Preparation and properties of a porous ZrO2/SiZrBOC ceramic matrix composite with high temperature resistance and low thermal conductivity

In this study, porous ZrO 2 /SiZrBOC and SiZrBOC ceramic matrix composites were produced via vacuum impregnation method, using SiZrBOC ceramic precursor as a matrix, ZrO 2 fiber prepared via electrospinning as the reinforcing agent and polyurethane foam as a skeleton. Polyurethane foam with open porosity is rather a substrate for the creation of a skeletal 3D structure. The preparation process and pyrolysis mechanism of ZrO 2 /SiZrBOC polyurethane foam impregnated with a precursor solution were expounded. The thermal conductivity tests and mechanical property measurements show that the lowest thermal conductivity (0.0378 W m −1 K −1 ) was achieved in the ZrO 2 /SiZrBOC ceramic matrix composite at the pyrolysis temperature of 800 ℃, being much inferior to that of the SiZrBOC composite (0.0861 W m −1 K −1 ). At 1400 ℃, the maximum compressive strength of the porous ZrO 2 /SiZrBOC ceramic matrix composites reached a value of 1.37 MPa, while that of the SiZrBOC composites was 0.22 MPa only. Therefore, the addition of ZrO 2 fibers improved the compressive strength and thermal insulation properties of the composites.