| 摘要 |
PURPOSE:To enable molding of large scale or complex shape having high density and free from crack by using a raw material powder containing a specific amount of silicon nitride whisker powder when molded article to be sintered is produced by casting molding of silicon nitride powder. CONSTITUTION:A slurry of a raw material powder consisting of 1-50wt.% silicon nitride whisker and 1-50wt.% silicon nitride powder containing >=90wt.% alphaphase is subjected to casting molding. The resultant molded article is small in shrinkage after drying and hardly causes crack. So the molded article is sintered under non-oxidizing atmosphere to provide silicon nitride ceramic sintered compact having excellent mechanical characteristics. When only alphatype is used as silicon nitride whisker powder, dense beta type silicon nitride sintered compact is obtained and when beta type is used, sintered compact having excellent toughness is obtained. |
