Advanced Arc Plasma Synthesis of Biomorphic Silicon Carbide Using Charcoal and Silicon Dioxide in Air

This work presents the results revealing the possibility of obtaining a cubic phase of silicon carbide with features of a biomorphic structure. Renewable plant raw materials were used as a source of carbon, in particular, pyrolyzed sawdust, which is a waste of a timber enterprise. Silicon dioxide powder was used as a source of silicon. The synthesis was realized using DC arc discharge plasma initiated in an open air. In this case, the oxidation of the synthesis products was prevented due to the effect of the reaction volume self-shielding from atmospheric oxygen. It was possible due to the generation of protective gaseous medium predominantly consisting of carbon dioxide and monoxide. The dependences of the product phase composition on the supplied energy and composition of initial components were established. The synthesis product was characterized by a significant excess of carbon, which was a caused by the erosion of the electrodes. After removal of chemically unbound carbon from synthesis product by annealing in an atmospheric furnace at 850 degrees C, obtained powder was sintered by the spark plasma sintering method. In the result, a bulk ceramic sample was obtained in which the only one crystalline phase of silicon carbide with a lattice parameter of 4.359 angstrom was identified. [GRAPHICS] .