High-temperature reaction between silicon carbide and nitrogen under pressure

The effects of temperature and nitrogen pressure are studied on the SiC Si₃N₄ transformation of silicon carbide powders of various phase compositions, specific surface areas, and contents of mixtures. It is shown that the degree of transformation increases with nitrogen pressure up to 10 MPa and that, in all temperature and pressure ranges of nitrogen, it is higher for bulk free powder than the preliminarily compacted material. In 30–60 min, a complete transformation of SiC into Si₃N₄ occurs under 10 MPa nitrogen pressure and at 1650–1750°C temperature.Institute of Inorganic Chemistry, Slovakian Academy of Sciences. Institute of Superhard Materials, Ukrainian Academy of Sciences, Kiev. Translated from Poroshkovaya Metallurgiya, No. 4(364), pp. 1–6, April, 1993.