Multilayer Cr/CrC Coatings as a Sustainable Alternative to Cadmium in Aerospace Applications

This study investigates the development of multilayer Cr/CrC coatings as a sustainable alternative to cadmium (Cd) for corrosion protection in aerospace components exposed to aggressive environments. The coatings were deposited on AISI 4130 steel and silicon (100) substrates using unbalanced magnetron sputtering, a physical vapor deposition (PVD) technique. Advanced characterization was performed using SEM, AFM, XRD, and TEM, revealing the formation of nanocomposite structures whose characteristics depend on the carbon content and the deposition conditions. The electrochemical performance of the coatings was evaluated through electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution, and the results showed a significant improvement in corrosion resistance, particularly when a Cr anchor layer was incorporated. These findings confirm that Cr/CrC coatings represent a viable and environmentally friendly alternative to cadmium for aerospace applications.