High-temperature oxidation of NiCrAlY/(ZrO2-Y2O3 and ZrO2-CeO2-Y2O3) composite coatings

Metal/ceramic coatings of Ni-22Cr-10Al-1Y/ZrO2-8Y2O3 and Ni-22Cr-10Al-1Y/ZrO2-25CeO2-2.5Y2O3, which were prepared by the air plasma spray method, were oxidized at 900, 1000, and 1100 °C in air. The major oxidation product was α-Al2O3, which was formed by the reaction of inwardly penetrating oxygen ions with Al at the metal/ceramic phase boundaries. The oxidation of Ni and, moreover, Cr also occurred to a certain extent.