HIGH STRENGTH DIAMOND-METAL COMPOSITE SINTERED COMPACT AND ITS PRODUCTION

摘要

PURPOSE: To facilitate the mass production of a high strength diamond-metal composite sintered compact and to enable the production of a large sized product of the sintered compact by specifying the binder and the sintering conditions in the production of the sintered compact which contains a diamond and a metallic binder as the binder. ;CONSTITUTION: In the production of this composite sintered compact, 1 to 90vol.% of a diamond powder and the remainder of a raw material of the metallic binder, 99 to 10vol.% of e.g. Ni₃Al powder are mixed, wherein the metallic binder is obtained by sintering its raw material at ≤1850°C, under 2000MPa pressure in the solid phase and therefore has high strength of ≥ 100MPa strength at room temp. The mixture, as it is or after forming it, is sintered in the solid phase for an appropriate time under such sintering conditions of temp. and pressure of ≤1850°C and ≤2000MPa respectively that the diamond is not thermodynamically stable, however it is metastable under the conditions. Thus the high strength diamond-metal composite sintered body, which contains substantially no graphite phase ans has high toughness and strength, can be produced and the disadvantageous need of using a device for generating a superhigh pressure exceeding 2000MPa can be eliminated.;COPYRIGHT: (C)1995,JPO