COMPOSITE SINTERED COMPACT

摘要

PROBLEM TO BE SOLVED: To provide a composite sintered compact which achieves a longer tool life.SOLUTION: The composite sintered compact comprises cubic boron nitride and a binder. The cubic boron nitride is included by 20 to 80 vol.% in the composite sintered compact. The binder comprises a Ti compound and an auxiliary binder component. The auxiliary binder component is composed of either or both of an Al compound and an Si compound. Also, the ratio of the total of the outlines of the auxiliary binder component to the total of the outlines of the grains of the cubic boron nitride is 1.4 to 2.8 in at least one cross-section of the composite sintered compact.