Oxidation behaviour of new electrolytically synthesized ceria modified platinum γ/γ′ coatings

This study investigates the influence of an electrodeposited ceria coating on the high temperature performance of a raw and platinum-diffused Ni-based superalloy. Both the CeO2 and the Pt/CeO2 coatings drastically improved the oxidation resistance of the substrate under isothermal and cyclic conditions at 1100 °C. In particular, whereas Pt-free CeO2-coated samples grew a duplex oxide scale composed of a top NiAl2O4 layer and an inner Al2O3, Pt/CeO2 coatings exhibited an exclusive α-Al2O3 scale that tended to rumple. None of these systems developed a secondary reaction zone (SRZ) because of the absence of any chemical gradient of aluminum between the substrate and the coating/oxide scale system.