Radiative Contribution to the Thermal Diffusivity and Conductivity of a Silicon Carbide Fiber Reinforced Glass-Ceramic

Abstract

The thermal diffusivity and conductivity of a silicon carbide fiber-reinforced lithium aluminosilicate glass-ceramic was measured using the laser-flash method. As indicated by the effect of specimen thickness on thermal conductivity and its positive temperature dependence, heat transfer by radiation makes a significant contribution to the total thermal conductivity. The observed dependence of the effect of specimen thickness on thermal conductivity suggests that radiative heat transfer between the carbon coated surfaces of dielectric materials for the laser-flash technique may be partially governed by the view factor between the specimen surfaces.