Design, Preparation and Thermal Properties of (La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_2O_7 Ceramic for Thermal Barrier Coatings

摘要

Based on the theory of phonon transport and thermal expansion, a new complex rare-earth zirconate ceramic (La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_2O_7, with low thermal conductivity and high thermal expansion coefficient, has been designed. The complex rare-earth zirconate (La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_2O_7 powder for thermal barrier coatings (TBCs) was synthesized by coprecipitation-calcination method. The phase, microstructure and thermal properties of the new material were investigated. The results revealed that single phase (La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_2O_7 with pyrochlore structure was synthesized. The thermal conductivity and the thermal expansion coefficient of the designed complex rare-earth zirconate ceramic is about 1.3W/m?K and 10.5X10~(-6)/K, respectively. These results imply that (La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_2O_7 can be explored as the candidate material for the ceramic layer in TBCs system.