Method of making a cutting insert with a polycrystalline super-hard structure

摘要

The method includes defining a rake face topology 12. A pre-sinter assembly includes a substrate body having a formation surface defining a topology complementary to the rake face topology. An aggregation of super-hard grains is disposed adjacent the formation surface of the substrate body. The substrate body includes a source of catalyst or binder material capable of promoting the sintering of the super-hard grains at a pressure and temperature at which the super-hard material is thermodynamically stable. The pre-sinter assembly is subjected to the pressure and temperature to provide a sintered polycrystalline super-hard structure joined to the formation surface of the substrate at a first major boundary of the super-hard structure. The structure has a second major boundary opposite the first. The substrate body is removed to expose the first major boundary of the super-hard structure defining the rake face topology. An alternative cutter structure, which may be for a machine tool, includes polycrystalline super-hard material in a first region adjacent the rake face which has lower hardness than that in a second region remote from the rake face.