Thermal radiation properties of C/SiC composites

The total hemisphere emissivity (ε_H) at 90℃ and the normal spectral reflectance at room temperature of 3D C/SiC composites were measured with the steady state calorimeter method and FTIR，respectively. The effects of the surface morphology，thickness of SiC coating and high temperature oxidation on the thermal radiation properties of 3D C/SiC were investigated. The results show that 3D C/SiC composites have excellent thermal radiation properties and the total hemisphere emissivity attains 0.83. With increasing the SiC coating thickness，the total hemisphere emissivity of 3D C/SiC composites decreases first and increases then. After oxidation，the thermal radiation properties of 3D C/SiC with three character surface remarkably increase.