| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride sintered body capable of heightening durability and reliability with excellent reproducibility by reducing dispersion of a sliding characteristic represented by a rolling life.SOLUTION: A silicon nitride sintered body includes silicon nitride particles and a sintering aid component containing a rare earth element and Al, and further includes at least one kind of metal element selected from Ti, Zr, Hf, W, Mo, Ta, Nb and Cr. The silicon nitride particles have needle crystalline particles, which have a long diameter L of ≤10 μm and a ratio (L/S) of the long diameter L to a short diameter S of ≥5, in the range of ≥50% and ≤80% in terms of the area ratio in the crystalline structure of the silicon nitride sintered body, and the largest diameter of a void existing in the silicon nitride sintered body is ≤2 μm, and the number of voids is ≤5 in the range of 30×30 μm. |
