Microstructure and Corrosion Resistance of Black Microarc Oxidation Ceramic Coatings on Magnesium Alloy

摘要

Black micro-arc oxidation (MAO) ceramic coatings were prepared on magnesium alloy in a silicate electrolyte; SEM,EDS and XRD were tested to analyze surface morphology,chemical composition and phase composition of ceramic coatings,Corrosion resistant in 3.5 ％ NaCl aqueous solution of magnesium alloy before and after MAO treatment was evaluated by polarization curves and electrochemical impedance spectroscopy (EIS); the weight loss of magnesium alloy with black MAO ceramic coatings in 3.5 ％ NaCl aqueous solution was studied through immersion experiment.The results indicated that,the black MAO ceramic coatings was composed by Mg,Al,Si,Cu and O; black MAO ceramic coatings could protect magnesium alloy substrate effectively; the corrosion resistant of black MAO ceramic coatings in neutral 3.5％ NaCl solution was favorable.