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Nickel aluminides are ideal materials for protective coatings because they possess high-temperature oxidation resistance and low corrosion rates in marine atmospheres. In this work, a double layered coating was formed by the electrochemical deposition of an initial Ni layer followed by an Al top layer deposited by pack cementation. The coatings were found to contain several Ni-Al on the upper areas and Ni-Fe phases on the substrate/coating interface, as a result of Ni diffusion during the aluminization step. Thermogravimetric high temperature oxidation tests and electrochemical corrosion measurements revealed significant increase of the samples’ resistance, compared to the uncoated steel.

Conventional anodizing and carbon deposition coating treatment is applied to open-cell Al foams aiming to enhance the corrosion performance of the material. The Al foams used were fabricated utilizing a dissolution-sintering technique based on powder metallurgy route. X-ray computed tomography and SEM were utilized to assess the structural characteristics of the produced foams. The corrosion properties of all samples produced were assessed experimentally, employing both polarization curves and EIS measurements utilizing a 0.6 M NaCl aqueous solution. Corrosion mechanisms along with appropriate modeling circuits were deduced. Both anodizing and carbon coatings resulted in an augment of the corrosion properties of the Al foams.