| Affiliation: | 1. Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China School of Materials Science and Engineering, University of Science and Technology of China, Hefei, China;2. Shanghai Spaceflight Precision Machinery Institute, Shanghai, China;3. Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China;4. Shandong Key Laboratory Advanced Aluminum Materials and Technology, Binzhou Institute of Technology, Binzhou, China |
| Abstract: | The combination of a microarc oxidation (MAO) film and water-based electrophoresis painting (EP) technology is a promising surface treatment for magnesium alloys, but the matching performance between them has not been investigated systematically. For fabricating the optimal composite coating, the influence of the MAO film condition and electrophoresis parameters on the overall performance of the composite coating was investigated by scanning electron microscopy, finite element modeling, electrochemical impedance spectroscopy, and immersion tests. The results indicate that the composite coating with an MAO voltage of 330 V and an EP voltage of 120 V shows the best corrosion resistance. Its excellent anticorrosion performance is attributed to the suitable thickness ratio of the MAO/EP coating and the excellent mechanical interlock effect of the MAO/EP interface. The microstructure of the MAO coating plays a key role; the uniform micropore size promotes a uniform electric field distribution in the initial electrophoresis process, which can considerably improve the sealing pore quality of the EP resin and further maximize the interfacial adhesion strength. |
