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 as 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.