EFFECT OF PROCESSING VARIABLES ON THE PROPERTIES OF CARBON-CARBON COMPOSITES

The mechanical properties and microstructure parameters of C-C composites have been studied. The properties were controlled after each step of manufacturing the composites. The impregnation-recarbonization cycles with liquid pitch have been applied to densification of the porous carbon skeleton obtained after carbonization. It has been shown that to obtain high-quality C-C composites, intermediate high-temperature treatment is needed. Such a treatment opens the closed pores, and in the following impregnation process the pores become filled with the carbon precursor. The chemical state of the surface of carbon fibres with respect to the translation of fibre strength in composites has been analyzed.