Synthesis of silicon oxynitride ceramic powders from smectite clays

Abstract

Two smectite clays (montmorillonite and hectorite) were utilized for the preparation of silicon oxynitride ceramic powders. Because of their high temperature properties, the nitride ceramics are major candidates for use in ceramic gas turbines and other high performance applications. The synthesis of ceramic powders was investigated by firing mixtures of smectite and charcoal under nitrogen flow at 1300–1500°C. Different phases appeared in small quantities in the powders which were mostly composed of silicon oxynitride (sialon or simgon), a reaction mechanism is discussed and proposed to obtain these materials.