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Thermophysical properties are studied: thermal conductivity, heat capacity and thermal diffusivity of spatially reinforced carbon-carbon composite materials. A structural model is proposed for thermal conductivity levels at 300 and 2500 K. Results of calculations are confirmed in manufacturing practice and studies of material properties. It is shown that anisotropy of thermal conductivity levels leads to a nonuniform thermal state of refractory carbon composite working surface fragments. It is established that structure formation for the surface of a carbon-carbon refractory wall is connected with composite components structural state inhomogeneity. Approaches are proposed for increasing the working surface life for refractory carbon materials.

Carbon material thermal conductivity is an important factor for providing thermal shock resistance. The effect of production factors on the reproducibility of thermal conductivity values during manufacture of three-dimensional reinforced high-density carbon-carbon composite is considered. An average level of thermal conductivity applies to more than 82% of workpieces. From 4.6 to 12.5% of workpieces have thermal conductivity not less than 44 and not more than 70 W/(m·K). It is established that a change in carbon fiber treatment temperature from 1600 to 2400°C may lead to an increase in materials thermal conductivity by 0.21 W/(m·K) for each 100°C. Adifference in framework structure may change average thermal conductivity within the limits of 3 W/(m·K). Variation of material apparent density from 1.89 to 1.98 g/cm3 gives a change in thermal conductivity by 1.1 W/(m·K) for each +0.1 g/cm3. A connection is established for a carbon-carbon composite of electrical conductivity ρ and thermal conductivity λ, corresponding in form to the Weidemann-Franz rule λρ = const.

Ways of improving the refractoriness of carbon-carbon composite materials due to increasing their density and reducing oxidation rate, and in turn due to reducing the combustion surface, are studied. Oxidation heterogeneous reaction surface in an Arrhenius equation expression is considered as the sum of object outer surface and the reaction surface within pores. It is shown that with an apparent density of 1.93 g/cm3 or more surface oxidation at normal pressure and ~500 °C almost corresponds to the nominal object surface. Processing measures are suggested for improving carbon material refractoriness due to an increase in density and changing surface structure by special high-temperature treatment regimes.

Silicided graphites, prepared by SGP technology, using a graphite nanofiller fraction of less than 100 μm, are promising materials no worse in properties than leading analogs of overseas firms. Nonetheless, in view of the available raw material base for carbon materials rapid evaluation methods are required for the quality of graphites used in the manufacture of silicided objects based on them. Volumetric reaction makes it possible to establish quite rapidly the suitability of test carbon material for manufacturing silicided objects based on them without recourse to compaction, firing, machining, and siliciding shaped objects. X-ray structural data for the degree of graphitization of carbon material γ, and also a change in its structural characteristics (La and Lc) during reaction with silicon may be additional criteria for the choice of graphite filler.

The surface properties of carbon fiber adsorbents prepared from different starting materials and by different procedures were investigated with the aim of optimizing their pore structure. The best results were obtained with carbonized fibers: at 900°C in flowing CO2 , their specific surface was increased from 0.5 to 2000 m2 /g.