摘要
通过向锰系磷酸盐溶液中添加促进剂,在AM 60镁合金表面得到了耐蚀性良好的化学转化膜。用电化学方法研究了该转化膜在质量分数为3.5%的NaCl溶液中的腐蚀行为。动电位极化曲线结果表明:转化膜的自腐蚀电位相对于合金基体的大幅正移,自腐蚀电流密度明显减小,但阳极钝化电位区间不很明显。EIS结果表明:转化膜的高频容抗弧曲率半径较合金基体的明显增大。SEM研究表明:转化膜呈结晶态,晶粒排列较为紧凑,无明显裂纹出现。EDX分析表明:转化膜表面含有O,P和Mn等元素。
A chemical conversion film with good corrosion resistance was obtained on the surface of AM60 magnesium alloy in manganese phosphate bath, to which an accelerant was added. The corrosion behavior of the film in 3.5% NaCl was investigated by electrochemical methods. The dynamic potential polarization curve tests show that the self-corrosion potential of the film shifts positively in large range and the corrosion current density decreases obviously comparing with that of the alloy substrate, however, the passivation potential extent in anodic branch of the polarization curve is not distinct. Electrochemical impedance spectroscopy （EIS） measurement illustrates that the culvature radius of capacitive impedance arc in high frequency is increased significantly comparing with that of the alloy substrate. SEM observation indicates that the film is presented in crystal form and the crystal grains are arranged compactly with no obvious cracks. EDX analysis illustrates that the film surface is composed of oxygen and phosphor as well as manganese.
出处
《电镀与环保》
CAS
CSCD
北大核心
2011年第3期27-30,共4页
Electroplating & Pollution Control
基金
国家自然科学基金(50971093)资助项目
