| 摘要 |
PURPOSE:To enhance the volume productivity of composite cutting bodies and prevent the occurrence of cracking by disposing a plurality of substrates in a vessel, opposing the concave parts and convex parts of the substrates via a pressure medium on the opposing surface sides thereof, and applying extra high pressure and high temp. to the powder material in the concave parts. CONSTITUTION:A plurality of substrates 9 consisting of a sintered hard metal are stacked and disposed within a vessel 6 made of high m.p. metal, by way of a pressure medium 10 which does not cause phase transition at the extra high pressure and high temp. A central concave part 12 and a central convex part 13 are formed to each substrate 9, and the concave parts 12 and the convex parts 13 are opposedly disposed by way of the medium 10. Cubic boron nitride powder, diamond powder or the like is packed in the concave parts 12, and after the application of high pressure and high temp., the powder is converted to a polycrystalline body 14, whereby a composite sintered body 15 is formed. since the polycrystalline body 14 slightly shrinks at the sintering, the lateral movement of the medium 10 between the concave parts 12 and the convex parts 13 is suppressed. The sintered body 15 is suitably divided radially and is formed to composite cutting bodies 20. At this time, the extra high pressure is applied by means of a piston 2 and the heating is accomplished by the current rings 17 provided with insulating plates 16, conductive plates 18 and carbon heaters 19. |
