초록 ▼

Shaped silicon carbide ceramic articles of high density, e.g., at least 90 percent of theoretical, are produced by cold pressing and sintering boron-containing high purity, submicron beta silicon carbide powder. The silicon carbide powder is produced preferably by gas phase reaction of silicon halid

Shaped silicon carbide ceramic articles of high density, e.g., at least 90 percent of theoretical, are produced by cold pressing and sintering boron-containing high purity, submicron beta silicon carbide powder. The silicon carbide powder is produced preferably by gas phase reaction of silicon halide, e.g., silicon tetrachloride, carbon source reactant, e.g., halogenated hydrocarbon, and boron source reactant, e.g., boron trichloride, with a hydrogen plasma.

대표청구항 ▼

A substantially pure submicron boron-containing beta silicon carbide powder composition consisting essentially of silicon carbide powder substantially all of the beta crystalline form, said powder having a surface area of between about 3 and about 15 square meters per gram, the number mean particle

A substantially pure submicron boron-containing beta silicon carbide powder composition consisting essentially of silicon carbide powder substantially all of the beta crystalline form, said powder having a surface area of between about 3 and about 15 square meters per gram, the number mean particle size of the silicon carbide particles comprising the powder being between 0.08 and 0.8 microns, coformed homogeneously distributed boron-containing additive in an amount equivalent to between 0.15 and 0.25 weight percent boron, based on the silicon carbide, and between 0.05 and 1.5 weight percent free carbon, based on the silicon carbide.