Electroarc Synthesis and Cleaning from Carbon Impurities of Cubic Silicon Carbide in the Air Atmosphere

The method is presented of producing a cubic phase of the silicon carbide beta-SiC by anneling in the air a powder product of the electroarc synthesis, which consists of beta-SiC, graphite and a small amount of silicon. Due to its high resistance of beta-SiC to the oxidation in the air we succeeded in the purification of it during the process of combustion of the graphite phase burning in the temperature interval of similar to 700-900A degrees C. According to the X-ray diffractometry, the obtained powder material contains beta-SiC with the content close to 99% (by volume). In this case according to the results of the scanning electron microscopy, beta-SiC is characterized by a wide (from similar to 0.1 to similar to 10 mu m) distribution of particles by size and typical shape for this phase crystals. The method of the electroarc synthesis of beta-SiC and its subsequent purification to the commercial purity for the first time is realized in the air without the use of protective inert gases.