Preparation of Black Coating on AM50 Alloys by Microarc Oxidation (MAO)

作者：Shao, Z. C.^*; Zhang, Q. F.; Wang, M.; Yang, L.

来源：Materials and Manufacturing Processes, 2014, 29(9): 1095-1100.

DOI：10.1080/10426914.2014.921695

• Alloys
• Black
• Coatings
• Corrosion
• Magnesium
• Mao

The black microarc oxidation (MAO) coating containing Cu2+ was prepared on AM50 magnesium alloys. When the additives (CuSO4 and C4H4KNaO6 center dot 4H(2)O) were added into the NaAlO2 solution, the color of the prepared coatings appearance changed from white to black. The effects of CuSO4 concentration and treatment time on the color of the coatings were investigated. The optimum formula of black coatings prepared by MAO has been acquired by a single-factor experiment and orthogonal experiment of L-9(3(4)) with four factors and three levels. The estimated optimum values of the process parameters are corresponding to NaAlO2 10 g/L, C4H4KNaO6 center dot 4H(2)O 1 g/L, CuSO4 1 g/L, and pH 11. The surface morphologies, structure, composition, and corrosion resistance of the MAO coatings were analyzed by scanning electron microscopy, X-ray diffraction (XRD), and electrochemical tests. The results of the above series of tests have shown that the properties and characteristics of the black coatings are improved. The black coating is irregular porous structure, which aperture size is about 0.1 similar to 0.2 mu m. The black coating mainly consists of MgO, MgAl2O4, and Cu3MgO4.

• 出版日期2014-9
• 单位沈阳理工大学