Cubic boron nitride sintered material

A cubic boron nitride sintered material comprising 30% by volume or more and 99.9% by volume or less of cubic boron nitride grains and 0.1% by volume or more and 70% by volume or less of a binder phase,

• the binder phase including:
• at least one selected from the group consisting of:
• a simple substance selected from the group consisting of a group 4 element, a group 5 element and a group 6 element of the periodic table, aluminum, silicon, cobalt and nickel;
• an alloy thereof;
• and an intermetallic compound thereof;
• at least one selected from the group consisting of:
• a compound consisting of at least one element selected from the group consisting of a group 4 element, a group 5 element and a group 6 element of the periodic table, aluminum, silicon, cobalt and nickel, and at least one element selected from the group consisting of nitrogen, carbon, boron and oxygen;
• and a solid solution derived from the compound;
• or
• at least one selected from the group consisting of a simple substance selected from the group consisting of a group 4 element, a group 5 element and a group 6 element of the periodic table, aluminum, silicon, cobalt and nickel, an alloy thereof, and an intermetallic compound thereof;
• and at least one selected from the group consisting of a compound consisting of at least one element selected from the group consisting of a group 4 element, a group 5 element and a group 6 element of the periodic table, aluminum, silicon, cobalt and nickel and at least one element selected from the group consisting of nitrogen, carbon, boron and oxygen, and a solid solution derived from the compound,
• the cubic boron nitride grain having a carbon content of 0.08% by mass or less,
• the cubic boron nitride sintered material being a cubic boron nitride sintered material free of free carbon,
• the cubic boron nitride grains having a calcium content of 0.02% by mass or more and 0.2% by mass or less, and
• wherein an interface between the cubic boron nitride grains has a carbon content equal to or smaller than that of the cubic boron nitride grains.