| 摘要 |
PURPOSE:To obtain beta-type silicon carbide powder having 1mum mean particle size, superior sinterability, and high purity by admixing a specified amt. of silicon nitride powder to a mixture of metallic Si and carbon powder, and calcining in a specified temp. range in nonoxidizing atmosphere. CONSTITUTION:To a mixture of metallic Si and carbon powder having each >=0.2wt.% content of impurities such as Fe, Al, 0.1-10wt.% silicon nitride powder having pref. <=10mum particle size is added and mixed. In this case, the metallic Si has pref. <=500mum particle size and the carbon powder has pref. <=10mum particle size. The raw material mixture is then sintered at 1250-1650 deg.C for 10min-2hr in nonoxidizing atmosphere such as N2, Ar. Thus, beta-type silicon carbide powder having high purity and above-described characteristics is obtd. Similar effect may be obtd. even if a same amt. of barium phosphate is used in place of the silicon nitride powder. |
