| abstract |
The cubic boron nitride sintered body is a cubic boron nitride sintered body comprising 50% by volume or more and less than 80% by volume of cubic boron nitride particles, and more than 20% by volume to 50% by volume or less of a bonding phase, wherein the bonding phase is group 4 of the periodic table A compound containing at least one element selected from the group consisting of elements, Group 5 elements, Group 6 elements, and aluminum, and at least one element selected from the group consisting of nitrogen, carbon, boron and oxygen, and , containing at least one selected from the group consisting of a solid solution derived from the compound, and using TEM-EDX, when the oxygen content is measured in a direction perpendicular to the interface between the cubic boron nitride particles, the cubic boron nitride A first region having an oxygen content greater than the average value of the oxygen content of the particles exists, the interface is present in the first region, and a length of the first region in a direction perpendicular to the interface is 0.1 nm or more 10 nm or less. |