Corrosion Resistance of Magnesium Alloy with Complex Surface-Modifying Micro-Arc Oxidation Coating and Organic Coating Studied by Neutral Salt Spraying
YUAN Bing, YUAN Sen, JIANG Bai-ling, YUAN Fang (School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China)
Magnesium alloy AZ91D was surface-modified by micro-arc oxidation (MAO). Several organic coatings were then prepared on the micro-arc oxidation coating of the Mg alloy. The corrosion resistance of the dual-phase surface-modification coatings was evaluated using neutral salt spray test. It was found that the micro-arc oxidation coating in combination with organic coatings contributed to significantly increase the corrosion resistance of the Mg alloy, which could make it possible for the Mg alloy after the dualphase surface-modification to be used in severely corrosive working conditions. Specifically, the micro-arc oxidation coating combined with electrophoresis coating was the most effective in increasing the corrosion resistance of the Mg alloy. The reason could lie in that the micro-arc oxidation coating was able to refine the surface microstructure of the Mg alloy and hence considerably increase the adhesion strength of the organic coatings thereon.
【CateGory Index】： TG174.451