CUBIC BORON NITRIDE POLYCRYSTALLINE ABRASIVE GRAIN AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a high-strength cBN abrasive grain with high heat resistance, suitable as abrasive grain for a whetstone intended for the heavy grinding or high-speed grinding of iron-based materials. SOLUTION: This abrasive grain is a polycrystalline substance consisting of cBN crystallites of <=1μm in grain size; wherein the ratio of the X-ray diffraction intensity (I220 ) of each cBN (220)-plane to the X-ray diffraction intensity (I111 ) of (111)-plane of the polycrystalline substance, namely I220 /I111 is >=0.1; and the polycrystalline substance is preferably incorporated with 0.01-0.5 vol.% of compressed-type hBN.