Making a cutter with shaped superhard material layer

摘要

A method of making a cutter comprises placing a pre-formed body 4 of hard material having a surface topography in a canister 14, placing an aggregated mass 2 of grains of superhard material over said surface topography, placing a punch 6 in contact with the superhard material, the punch 6 having a surface with a topography inverse to that of the hard material body to imprint a pattern in the superhard material complementary to the surface topography of the punch 6. The surface of the punch 6 contacting the superhard material being formed of a ceramic material that does not react chemically with the superhard material and/or a sinter catalyst for the superhard material. A pressure of greater than 3 GPa is then together with a temperature sufficiently high for the catalyst to melt to form the cutter structure with a layer of polycrystalline superhard material bonded to the hard material and having a surface topography corresponding to the surface topography of the hard material.