Superhard tool tip, method for making same and tool comprising same

A tip for a twist drill or an end mill, the tip comprising a superhard structure joined to a cemented carbide substrate by at least two intermediate layers disposed between the superhard structure and the cemented carbide substrate, the intermediate layers comprising grains of superhard material and grains of a metal carbide material dispersed in a metal binder material comprising cobalt (Co), each intermediate layer comprising different compositions of diamond grains, metal carbide grains, and metal binder;

• the tip comprising at least two flutes, a peripheral side of the superhard structure defining a cylindrical land connecting the flutes, the superhard structure comprises a material selected from any of polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN) and has a thickness greater than 1 mm.

A method of machining a body comprising carbon fibre-reinforced polymer (CFRP) material using a twist drill or an end mill comprising a tip, the tip comprising a superhard structure joined to a cemented carbide substrate by at least two intermediate layers disposed between the superhard structure and the cemented carbide substrate, each intermediate layer comprising grains of superhard material and grains of a metal carbide material dispersed in a metal binder material, the intermediate layers comprising different compositions of diamond grains, metal carbide grains, and metal binder, wherein the superhard structure comprises a material selected from any of polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN) and has a thickness greater than 1 mm, the method further comprising removing material from the blank body to form at least two flutes such that a peripheral side of the superhard structure defines a cylindrical land connecting the flutes.