Optimization of anodizing cycles for enhanced performance

Anodizing of aluminium alloys is often used to improve appearance, corrosion resistance or adhesion with organic coatings, with properties of the oxides tailored by controlling the anodizing conditions. Some electrolytes can be used in relatively wide ranges of concentration, temperature and potential or current, while others display a narrower operational range. Optimization of the anodizing process is a non-trivial task, involving the control of voltage and electrolyte nature, concentration and temperature. In this work, potentiodynamic anodizing is proposed as a tool to characterize rapidly the behaviour of electrolyte/alloy combinations over a wide range of potential. It is shown that each electrolyte/alloy displays a fingerprint response, carrying information on the potential/current intervals suitable for porous oxide growth, on the oxidation behaviour of the second phase material on the alloy surface and on the maximum applicable potential or current