Taketsushoarufuaamatahabeetaatankakeisokaranarujitsusainimukonoseikeitaioyobisonoseizohoho

摘要

The invention is substantially pore-free shaped articles which consist essentially of polycrystalline alpha - or beta -silicon carbide in the form of a single-phase homogeneous microstructure having grain sizes not exceeding 8 mu m, and which are manufactured from SiC powder, without the concomitant use of sintering aides, by isostatic hot-pressing in a vacuum-tight casing at temperatures of from about 1900 DEG C. to 2300 DEG C. and at pressures of from about 100 to 400 MPa. The SiC starting materials have alpha - and/or beta -SiC powders having a total content of metallic impurities not exceeding 0.1% by weight and a particle size of 4 mu m and finer.