| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride sintered body having stable durability in terms of peeling resistance, and imparting low damage to a mating material, and to provide a slide member using the silicon nitride sintered body.SOLUTION: There is provided the silicon nitride sintered body containing Mg and at least one kind of rare earth elements. The silicon nitride sintered body has silicon nitride particles and a grain boundary phase containing Mg and at least one kind of rare earth elements. In the silicon nitride sintered body, a ratio (RExOy/MgO) in the case of oxide conversion of each of Mg and at least one kind of rare earth elements (RE) is in the range of 0.05 to 5, an average value of long axial length L of the silicon nitride particle existing in an optionally set area of 20×20 μm is 5.0 μm or less, an average value of a ratio of long axial length L to short axial length S (L/S) is 5 or less, pores each having an area of 0.01 μmor more is contained in an amount of 0.01-5% by an area ratio in the optionally set area of 300×300 μm, and the average value of distance between centers of gravity of the closest pores is 5 μm or more and a variation coefficient of the distance between centers of gravity is 1.5 or less. |
