POWDER COMPOSITION FOR PRODUCING CARBON/SILICON CARBIDE COMPOSITE MATERIAL, PRODUCTION OF CARBON/SILICON CARBIDE COMPOSITE MATERIAL AND CARBON/SILICON CARBIDE COMPOSITE MATERIAL

摘要

PURPOSE:To improve moldability and sinterability and to improve density, bending strength, etc., by compounding =1 kinds of sintering assistant powders selected from a group of boron (compd.) with a mixture composed of the fine particles of a self- sinterable spheroidal carbonaceous material and SiC powder. CONSTITUTION:The mixture (C) is obtd. by compounding 5 to 30 pts.wt. fine particles (A) of the self-sinterable spheroidal carbonaceous material which are mesocarbon microbeads of =20mum average grain size contg. =5wt.% binder component (beta-resin) made from a coal tar as a raw material and 95 to 70 pts.wt. SiC powder (B) having =1mum average grain size. The powder compsn. (D) for producing the C/SiC composite material is then produced by mixing 100 pts.wt. component C and 0.5 to 5 pts.wt. sintering assistant powders of =1mum average size selected from metal B, B4C, etc., for 30 minutes to one hour by a dry process. The component D is subjected to a pressurized molding and is temporally calcined in an nonoxidative atmosphere, following which the molding is subjected to regular calcination for 0.2 to 3 hours at 1900 to 2400 deg.C in a gaseous N2 atmosphere, by which the C/SiC composite material having =20kgf/mm2 bending strength is produced.