The preparation and corrosion behaviors of MAO coating on AZ91D with rare earth conversion precursor film

被引：142
作者：
Cai, Jingshun [1 ]
Cao, Fahe [1 ]
Chang, Linrong [1 ]
Zheng, Junjun [1 ]
Zhang, Jianqing [1 ,2 ]
Cao, Chunan [1 ,2 ]
机构：
[1] Zhejiang Univ, Dept Chem, Hangzhou 310027, Zhejiang, Peoples R China
[2] Chinese Acad Sci, State Key Lab Corros & Protect, Inst Met Res, Shenyang 110016, Peoples R China
来源：
APPLIED SURFACE SCIENCE | 2011年 / 257卷 / 08期
关键词：
Magnesium alloy; Rare earth conversion film; Micro-arc oxidation; Porosity; MG-AL ALLOYS; MAGNESIUM ALLOYS; ELECTROLYTE; CERIUM; RESISTANCE; PHOSPHATE;
D O I：
10.1016/j.apsusc.2010.11.153
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
A novel kind of micro-arc oxidation (MAO) coating was prepared on magnesium alloy surface coated with rare earth conversion film (RE-film) in an alkaline aluminum oxidation electrolyte by AC power source. Inspection of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) microspectroscopy, the structure and composition of MAO coating formed on AZ91D with RE-film under different applied voltages were investigated and the performance of the optimized MAO coating compared with the MAO coating directly formed on magnesium alloy. As the pretreatment of magnesium alloy with RE-film, the cerium oxides can be incorporated into the MAO coatings, reduce porosity of the MAO coating surface and enhance the thickness of MAO coating. These structure features and the cerium oxides incorporated into the MAO coating result in greatly improved corrosion resistance. Base on electrochemistry impedance spectroscopy (EIS) measurement, the electronic structure and composition analysis of the MAO coating, a double-layer structure, with a compact inner layer and a porous outer layer, of the coating was proposed for understanding its corrosion process. (C) 2010 Elsevier B.V. All rights reserved.
引用
收藏
页码：3804 / 3811
页数：8
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