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 to a substrate along an interface therebetween, the substrate being formed of cemented carbide and a metal binder phase dispersed therein, comprises placing a layer comprising one or more elements or alloys thereof on the interface on one or other of the body of polycrystalline diamond material or substrate; the one or more elements being 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 or the substrate is then placed on the layer and the body of polycrystalline material, the layer and the substrate 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 with the substrate so that the metal from the binder phase infiltrates into the adjacent body of polycrystalline diamond material to form a bond between the body of polycrystalline diamond material and the substrate.