METHOD FOR PRODUCING DIAMOND POLYCRYSTAL, DIAMOND POLYCRYSTAL, CUTTING TOOL, WEAR-RESISTANT TOOL, AND GRINDING TOOL

摘要

This method for producing a diamond polycrystal comprises: a first step for subjecting a high-pressure-phase carbon powder to a heat treatment at 1300°C or higher to thereby obtain a heat-treated carbon powder; and a second step for sintering the heat-treated carbon powder under a condition of from 12 GPa to 25 GPa and from 1200°C to 2300°C to thereby obtain a diamond polycrystal.