CUBIC BORON NITRIDE SINTERED COMPACT TOOL

摘要

A cubic boron nitride sintered body tool has, at least at a cutting edge, a cubic boron nitride sintered body composed of a cubic boron nitride particle and a binder phase. The content of cBN is not less than 20 volume % and not more than 60 volume %. The binder phase contains at least Al 2 O 3 and a Zr compound. On any straight line in the sintered body, the mean value of a continuous distance occupied by Al 2 O 3 is not less than 0.1 µm and not more than 1.0 µm, and the standard deviation of the continuous distance occupied by Al 2 O 3 is not more than 0.8. On the straight line, X/Y is not less than 0.1 and not more than 1 where X represents the number of points of contact between Al 2 O 3 and the Zr compound, and Y represents the sum of the number of points of contact between Al 2 O 3 and cBN and the number of points of contact between Al 2 O 3 and binder phase component(s) other than Al 2 CO 3 and the Zr compound. The Zr compound has an average particle size of not less than 0.01 µm and not more than 0.1 µm.