PROCESS FOR IMPROVING THE METALIZATION CHARACTERISTICS OF CUBIC BORON NITRIDE RICH IN BORON, PERFECTED CUBIC BORON NITRIDE PRODUCED BY SUCH PROCESS AND IMPLEMENT FOR METALIZED CRUSHING CONTAINING ABRASIVE NITRATE BUBBLES

摘要

Boron rich cubic boron nitride suitable for use in electroplating processes (e.g. nickel plating) has been made by an acid leaching process. Boron rich aggregated cubic boron nitride grinding grits are leached in a mixture of nitric and sulfuric acids, the following conditions being typical; (a) volume ratio of 67% nitric acid to 98% sulfuric acid of 10:20; (b) temperature of 250 DEG C; and (c) for a time of 1 hour. The process removes sufficient free surface boron to reduce the conductivity at the surface, resulting in an abrasive which does not overplate. FIG. 1 is a photomicrograph of a typical plated surface containing the improved CBN grinding grit of this invention, and FIG. 3 is an X-ray diffraction pattern characteristic of this new product.