| 摘要 |
Method comprises: (i) intimately mixing a mass of particulate diamond crystals with a bonding agent in the proportions of 60-95 vol.% of diamond to 40-5 vol.% bonding agent, the latter comprising (a) elements, and metallic alloys contg. such elements, which react with C to form stable carbides having m.pts. above 1600 deg.C, and which thereby inhibit prodn. of free graphite by retrogressive transformation from diamond, and (b) metals, and alloys contg. metals, which do not form stable carbides, but which produce a bond with diamond having a min. m.pt. of 1600 deg.C or more when heated in contact with the diamonds in the solid state and which also inhibit retrogressive transformation of the diamond; (ii) heating the mixt. to 1100-1600 deg.C and compressing it at 10-40 kbars, the pressure temp. combination lying in the graphite stability field; and (iii) holding thses conditions for at least three minutes to cause plastic deformation of the diamond crystals so that contact between diamonds occur over surfaces and so that substantial chemical equilibrium is achieved between bonding agent and diamond crystals, so that a stable diamond compact with m.pt. 1600 deg.C and min. compressive strength of 10 kbars at ambient temp. is produced.
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