| abstract |
Disclosed is a cubic boron nitride sintered compact which has excellent wear resistance. Specifically disclosed is a cubic boron nitride sintered compact which is characterized by containing about 30-70% by volume of cubic boron nitride with the balance made up of unavoidable impurities and a binder phase that is composed of at least one substance selected from among oxides, carbides, nitrides and borides of Ti, Al, Zr, Y, Ce, Mg and Ca and mutual solid solutions of the oxides, carbides, nitrides and borides. The cubic boron nitride sintered compact is characterized in that: alpha-Al2O3, ZrB2, ZrO2 and ZrO are contained therein; and when the X-ray diffraction intensity of the (110) plane of alpha-Al2O3 is represented by Ia, the X-ray diffraction intensity of the (101) plane of ZrB2 is represented by Izb and the X-ray diffraction intensity of the (111) plane of ZrO is represented by Izo, the ratio of Izb to Ia, namely (Izb/Ia) satisfies 0.13 =< (Izb/Ia) <= 0.30 and the ratio of Izo to Ia, namely (Izo/Ia) satisfies 0.05 =< (Izo/Ia) <= 0.20. |