Effects of processing parameters on the production of β-SiAlON powder from kaolinite

In this study, the production of β′-Si6−zAlzOzN8−z (z = 3) powders by the carbothermal reduction and nitridation of kaolinite (Al2O3·2SiO2·2H2O) of Turkish origin (Çan-Çanakkale) was investigated with different processing parameters. Temperature and gas flow rate had a great influence on the yield and amount of the final silicon aluminium oxynitride (SiAlON) phase in the product. Synthesis took place in the temperature range of 1400-1475 °C from the mixtures of kaolinite and reducing agent, i.e., solid carbon particles. Changes in gas flow rate had an influence on the final powder yield. Product after the process was mainly of β′-Si3Al3O3N5 powder along with small amount of Al2O3 and mullite phases were also present.