Patent ID: 9403215
Filing Date: 2016-08-02
CPC Classification: B23B,B82Y,C04B,Y10T

Claim Text:
1. A cutting tool comprising: a cutting edge composed of a polycrystalline body including high-pressure-phase hard grains that contain one or more elements selected from the group consisting of boron, carbon, and nitrogen, the polycrystalline body being formed by subjecting a non-diamond carbon material and/or boron nitride, serving as a starting material, to direct conversion sintering under ultra-high pressure and high temperature without adding a sintering aid or a catalyst, wherein letting the radius of curvature of the nose of the cutting edge of the cutting tool be R the radius of curvature R the sintered grains constituting the polycrystalline body have an average grain size of 60 nm or less.