Abstract: An object is to prolong the life of a cubic boron nitride cutting tool used for cutting a heat-resistant alloy. A cubic boron nitride cutting tool includes an edge tip made of a sintered cubic boron nitride compact having a thermal conductivity within the range of 20 to 70 W/m·K and including cubic boron nitride particles having an average particle diameter within the range of 0.5 ?m to 2 ?m; and a base metal that holds the edge tip at a corner portion of the base metal, wherein a cutting edge formed on the edge tip of the tool has a positive rake angle.

Abstract: A sintered body of the present invention is a sintered body including a first material and cubic boron nitride. The first material is partially-stabilized ZrO2 including 5 to 90 volume % of Al2O3 dispersed in crystal grain boundaries or crystal grains of partially-stabilized ZrO2.

Abstract: A sintered compact has a first material, a second material, and a third material. The first material is cubic boron nitride. The second material is a compound including zirconium. The third material is an aluminum oxide and the aluminum oxide includes a fine-particle aluminum oxide. The sintered compact has a first region in which not less than 5 volume % and not more than 50 volume % of the fine-particle aluminum oxide is dispersed in the second material. On arbitrary straight lines in the first region, an average value of continuous distances occupied by the fine-particle aluminum oxide is not more than 0.08 ?m and a standard deviation of the continuous distances occupied by the fine-particle aluminum oxide is not more than 0.1 ?m.

Abstract: The surface-coated cBN sintered material includes a cBN sintered material containing cBN particles and a binder, and a coating. A proportion of the cBN particles in the cBN sintered material is 80 to 98% by volume, the binder contains a first compound including at least one element of Al and Cr and at least one element of N, B and O. The coating contains a layer A in contact with the cBN sintered material. The layer A is constituted of Alx1Cry1Mz1Ca1Nbb1Oc1 (provided that M is at least one element of Ti, V, Nb and Si, and 0.25?x1?0.75, 0.25?y1?0.75, 0?z1?0.5, x1+y1+z1=1, 0?a1?0.5, 0.5?b1?1, 0?c1?0.1, and a1+b1+c1=1 are satisfied).

Abstract: A cutting tool includes a cutting insert that is held in a holder in a detachable manner. The cutting insert has a substantially regular quadrangular shape in plan view and includes four round corners. The cutting insert is formed of CBN sinter as a whole. The cutting insert includes two principal surfaces that are upper and lower surfaces opposite to each other, and four side surfaces that are arranged so as to connect the principal surfaces to each other. A boundary portion (ridge line portion) between each of the principal surfaces and each of the side surfaces forms a cutting edge. In a central portion of each of the side surfaces of the cutting insert, a groove for absorbing a crack, having a substantially V-shape in cross section, is formed all around the cutting insert so as to be recessed with respect to the side surfaces.

Abstract: A surface-coated boron nitride sintered body tool is provided, in which a cutting edge portion includes a compound sintered body and a coating layer. The compound sintered body includes cBN particles. The compound sintered body includes 45-80 vol % of cBN particles. A first particle size distribution curve of the cBN particles has one or more peaks in a range in which a particle size is 0.1-0.7 ?m. A second particle size distribution curve of the cBN particles has a first peak having a maximum peak height in a range in which the particle size is 2.0-7.0 ?m. An integral value ratio (Io/It×100) is 1-20, in the second particle size distribution curve, the integral value Io being in the range in which the particle size is 0.1-0.7 ?m, and the integral value It being in an entire range.

Abstract: A cutting tool includes a base material and a coating formed on the base material. The base material is a sintered body containing 30 to 80% by volume of cubic boron nitride, and a binder. The surface in contact with the coating, of the base material, has a plurality of convex portions made of the cubic boron nitride and a plurality of concave portions made of the binder. A surface roughness Rsub of the surface in contact with the base material, is 0.1 to 0.4 ?m. A surface roughness Rsurf of an outermost surface of the coating is 0 to 0.15 ?m. A surface roughness Rasurf of the outermost surface of the coating is 0 to 0.1 ?m. The surface roughness Rsub of the surface in contact with the coating, of the base material, is greater than the surface roughness Rsurf of the outermost surface of the coating.

Abstract: A sintered compact according to the present invention includes: a first material that is cubic boron nitride; a second material that is an oxide of zirconium; and a third material that is an oxide of aluminum, the second material including cubic ZrO2 and ZrO, the third material including ?-Al2O3, and the sintered compact satisfying the following relation: 0.9?Izro2(111)/Ial(110)?30; and 0.3?Izro(111)/Ial(110)?3, where Ial(110), Izro2(111), and Izro(111) respectively represent X-ray diffraction intensities of a (110) plane of the ?-Al2O3, a (111) plane of the cubic ZrO2, and a (111) plane of the ZrO.

Abstract: A surface-coated boron nitride sintered body tool is provided, in which at least a cutting edge portion includes a cubic boron nitride sintered body and a coating film formed on a surface of the cubic boron nitride sintered body. The coating film includes an A layer and a B layer. The A layer is formed of columnar crystals each having a particle size of 10 nm or more and 400 nm or less. The B layer is formed of columnar crystals each having a particle size of 5 nm or more and 70 nm or less. The B layer is formed by alternately stacking two or more compound layers having different compositions. The compound layers each have a thickness of 0.5 nm or more and 300 nm or less.

