Investigation of exfoliation corrosion of rolled AA8090 Al-Li alloy using electrochemical impedance spectroscopy

来源期刊：中国有色金属学报(英文版)2003年第2期

论文作者：李劲风 张昭 曹发和 程英亮 张鉴清 曹楚南

文章页码：320 - 324

Key words：rolled AA8090 Al-Li alloy; exfoliation degree; electrochemical impedance spectroscopy (EIS)

Abstract: The exfoliation morphologies and electrochemical impedance spectroscopy (EIS) features of as-received rolled AA8090 Al-Li alloy in EXCO solution were studied. The EIS was simulated using an equivalent circuit. The results show that once the exfoliation occurs, the EIS is composed of two capacitive arcs at high frequency and mediate-low frequency; among them, the capacitance corresponding to high frequency (C₁) is originated from original flat alloy surface, while the capacitance corresponding to mediate-low frequency (C₂) from new interface exposed to EXCO solution due to the exfoliation and the ratio of C₂ to C₁ increases with exfoliation degree. It is advanced that the exfoliation degree can be quantitatively judged through this ratio.