Arc ion plated-Cr2O3 intermediate film as a diffusion barrier between NiCrAlY and γ-TiAl

The effectiveness of an arc ion plated-Cr2O3 intermediate film as a diffusion barrier between NiCrAlY and gamma-TiAl was evaluated by annealing at 1000 degrees C. The results showed that Cr2O3 acted as an active diffusion barrier by formation of two continuous Al-rich oxide layers at both the TiAl/Cr2O3 and Cr2O3/NiCrAlY interfaces, suppressing the inward diffusion of Ni from NiCrAlY overlay coating to gamma-TiAl substrate effectively. (C) 2009 Elsevier Ltd. All rights reserved.