CMAS corrosion behavior of Sc doped Gd2Zr2O7 /YSZ thermal barrier coatings and their corrosion resistance mechanisms

YSZ thermal barrier coatings (TBCs) are vulnerable to calcium-magnesium-alumina-silicate (CMAS) attack, and a CMAS resistant TBC of Sc doped Gd2Zr2O7/YSZ are developed in this study. At 1250 degrees C, corrosion products form a reaction layer at the CMAS/coating interface, which largely suppresses CMAS further infiltration. Compared with Gd2Zr2O7, Sc doped Gd2Zr2O7 has a higher ability to keep its lattice structure in the presence of CMAS, which is beneficial to maintain the coating microstructure under CMAS conditions, alleviating the coating degradation. First-principles calculation was conducted to investigate the corrosion products formation mechanisms, and the characteristics of CMAS/reaction layer and reaction layer/coating interfaces.

Automated summary

A CMAS resistant TBC of Sc doped Gd2Zr2O7/YSZ has been developed, which has a higher ability to maintain its lattice structure and coating microstructure under CMAS conditions, alleviating coating degradation.