An overview of ultra-high temperature ceramic for thermal insulation: Structure and composition design with thermal conductivity regulation

As hypersonic aircraft reach higher speeds, the aerodynamic heating they generate becomes increasingly severe, presenting a challenge for thermal protection materials. While ultra-high temperature ceramics (UHTCs) can meet the requirements of high-temperature resistance as thermal protection materials, their high thermal conductivity poses a challenge to resist the propagation of heat generated by aerodynamic heating from the surface of the fuselage to the interior. Therefore, in order to ensure the operating temperature of electronic components inside the fuselage, research on thermal insulation UHTCs is necessary. This paper proposes two methods to reduce the thermal conductivity of UHTCs based on their heat transfer mechanism. The first method is to form high-entropy solid solution ceramics, while the second method is to prepare porous ceramics. These methods have the potential to reduce the thermal conductivity of UHTCs and meet the application requirements of ultrahigh temperature thermal insulation.