The temperature field of industrial furnaces for high-temperature treatment of carbon composite blanks is studied. An error is established for temperature field reproduction within a furnace space. Mechanical, physical, and thermophysical properties of carbon blanks are studied. A safe temperature range is established for completing the production process. The required material properties are produced with observation of production regimes, and there is no distortion of component geometry.
High-temperature treatment (HTT) of blanks after carbonization is an important stage of production processes in the manufacture of composites and structural graphite. High-temperature treatment controls the true density of carbon materials, its thermal and electrical conductivity, and also oxidation rate and other chemical processes. At the same time, analysis of structural parameter formation for carbon-carbon composite materials (CCCM), establishment of temperature limits and instructions for HTT have received less attention compared with two other main production processes, i.e., carbonization of blanks and carbon matrix compaction.
The aim of this work is to study formation of CCCM structural parameters during high-temperature treatment, substantiation on the basis of this of specification for production processes, and establishment of the completion limits for individual HTT stages. Currently domestic industry is based on CCCM series production catering primarily for electrical engineering and chemical enterprises with high-strength and heat-resistant carbon materials and large thin-walled shapes. Clarification of temperature limits for improvement of the structure is of considerable economic importance on a background of a steady increase in cost of power generation resources.
The composites studied were based on carbon fiber from polyacrylonitrile filament and a combined carbon matrix of phenol formaldehyde resin coke and pyrolytic deposition of carbon within pores. The fundamental production scheme for manufacturing CCM products has been described previously. Reinforcement of the structure was created by winding or laying on a mandrel. An autoclave or compression method was used in order to harden the phenolformaldehyde of the original binder. Carbonization was carried out within furnaces with a controlled reducing gas atmosphere. The raw material for preparing pyrolytic carbon was supply-line hydrocarbon natural gas, containing 90-95% carbon, and the rest was mainly hydrogen.