A novel silica aerogel/porous Y2SiO5 ceramics with low thermal conductivity and enhanced mechanical properties prepared by freeze casting and impregnation

A novel silica aerogel/porous Y2SiO5 composite was prepared by freeze casting and sol-gel impregnation. Porous Y2SiO5 ceramics with different solids contents were prepared at 1400 °C. The pore structure, porosity and mechanical properties of the porous Y2SiO5 ceramics before and after impregnating of silica aerogel were investigated. The results show that the room-temperature thermal conductivity decreases and the compressive strength increases remarkably while impregnating porous Y2SiO5 with silica aerogel. The silica aerogel/porous Y2SiO5 composite exhibits a high compressive strength (i.e. 9.3 MPa) and a low thermal conductivity (i.e. 0.260 W/(mK)). This work reports an optimal processing method of silica aerogel/porous Y2SiO5 composite with the potential application as a high-temperature thermal insulation material.