Effects of Fe2O3 concentration on microstructures and properties of SiC-based ceramic foams

Polyurethane foams were used as carriers to fabricate SiC-based ceramic foams. The compressive strength and thermal shock-resistance of SiC-based ceramic foams were investigated with concentration of Fe2O3. Using scanning electron microscopy and energy dispersive spectroscopy, the microstructure and composition of SiC-based ceramic foams in micro-scale were observed. It is found that when the concentration of Fe2O3 increases, the number of cyclic thermal shock of the ceramic foams decreases obviously, and its compressive strength at room temperature increases rapidly. The concentration of Fe2O3 pays an important rule for the sinter behavior of the SiC-based ceramic foams. Superfluous Fe2O3 causes the formation of excessive glass phase in the ceramic foams.