Purpose

This study aims to investigate the effect of different pore diameter and pore length on corrosion properties of anodic aluminum oxide (AAO) film.

Design/methodology/approach

AAO layer was produced by two-step anodization aluminum in oxalic acid. The surface morphology was investigated using field emission scanning electron microscopy. The pore diameters were ranging from 25 ± 5 to 65 ± 5 nm and the pore length ranging from 5 to 17 µm. The corrosion properties of the AAO films was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy tests. Corrosion properties and morphology of the anodic films depending on anodization times and pore expansion times were evaluated.

Findings

All highlights of this work can be summarized with the following specified below: more treatment with the protective barrier layer of the solution as the pore diameter increases depends on the morphology of the nanotube structured AAO layer. The excellent corrosion resistance renders AAO films without pore expansion very promising. The oxide layer thickness does not affect the corrosion resistance. The better corrosion resistance of AAO films at low pore length can be ascribed to the barrier layer thickness and the more homogeneous structure. The presence of defects for the higher pore length decreases its corrosion resistance.

Originality/value

The AAO films were fabricated by a two-step anodization method in oxalic acid. The anodization times and pore expansion times affect the corrosion performance. The AAO film without pore expansion has good corrosion resistance. The corrosion resistance decreases as the pore length increases.

中文翻译：

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两步阳极氧化工艺生产的阳极氧化铝的电化学腐蚀行为评估

目的

本研究旨在研究不同孔径和孔径对阳极氧化铝膜的腐蚀性能的影响。

设计/方法/方法

通过在草酸中对铝进行两步阳极氧化来生产AAO层。使用场发射扫描电子显微镜研究了表面形态。孔直径是从25±5至65±5纳米和孔长度范围为5〜17  μ米。通过电位动力学极化和电化学阻抗谱测试分析了AAO膜的腐蚀性能。评价了阳极膜的腐蚀性能和形态，这取决于阳极氧化时间和孔扩张时间。

发现

这项工作的所有亮点可以概括为以下几点：随着孔径的增加，用溶液的保护性阻挡层进行的更多处理取决于纳米管结构的AAO层的形态。优异的耐腐蚀性使无孔膨胀的AAO膜非常有前途。氧化物层的厚度不影响耐腐蚀性。在低孔长度下，AAO膜的更好的耐腐蚀性可以归因于阻挡层的厚度和更均匀的结构。高孔径的缺陷的存在降低了其耐腐蚀性。

创意/价值

通过两步阳极氧化法在草酸中制备AAO膜。阳极氧化时间和孔扩张时间影响腐蚀性能。没有孔膨胀的AAO膜具有良好的耐腐蚀性。耐腐蚀性随着孔长度的增加而降低。