腐蚀电化学行为的影响
(上海大学 上海市现代冶金与材料制备重点实验室, 上海 200072)
摘 要: 采用阵列电极技术、扫描电子显微镜、自腐蚀电位、极化曲线和电化学阻抗等电化学方法研究F−对铜在5%Na2SO4溶液中腐蚀电化学行为的影响。结果表明：F−使铜表面的腐蚀电流密度增大，自腐蚀电位负移，电化学阻抗降低，铜表面各区域的自腐蚀电位标准方差由21. 08增加到28.31，阻抗标准方差由1.431增加到2.071。F−的存在使铜表面的腐蚀产物膜层的形貌及结构发生明显变化，腐蚀产物膜层由均匀致密分布的颗粒状转变为凹凸不平、疏松的多坑状。说明F−能加剧铜的腐蚀并破坏铜表面腐蚀产物膜层，加剧局部微区腐蚀的发生，铜腐蚀趋于不均匀。
关键字: 阵列电极；铜；F−；电化学阻抗谱；腐蚀
copper in 5％Na2SO4 solution by using electrode array
（Key Laboratory of Modern Metallurgy and Material Processing of Shanghai,
Shanghai University, Shanghai 200072, China）
Abstract:Using self-corrosion potential polarization curve and electrochemical impedance spectrum, the effect of F− on the corrosion electrochemical behavior of copper in 5%Na2SO4 solution was investigated by the electrode array and scanning electron microscopy. The results show that F− makes the current density increased, self-corrosion potential and electrochemical impedance decreased. The addition of F− leads to the variance of the self-corrosion potential increasing from 21.07 to 28.31 and that of total impedance increasing from 1.431 to 2.107. F− makes a great change on the morphology and structure of corrosion product film, and the structure of corrosion product film on the copper surface is transformed from uniform and compact structure to porous and uneven structure, which indicates that the presence of F− can erode a part of the corrosion product film and accelerate the localized corrosion. The corrosion of copper tends to be inhomogeneous when F− is added.
Key words: electrode array; copper; F−; electrochemical impedance spectrum; corrosion
