JPS6476967A - Composite sintered compact of silicon carbide and production thereof - Google Patents

Abstract

PURPOSE:To obtain the titled dense compact having a layer structure in which an electrical insulator layer is present on the surface and excellent surface, oxidation, creep and impact resistance, by blending SiC powder with a rare earth element compound, Al compound and/or B compound, etc., heating and sintering the resultant blend or compact without pressure. CONSTITUTION:SiC powder is added and blended with 0.021-65.000atom.% (expressed in terms of rare earth element oxide) rare earth element compound (e.g., Y2O3) and 0.006-85.0atom.% total amount of one or more of Al, B, C or compounds thereof as a sintering assistant so as to provide total 100atom.% The resultant blend or a compact, as necessary, prepared by forming the blend, as necessary, is prefired at 300-1,600 deg.C and then fired at 1,600-2,300 deg.C without pressure for >=3hr, preferably at a low temperature and subsequently fired at a high temperature in a nonoxidizing atmosphere or vacuum to afford the titled two-layered compact having the central part which is a layer rich in SiC and a surface layer which is an electrical insulator layer, rich in the rare earth element oxide and having 10<11>OMEGA.cm electric specific resistance.