mg5Sn. Overall, the study demonstrates that coating HAP onto the surface of MgSn alloys is able to improve their corrosion behavior and suppress the hydrogen evolution rate (HER) of the MgSn alloys. This improvement in other ways will increase their potential for industrial applications specifically in biomedical applications.