The formation process of a lithium-based conversion layer on AA2024-T3 and its corrosion protective behavior are studied using electrochemical noise (EN). Wavelet transform, as well as noise resistance analysis, have been employed to interpret the EN data. The EN data confirmed five different stages during the conversion layer growth, accompanied by anodic dissolution, increasing corrosion protection of the conversion layer, and adsorption, growth and desorption of hydrogen bubbles simultaneously. The detachment of hydrogen bubbles, localized and uniform corrosion generate different features in the EN signals with energy maxima in high, intermediate and low frequency bands, respectively. In addition, EN results show that the lithium-based conversion layer still provides efficient protection after re-immersion in a corrosive environment, even though localized damage occurs. Moreover, the EN data corresponds well with the morphological layer formation and breakdown observed with microscopy techniques. The results demonstrate that EN is a powerful tool to provide continuous time- and frequency-resolved information about inhibition efficiency.

使用电化学噪声 (EN) 研究了 AA2024-T3 上锂基转换层的形成过程及其腐蚀防护行为。小波变换以及抗噪声分析已被用于解释 EN 数据。EN数据证实了转化层生长过程中的五个不同阶段，伴随着阳极溶解、转化层腐蚀保护的增加以及氢气泡的同时吸附、生长和解吸。氢气泡的脱离、局部腐蚀和均匀腐蚀在 EN 信号中产生了不同的特征，分别在高、中、低频段具有能量最大值。此外，EN 结果表明，锂基转换层在重新浸入腐蚀环境后仍能提供有效保护，即使发生局部损坏。此外，EN 数据与显微镜技术观察到的形态层形成和分解很好地对应。结果表明，EN 是一种强大的工具，可提供有关抑制效率的连续时间和频率分辨信息。