Effect of mechanical activation on the formation of Si3N4-SiC composite powders

Abstract

The paper examines how the mechanical activation of an initial silicon-carbon powder mixture and the temperature of its subsequent treatment influence the specific surface and phase composition of the end products. It is established that the preliminary mechanical activation of Si-C mixtures significantly increases the nitration rate of silicon and decreases the temperatures of formation of silicon carbide and silicon nitride (1200–1300 °C). The products resulting from the nitration of mechanically activated mixtures consist of α-Si3N4 whiskers with an aspect ratio of 10–100, silicon, carbide, and silicon nitride particles to 100 nm in size, and their agglomerates.