Study on phosphate conversion coatings for Mg-Li alloy

被引：0
|
作者：
Jiang X. [1 ]
Zhang C.-H. [1 ]
Gao L.-L. [1 ]
机构：
[1] College of Material Science and Chemical Engineering, Harbin Engineering University
来源：
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University | 2010年 / 31卷 / 03期
关键词：
Chemical conversion; Coating structure; Corrosion resistance; Mg-Li alloy; Phosphate;
D O I：
10.3969/j.issn.1006-7043.2010.03.022
中图分类号：
学科分类号：
摘要：
In order to improve the corrosion resistance of Mg-Li alloys, a room temperature chromium-free phosphate surface conversion technique for Mg-Li alloys was investigated. The corrosion resistance and structure of the phosphate conversion coating were characterized by investigating its polarization curves and evolved hydrogen using scanning electron microcopy (SEM) and energy dispersive spectrometer (EDS). The results indicated that the optimum conversion time was 9 min and the phosphate conversion coating increased the corrosion potential, reduced the corrosion current and the hydrogen evolution rate of the Mg-Li alloy, improving its corrosion resistance. The phosphate conversion coating, which formed flower-shaped clusters covering the Mg-Li alloy surface, was composed of Mg, O, P and a small amount of C, Mn, K, and Na. Analysis of the hardness and adhesion properties showed that the hardness of the phosphate conversion coating was obviously higher than that of an untreated Mg-Li alloy, and the adhesion property between phosphate conversion coating and Mg-Li alloy was excellent. Therefore, the phosphate conversion coating could provide good protection for a Mg-Li alloy.
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页码：391 / 394
页数：3
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