Polycrystalline diamond composite compact element, tools incorporating same and method for making same

Abstract

The invention relates to a PCD composite compact element comprising a PCD structure integrally bonded at an interface to a cemented carbide substrate; the PCD structure comprising coherently bonded diamond grains having a mean size no greater than 15 microns; the cemented carbide substrate comprising carbide particles dispersed in a metallic binder, the carbide particles comprising a carbide compound of a metal; wherein the ratio of the amount of metallic binder to the amount of the metal at points in the substrate deviates from a mean value by at most 20 percent of the mean value. The invention further relates to a method for making a PDC compact element comprising a PCD structure integrally bonded to a substrate formed of cemented carbide; the method including introducing a source of excess carbon to the substrate at a bonding surface of the substrate to form a carburised substrate; contacting an aggregated mass of diamond grains with the carburised substrate; and sintering the diamond grains in the presence of a solvent/catalyst material for diamond; wherein the mean size of the diamond grains in the aggregated mass is no greater than 30 microns.

Dependencies are inferred from the claim text.