| 摘要 |
PROBLEM TO BE SOLVED: To provide a rolling element having high strength and low Young's modulus and a method for manufacturing the same.SOLUTION: A rolling element comprises (a) crystals of &bgr;-silicon nitride, (b) a grain boundary phase containing a rare earth element, silicon, aluminum, oxygen and nitrogen, and (c) grains containing one or more elements selected from the group consisting of Ti, Zr, Hf, W, Mo, Ta, Nb, V and Cr, wherein the above (b) occupies an area ratio of ≥10% in a cross section of the rolling element, the above (a) has an average grain size of ≤1 μm in major axes, and the above (c) has an average grain size of ≤1 μm. |
