Synthesis of spherical beta-silicon carbide particles by ultrasonic spray pyrolysis

Abstract

Fine agglomerate-free spherical beta-SiC powder was synthesized from a dispersion of colloidal silica, saccharose, and boric acid, by means of an ultrasonic spray pyrolysis method, Droplets of 2.2 mu m were formed with an aerosol generator, operated at 2.5 MHz, and carried into a reaction furnace at 900 degrees C with argon, Spherical X-ray amorphous gel particles of 1.1 mu m were obtained, beta-SiC particles with a mean diameter of 0.79 mu m and spherical shape resulted when the SiC gel precursor particles were heated at 1500 degrees C in argon.