| 摘要 |
PURPOSE:To easily produce the superfine powder of a high-melting-point carbide excellent in sinterability by hydrolyzing a transition-metal alkoxide in a suspension of carbon in alcohol under specified conditions, drying the formed gel, heating and then disintegrating the dry gel. CONSTITUTION:A carbon suspension, alcohol and a transition-metal alkoxide, alcohol and water are mixed, the pH of the mixture is controlled to a value close to the isoelectric point of the transition-metal oxide, and hydrolysis is carried out. The water is removed by heating, etc., to dry the product, and a metal oxide gel in which fine carbon grains are uniformly dispersed is obtained. The gel is heated (ordinarily at about 1250 deg.C) in vacuum or in an inert gas to obtain a granular carbide which is disintegrated for several minutes by an ultrasonic wave, etc., into fine powder. By this method, the superfine powder of a high-melting-point carbide such as ZrC, TiC and TaC having 4 about 1mu grain diameter is easily obtained. |
