Method of manufacturing crystalline silicon carbide

Abstract

A method of manufacturing silicon carbide whiskers in which a carbon and silicon containing material having a thin configuration and sufficient porosity to permit both the passage of a gas therethrough and to provide spaces for growing whiskers therein is charged on a gas-permeable tray, and heated in a furnace of non-oxidizing atmosphere. The tray is moved intermittently through a series of temperature zones, increasing stage-by-stage from about 400.degree. C. to 1,300.degree. C., while a non-oxidizing gas is circulated through the porous material to remove any impurities. Thereafter, the heated tray is intermittently moved through a series of increasing temperature stages from about 1,350.degree. C. to 1,450.degree. C. to effect whisker growth. The treated silicon carbide-containing material is dispersed in a two-phase mixture of a hydrophobic organic liquid and water. The desired silicon carbide whiskers can be isolated from the aqueous phase.