Simultaneous synthesis of TiN–Si₃N₄ composite powders from TiSi₂ in NH₃ atmosphere

Abstract

The NH₃ nitriding process of TiSi₂ micrometer-sized powders were investigated in this paper. TiSi₂ powders were heat-treated under NH₃ flow in a temperature range of 1,100 to 1,300 °C. The composition and morphology of the resulting composites were characterized by X-ray powder diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and transmission electron microscopy. Under NH₃ flow, TiSi₂ grains were first transformed into TiN and Si. Subsequently, Si was transformed into Si₃N₄ and SiO₂ fibers. From this process, mixed materials comprising TiN particles with Si₃N₄ fibers were obtained.