Thermal barrier coatings adherence and spallation: Interfacial indentation resistance and cyclic oxidation behaviour under thermal gradient

One of the most critical damage of Thermal barrier coatings (TBC) results from the spallation of the yttria stabilized zirconia (YSZ) layer. The toughness of the interface between the bond coat (BC) and the top coat (TC), measured using indentation technique, is the main parameter that controls the adherence of the zirconia layer. Cyclic oxidation tests, with and without through thickness thermal gradient, are performed and monitored to investigate spallation mechanisms and overall TBC durability.