Abstract: The corrosion behavior and electrochemical impedance spectroscopy (EIS) features of 8090 AI-Li alloys in EXCO solution were investigated, and the EIS was simulated using an equivalent circuit. At the beginning of immersion in EXCO solution, the EIS is comprised by a depressed capacitive arc at high-mediate frequency and an inductivearc at low frequency, and the inductive component decreases and disappears with immersion time. Once exfoliation or severe pitting corrosion is produced, two capacitive arcs appear in the EIS. These two capacitive arcs are originated from the two parts of the corroded aUoy surface, the original flat alloy surface and the new inter-face exposed to the aggressive EXCO solution due to the exfoliation or pitting corrosion.Some corrosion development features of 8090 AI-Li alloys in EXCO solution can be obtained through simulated EIS information.

Key words: 8090 Al-Li alloy, exfoliation, electrochemical impedence spectroscopy (EIS)