Thermal transport properties of carbon-carbon fibre composites. I. Thermal diffusivity measurements

Thermal diffusivity measurements are reported for a series of uniaxially and biaxially reinforced carbon-carbon fibre composites densified by multiple infiltrations of chemical vapour deposited carbon and subsequent graphitization. Measurements were made in the principal directions of fibre reinforcement over the temperature range 500-3000 K. There is an overall increase in diffusivity with increasing density. Anisotropy ratios of ca . 4 for one-dimensional composites and ca . 2.8 for two-dimensional composites are surprisingly low. All data show a thermal conductivity decrease with temperature typical of a phonon conductor.