RE-SINTERED BORON-RICH POLYCRYSTALLINE CUBIC BORON NITRIDE AND METHOD FOR MAKING SAME

摘要

RE-SINTERED BORON-RICH POLYCRYSTALLINE CUBIC BORON NITRIDE AND METHOD FOR MAKING SAME Disclosed is a method for making re-sintered polycrystalline CBN compact which comprises placing sintered boron-rich polycrystalline CBN particles in a high temperature/high pressure apparatus and subjecting said boron-rich CBN particles to a pressure and a temperature adequate to re-sinter said particles, the temperature being below the reconversion temperature of CBN, for a time sufficient to re-sinter the polycrystalline CBN particles therein. The boron-rich polycrystalline CBN particles in the HP/HT apparatus contain no impurity which would interfere with the sintering process (CBN sintering inhibiting impurities) and no sintering aid material.