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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (15): 1487-1493. 上一篇    下一篇

研究论文

镁合金在含F－的NaOH溶液中钝化行为的电化学研究

周琼宇1，盛敏奇1，钟庆东*,1,2，林海1，钮晓博2，王毅2   

  1. (1上海大学 上海市现代冶金与材料制备重点实验室 上海 200072)
    (2上海电力学院 能源与环境工程学院 上海 200090)
  • 投稿日期:2009-10-13 修回日期:2010-01-19 发布日期:2010-04-12
  • 通讯作者: 钟庆东 E-mail:qdzhong@shu.edu.cn
  • 基金资助:

    国家自然科学基金 (Nos. 50571059，50615024)；教育部新世纪优秀人才支持计划 (No. NCET-07-0536)；教育部创新团队计划 (No. IRT0739)资助项目.

Electrochemical Study for Magnesium Alloy Passivating Behavior in the NaOH Solution with F－

Zhou Qiongyu1 Sheng Minqi1 Zhong Qingdong*,1,2 Lin Hai1 Niu Xiaobo2 Wang Yi2   

  1. (1 Key Laboratory of Modern Metallurgy and Material Processing, Shanghai University, Shanghai 200072)
    (2 Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090)
  • Received:2009-10-13 Revised:2010-01-19 Published:2010-04-12

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采用极化曲线、电容-电位曲线、Mott-Schottky分析以及电化学阻抗(EIS)等电化学方法研究了镁合金在含F－ NaOH溶液中的阳极钝化行为. 结果表明, 在－1.2～1.8 V的电位范围内, 镁合金在含F－的NaOH溶液中发生阳极钝化. 所形成的钝化膜表现出n型半导体的导电特性. 在0.7～1.8 V的电位范围内, 随着F－浓度增大, 镁合金的阳极极化电流密度呈现出随着电位升高而逐渐增大的趋势, 随着F－浓度增大这一趋势逐渐减弱. 并且F－浓度的增大使得镁合金表面空间电荷层电容和钝化膜的载流子密度都不断减小. 通过极化曲线和电化学阻抗共同说明, 在5%的Na2SO4溶液中, NaOH溶液中阳极钝化后的镁合金随着钝化体系中F－浓度的增加其耐蚀性逐渐减弱.

关键词: 镁合金, 钝化, Mott-Schottky分析, 电化学阻抗

In this paper, the Tafel test, capacitance-potential curve, Mott-Schottky plot and electrochemical impedance spectroscopy were used to study the passivating behavior of magnesium alloy in the NaOH solution with F－. The results showed that there were anodic passivation of magnesium alloy in NaOH solution with F－ between －1.2 V and 1.8 V. The passivation film take on the conductive characteristics of n-type semiconductor. Between 0.7 V and 1.8 V the trend of the electricity density increased along with the increasing of F－ was restrained in evidence. At the same time, as the concentration of F－ increased, the capacitance and the carriers density decreased gradually. From the Tafel curves and the electrochemical impedance spectroscopy, it showed that the anti-corrosion of the passivation film of magnesium in 5% Na2SO4 electrolyte gradually decreased with the concentration of F－ increased in the NaOH solution.

Key words: magnesium alloy, passivation, Mott-Schottky analysis, electrochemical impedance spectroscopy