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

Abstract

Thermal barrier coating materials play a crucial role ensuring the efficient and stable operation of gas turbines. The thermophysical and mechanical properties of GZ1-x-GTx (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 Gd2Zr2O7-GdTaO4 composite ceramics significantly improved with an increase in the second phase GdTaO4 content. Among all the ceramics designed, GZ0.5-GT0.5 exhibited the lowest thermal conductivity (0.920 W m−1 K−1 at 800 °C) and the highest fracture toughness (2.02 MPa m1/2). Additionally, the molten CMAS interacted with the Gd2Zr2O7-GdTaO4 composite ceramics, forming a dense apatite layer, which positively contributed to inhibiting CMAS infiltration. Considering its excellent thermal, mechanical, and corrosion resistance properties, Gd2Zr2O7-GdTaO4 composite ceramics are considered a promising material for thermal barrier coatings.