Corrosion behavior of Al₂O₃-modified Yb₂SiO₅ environmental barrier coating under water vapor conditions at 1500 °C

Al₂O₃-modified Yb₂SiO₅ was prepared as environmental barrier coating (EBC), and the water vapor corrosion behavior at 1500 °C was investigated. The residual phase, Yb₂O₃, was observed in the as-prepared coating besides Yb₂SiO₅ and Al₂O₃, which preferred to react with Al₂O₃ to form toughened Yb₃Al₅O₁₂, meanwhile gave rise to the growth of diffusion layer (Yb₂Si₂O₇) and prevented the generation of the porous region under EBC layer after exposure. The growth stress of the TGO layer and the thermal stress during cooling were the driving sources of delamination, which limited the service life of EBCs. Conclusions on phase transformation and interface evolution in this work are expected to guide the design of rare earth silicate EBCs.