Corrosion study of graphene oxide coatings on AZ31B magnesium alloy

Abstract

The aim of this study was to produce graphene oxide (GO) coatings on biodegradable AZ31B magnesium (Mg) alloy. GO was synthesized by improved Hummers’ method, and a suspension was prepared in deionized water by ultrasonication. GO coatings were developed on AZ31B Mg alloy by electrophoretic deposition (EPD). The EPD parameters, such as voltage and time, were optimized to obtain uniform GO coatings. Characterization was carried out using Fourier transform infrared spectroscopy, X-ray diffraction, atomic force microscopy (AFM), and scanning electron microscopy. GO was found to have a thickness of approximately 0.7–1 nm as determined by AFM. Electrochemical behavior of coatings was evaluated by Tafel analysis and electrochemical impedance spectroscopy (EIS) in Ringer’s lactate solution. GO coatings improved the corrosion resistance of the AZ31B Mg alloy by 16× in Ringer’s lactate solution as compared to bare Mg alloy. Show more