Effects of Hydrothermal Treatment on Firing Process of Silicon Nitride Ceramics

Abstract

The firing behavior of α-Si₃N₄ powder corroded under hydrothermal conditions was investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM analysis suggest that the hydorothermal treatment enhances the α-β phase transition in α-Si₃N₄ and the formation of Si₂ON₂ phase from α-Si₃N₄ during firing at high temperature. In paticular, TEM analysis indicate that the grown β-Si₃N₄ grains contain an α-Si₃N₄ core under the α-β phase transition in α-Si₃N₄.