Tribocorrosion Characteristics of Hard Anodized Al Alloys on Hydrogen Valve Application for Fuel Cell Electric Vehicles

Abstract

In this study, the electrochemical and mechanical characteristics of 6061‐T6 aluminum alloy and hard anodized specimens are investigated after tribocorrosion experiments with rotational speed in dry, distilled water, and sulfuric acid solution. The tribocorrosion experiments indicate that the corrosion potential of aluminum alloys and hard anodized specimens decrease with the initiation of friction/wear. In particular, the increase in the wear track width of an aluminum alloy and the exposure of the base material by completely destroying the anodized layers of the hard anodized specimens dramatically decrease the corrosion potential. Compared to the dry conditions, both the width and depth of damage in the distilled water and sulfuric acid solution increase dramatically. However, damage in the distilled water and sulfuric acid solutions do not present a significant difference. The results are attributed to the fact that the presence of fluid has a greater impact on damage degree in a material than corrosion. In particular, the brittleness and porosity of a hard anodized layer facilitates the impingement and penetration of fluid, making it relatively easy to generate and propagate cracks. These cracks accelerate the degradation and damage to the material by synergistic effects of wear and corrosion.