Marco ATTIA, Wyman ZHUANG
DOI Number: 10.60853/a3vy-er39
Conference number: HiSST-2024-00371
Carbon/Carbon composites are currently the material of choice for use on advanced thermal protection systems for high speed flight vehicles due to their excellent thermophysical properties and high specific stiffness and strength in hypersonic flight operational environments. The ultra-high thermophysical properties of carbon/carbon are essential for design purposes, especially where limited data exists for the temperature range of interest. To address this need, the thermophysical properties of a nominated high density carbon/carbon material were characterized. Properties such as specific heat, thermal diffusivity, thermal expansion and thermal conductivity for the material in all three material orientations (x,y,z) were investigated between ambient temperature to 2600°C. The thermophysical assessment of the carbon/carbon composite is provided in two parts, the first set of thermal properties were determined for the material in its untreated state (no heat treatment), and the second set demonstrates the effect of heat treatment on the thermal properties. The Coefficient of thermal expansion (CTE), diffusivity as well as conductivity of the composite exhibit a distinctive shift in the material properties in the temperature range of 1300-1500°C. Subsequent thermal analyses beyond that temperature range is markedly different and therefore suggestive of the thermophysical properties which are to be expected should the composite be subjected to heat treatment. The microstructures changes of the carbon/carbon pre- and post-heat treatment were also examined by scanning electron microscopy/energy dispersive X-ray spectroscopy as well as optical microscopy. The findings are useful to assess the performances of the carbon/carbon composite in extremely high temperature conditions for the potential applications of hypersonic vehicle structure and components.