Impact of anodizing on the hydrogen permeation of aluminum determined via Devanathan-Stachurski-method

Aluminum alloys are increasingly being used instead of high-strength steels in the field of hydrogen technologies, due to their reduced susceptibility to hydrogen embrittlement. Nevertheless, hydrogen diffusion through the material needs to be reduced, mainly because aluminum alloys exhibit a substantially increased permeation rate compared to high-purity aluminum. Aluminum oxide is suitable for this purpose and is most easily applied by anodizing. The Devanathan-Stachurski-method is selected for the quantification of hydrogen permeation. Applying this method to anodized layers, a novel approach in this context, requires tailored sample preparation to ensure in-situ electrochemical hydrogen evolution. An adsorption Pd coating proved to be suitable. The t lag -method is validated for calculating the effective diffusion coefficient from the measurement data. As a conclusion, the results demonstrate that hydrogen diffusion through anodized layers can be quantified by means of the Devanathan-Stachurski–method in an accurate and reproducible way. Additionally, it shows that anodized layers markedly reduce hydrogen diffusion.