| 摘要 |
PURPOSE:To obtain the titled ultrafine powder efficiently and economically with a small amount of heat energy, by forming a mixture of a metallic carbide subliming at a high temperature, a metal and carbon to give a porous solid material having specific relative density, and vaporizing the solid material by vaporization method in gas. CONSTITUTION:Metallic Si powder is blended with about 2-30wt% carbon powder uniformly, put in a crucible made of boron nitride, heated up to the melting point of Si in vacuum, to form the porous solid material 7 consisting of a metallic carbide subliming at high temperature, metallic Si and carbon, having <=60% relative density. Then, this solid material 7 is placed on the copper house 6 cooled with water in the vacuum chamber 1, the chamber is evacuated by the vacuum pump 2, gases such as CH4, C2H2, etc. are introduced through the pipe 4, the insulator 5 made of boron nitride from the nozzle 3 to the chamber, a partial gas pressure is adjusted to about 10Torr. Optionally an Ar gas for controlling particle diameters of prepared ultrafine powder is fed from the pipe 10 to the vacuum chamber, an electric current is sent from the DC electric source 8 in between the nozzle 3 and the solid material 7 to generate arc discharge, the solid material 7 is sublimated, condensed on the collecting plates 9 cooled with water and piled to give ultrafine powder of SiC having 0.01-0.1mu. |
