Abstract This work explores the use of an AC-DC-AC method for the faster evaluation of the anticorrosion performance provided by anodic films grown on an aerospace aluminium alloy. The test is based on the cyclic application of a cathodic potential step followed by a step of free corrosion and, finally, the measurement of the electrochemical impedance response of the treated surface. During the cathodic polarization step in each cycle, alkalinisation is induced on the specimen surface, which results in attack of the porous anodic oxide. The effects of the magnitude and the duration of the cathodic polarization step are considered, and the impedance responses measured during the various cycles are compared to the responses measured during natural immersion for longer times. The methodology is applied for two types of anodic oxides, which are similar for thicknesses but differ for pore morphology and corrosion behaviour. Qualitative correlation is found between the electrochemical testing method and longer term immersion tests at the free corrosion potential, suggesting that the methodology can provide a faster estimation of anticorrosion performance compared to immersion test.

中文翻译：

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探索使用 AC-DC-AC 技术加速评估铝合金阳极膜的防腐性能

摘要 这项工作探索了使用 AC-DC-AC 方法更快地评估在航空航天铝合金上生长的阳极薄膜提供的防腐性能。该测试基于阴极电位步骤的循环应用，然后是自由腐蚀步骤，最后是对处理过的表面的电化学阻抗响应的测量。在每个循环的阴极极化步骤中，样品表面会发生碱化，这会导致多孔阳极氧化物的腐蚀。考虑了阴极极化步骤的幅度和持续时间的影响，并将在各种循环期间测量的阻抗响应与在更长时间内自然浸没期间测量的响应进行比较。该方法适用于两种类型的阳极氧化物，它们的厚度相似，但孔隙形态和腐蚀行为不同。在自由腐蚀电位下，电化学测试方法与长期浸泡测试之间存在定性相关性，这表明与浸泡测试相比，该方法可以更快地评估防腐性能。