Sintered cubic boron nitride compact and sintered cubic boron nitride compact tool

Abstract

It is an object of the present invention to provide a sintered cBN compact having excellent wear resistance and fracture resistance even in machining centrifugally cast iron having a property of being difficult to machine, and to provide a sintered cBN compact tool. A sintered cBN compact of the present invention contains 20% by volume or more and 65% by volume or less of cBN and, as a binder, 34% by volume or more and less than 80% by volume of Al2O3, at least one selected from the group consisting of nitrides, carbides, carbonitrides, borides, and boronitrides of Zr and solid solutions thereof (hereinafter, referred to as “X”), and ZrO2, the total amount of X and ZrO2 being 1.0% by volume or more and 6.0% by volume or less, the volume ratio of ZrO2 to Al2O3, ZrO2/Al2O3, being 0.010 or more and less than 0.100, in which the ratio Itetragonal ZrO2(101)/IαAl2O3(110) is 0.1 or more and 3 or less, where Itetragonal ZrO2(101) is the intensity of the (101) plane of tetragonal ZrO2 and IαAl2O3(110) is the intensity of the (110) plane of αAl2O3 among X-ray diffraction peaks of the sintered cBN compact.

Dependencies are inferred from the claim text.