Advanced Arc Plasma Synthesis of Biomorphic Silicon Carbide Using Charcoal and Silicon Dioxide in Air
Abstract The paper presents the results of experimental studies on the advanced synthesis method for a cubic phase of silicon carbide using charcoal and silicon dioxide as precursors. The charcoal used for the synthesis was obtained by steam pyrolysis of wood wastes (sawdust). It was found that the arc synthesis could be executed in air due to the protective CO and CO2 environment formation by charcoal oxidation. With an increase of the amount of supplied energy by direct current arc plasma synthesis, the products of two crystalline phases were formed: graphite and cubic phase of silicon carbide. The phase of silicon carbide was extracted from the synthesis product by its annealing in air at 850 °C. The resulting cubic SiC phase was characterized by an elementary cell parameter of 4.359 Å. According to the data of scanning electron microscopy, the morphology of crystals obtained is common for the biomorphic silicon carbide which was identified in the synthesis product. The ceramics synthesized by spark plasma sintering from the obtained material was characterized by a density of ~2.0 g/cm3.
