Light and strong nano-SiC foam with extremely low thermal conductivity

Abstract We herein report a porous nano-SiC foam fabricated by foam-gelcasting-freeze drying method with ultra-high porosity (96%). Porous nano-SiC sintered at 1300°C and 1400°C exhibit excellent balanced high compressive strength (1.44 MPa) and low thermal conductivity (0.064 W/(m·K)). The porous nano-SiC can be invoked as a candidate for high temperature thermal insulation. The low thermal conductivity mainly originates in the high porosity and the strong scattering of phonons by the nanostructure of the skeleton.