Sintering-resistant porous BaZrO3 ceramics using a particle-stabilized foam method for thermal insulation applications

Abstract

Sintering and phase transitions of materials in current large-area thermal insulation systems are critical problems for hypersonic vehicles. Searching for thermal insulation materials with good structure stability, thermal stability, and superior insulation performance is urgent for the development of these vehicles. Herein, we reported a novel porous BaZrO₃ ceramic fabricated by a particle-stabilized foam method. By controlling the sintering temperature, the porosity (92.96%–94.62%), thermal conductivity (0.088–0.193 W/(m·K)), and strength (0.30–1.31 MPa) of the porous ceramics are tunable. Most importantly, these porous BaZrO₃ ceramics exhibit excellent sintering resistance. After being heat treated at 1300°C for 6 h, the shrinkage of porous BaZrO₃ ceramics is nearly 0. The shrinkage of the samples heat-treated even at 1600°C is still lower than 3%, demonstrating outstanding high-temperature structure stability. Our results demonstrate that porous BaZrO₃ ceramics are promising candidates for high-temperature thermal insulation applications.