Abstract: A diamond cutting tool comprises a base metal part and a diamond part joined to the base metal part, wherein the base metal part is made of an alloy containing tungsten carbide, the diamond part configures at least a cutting blade, the cutting blade comprises a portion of a rake face, a portion of a flank face, and a ridge line at which the rake face and the flank face cross, the diamond cutting tool has a region A, the region A is a region that is present bridging over the three, which are the rake face, the ridge line, and the flank face on the surface of the cutting blade, and the region A has a surface roughness Ra of not more than 0.2 ?m and a concentration of tungsten element of not more than 1 mass %.

Abstract: cBN sintered material, including cBN particles; a binder phase; and a first phase, wherein the content of the cBN particles in the cBN sintered material is 25% to 80% by volume, the binder phase contains either or both of one or more first compounds, and a solid solution derived from the first compound, the first phase contains cobalt, tungsten, and at least one first element selected from the group consisting of the elements contained in the binder phase, the total content of cobalt and tungsten in the cBN sintered material is 1.0% to 6.0% by mass, the binder phase consists of multiple binder phase particles containing 50% or more of first binder phase particles on a number basis, surfaces of the first binder phase particles include 50% by area or more of a first region which is in contact with the first phase.

Abstract: A cubic boron nitride sintered material includes: 40 to 80 volume % of cubic boron nitride grains; and 20 to 60 volume % of a binder phase, wherein an average grain size d of the cubic boron nitride grains is 0.1 to 3 ?m, the binder phase includes at least one selected from a second group consisting of a simple substance of one element selected from a first group, an alloy consisting of two or more elements selected from the first group, and an intermetallic compound consisting of two or more elements selected from the first group, or at least one selected from a fourth group consisting of a first compound and a solid solution originated from the first compound, and in a cross section of the cubic boron nitride sintered material, a variation coefficient Z of an area ratio of the cubic boron nitride grains is 0.25 or less.

Abstract: A drill includes a blade tip part that is formed of diamond and a trunk part that is formed of diamond and is continuous with the blade tip part, the drill rotating about a drill axis, the blade tip part includes N cutting edges where N is an integer of no less than 4, and a proportion of S1 to S2 is no less than 30% and no more than 60%, where S1 is an area of the drill in a cross-section with the drill axis as a normal line, the cross-section including a boundary between the blade tip part and the trunk part, r is a maximum value of a distance from the drill axis to an outer edge of the drill in the cross-section and S2 is an area of a circle with r as a radius.

Abstract: cBN sintered material, including cBN particles; a binder phase; and a first phase, wherein the content of the cBN particles in the cBN sintered material is 25% to 80% by volume, the binder phase contains either or both of one or more first compounds, and a solid solution derived from the first compound, the first phase contains cobalt, tungsten, and at least one first element selected from the group consisting of the elements contained in the binder phase, the total content of cobalt and tungsten in the cBN sintered material is 1.0% to 6.0% by mass, the binder phase consists of multiple binder phase particles containing 50% or more of first binder phase particles on a number basis, surfaces of the first binder phase particles include 50% by area or more of a first region which is in contact with the first phase.

Abstract: A cubic boron nitride sintered material comprising cubic boron nitride grains, a binder phase, and a void, in which a percentage of the cubic boron nitride grains based on the total of the cubic boron nitride grains and the binder phase is 40 vol % to 70 vol %, a percentage of the binder phase based on the total of the cubic boron nitride grains and the binder phase is 30 vol % to 60 vol %, the binder phase includes 10 vol % to 100 vol % of aluminum oxide grains, an average grain size of the aluminum oxide grains is 50 to 250 nm, the cubic boron nitride sintered material comprises 0.001 vol % to 0.100 vol % of one or more first voids, and at least one portion of each of the first voids is in contact with the aluminum oxide grains.

