A cubic boron nitride sintered material comprises 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 cubic boron nitride grain having a carbon content of 0.08% by mass or less, the cubic boron nitride sintered material being free of free carbon.

A cubic boron nitride sintered material comprises 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 cubic boron nitride grain having a carbon content of 0.08% by mass or less, the cubic boron nitride sintered material being free of free carbon.

A cubic boron nitride sintered material includes: more than 80 volume % and less than 100 volume % of cubic boron nitride grains; and more than 0 volume % and less than 20 volume % of a binder phase. The binder phase includes: at least one selected from a group consisting of a simple substance, an alloy, and an intermetallic compound selected from a group consisting of a group 4 element, a group 5 element, a group 6 element in a periodic table, aluminum, silicon, cobalt, and nickel. A dislocation density of the cubic boron nitride grains is more than or equal to 3×10.sup.17/m.sup.2 and less than or equal to 1×10.sup.20/m.sup.2.

A cubic boron nitride sintered material comprises 30% by volume or more and 80% by volume or less of cubic boron nitride grains and 20% by volume or more and 70% by volume or less of a binder phase, the cubic boron nitride grains having a dislocation density of 3×10.sup.17/m.sup.2 or more and 1×10.sup.20/m.sup.2 or less.

A material 100 for an anti-theft device is described. The material 100 comprises a binder 102, a first type of particles 104, a second type of particles 106, and graphene layer 114 between the binder and each of the first type of particles 104 and second type of particles 106. The first type of particles 104 are selected from at least one of diamond and cubic boron nitride ‘CBN’, and the second type of hard particles are selected from at least one of a metallic carbide and a ceramic material. The first particles resist a cutting action of a cutting tool and the second particles degrade the cutting tool during the cutting action. The graphene bonds the particles to the binder to prevent the particles being dislodged by a cutting action. The result of the combination of these actions is to delay the time for an operator of a cutting tool to cut through the material 100.

A cubic boron nitride sintered material includes: more than 80 volume % and less than 100 volume % of cubic boron nitride grains; and more than 0 volume % and less than 20 volume % of a binder phase. The binder phase includes: at least one selected from a group consisting of a simple substance, an alloy, and an intermetallic compound selected from a group consisting of a group 4 element, a group 5 element, a group 6 element in a periodic table, aluminum, silicon, cobalt, and nickel. A dislocation density of the cubic boron nitride grains is more than or equal to 3×10.sup.17/m.sup.2 and less than or equal to 1×10.sup.20/m.sup.2.

A cubic boron nitride sintered material comprises 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 cubic boron nitride grain having a carbon content of 0.08% by mass or less, the cubic boron nitride sintered material being free of free carbon.

A cubic boron nitride sintered material comprises 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 cubic boron nitride grain having a carbon content of 0.08% by mass or less, the cubic boron nitride sintered material being free of free carbon.

A composite sintered material includes: a plurality of diamond grains having an average grain size of less than or equal to 10 μm; a plurality of cubic boron nitride grains having an average grain size of less than or equal to 2 μm; and a plurality of aluminum oxide grains having an average grain size of less than or equal to 0.5 μm; and a remainder of a binder phase, wherein at least parts of adjacent diamond grains are bound to one another, the binder phase includes cobalt, in the composite sintered material, a content of the diamond grains is from 30 to 92 volume %, a content of the cubic boron nitride grains is from 3 to 40 volume %, a content of the aluminum oxide grains is from 2 to 15 volume %, and a content of the cobalt is from 3 to 30 volume %.

A cubic boron nitride sintered material comprises 30% by volume or more and 80% by volume or less of cubic boron nitride grains and 20% by volume or more and 70% by volume or less of a binder phase, the cubic boron nitride grains having a dislocation density of 3×10.sup.17/m.sup.2 or more and 1×10.sup.20/m.sup.2 or less.