Abstract: A sintered body of the present invention is a sintered body including a first material and cubic boron nitride. The first material is partially-stabilized ZrO2 including 5 to 90 volume % of Al2O3 dispersed in crystal grain boundaries or crystal grains of partially-stabilized ZrO2.

Abstract: A sintered compact according to the present invention includes: a first material that is cubic boron nitride; a second material that is an oxide of zirconium; and a third material that is an oxide of aluminum, the second material including cubic ZrO2 and ZrO, the third material including ?-Al2O3, and the sintered compact satisfying the following relation: 0.9?Izro2(111)/Ial(110)?30; and 0.3?Izro(111)/Ial(110)?3, where Ial(110), Izro2(111), and Izro(111) respectively represent X-ray diffraction intensities of a (110) plane of the ?-Al2O3, a (111) plane of the cubic ZrO2, and a (111) plane of the ZrO.

Abstract: A sintered compact has a first material, a second material, and a third material. The first material is cubic boron nitride. The second material is a compound including zirconium. The third material is an aluminum oxide and the aluminum oxide includes a fine-particle aluminum oxide. The sintered compact has a first region in which not less than 5 volume % and not more than 50 volume % of the fine-particle aluminum oxide is dispersed in the second material. On arbitrary straight lines in the first region, an average value of continuous distances occupied by the fine-particle aluminum oxide is not more than 0.08 ?m and a standard deviation of the continuous distances occupied by the fine-particle aluminum oxide is not more than 0.1 ?m.

Abstract: A tool includes, at least on its edge, a sintered cBN compact which includes cBN particles and a bonding phase, a plurality of flutes is formed on a rake face, each of the flutes having a starting end on the edge ridgeline and causing the edge ridgeline to be wavy, and the terminal end of the flute is disposed inwardly of the edge ridgeline. It is preferable that the flute width of the flute decreases with distance from the edge ridgeline, the flute depth of the flute decreases with distance from the edge ridgeline, and the rake face has a positive rake angle.

Abstract: A compound sintered body contains cubic boron nitride particles and binder particles. The composite sintered body contains 40 vol % or more and 80 vol % or less of the cubic boron nitride particles. The binder particles contain TiCN particles. The composite sintered body shows a first peak belonging to a (200) plane of the TiCN particles in a range in which a Bragg angle 2? is 41.7° or more and 42.6° or less in an X-ray diffraction spectrum measured using a Cu-K? ray as a ray source.

Abstract: Provided is a cubic boron nitride sintered body having good wear resistance and fracture resistance. A method for manufacturing a cubic boron nitride sintered body of the present invention is a method for manufacturing a cubic boron nitride sintered body having a cubic boron nitride particle content of 80% by volume or more and 99% by volume or less. The method includes a first step of preparing cubic boron nitride particles; a second step of coating surfaces of the cubic boron nitride particles with a coating material so as to obtain coated particles; a third step of mixing the coated particles and a binder to obtain a mixture; and a fourth step of sintering the mixture.

Abstract: A cubic boron nitride sintered body includes cubic boron nitride, a binder, and a metal catalyst element, a content by percentage of the cubic boron nitride is 50 vol % or more and 85 vol % or less, a content by percentage of the catalyst is 0.5 mass % or more and 5 mass % or less. A sum of a detected peak value of nitrogen and a detected peak value of boron at each of arbitrary measurement points on line segments is calculated, a measurement point at which the sum is a half or less of a maximum value among the sums at all measurement points respectively is identified as a binder-portion measurement point, and a ratio of the number of measurement points at which the catalyst element is not detected among the binder-portion measurement points, to a total number of all binder-portion measurement points, is 30% or less.

Abstract: A surface-coated boron nitride sintered body tool includes a cubic boron nitride sintered body and a coating film formed thereon. The coating film includes an A layer and a C layer. The A layer is formed of Ti1-xaMaxaC1-yaNya (where Ma is one or more of Cr, Nb and W; 0?xa?0.7; 0?ya?1). The C layer is formed of Al1-(xc+yc)CrxcMcycN (where Mc is one or more of Ti, V and Si; 0.2?xc?0.8; 0?yc?0.6; 0.2?xc+yc?0.8). The A layer is formed on an outermost surface of the coating film or between the outermost surface of the coating film and the C layer. A distance between the outermost surface of the coating film and an upper surface of the C layer is 0.1 ?m or more and 1.0 ?m or less.

Abstract: A surface-coated boron nitride sintered body tool is provided, in which at least a cutting edge portion includes a cubic boron nitride sintered body and a coating film formed on a surface of the cubic boron nitride sintered body. The coating film includes an A layer and a B layer. The A layer is formed of columnar crystals each having a particle size of 10 nm or more and 400 nm or less. The B layer is formed of columnar crystals each having a particle size of 5 nm or more and 70 nm or less. The B layer is formed by alternately stacking two or more compound layers having different compositions. The compound layers each have a thickness of 0.5 nm or more and 300 nm or less.