Patent ID: 7081424

Claim:
A high-strength, highly thermally conductive sintered compact of cubic boron nitride containing cubic boron nitride (cBN) grains and a binder binding said cBN grains together, the sintered compact being formed of: at least 40% by volume and at most 85% by volume of cBN grains; and a binder corresponding to a 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 4 a, 5 a and 6 a groups of the periodic table and a solid solution thereof, an aluminum compound, and an unavoidable impurity, wherein said cBN grains contain at most 0.03% by mass of Mg and at least 0.001% by mass and at most 0.05% by mass of Li.