Abstract: A diamond tool includes a diamond at least on a cutting edge including one or two or more diamond grains including a diamond phase composed of a diamond crystal structure and a graphite phase composed of a graphite crystal structure. When a ratio I?*/I?* between an intensity of a ?* peak derived from a ? bond of carbon in the graphite phase and an intensity of a ?* peak derived from a ? bond of carbon in the graphite phase and a ? bond of carbon in the diamond phase is determined for the diamond grain by measuring an energy loss associated with excitation of K-shell electrons of carbon by electron energy loss spectroscopy, the ratio I?*/I?* of the diamond grain on a surface of the cutting edge is 0.1 to 2 and a ratio I?*/I?* of the diamond grain at a depth position of 0.5 ?m from the surface of the cutting edge is 0.001 to 0.1.

Abstract: A tool of the present disclosure includes a tip end portion. The tip end portion has a surface. At least a part of the surface includes a plurality of protrusions, a first recess provided by contact between ends of two adjacent protrusions of the protrusions, and a second recess different from the first recess. The second recess is provided inside at least one of the protrusions or provided to extend across the two adjacent protrusions.

Abstract: There is provided a diamond cutting tool including a cutting edge portion containing single crystal diamond or binderless polycrystalline diamond and graphite, wherein when Raman spectroscopy is performed on a surface of the cutting edge portion, a ratio R1 of Ig1 to a sum of Id1 and the Ig1 is equal to or more than 0.5 and equal to or less than 1, where the Idi represents a peak intensity of first carbon in the surface, the Ig1 represents a peak intensity of second carbon in the surface, the first carbon represents carbon that forms the single crystal diamond or the binderless polycrystalline diamond.

Abstract: A method for manufacturing a cutting tool having a rake face, a flank face, and an edge having a ridge line interconnecting the rake face and the flank face, wherein on the flank face there is a cutting edge region from the ridge line of the edge to a point A away therefrom on the side of the flank face by a distance X, the method comprising producing and processing the flank face with a laser, the producing and processing being producing and processing the cutting edge region along the ridge line of the edge with a first laser beam having a depth of focus equal to or deeper than a width of the cutting edge region when the distance X is the width of the cutting edge region, the distance X being 0.2 mm or more and 5 mm or less.

Abstract: A composite sintered material includes: a plurality of diamond grains having an average grain size of less than or equal to 10 ?m; a plurality of cubic boron nitride grains having an average grain size of less than or equal to 2 ?m; and a plurality of aluminum oxide grains having an average grain size of less than or equal to 0.5 ?m; 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 %.

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 including cubic boron nitride particles; 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 composite sintered material includes a plurality of diamond grains, a plurality of cubic boron nitride grains, and a remainder of a binder phase, wherein the binder phase includes cobalt, a content of the cubic boron nitride grains in the composite sintered material is more than or equal to 3 volume % and less than or equal to 40 volume %, and an average length of line segments extending across continuous cubic boron nitride grains in appropriately specified straight lines extending through the composite sintered material is less than or equal to a length three times as large as an average grain size of the cubic boron nitride grains.

Abstract: A composite sintered material includes: a plurality of diamond grains having an average grain size of less than or equal to 10 ?m; a plurality of cubic boron nitride grains having an average grain size of less than or equal to 2 ?m; 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 more than or equal to 30 volume % and less than or equal to 94 volume %, a content of the cubic boron nitride grains is more than or equal to 3 volume % and less than or equal to 40 volume %, and a content of the cobalt is more than or equal to 3 volume % and less than or equal to 30 volume %.

Abstract: A composite sintered material contains cubic boron nitride particles and binder particles. The composite sintered material 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 material 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: A sintered material contains hard particles composed of one or more selected from the group consisting of cubic boron nitride, Al2O3, AlON, SiAlON, TiC, TiCN, TiN, WC, and diamond, a metallic binder phase mainly composed of Co or Ni and containing at least one element selected from the group consisting of Co, Ni, Al, W, V, and Ti, and Al2O3 dispersed in the metallic binder phase.

Abstract: A method for manufacturing a cubic boron nitride cutting tool including a base metal and sintered cubic boron nitride compact at a corner portion of the base metal, capable of improving the accuracy of the center height and reducing the angle of inclination or width of a negative rake face; and the cubic boron nitride cutting tool. The method includes grinding the compact by pressing it against an end face of a grindstone of a grinder to form flank and rake faces on the compact while the base metal of the cutting tool is held by a chuck of the grinder, so that the compact is substantially ground. The rake face is formed to be recessed from a top face of the base metal or only a portion of the compact that protrudes from a base-metal rake face is ground while the tool is continuously held by the chuck.

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 including cubic boron nitride particles; 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: 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 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 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.