| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a silicon nitride sintered product, capable of overcoming the defects of conventional two step sintered products and efficiently producing the silicon nitride sintered product having a high purity, a high density and a high strength, and to obtain the sintered product by the method. SOLUTION: This silicon nitride sintered product has a relative density of >=97%, and is obtained by nitriding a molded product comprising a sintering auxiliary and metal silicon containing metal impurities in an amount of <0.4wt.% in the presence of aluminum trioxide powder in such a state as not brought into contact with the molded product, and subsequently sintering the nitride product. This method for producing the silicon nitride sintered product having a relative density of >=97% comprises nitriding a molded product comprising a sintering auxiliary and metal silicon having metal impurities of <0.4wt.% in the presence of aluminum trioxide powder in such a state as not brought into contact with the molded product in a nitrogen gas atmosphere at a temperature of 1200-1500 deg.C, and subsequently sintering the nitrided product at a temperature of 1500-2000 deg.C. Thereby, the silicon nitride sintered product having a high density is obtained. |
