Ultrahigh hardness nanocrystalline diamond bulk material and method for its production

摘要

PROBLEM TO BE SOLVED: To provide a diamond bulk material that has a higher hardness and resilience, and a broader utility than the conventional, and to provide a production method therefor.SOLUTION: Provided is a method for producing a diamond bulk material by a method comprising (1) a step for inputting, into a metal-mold, a seedless onion-like carbon as a raw material, and pressing into a preform having a certain shape, (2) a step for inputting the preform into a high-pressure synthesis metal-mold and thermo-holding there for 1 to 600 minute under the condition of a pressure of 4 to 25 GPa and a temperature of 1200 to 2300°C, and (3) a step for releasing the pressure, and for cooling.SELECTED DRAWING: Figure 6