Effects of GdTaO4 content on the thermal properties and CMAS corrosion of Gd2Zr2O7-GdTaO4 composite ceramics

Thermal barrier coating materials play a crucial role ensuring the efficient and stable operation of gas turbines. The thermophysical and mechanical properties of GZ 1-x -GT x (x = 0, 0.1, 0.3, 0.5) composite ceramics, as well as the corrosion resistance properties against calcium magnesium aluminum silicate (CMAS) at 1250 °C, were investigated. The results indicated that the overall properties of Gd 2 Zr 2 O 7 -GdTaO 4 composite ceramics significantly improved with an increase in the second phase GdTaO 4 content. Among all the ceramics designed, GZ 0.5 -GT 0.5 exhibited the lowest thermal conductivity (0.920 W m −1  K −1 at 800 °C) and the highest fracture toughness (2.02 MPa m 1/2 ). Additionally, the molten CMAS interacted with the Gd 2 Zr 2 O 7 -GdTaO 4 composite ceramics, forming a dense apatite layer, which positively contributed to inhibiting CMAS infiltration. Considering its excellent thermal, mechanical, and corrosion resistance properties, Gd 2 Zr 2 O 7 -GdTaO 4 composite ceramics are considered a promising material for thermal barrier coatings.