A method for attaching a pre-sintered body of polycrystalline diamond material to a substrate

A method of attaching a pre-sintered body of polycrystalline diamond material 12 to a substrate 14 along an interface 18 therebetween, the substrate 14 being formed of cemented carbide with a metal binder phase dispersed therein, comprises placing a layer 16 comprising one or more elements or alloys thereof on the interface on one or other of the body of polycrystalline diamond material 12 or substrate 14. The one or more elements or alloys are selected to form a eutectic mixture with the metal in the binder phase, the eutectic mixture having a lower melting point than the melting point of the metal in the binder phase of the substrate. The other of the body of polycrystalline diamond material 12 or the substrate 14 is then placed on the layer and the body of polycrystalline diamond material 12, the layer 16 and the substrate 14 are then subjected to a predetermined temperature at least equal to or greater than the melting point of the eutectic mixture at substantially ambient pressure or a vacuum to melt the metal in the binder phase at the interface 18 with the substrate 14 so that the metal from the binder phase infiltrates into the adjacent body of polycrystalline diamond material 12 to form a bond between the body of polycrystalline diamond material 12 and the substrate 14. The metal in the binder phase may be cobalt. The method is preferably used to join a thermally stable polycrystalline diamond (TSP) to a substrate, and may be used to join a PCD cutting element to a cutting tool.