Performance analysis of (Y1-xDyx)2CrTaO7 as promising thermal barrier material

Abstract

To investigate whether doping can enhance phonon point defect scattering to reduce the thermal conductivity of RE 2 CrTaO 7 materials, (Y 1-x Dy x ) 2 CrTaO 7 (X = 0, 0.3, 0.5, 0.7, and 1) samples were prepared via solid-state sintering method. In addition, their crystal structure and thermophysical properties were studied in this paper. The results show that the synthesized (Y 1-x Dy x ) 2 CrTaO 7 had defective fluorite structure, with the crystal cells belonging to orthorhombic system. The doping leads to an increase in defect concentration in ceramics, which improves their own thermophysical properties. The thermal conductivity of five (Y 1-x Dy x ) 2 CrTaO 7 samples at 1000 °C is 1.0180-0.9453W/m·K, which is about 57% lower than that of the traditional YSZ material. Furthermore, the coefficient of thermal expansion is slightly lower than that of YSZ. In this study, (Y 0.5 Dy 0.5 ) 2 CrTaO 7 has the best thermophysical properties, the lowest thermal conductivity (0.9453W/m·K), and the highest thermal expansion coefficient (10.5 × 10 −6 K −1 ).