SILICON NITRIDE POWDER AND PREPARATION THEREOF

摘要

PURPOSE:To obtain silicon nitride powder used for producing a sintered silicon nitride body having high oxidation resistance and high-temperature strength characteristic, by containing a specific amount of SiO2 in silicon nitride powder. CONSTITUTION:A raw material silicon nitride powder is calcined at 800-1,200 deg.C in air and then wet pulverized together with a sintering assistant consisting essentially of Y. The pulverized material is then dried to produce the aimed silicon nitride powder containing 4.5-7.5wt% SiO2 in the powder.