Multilayer PEO coatings with encapsulated cerium for active corrosion protection of aluminium

This work aims to develop multilayer coating systems to enhance the long-term corrosion performance of aluminium-based components. The systems consists of a high-performance ceramic matrix that provides physical barrier protection, and a topcoat layer containing encapsulated Ce-based inhibitors, offering active corrosion protection through controlled released mechanisms. Two types of nanoparticles were used for the encapsulation, zeolite and halloysite nanotubes, each with different release triggers and kinetics. Multifunctional coatings demonstrated a superior corrosion performance compared to the passive unmodified coatings. Inhibitor release from the nanoparticles was triggered by ionic exchange processes and changes in pH associated with corrosion activity.