Ultrafine powders of silicon carbide synthesized by microwave and conv
entional heating are described. Silicon carbide powders with diameters
in the nanometer range were formed by reducing SiO2 with various form
s of carbon in a nitrogen atmosphere. Ultrafine SiO2 powder, phenolfor
maldehyde resin and ultrafine carbon black were used as starting mater
ials. The properties of the powders were determined by means of X-ray
diffraction, TEM, etc. The results showed that the technique and condi
tions for preparing samples, as well as the temperature and type of he
ating, had obvious effects on the powders characteristics.