MATERIAL CERAMICO ELETRICAMENTE ISOLANTE,CORPO SINTERIZADO E PROCESSO PARA A PRODUCAO DE UM CORPO CERAMICO DE CARBETO DE SILICIO

摘要

Sintered silicon carbide body having a D.C. electrical resistivity of at least 108 Ohm cm at 25 DEG C., a density of at least 2.95 g/cm3 is formed upon sintering in a nitrogenous atmosphere at a temperature of about 2250 DEG C. or greater, a shaped body composed essentially of carbon or carbon source material in amount sufficient to provide up to 2.5 percent uncombined carbon; from about 0.4 to about 2.0 percent boron carbide; up to 25 percent of temporary binder and a balance of silicon carbide which is predominantly alpha-phase. The shaped body may additionally include other sintering aids such as BN or Al without destruction of desired high electrical resistivity.