Thermally stable diamond polycrystalline diamond constructions

摘要

A polycrystalline diamond body 57 has a top surface 52 and a side surface 58. The body is made from bonded diamond crystals. The body is attached to a substrate 60. There is a region 56 where the gaps between the crystals are free of a group VIII metal. There is another region where the gaps between the crystals contain a group VIII metal. The region free of the metal extends over the top surface and at least half of the side surfaces of the body; it is between 0.02mm and 0.09mm deep. The separate regions can be formed by treating only a portion of a body whose gaps initially all contain the metal. Leaching is one such treatment. The group VIII transition metal could be a catalyst for sintering the diamond crystals.