Abstract: A cubic boron nitride sintered material comprising cubic boron nitride grains, a binder phase, and a void, in which a percentage of the cubic boron nitride grains based on the total of the cubic boron nitride grains and the binder phase is 40 vol % to 70 vol %, a percentage of the binder phase based on the total of the cubic boron nitride grains and the binder phase is 30 vol % to 60 vol %, the binder phase includes 10 vol % to 100 vol % of aluminum oxide grains, an average grain size of the aluminum oxide grains is 50 to 250 nm, the cubic boron nitride sintered material comprises 0.001 vol % to 0.100 vol % of one or more first voids, and at least one portion of each of the first voids is in contact with the aluminum oxide grains.

Abstract: A cubic boron nitride sintered material includes: 0 to 85 volume % of cubic boron nitride grains; and a binder phase, wherein the binder phase includes at least one selected from a group consisting of one or more first compounds and a solid solution originated from the first compounds, the cubic boron nitride grains include, on number basis, more than or equal to 50% of cubic boron nitride grains each having an equivalent circle diameter of more than 0.5 ?m, and includes, on number basis, less than or equal to 50% of cubic boron nitride grains each having an equivalent circle diameter of more than 2 ?m, and when a mass of the cubic boron nitride grains is assumed as 100 mass %, a total content of lithium, magnesium, calcium, strontium, beryllium, and barium in the cubic boron nitride grains is less than 0.001 mass %.

Abstract: A cubic boron nitride sintered material includes: to 98 volume % of cubic boron nitride grains; and a binder phase, wherein the binder phase includes at least one selected from a group consisting of one or more first compounds and a solid solution originated from the first compounds, the cubic boron nitride grains include, on number basis, more than or equal to 50% of cubic boron nitride grains each having an equivalent circle diameter of more than 0.5 ?m, and includes, on number basis, less than or equal to 50% of cubic boron nitride grains each having an equivalent circle diameter of more than 2 ?m, and when a mass of the cubic boron nitride grains is assumed as 100 mass %, a total content of lithium, magnesium, calcium, strontium, beryllium, and barium in the cubic boron nitride grains is less than 0.001 mass %.

Abstract: A diamond cutting tool comprises a base metal part and a diamond part joined to the base metal part, wherein the base metal part is made of an alloy containing tungsten carbide, the diamond part configures at least a cutting blade, the cutting blade comprises a portion of a rake face, a portion of a flank face, and a ridge line at which the rake face and the flank face cross, the diamond cutting tool has a region A, the region A is a region that is present bridging over the three, which are the rake face, the ridge line, and the flank face on the surface of the cutting blade, and the region A has a surface roughness Ra of not more than 0.2 ?m and a concentration of tungsten element of not more than 1 mass %.

Abstract: A drill includes a blade tip part that is formed of diamond and a trunk part that is formed of diamond and is continuous with the blade tip part, the drill rotating about a drill axis, the blade tip part includes N cutting edges where N is an integer of no less than 4, and a proportion of S1 to S2 is no less than 30% and no more than 60%, where S1 is an area of the drill in a cross-section with the drill axis as a normal line, the cross-section including a boundary between the blade tip part and the trunk part, r is a maximum value of a distance from the drill axis to an outer edge of the drill in the cross-section and S2 is an area of a circle with r as a radius.

Abstract: A cubic boron nitride sintered material includes 40% by volume or more and 96% by volume or less of cubic boron nitride grains and 4% by volume or more and 60% by volume or less of a binder phase, and the cubic boron nitride grains have a dislocation density of less than 1×105/m2.

Abstract: A polycrystalline cubic boron nitride comprising 96% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8×1015/m2, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of less than 100 nm.

Abstract: A polycrystalline cubic boron nitride comprising 98.5% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8×1015/m2, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of 0.1 ?m or more and 0.5 ?m or less.

Abstract: A polycrystalline cubic boron nitride comprising 96% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of 8×1015/m2 or less, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of less than 100 nm.

Abstract: 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 3×1017/m2 or more and 1×1020/m2 or less.

Abstract: 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 3×1017/m2 or more and 1×1020/m2 or less.

Abstract: The 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 1×1015/m2 or more and 1×1017/m2 or less.

Abstract: A polycrystalline cubic boron nitride comprising 98.5% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8×1015/m2, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of 0.1 ?m or more and 0.5 ?m or less.