Thermal barrier coating adherence to Hf-modified B2 NiAl bond coatings

The durability of thermal barrier coatings (TBCs) deposited on Hf-modified B2 NiAl bond coatings has been investigated under thermal cycling conditions. The rate of bond coat oxidation and rumpling during thermal cycling was characterized and the cycles to failure measured. The location of cycling-induced cracks in the TBC multilayer was influenced by the bond coat composition but variation in TBC lifetime was small, despite the different failure modes. Analysis of the cycle-dependent degradation phenomena demonstrate a trade-off between rumpling resistance and interfacial toughness as a function of bond coat composition.