NIIGrafit

The laser heating of a cell of a representative volume of thermoplastic tape is modeled, and the procedure for generating filaments within the cell is revised. The bi-parametric problem of finding the optimum process for automated layup and winding is solved, and samples are manufactured to determine the specific energy of delamination at the limiting process parameters of a robotic layup system.

The aim of the analysis and development of engineering specifications is to formulate the technical level of friction composite carbon–carbon material suitable for the manufacture of aircraft brake discs, as well as to substantiate the composition and requirements for such material formed on the basis of textile techniques. It is shown that the main characteristics that determine the quality parameters of blanks are the bulk density (filling coefficient of a blank by carbon material) and structure of the formed material.

In the present paper, we report polymer composites based on phenolic resin filled with hexagonal boron nitride; hot compression molding coupled with solution-based mixing were used to manufacture the composites. The paper presents experimental results on the physical and physicochemical properties of the obtained composites: thermal stability in air and argon, dielectric constant and dielectric loss tangent, active electrical resistance, thermal conductivity (mean and anisotropy), and mechanical strength. It is shown that the proposed technique of composite manufacturing, including the application of high-process pressures, makes it possible to obtain materials with high anisotropy of thermal conductivity, extremely high-filler content, and excellent dielectric properties, all of which are very important for prospective highly efficient lightweight heatsink elements for electronic devices. Experimental values of thermal conductivity and dielectric constant were analyzed using known mathematical models. Experimental values for thermal conductivities (up to 18.5 W·m−1·K−1) of composites at filler loadings of 65–85 vol.% are significantly higher than published data for bulk boron nitride/polymer composites.

Экспериментальное и численное исследование формирования теплофизических характеристик углеродных композиционных материалов. Сообщение 2. Численное моделирование работоспособности огнеупорной детали из углеродного композиционного материала

Исследованы особенности поведения экспериментального трехмерно

Production technology of products based on the syntactic carbon foams designed to operate in extreme conditions is proposed. The components and regime parameters for the production of foams of an open-pore cellular structure with specified thermophysical and strength characteristics for manufacturing the large-sized products of complex shape are determined.

The article presents the researchresults on the empirical dependencies ofa carbon-carbon composite material (CCCM) with orthogonal reinforcement (3D) characteristics (specific electrical resistance, thermal conductivity coefficient, dynamic elastic modulus, coefficient of thermal linear expansion, density). The definition of these characteristics was made in accordance with the regulatory documents (GOST and ASTM). Based on the tests and calculations results, a number of formulas were obtained that describe the empirical relationships between the characteristics of the material. According to these formulas it is possible to calculate the value of the sought-for material characteristic from known values of one or several characteristics through the calculated constant for a given relationship. It should be noted that the formulas and graphical dependencies given in the article are valid only for this particular material.

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.