With the silicon carbide powder the body null where is strengthened very from the organopolysiloxane restoration

摘要

PURPOSE: To form a silicon carbide sintered compact with a high density, a green body of which can be machined, by molding a homogeneous mixture of specified composition composed of silicon carbide powder, a metal-containing sintering aid and organopolysiloxane to prepare the green body and sintering the green body. ;CONSTITUTION: The silicon carbide sintered compact is prepared by three processes (a) to (c) described below. (a) The homogeneous mixture substantially composed of the silicon carbide powder, the metal-containing sintering aid and preceramic organopolysiloxane is prepared. At that time, the metal-containing sintering aid is made to be existed therein so that 0.1 to 3.0 wt.% of metals exists based on weight of the silicon carbide powder and the precermic organopolysiloxane is made to be existed therein so that free carbon value of the mixture is at a level of ≥0.2 wt.% based on total weight of the carbides derived from the silicon carbide powder and the preceramic organopolysiloxane. (b) The homogeneous mixture is molded at a temp. of ≤500°C under pressure to prepare the green body capable of handling. (c) The green body is sintered at a temp. of ≥1900°C in an inert atmosphere to obtain the silicon carbide sintered compact having ≥2.4 g/cm³ density.;COPYRIGHT: (C)1990,JPO