Composite polycrystalline diamond compact with discrete particle size areas

Abstract

A polycrystalline diamond compact for use in cutting operations that require improved impact strength and non-uniform edge wear. The compact includes a substrate, with multiple, laterally spaced, abrasive diamond particle areas segregated by different particle sizes bonded to the substrate. The polycrystalline diamond areas formed of finer size diamond particles provide higher abrasion resistance wear at a slower rate thus producing a non-linear cutting, edge to the work zone. The areas of different average size diamond particles, in one embodiment, are arranged in concentric rings with each ring of a different particle size. Alternating rings may be formed of uniform size diamond a particles. The areas also may be in the form of spaced grooves inlaid from the end surface of polycrystalline diamond layers. The polycrystalline diamond layer may also have a non-planar end with the discrete areas radially spaced across the layer. Alternately, a plurality of depressions are formed in a working surface of the substrate, with polycrystalline diamond filling all of the depressions. At least one of the depressions is filled with polycrystalline diamond having a different average particle size than that of the diamond filling the other depression. The depressions are thus separated by barriers formed of a harder material.