Synergistic effect of Re-base diffusion barrier and Pt modification on the oxidation behaviour of NiCrAlY coatings

The cyclic oxidation behaviour at 1050 °C and isothermal oxidation behaviour at 1100 °C of a low-diffusion Pt-modified NiCrAlY coating with Re-base diffusion barrier were investigated, compared with conventional NiCrAlY, Pt-free NiCrAlY with Re-base diffusion barrier and Pt-modified NiCrAlY without Re-base diffusion barrier coatings. The results revealed that Pt-modified NiCrAlY coating with Re-base diffusion barrier exhibited the best oxidation resistance and lowest interdiffusion extent. The role of Re-base diffusion barrier in inhibiting elemental interdiffusion and the contribution of Pt to the growth rate and adhesion of Al2O3 scale, as well as the long-term stability of Re-base diffusion barrier, are discussed.