CMAS Corrosion Resistance Behavior and Mechanism of Hf6Ta2O17 Ceramic as Potential Material for Thermal Barrier Coatings

Thermal barrier coatings (TBCs) have been seriously threatened by calcium-magnesium-alumina-silicate (CMAS) corrosion. The search for novel ceramic coatings for TBCs with excellent resistance to CMAS corrosion is ongoing. Herein, CMAS corrosion resistance behavior and the mechanism of a promising Hf6Ta2O17 ceramic coating for TBCs are investigated. The results show that temperature is the most important factor affecting the CMAS behavior and mechanism. At 1250 degrees C, the corrosion products are composed of dense reaction products (HfSiO4, CaXHf6-xTa2O17-x) and CMAS self-crystallization products. At 1300 and 1400 degrees C, the corrosion products are mainly dense CaTa2O6 and HfO2, which prevent further CMAS infiltration.