| 摘要 |
A method of forming a polycrystalline superhard construction comprising: preparing a metastable solid solution to form a catalyst-binder mixture by mechanically alloying a first mass comprising a source of elemental carbon and a second mass of a catalyst comprising an elemental metal powder or metal alloy powder, the first mass comprising between 3 wt% to 15 wt% of source of elemental carbon, and the second mass comprising between 85 wt% to 97 wt% catalyst powder. The catalyst-binder mixture is mixed with a mass of superhard particles to form a green body which is then treated at a pressure of around 5.5 GPa or greater and a temperature to sinter together the grains of superhard material to form a polycrystalline superhard construction comprising a superhard phase and a binder phase, an amount of the superhard phase precipitating in part in the binder phase during the step of sintering. Preferably the source of elemental carbon comprises graphite and/or amorphous carbon powder. Preferably the elemental metal powder or metal alloy powder comprises one or more of the metals cobalt, iron, manganese, nickel, platinum, or ruthenium. |
