| 摘要 |
PURPOSE:To obtain a sintered compact having reduced unevenness in strength and excellent in surface precision and fracture toughness by heat-treating a sintered compact of a mixture of powders of silicon nitride with silicon carbide, etc., at a prescribed temp. and removing the surface layer of the heat-treated sintered compact. CONSTITUTION:A mixture of powders of silicon carbide and silicon nitride with a sintering aid, etc., is sintered. The resulting sintered compact is heat- treated at 800-2,300 deg.C in an oxidizing or nonoxidizing atmosphere and the surface layer of the heat-treated sintered compact. is removed by 10-200mum thickness by NC lathing, planing or barrel polishing to obtain the objective silicon nitride-silicon carbide composite sintered compact having a fine structure in which silicon carbide particles having <=1mum average particle diameter have been dispersed at the grain boundaries and silicon carbide particles having several to several hundred nm particle diameters have been dispersed in silicon nitride grains. |
