Features of SiAlON synthesis from kaolin

Abstract

Under conditions of experimental–industrial synthesis of SiAlON from kaolin with the use of carbothermal reduction the fabrication of single-phase β′-SiAlON with z=2 is limited by a set of technological parameters: temperature and time of treatment, composition and volume of mixture. The introduction of iron additives in mixture is accompanied by the formation of iron silicides. The regions of melt of the highest iron silicides are the zones of SiAlON formation according to the VLS-mechanism. The powders synthesized in the temperature range of 1723–1873 K from the mixtures of kaolin, carbon, silicon carbide, and iron are the composite ones.