| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride sintered compact and a manufacturing method thereof and a rolling element for bearing which is superior in peel resistance, wear resistance, rolling contact fatigue life and workability and is cheap.SOLUTION: A silicon nitride sintered compact has: (a) crystals of &bgr;-silicon nitride; (b) a grain boundary phase containing La and Al; and (c) particles containing not less than one element selected from Ti, Zr, Hf, W, Mo, Ta, Nb, V and Cr. As for (a), a mean particle diameter in the longer axis is not more than 3 μm, the greatest particle diameter in the longer axis is not more than 30 μm, and an aspect ratio is not more than 5. As for (b), a weight ratio between aluminum oxide converted into oxide and lanthanum oxide converted into oxide is 1:0.3-1:4. A mean particle diameter of (c) is not more than 3 μm. A diameter of aggregate of micropore is not more than 100 μm. |
