Effect of Hf addition in (Ni,Pt)Al bond coat on thermal cycling behavior of a thermal barrier coating system at 1100 °C

Thermal cycling behavior of thermal barrier coatings deposited on Hf-doped (Ni,Pt)Al bond coats were investigated, comparing with conventional (Ni,Pt)Al at 1100 degrees C, to elucidate the effect of Hf addition into (Ni,Pt)Al bond coat on failure mode of TBCs. The results revealed that thermal cycling resistance of TBCs was significantly improved with addition of Hf, where relatively lower oxidation rate constant and decreased scale rumpling tendency were achieved. The effects of Hf incorporation on scale rumpling tendency and failure modes of the TBCs were discussed. Moreover, residual stress, Young's modulus and hardness in top coat were determined with increasing thermal cycles.