Microstructure and Corrosion Resistance of Electrophoretic Deposited Carbonated Hydroxyapatite-Graphene Oxide Composite Coatings on AZ91 Magnesium Alloy

摘要

Carbonated hydroxyapatite-graphene oxide (GO) composite coatings were obtained on AZ91 magnesium alloy using electrophoretic deposition from isopropanol suspensions. The results showed that ultrasonic treatment exfoliated GO sheets and promoted CO2 adsorption on the surface of GO sheets. Subsequently, B-type carbonated HA was generated during ultrasonication-assisted EPD. The experimental results manifested that microstructures and porosity, carbonated HA content and the formation of GO-Mg complexes in pores/cracks had a significant synergistic effect on improving corrosion resistance of AZ91 magnesium alloy. HA-GO-0.33 composite coating had shown superior performance of corrosion prevention in the 0.9 wt. % NaCl solution which provided some corrosion theoretical basis for the application of Mg alloy in the direction of human implantation.