Combining anodising and anaphoresis to enhance the chemical protection of Al alloys

Aluminum alloys are promising alternatives to stainless steel in industrial applications due to their superior thermal conductivity and low weight. However, their use in the Food and Beverage industry requires effective surface treatments to withstand aggressive cleaning agents. This study evaluates the chemical resistance of polyurethane anaphoretic e-coatings on AA6082 alloy, examining the influence of curing temperature and the application of a prior anodic layer. Chemical resistance was assessed through immersion tests based on the Ecolab standard and electrochemical impedance spectroscopy. The results indicate that e-coatings cured at 180 °C exhibit superior barrier properties compared to those cured at standard conditions (120 °C) due to higher crosslinked network. Additionally, a thin anodic layer enhances the overall chemical protection by preventing e-coating swelling, as it limits reactions at the metal/coating interface.