Structure, mechanical properties, and thermal conductivity of BaZrO3 doped at the A-B site

BaZrO3 with the ABO3 perovskite structure can be doped at the A or B sites to obtain the corresponding properties. In this study, BaZrO3 was doped with Ca2+, Sr2+, Ti4+, and Ce4+. The structure, phase composition, and mechanical and thermal properties of the composites were investigated. The sintered Ba1-xCaxZrO3 samples with x = 0.2 and 0.4 exhibited relatively superior comprehensive behaviours; the cold modulus of rupture was increased by 127.36% and 134.59%, while that for BaZr0·8Ti0·2O3 and BaZr0·8Ce0·2O3 was increased by 99.30% and 112.37%, respectively. Further increases in strength and density were obtained in the Ba0·8Ca0·2Zr0·8Ti0·2O3 and Ba0·6Ca0·4Zr0·8Ti0·2O3 co-doped samples, and the corresponding apparent porosities were greatly decreased from 30.6% to below 1.0%. The thermal conductivities of the doped samples were generally low, achieving a minimum of 0.361 W/(m·K). The combination of high strength and low thermal conductivity demonstrate the significant application potential of BaZrO3-based composite materials.