Process for producing diamond compacts

摘要

PCT No. PCT/AU89/00273 Sec. 371 Date May 15, 1990 Sec. 102(e) Date May 15, 1990 PCT Filed Jun. 27, 1989 PCT Pub. No. WO90/01986 PCT Pub. Date Mar. 8, 1990.A diamond compact comprised of more than 60 volume percent and less than 90 volume percent of diamond crystals connected by a silicon carbide bond. The bond contains more than 500 parts per million of nitrogen and/or phosphorus and the compact possesses a low electrical resistivity of less than 0.2 ohm cm. The compact may be produced by a process in which the diamond crystals are intimately mixed with a bonding agent comprising silicon and the mixture is subjected within a confining space to a high temperature and pressure within the graphite stability field to cause silicon in the bonding agent to react extensively with carbon in the diamond crystals to form the silicon carbide bond. To produce the low electrical resistivity, a material containing nitrogen and/or phosphorus is introduced into the confining space prior to application of the high temperature and pressure conditions. In a modified process, the mixed diamond crystals and bonding agent are placed immediately adjacent to one or more bodies of silicon within the confining space prior to application of the high pressure and temperature conditions. In this process, the nitrogen and/or phosphorus containing material may be mixed with the diamond crystals and bonding agent and/or with one of the additional bodies of silicon prior to application of the high temperature and pressure conditions.