| 摘要 |
A method of making a super-hard article (such as a tool or twist drill) comprising a super-hard structure bonded to a substrate 18 (which may be cemented carbide), the super-hard structure comprising a sintered plurality of super-hard grains (such as polycrystalline diamond, PCD, or polycrystalline cubic boron nitride, PCBN). The method includes providing raw material powder suitable for sintering the super-hard structure. The raw material powder is combined with organic binder material in a liquid medium to form a paste. The content of the raw material powder between 60-85 mass per cent of the paste and the composition of the paste is such that it has a shear rate of at most 25 inverse second (s-1). The substrate assembly, having a formation surface area configured for forming a boundary of the super-hard structure, the substrate also comprises a recess 16 coterminous with the formation surface area. The paste is extruded into contact with the formation surface area to provide a paste assembly. The paste assembly is heat treated to remove the binder material and provide a pre-sinter assembly. The pre-sinter assembly is subjected to a pressure and temperature sufficient to sinter the raw material powder and transform it into the super-hard structure bonded to the substrate at a boundary coterminous with the formation surface area. |
