Organosilicon resin-based carbon/ceramic polygranular composites with improved oxidation resistance

We examined the thermo-mechanical properties of carbon materials modified with silicon oxycarbide (Si-O-C) and silicon carbide (Si-C). These compounds were obtained by the impregnation of carbon components with a silicon-containing polymer resin. Graphite and anthracite powders were used as carbon components, and poly[methyl(phenyl) siloxane] resin (P) was used as the ceramic precursor. Carbon/polymer compositions (C/P) were subjected to two-stage annealing, first to 1,000 °C and next to 2,000 °C in an inert atmosphere, leading to the formation of C/Si-O-C and C/Si-C composite samples, respectively. The materials were then examined under conditions of isothermal oxidation to determine their oxidation resistance and the mechanical properties before and after oxidation tests. The structure of the samples before and after oxidation was studied. C/Si-C composites, despite their high porosity, proved to have enhanced resistance to oxidation at 600 °C, although they had lower mechanical properties in comparison to C/Si-O-C samples.