Influence of Li addition to passivity behavior of pure Al in NaCl acidic solution

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• 作者：H. N. Wang ; C. Z. Liu ; L. Lu ; R. S. Li and D. Lin
• 刊名：Materials and Corrosion
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：68
• 期：1
• 页码：58-64
• 全文大小：768K
• ISSN：1521-4176

文摘

The passive films on pure Al, Al-1Li alloy, and Al-2Li alloy were formed at a passive potential of −0.75 V_SCE by potenyiostatic polarization for 30 min in 0.1 mol/L NaCl acidic solution (pH = 2). The corrosion resistances, semiconducting properties, and compositions of the passive films were, respectively, investigated by electrochemical impedance spectrum (EIS), Mott–Schottky (M–S) approach, and X-ray depth photoelectron spectroscopy (XPS). The results showed that 1 and 2 wt% Li addition to pure Al improved its passivity resistance, especially for 2 wt% Li. Moreover, Li participated in the passive film formation process. The incorporation of Li₂O by filling in the lattice interstitial position of Al₂O₃ could decrease oxygen vacancy concentration but did not change the n-type semiconductor character of the passive films on pure Al. The increasing of passivity resistance was attributed to the decreasing of oxygen vacancy concentration and the increasing of Fermi energy of the passive films due to Li addition to pure Al.