Preparation of sialon-transition metal silicide composites

A process to prepare sialon-transition metal silicide composites is proposed in the present study. The oxides of transition metals are used as the starting materials and the metal silicides are formed in situ in sialons at elevated temperature. The metal oxides, silica and alumina in starting materials first form a liquid phase on sintering to assist the densification in the graphite furnace. The transition metals then precipitate out to react with Si3N4 to form silicides. The sialon-metal silicide composites with uniform microstructures can be produced. By applying a suitable post-sintering heat-treatment, metallic fibers can also be formed in situ in the surface region on samples. Results for both sialon-Cr-silicide and sialon-Fe-silicide composites are demonstrated in the present study. (c) 2004 Elsevier Ltd. All rights reserved.