CUBIC BORON NITRIDE COMPOSITE POLYCRYSTAL AND METHOD FOR MANUFACTURING THE SAME, CUTTING TOOL, WIRE DRAWING DIE, AND GRINDING TOOL

摘要

PROBLEM TO BE SOLVED: To provide a cubic boron nitride composite polycrystal having a high hardness even at a high temperature and a method for manufacturing the same; and a cutting tool, a wire drawing die, and a grinding tool including the same.SOLUTION: The provided cubic boron nitride composite polycrystal is constituted by wurtzite-type boron nitride, cubic boron nitride, and inevitable impurities; the content of the wurtzite-type boron nitride is 0.1-10 vol.%; the average particle diameter of the cubic boron nitride is 500 nm or below; the Vickers hardness of the cubic boron nitride composite polycrystal at 1200°C is 15 GPa or above.