Effects of Added Al Powder on the Properties of Sialon-ZrN Composites Fabricated by Aluminothermic Reduction and Nitridation

摘要

Sialon-ZrN composites were synthesized from zircon and aluminium via an aluminothermic reduction and nitridation process. The effects of extra Al powder on the product phase compositions and morphologies were studied. Products with different phases and morphologies result from different surplus amounts of additional Al. With increases of Al, after firing at 1500 °C, the amount of ZrSiO_4 decreased and the amount of sialon increased. The phase evolution of the specimens indicated that 8 mol-% extra Al powder contributed to the best decomposition of zircon and led to improved formation of sialon-ZrN composites.