Patent ID: 9393629
Filing Date: 2016-07-19
CPC Classification: B23C,B23P,Y10T

Claim Text:
1. A cutter element for a rotary machine tool having an axis of rotation in use, the cutter element comprising at least three cutting edges configured operable to cut a body when moved in a direction that is substantially non-aligned with the axis of rotation, and defined by at least one cutter structure comprising electro-discharge machine cuttable polycrystalline boron nitride (PCBN) material, the PCBN material comprising at least 80 volume per cent cubic boron nitride grains dispersed in a binder matrix comprising compounds containing cobalt and tungsten, wherein the tool has a lateral cross-section diameter of 10 to 25 mm, and wherein consecutive cutting edges are spaced apart by at most 5 mm azimuthally about the axis of rotation, and wherein the cutter structure is joined to a cemented carbide substrate by an intermediate layer between the cutter structure and the substrate, the intermediate layer comprising grains of metal carbide and grains of cubic boron nitride dispersed in a matrix material.