Fundamental physical properties of Ta2O5 and Yb2O3 codoped strontium zirconate for thermal barrier coating applications

摘要

An advanced ceramic material with perovskite structure, Ta2O5 (5 mol.-%) and Yb2O3 (5 mol.-%)ncodoped SrZrO3 [Sr(Zr0?9Ta0?05Yb0?05)O3, SZTY], was investigated as a material for thermalnbarrier coating applications. Sr(Zr0?9Ta0?05Yb0?05)O3 was synthesised using ball milling beforensolid state sintering, and had a minor second phase of Yb2O3. The material showed good phasenstability not only from 200 to 1400uC, but also at a high temperature of 1450uC for a long period,nanalysed by differential scanning calorimetry and X-ray diffraction respectively. The thermalnexpansion coefficients of the sintered bulk SZTY were recorded by a high temperature dilatometernand revealed a positive influence on phase transitions of SrZrO3 by codoping Ta2O5 and Yb2O3.nThe thermal conductivities of SZTY were decreased at least y23% in contrast to that of SrZrO3nand 8YSZ in the testing temperature range. The chemical compatibility of SZTY with 8YSZ ornAl2O3 was also evaluated in this study.