Induction plasma synthesis of ultrafine SiC powders from silicon and CH4

• Published in: Journal of materials science 1995-11, Vol.30 (22), p.5589-5599
• Main Authors: GUO, J. Y, GITZHOFER, F, BOULOS, M. I
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Powders
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/bf00356691

Ultrafine SiC powders have been synthesized from elemental silicon and methane using induction plasma technology. The powder products were characterized by XRD, thermogravimetric analysis, SEM and TEM, electron probe microanalysis, IR spectroscopy, and surface area measurement. The powders collected from various sections of the reactor system showed different features reflecting different compositions and powder morphologies. The purest SiC powder was collected in the metallic filter. It was composed of both alpha- and beta-phase of SiC with small levels of free silicon and carbon. The reaction route used is based on the evaporation of the injected pure silicon starting powder, followed by carburization of the silicon vapor using methane. The silicon evaporation rate was found to depend strongly on the particle size of the silicon powder. Using silicon powder with a mean particle diameter of 100 microns, at a plasma power level of 43.2 kW, the conversion of silicon to SiC and the overall SiC content in the product powder was 44.2 percent and 50.8 wt pct, respectively. (Author)