复合钙钛矿型 Ba(Zn_1/3Ta_2/3)O₃ 陶瓷作为热障涂层陶瓷层材料的基础性能评价

Ba(Zn_1/3Ta_2/3)O₃ (BZT) ceramic was synthesized by a solid-state reaction method using BaCO₃, ZnO, and Ta2O₅ powders as the raw materials. The phase structure, high-temperature phase stability, thermal conductivity, coefficient of thermal expansion, and adaptability of spraying process of BZT were investigated and characterized, and compared with Ba(Mg_1/3Ta_2/3)O₃ (BMT), Ba(Ni_1/3Ta_2/3)O₃ (BNT), and Ba(Sr_1/3Ta_2/3)O₃ (BST) to evaluate the potential application of BZT as a top coating material for thermal barrier coatings. The results indicate that no phase transition occurs during the heating from room temperature to 1500 ºC, and BZT is quite stable up to 1600 °C for 48 h, without the occurrence of decomposition, showing excellent high-temperature phase stability. The thermal conductivity of BZT is only 1.65 W·m^-1·K^-1 at 1200 ºC, which is significantly lower than those of BMT (2.57 W·m^-1·K^-1), BNT (2.56 W·m^-1·K^-1) and BST (2.11 W·m^-1·K^-1), showing better high-temperature heat insulation ability. The average coefficient of thermal expansion of 11.3×10^-6 K^-1 for BZT from 200 ºC to 1400 ºC is higher than these of BNT (10.7×10^-6 K^-1) and BST (8.1×10^-6 K^-1). The plasma-sprayed BZT coating has single perovskite structure, and the adhesion between the layers is compact for YSZ/BZT double-ceramic-layer coatings. Therefore, BZT ceramic might be a promising candidate material for novel thermal barrier coatings.