| 摘要 |
A method of producing a thermally stable polycrystalline diamond compact comprises placing in a high pressure/high temperature apparatus a mass of polycrystalline diamond particles, the mass having a front face and a rear face, and a mass of catalyst metallic material, and then subjecting the masses to high pressure and temperature such that the metallic material infiltrates the mass of diamond particles so as to form, on subsequent cooling, a solid composite compact. The grain size and/or packing density of the polycrystalline diamond particles is varied between said front face and rear face in such manner that, in the finished compact, material nearer the rear face is less wear resistant than material nearer the front face, so that the compact is self-sharpening in use. Alternatively or additionally, the wear resistance is varied by including an additive with the diamond particles, the proportion of the additive varying between the front face and rear face. |
