腐蝕電化學(xué)行為的影響
(上海大學(xué) 上海市現(xiàn)代冶金與材料制備重點實驗室, 上海 200072)
摘 要: 采用陣列電極技術(shù)、掃描電子顯微鏡、自腐蝕電位、極化曲線和電化學(xué)阻抗等電化學(xué)方法研究F−對銅在5%Na2SO4溶液中腐蝕電化學(xué)行為的影響。結(jié)果表明：F−使銅表面的腐蝕電流密度增大，自腐蝕電位負(fù)移，電化學(xué)阻抗降低，銅表面各區(qū)域的自腐蝕電位標(biāo)準(zhǔn)方差由21. 08增加到28.31，阻抗標(biāo)準(zhǔn)方差由1.431增加到2.071。F−的存在使銅表面的腐蝕產(chǎn)物膜層的形貌及結(jié)構(gòu)發(fā)生明顯變化，腐蝕產(chǎn)物膜層由均勻致密分布的顆粒狀轉(zhuǎn)變?yōu)榘纪共黄健⑹杷傻亩嗫訝睢Ｕf明F−能加劇銅的腐蝕并破壞銅表面腐蝕產(chǎn)物膜層，加劇局部微區(qū)腐蝕的發(fā)生，銅腐蝕趨于不均勻。
關(guān)鍵字: 陣列電極；銅；F−；電化學(xué)阻抗譜；腐蝕
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
