초록 ▼

The invention provides a method for the preparation of an ultrafine powder of silicon carbide having an extremely fine and uniform particle size distribution of spherical agglomerate particles each formed of crystallites of 5 nm or smaller in size. The silicon carbide powder is prepared by the vapor

The invention provides a method for the preparation of an ultrafine powder of silicon carbide having an extremely fine and uniform particle size distribution of spherical agglomerate particles each formed of crystallites of 5 nm or smaller in size. The silicon carbide powder is prepared by the vapor phase pyrolysis of a specified methyl hydrogen(poly)silane as diluted with a carrier gas, e.g. hydrogen, to give a concentration of 40% by volume or lower at a temperature of 750°to 1600°C. The silicon carbide powder can readily be sintered at a temperature of 1750°to 2500°C. even without addition of a sintering aid to give a sintered body of extremely high density reaching 80% or larger of the theoretical value which can never be obtained of the conventional silicon carbide powders.

대표청구항 ▼

A method for preparation of a silicon carbide powder composed of polycrystalline agglomerate particles of silicon carbide each having a substantially spherical configuration of 0.01 to 1 mb5 nm which comprises pyrolyzing, in a vapor phase, a methyl hydrogen(poly)silane compound represented by the ge

A method for preparation of a silicon carbide powder composed of polycrystalline agglomerate particles of silicon carbide each having a substantially spherical configuration of 0.01 to 1 mb5 nm which comprises pyrolyzing, in a vapor phase, a methyl hydrogen(poly)silane compound represented by the general formula (CH3)aSibHc, in which the suffix b is 1, 2 or 3 and the suffixes a and c are related to b by the set of equations and inequalities 2b+1≥a, a≥b, 2b+1≥c≥1 and a+c=2b+2, diluted with a carrier gas to a concentration in the range from 0.2 to 40% by volume in the gaseous mixture at a temperature in the range from 750°to 1600°C.