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| Influences of C3H8O3 Concentration on Formation and Characteristics of MAO Coatings on AZ91D Magnesium Alloy |
| WANG Shuyan1, 2, XIA Yongping1, LIU Li1 |
1. School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China;
2. Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003, China |
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Abstract Microarc oxidation (MAO) coatings were obtained on the AZ91D magnesium alloy by AC pulse electrical source in a silicate-aluminate based composite electrolyte containing various concentrations of C3H8O3. The morphologies and thickness of ceramic coatings were characterized by SEM and layer thickness meter, respectively. The corrosion resistance of coatings in a 3.5%NaCl neutral solution was evaluated by the immersion test and electrochemical impedance spectroscopy (EIS). The results showed that the striking voltage and final voltage increased gradually with the increase of C3H8O3 concentration during the MAO process. With the increase of C3H8O3 concentration in the electrolyte, the corrosion resistance of the coatings increased at first and then decreased gradually, however, the variation of the coating thickness was not obvious. The EIS results showed that the corrosion resistance of the coatings was influenced by the inner dense layer. The coating exhibited better corrosion resistance in the electrolyte containing 5 mL/L C3H8O3 due to its relatively compact microstructure.
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[1] Zhong H, Liu P Y, Zhou T T. Applications and prospects of magnesium and its alloys in aerospace [J]. Aviat. Eng. Maint., 2002, (4): 41-42
(钟皓, 刘培英, 周铁涛. 镁及镁合金在航空航天中的应用及前景 [J]. 航空工程与维修, 2002, (4): 41-42)
[2] Zi B T, Wang H. Magnesium alloy and its applications in industry [J]. Chin. J. Rare Met., 2004, 28(1): 229-232
(訾炳涛, 王辉. 镁合金及其在工业中的应用 [J]. 稀有金属, 2004, 28(1): 229-232)
[3] Caton P D. Magnesium-an old material with new applications [J]. Mater. Des., 1991, 12(6): 309-316
[4] Gray J E, Luan B. Protective coatings on magnesium and its alloys-a critical review [J]. J. Alloys Compd., 2002, 336(1-2): 88-113
[5] Liang J, Srinivasan P B, Blawert C, et al. Comparison of electrochemical corrosion behavior of MgO and ZrO2 coatings on AM50 magnesium alloy formed by plasma electrolytic oxidation [J]. Corros. Sci., 2009, 51(10): 2483-2492
[6] Srinivasan P B, Blawert C, Dietzel W. Dry sliding wear behavior of plasma electrolytic oxidation coated AZ91 cast magnesium alloy [J]. Wear, 2009, 266(11-12): 1241-1247
[7] Zhang R F, Zhang S F, Duo S W. Influence of phytic acid concentration on coating properties obtained by MAO treatment on magnesium alloys [J]. Appl. Surf. Sci., 2009, 255(18): 7893-7897
[8] Wang L, Chen L, Yan Z C, et al. The influence of additives on the stability behavior of electrolyte discharges and PEO films characteristics [J]. J. Alloys Compd., 2010, 493(1-2): 445-452
[9] Lv G H, Chen H, Wang X Q, et al. Effects of additives on structure and corrosion resistance of plasma electrolytic oxidation coating on AZ91D magnesium alloy in phosphate based electrolyte [J]. Surf. Coat. Technol., 2010, 205(s1): s6-s40
[10] Zhao F, Liao A D, Zhang R F, et al. Effects of sodium tungstate on properties of micro-arc coatings on magnesium alloys [J]. Trans. Nonferrous Met. Soc. Chin., 2010, 20(s2): s683-s687
[11] Wu D, Liu X D, Lu K, et al. Influence of C3H8O3 in the electrolyte on characteristics and corrosion resistance of the microarc oxidation coatings formed on AZ91D magnesium alloy surface [J]. Appl. Surf. Sci., 2009, 255(16): 7115-7120
[12] Ikonopisov S. Theory of electrical breakdown during formation of barrier anodic films [J]. Electrochim. Acta, 1977, 22(10): 1077-1082
[13] Wang H B, Fang Z G, Jiang B L. Microarc Oxidation Technology and Its Applications in Sea Environments [M]. Beijing: National Defense Industry Press, 2010
(王虹斌, 方志刚, 蒋百灵. 微弧氧化技术及其在海洋环境中的应用 [M]. 北京: 国防工业出版社, 2010)
[14] Jiang B L, Xia T, Shi H Y, et al. The study on dielectric strength and corrosion resistance of ceramic coating prepared by micro-arc oxidation on magnesium alloy [J]. Trans. Mater. Heat Treat., 2005, 26(2): 82-85
(蒋百灵, 夏天, 时惠英等.镁合金微弧氧化陶瓷层的绝缘强度及耐蚀性的研究 [J]. 材料热处理学报, 2005, 26(2): 82-85)
[15] Ghasemi A, Raja V S, Blawert C, et al. The role of anions in the formation and corrosion resistance of the plasma electrolytic oxidation coatings [J]. Surf. Coat. Technol., 2010, 204(9-10): 1469-1478
[16] Su P B, Wu X H, Guo Y, et al. Effects of cathode current density on structure and corrosion resistance of plasma electrolytic oxidation coatings formed on ZK60 Mg alloy [J]. J. Alloys Compd., 2009, 475(1-2): 773-777
[17] Zhang J Q. Electrochemical Measurement Technology [M]. Beijing: Chemistry Industry Press, 2010
(张鉴清. 电化学测试技术 [M]. 北京: 化学工业出版社, 2010)
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