Electrochemical impedance characteristics of pure Al and Al-Sn alloys in NaOH solution
Electrochemical impedance characteristics of pure Al and Al-Sn alloys in NaOH solution
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DOI：
10.1016/s0010-938x(00)00060-3
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发表时间：
2001-03
影响因子：
8.3
通讯作者：
Kyung-Keun Lee;K. Kim
中科院分区：
文献类型：
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作者：
Kyung-Keun Lee;K. Kim
本文报道了纯铝和铝锡合金在碱性溶液中的交流阻抗分析。发现纯铝的阻抗谱在中频处由两个相交的电容性回线组成。高频和低频下的电容振荡分别是由于金属/表面氧化膜界面的电荷转移反应和表面氧化膜的介电性质引起的。在中频的感应回路的结果从表面电荷积聚在金属/氧化物膜界面所造成的引入和运输通过氧化物膜的Al 3+离子的速率差。Al-Sn合金的阻抗谱随电极电位的变化呈现出离散性。在Al处于活化状态而Sn处于免疫状态的电位范围内，Al-Sn合金的阻抗谱由一个电容性的峰组成，然后随着电极电位的变化，转变为一个表示负极化电阻的反峰。此外，铝锡合金具有相同的阻抗谱观察纯铝在电位，其中锡溶解。
Electrochemical impedance analysis of pure Al and Al–Sn alloys in alkaline solution is reported. The impedance spectrum of pure Al is found to consist of two intersecting capacitive semicircles with a loop at intermediate frequencies. The capacitive semicircles occurring at the high and low frequencies are due to the charge transfer reaction at the metal/surface oxide film interface and the dielectric properties of surface oxide film, respectively. The inductive loop at medium frequencies results from the surface charge build-up at the metal/oxide film interface caused by the rate difference of introduction into and transport through the oxide film of Al3+ions. Al–Sn alloys show discrete impedance spectra according to their electrode potential. In the potential range where Al is in the active state and Sn is in immunity, the impedance spectra of Al–Sn alloys are composed of only a capacitive semicircle and then converted into a reverse semicircle indicating a negative polarization resistance with the electrode potential. In addition, Al–Sn alloys have the same impedance spectra as that observed for pure Al at the potentials in which Sn is dissolved.