This study investigated the damage prevention potential range of anodized 5083-H321 aluminum alloy under a cavitation-erosion environment in seawater. Various applied potential conditions were determined through the cathodic polarization experiment. Then cavitation-erosion experiments were conducted with the applied potentials and the current density, weight loss, and surface damage depth were analyzed. The results presented excellent cavitation-erosion resistance in the concentration polarization section (−1.0~−0.8 V).

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To evaluate the corrosion resistance of the 5xxx series (5052-O and 5083-H321) Al-Mg alloys and the 6xxx series (6061-T6) Al-Mg-Si alloys used in marine environments, various electrochemical experiments were conducted and the surface damages were analyzed. In the results of cathodic polarization experiments, 6061-T6 was judged to have the best anticorrosive properties because of the lowest required current density in the cathodic protection potential section and of uniform calcareous deposit formed on the surface. In addition, in the results of cyclic polarization experiments, the pitting resistance of 6061-T6 was shown to be the highest During the anodic polarization experiments 6061-T6 presented the least surface damage. Through electrochemical experiments, 6061-T6 was selected as an aluminum alloy material with excellent corrosion resistance in marine environments.

In this study, the influences of electrolytic gas generation on the surface of aluminum as a cushioning media against cavitation bubbles were experimentally investigated. The electrolytic gas evolution was controlled by applying electric current to the metal with different polarity and current densities. The surface of the metal specimen was either polarized anodically or cathodically while simultaneously being subject to vibratory cavitation. It was revealed that the surface damage behavior was mainly dependent on the current densities applied to the metal. It was apparent that a moderate current density range of between [Formula: see text] and [Formula: see text] A/cm2 applied cathodically can produce electrolytic gas evolution to cushion the cavitation bubbles sufficiently. However, application of a too a high current density (greater than [Formula: see text] A/cm[Formula: see text] may lead to cathodic corrosion of Al alloys.

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