Preparation of SiOC Foam Ceramics Using Polysiloxane

The SiOC foam ceramics were prepared using polyurethane sponge and polysiloxane as raw materials. The effects of the pyrolysis temperature, the concentration of polysiloxane solutions, and the content of SiC nano-powder on compression strength of the SiOC foam ceramics have been investigated respectively. The optimum compression strength of SiOC foam ceramics is obtained at the pyrolysis temperature of 1250°C and the concentration of solution PSO of 0.8 g/ml. Adding SiC nano-powder into PSO can effectively increase compression strength of samples, and the maximum compression strength, 20.8 MPa, is obtained when the content of SiC nano-powder is 5 wt%. Microstructural study reveals that the foam ceramics have an open, uniform and interconnected porous structure with high porosity of 80%.