Properties of SiC,Si3N4 and SiO2 ceramic powders produced by vibration ball milling

SiC, Si₃N₄ and SiO₂ powders were ground by a vibration ball mill, the pot and balls of which were made of Si₃N₄ ceramics, in a purified methanol medium. The mean particle diameters of SiC and SiO₂ powders were ca. 0.1 μm and thus ultrafine particles were manufactured. The increasing rate of specific surface area by fine grinding was largest on SiO₂ powders, and the rate decreased gradually with an increase in grinding time. The specific surface area of Si₃N₄ powders increased proportionally with an increase in grinding time. The grindability was obtained in the following order: SiO₂ > SiC > Si₃N₄. The ground SiC powders showed a large lattice strain and little fragmentation of crystallites. The strain and the crystallite size of ground Si₃N₄ powders were moderate.