Improved sandwich structured ceramic matrix composites with excellent thermal insulation

An improved sandwich structured composite with low thermal conductivity used in high temperature is discussed, which have a great potential to be used in thermal protection system. This composite was composed of compound core material and C/SiC laminates. It is crucially noted that the compound core material is composed of reticulated SiC foam and SiO2 powders. In this paper, the thermal conductivity of compound core was much lower than that of unfilled SiC foam in high temperature. It was also observed that the thermal conductivities of compound cores with the density ranged from 1.23 to 1.38 g/cm3 increased accordingly. A mathematical relation was derived to calculate the theoretical effective thermal conductivity of sandwich structured composite, and the results agreed with the measured data with an error of 5%.