摘要 |
PROBLEM TO BE SOLVED: To obtain a sintered silicon nitride compact having high thermal conductivity and excellent mechanical characteristics in combination by sintering under relatively mild conditions, and eventually to provide the inexpensive sintered silicon nitride compact. SOLUTION: This method for manufacturing the sintered silicon nitride compact consists in adding at least one selected from a group consisting of rare earth oxide, silicon oxide and magnesium oxide to silicon nitride powder of >=0.80 in average circularity of the silicon nitride particles constituting the powder, >=10 to <80 in β type formation rate, 0.5 to 1.8 mass% in oxygen quantity and 12 to 22 m2/g in specific surface area in such a manner that the total content attains 2.5 to 14 mass%, and further adding silicon nitride whiskers at 0.1 to 8.5 mass% thereto, then mixing the powder, molding the mixture and sintering the molding in a nitrogen atmosphere. |