Superior performance of YSZ thermal barrier coatings with oxide dispersion strengthened bond coats

Advanced thermal barrier coatings are essential to increase the efficiency of next-generation gas turbine engines. One limiting factor of the TBC lifetime is the growth of the TGO during thermal exposure resulting in accelerated crack growth at the top coat-bond coat interface. The oxidation resistance and the temperature of the bond coat are key factors influencing the TGO growth rate. Aluminum oxide dispersion strengthened (ODS) bond coats provide a slower oxygen scale growth during thermal exposure in comparison to standard bond coats. ODS powders with higher aluminum oxide additions were produced to fit the CTE of the ODS bond coat to the one of the top coat. The thermal cycling performance of the ODS bond coat TBC systems combined with a single crystal substrate ERBO 1 was superior in comparison to previous samples. Cross sections of the samples were analyzed by SEM, TEM and laser microscope. The cyclic life of the samples was evaluated especially with respect to diffusion processes, material properties, and bond coat temperature.