Electrochemical performance of microarc oxidation films formed on AZ91D alloy in two group electrolytes
Electrochemical performance of microarc oxidation films formed on AZ91D alloy in two group electrolytes作者机构:State Key Laboratory of Die and Mould Technology Huazhong University of Science and Technology
出 版 物:《中国有色金属学会会刊:英文版》 (Transactions of Nonferrous Metals Society of China)
年 卷 期:2005年第15卷第4期
页 面:777-783页
核心收录:
学科分类:080503[工学-材料加工工程] 0806[工学-冶金工程] 08[工学] 0818[工学-地质资源与地质工程] 0815[工学-水利工程] 0805[工学-材料科学与工程(可授工学、理学学位)] 0703[理学-化学] 0813[工学-建筑学] 0814[工学-土木工程] 0702[理学-物理学]
基 金:Project(2002ABB051) supported by the Natural Science Foundation of Hubei Province and the Research Foundation ofHUST China
摘 要:The phase composition and electrochemical performances of microarc oxidation(MAO) films prepared on AZ91D alloy by using step-down current method in a phosphate electrolyte(P-film) and silicate electrolyte(Si-film) were studied. The results show that P-film is mainly composed of Mg, MgAl2O4 and MgO, and Si-film is composed of Mg2SiO4 and MgO. There clearly exists a fluoride-enriched zone with the thickness of about 12μm for P-film and 0.71μm for Si-film at the MAO coating/substrate interface. The electrochemical tests show that both P-film and Si-film can enhance the corrosion resistance of AZ91D magnesium alloy significantly. The corrosion failure process of the two films in 5%(mass fraction) NaCl solution is quite different.