Ceramic aerogel is regarded as an ideal thermal insulation material for its low density, low thermal conductivity and excellent fire resistance and corrosion resistance. However, the brittle nature of ceramics and high-temperature crystallization behaviors make ceramic aerogels exhibit serious strength degradation and even structural collapse during thermal shock or long-term high-temperature exposure. Therefore, having excellent mechanical properties and thermal stability at the same time has become a prerequisite for the further development and application of ceramic aerogels in the field of thermal insulation. This paper reports a polycrystalline boron nitride (hBNAGs) and silicon carbide (βSiCAGs) ceramic aerogel material with a hyperbolic, double-walled microstructure. It also has negative Poisson's ratio and negative thermal expansion characteristics, and is ultra-light and ultra-lightweight. Four characteristics: elasticity, high thermal stability and excellent heat insulation.

The research team prepared and synthesized hBN and βSiC ceramic aerogel materials based on the preliminary three-dimensional graphene aerogel research foundation and using multi-scale structured design, using template-free chemical vapor deposition methods. This type of ceramic material is composed of a nano-layered double-walled pore structure, presenting a hyperbolic structure as a whole. These special "superstructure" designs endow the material with negative Poisson's ratio (-0.25) and negative linear thermal expansion (-1.8×10-6/K) characteristics, enabling the material to exhibit excellent deformability while maintaining thermal stability sex. In the severe thermal shock test (approximately 275°C/s) and long-term high-temperature oxygen-free exposure, this type of material exhibits excellent thermal stability and almost zero strength loss. At the same time, the double-wall substructure of the material effectively reduces the thermal conductivity of the skeleton and reduces air heat conduction and heat convection, so as to achieve an ultra-low thermal conductivity lower than that of air (approximately 2.4 mW/m•K in vacuum and approximately 2.4 mW/m•K in air. Is 20 mW/m•K). The research results have been highly commented.

Ceramic aerogel is super light, super elastic, structure and thermal stability performance display