| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a grindstone capable of smoothing the surface of polycrystalline diamond with a simple process by direct grinding.SOLUTION: In a grindstone 2 which has metal, resin or ceramics as a base material and in which diamond particles 8 exist in a scattered manner inside and on the surface of the base material, iron powder particles 9 exist in a scattered manner inside and on the surface of the base material, the particle diameter of diamond particles 8 is 2μm or more and 6μm or less, and the particle diameter of the iron powder particles 9 is the same or smaller comparing to the particle diameter of the diamond particles 8. Further, based on a value which is proportional to a ratio of volume of the diamond particles 8 and the iron powder particles 9 which occupies in the total volume of grindstone 2 and is a concentration ratio shown by a value at 100 with respect to a volume ratio of 25%, a concentration ratio of the diamond particles 8 is 10 or more and 100 or less, and a concentration ratio of the iron powder particles 9 is 5 or more and 50 or less.</p> |
