Novel high-temperature-resistant Y₂SiO₅ aerogel with ultralow thermal conductivity

A novel Y₂SiO₅ ternary aerogel was prepared from tetraethoxysilane and yttrium chloride hexahydrate via the sol-gel method followed by high-temperature calcination. The effects of different calcination temperatures on the microstructure, mechanical and thermal stability of the Y₂SiO₅ aerogels were investigated. The aerogels exhibited low densities of 0.33-0.62 g/cm³, low thermal conductivities of 0.029-0.05 W/(m·K), and a relatively high strength of 0.16-56.47 MPa. Moreover, compared with the Al₂O₃–SiO₂ aerogel, the Y₂SiO₅ aerogel has higher thermal stability and more excellent high-temperature insulation, which has potential applications as a thermal protection material in hypersonic vehicles.