Abstract: A polycrystalline diamond abrasive element, particularly a cutting element, comprises a table of polycrystalline diamond bonded to a substrate, particularly a cemented carbide substrate, along a non-planar interface. The non-planar interface typically has a cruciform configuration. The polycrystalline diamond has a high wear-resistance, and has a region adjacent the working surface lean in catalysing material and a region rich in catalysing material. The region lean in catalysing material extends to a depth of 40 to 90 microns, which is much shallower than in the prior art. Notwithstanding the shallow region lean in catalysing material, the polycrystalline diamond cutters have a wear resistance, impact strength and cutter life comparable to that of prior art cutters, but requiring only 20% of the treatment times of the prior art cutters.

Abstract: A polycrystalline diamond abrasive element, particularly a cutting element, comprises a table of polycrystalline diamond bonded to a substrate, particularly a cemented carbide substrate, along a non-planar interface. The non-planar interface typically has a cruciform configuration. The polycrystalline diamond has a high wear-resistance, and has a region adjacent the working surface lean in catalysing material and a region rich in catalysing material. The region lean in catalysing material extends to a depth of 40 to 90 microns, which is much shallower than in the prior art. Notwithstanding the shallow region lean in catalysing material, the polycrystalline diamond cutters have a wear resistance, impact strength and cutter life comparable to that of prior art cutter, but requiring only 20% of the treatment times of the prior art cutters.

Abstract: A tool insert comprises a working layer of ultra-hard abrasive, particularly PCD, bonded to a substrate along an interface. The working layer presents a working surface and a periphery around the working surface which provides a cutting edge for the insert. The working layer of ultra-hard abrasive has a first region extending into the layer from the working surface, and a second region in contact with the first region, the wear resistance of the first region being less than that of the second region. The wear resistance of the first region is between 50% and 95% of that of the second region, preferably between 60% and 90%, most preferably between 70% and 89%.

Abstract: A polycrystalline diamond abrasive element, particularly a cutting element, comprises a layer of polycrystalline diamond having a working surface and bonded to a substrate, particularly a cemented carbide substrate, along an interface. The polycrystalline diamond abrasive element is characterised by using a binder phase that is homogeneously distributed through the polycrystalline diamond layer and that is of a fine scale. The polycrystalline diamond also has a region adjacent the working surface lean in catalysing material and a region rich in catalysing material.