| abstract |
(57) Abstract: Provided is a silicon nitride sintered body excellent in strength from normal temperature to 1000 ° C., static fatigue characteristics, oxidation resistance and wear resistance. SOLUTION: Silicon nitride is used as a main crystal phase, and its grain boundary phase is RE 2 Si 3 N 2 O 5 and / or RE 3 AlSi 2 O 7 N 2 (Where RE is at least one element from Group 3a of the periodic table) and W, Mo, Cu, Mn, Fe And at least one crystal phase selected from nitride, carbide and silicide of Nb and Nb. |