High temperature oxidation interfacial growth kinetics in YSZ thermal barrier coatings with bond coatings of NiCoCrAlY with 0.25% Hf

▶ Isothermal oxidation of standard (STD) and vertically cracked (VC) TBCs has been investigated. ▶ The temporal TGO growth kinetics is parabolic in the temperature range between 900 and 1100 °C. ▶ Activation energies correspond to growth kinetics controlled by the diffusion of O2 in Al2O3. ▶ Variation in oxidation of TBCs is attributed to its microstructure and in-situ oxygen ingression. ▶ Doping TBC bond coat with Hf appears to have potential for enhancing the development of robust TBCs.