HIGH-STRENGTH, HIGHLY THERMALLY CONDUCTIVE SINTERED COMPACT OF CUBIC BORON NITRIDE

摘要

The present high-strength, highly thermally conductive sintered compact of cubic boron nitride contains cubic boron nitride (cBN) grains and a binder binding the grains. More specifically, it is formed of at least 40% by volume and at mos t 85% by volume of cBN grains, and a binder corresponding to the remainder and formed of at least one selected from the group consisting of a nitride, a carbide, a boride, and an oxide of an element belonging to the 4a, 5a and 6a groups of the periodic table and a solid solution thereof, an aluminum compound, and an unavoidable impurity, a nd the cBN grains contain at most 0.03% by mass of Mg and at least 0.001% by mass a nd at most 0.05% by mass of Li.