Preparation and thermal performance analysis of novel multilayer cladding structure composites.

With regard to the adiabatic principle of insulation, a novel multilayer cladding structure composites (MCSC) with vacuum inside was put forward, which could be used in high temperature insulation field. In the composites, SiO2 was used to fill the microcracks and protect the carbon matrix from oxidizing. This novel material was composed of two parts, one was the core material consisted of SiC foam ceramic, the other was the flawless outer shell consisted of carbon fiber reinforced composites with vacuum inside that produced by Chemical Vapor Infiltration (CVI) Pyrolytic Carbon (PyC) and silicasol-infiltration-sintering methods. Material density was 0.81 g/cm³. The effective thermal conductivity of MCSC ranged from 0.193 W/m · K to 0.721 W/m· K within the temperature from 303 K to 703 K, which was 13.5-23.3% lower than the value of SiC ceramic foam core materials. However, at 1473 K, the measured data of MCSC and SiC foam were 1.815 W/m · K and 1.911 W/m · K, respectively. It was only 5.02% lower than that of SiC foam. [ABSTRACT FROM AUTHOR]