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

Resumo

The method is presented of producing a cubic phase of the silicon carbide β-SiC by anneling in the air a powder product of the electroarc synthesis, which consists of β-SiC, graphite and a small amount of silicon. Due to its high resistance of β-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 ~ 700–900°C. According to the X-ray diffractometry, the obtained powder material contains β-SiC with the content close to 99% (by volume). In this case according to the results of the scanning electron microscopy, β-SiC is characterized by a wide (from ~ 0.1 to ~10 μm) distribution of particles by size and typical shape for this phase crystals. The method of the electroarc synthesis of β-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.