Thermally stable ultra-hard polycrystalline materials and compacts including an alkali metal

摘要

Thermally stable ultra-hard polycrystalline materials and compacts comprise an ultra-hard polycrystalline body 28 that wholly or partially comprises one or more thermally stable ultra-hard polycrystalline regions having interstitial regions where a catalyst in the form of an alkali metal from Group 1 of the periodic table is present. A substrate 36 can be attached to the body 28. The thermally stable ultra-hard polycrystalline region can be positioned along all or a portion of an outside surface of the body, or can be positioned beneath a body surface (fig 3D. The thermally stable ultra-hard polycrystalline region can be provided in the form of a single element or in the form of a number of elements. The thermally stable ultra-hard polycrystalline region can be formed from precursor material, such as diamond and/or cubic boron nitride. The mixture can be sintered by high pressure/high temperature process.