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 cemented carbide including a hard phase, a binding phase, and inevitable impurities. The hard phase satisfies a first hard phase composed mainly of tungsten carbide, and a second hard phase composed mainly of a compound. The compound contains multiple types of metallic elements including tungsten and at least one element selected from carbon, nitrogen, oxygen, and boron. The second hard phase satisfies D10/D90<0.4, wherein D10 denotes a cumulative 10% grain size in an area-based grain size distribution on a surface or cross section of the cemented carbide, and D90 denotes a cumulative 90% grain size in the area-based grain size distribution, and satisfies ?2<5.0, wherein ?2 denotes the variance of the distance between the centroids of the nearest two of the second hard phases. The average grain size DW of the first hard phase ranges from 0.8 to 4.0 ?m and satisfies DM/DW<1.0, wherein DM denotes the average grain size of the second hard phase.

Abstract: A cemented carbide including a hard phase, a binding phase, and inevitable impurities. The hard phase satisfies a first hard phase composed mainly of tungsten carbide, and a second hard phase composed mainly of a compound. The compound contains multiple types of metallic elements including tungsten and at least one element selected from carbon, nitrogen, oxygen, and boron. The second hard phase satisfies D10/D90<0.4, wherein D10 denotes a cumulative 10% grain size in an area-based grain size distribution on a surface or cross section of the cemented carbide, and D90 denotes a cumulative 90% grain size in the area-based grain size distribution, and satisfies ?2<5.0, wherein ?2 denotes the variance of the distance between the centroids of the nearest two of the second hard phases. The average grain size DW of the first hard phase ranges from 0.8 to 4.0 ?m and satisfies DM/DW<1.0, wherein DM denotes the average grain size of the second hard phase.

Abstract: Provided are a cemented carbide having excellent plastic deformation resistance and a cutting tool in which the cemented carbide is used as a substrate. A cemented carbide includes a hard phase containing tungsten carbide particles and a binder phase containing, as a main component, an iron-group element, wherein the formula B/A?0.05 is satisfied, where A represents the number of the tungsten carbide particles, and B represents the number of tungsten carbide particles whose number of contact points with other tungsten carbide particles is 1 or less. Preferably, the iron-group element includes cobalt, and the cobalt content in the cemented carbide is 8% by mass or more. Preferably, the tungsten carbide particles have an average particle diameter of 3 ?m or more.

Abstract: A sintered compact contains cubic sialon, ?-sialon, and at least one of a first component and a second component. The first component is at least one element selected from the group consisting of iron, cobalt, nickel, and group 4 elements, group 5 elements, and group 6 elements of the periodic table. The second component is at least one compound containing at least one element selected from the group consisting of group 4 elements, group 5 elements, and group 6 elements and at least one element selected from the group consisting of carbon, nitrogen, and boron.

Abstract: A sintered compact contains cubic sialon, ?-sialon, and at least one of a first component and a second component. The first component is at least one element selected from the group consisting of iron, cobalt, nickel, and group 4 elements, group 5 elements, and group 6 elements of the periodic table. The second component is at least one compound containing at least one element selected from the group consisting of group 4 elements, group 5 elements, and group 6 elements and at least one element selected from the group consisting of carbon, nitrogen, and boron.

Abstract: It is an object of the invention to provide a tool for precision finishing and grooving of quenched steel by thinning a coating film of a CBN sintered compact tool. The invention provides a surface-coated high hardness material for tool comprising a cubic boron nitride sintered compact (CBN sintered compact, hereinafter) as a substrate and at least one coating film layer formed on the surface of the substrate wherein said coating film layer has thickness of 0.1 ?m or more and less than 1 ?m and comprises, as main component, a compound having at least one kind of element selected from C, N and O, and Ti and Al. If this material is used as a grooving tool, excellent performance is exhibited. Examples of the coating film are an intermediate layer, a wear-resistant film, a surface layer and the like.

Abstract: [Problems] It is an object of the invention to provide a tool for precision finishing and grooving of quenched steel by thinning a coating film of a CBN sintered compact tool. [Means to Solve the Problem] The invention provides a surface-coated high hardness material for tool comprising a cubic boron nitride sintered compact (CBN sintered compact, hereinafter) as a substrate and at least one coating film layer formed on the surface of the substrate wherein said coating film layer has thickness of 0.1 ?m or more and less than 1 ?m and comprises, as main component, a compound having at least one kind of element selected from C, N and O, and Ti and Al. If this material is used as a grooving tool, excellent performance is exhibited. Examples of the coating film are an intermediate layer, a wear-resistant film, a surface layer and the like.

Abstract: It is an object of the invention to provide a tool for precision finishing and grooving of quenched steel by thinning a coating film of a CBN sintered compact tool. The invention provides a surface-coated high hardness material for tool comprising a cubic boron nitride sintered compact (CBN sintered compact, hereinafter) as a substrate and at least one coating film layer formed on the surface of the substrate wherein said coating film layer has thickness of 0.1 ?m or more and less than 1 ?m and comprises, as main component, a compound having at least one kind of element selected from C, N and O, and Ti and Al. If this material is used as a grooving tool, excellent performance is exhibited. Examples of the coating film are an intermediate layer, a wear-resistant film, a surface layer and the like.

Abstract: The present invention provides a cubic boron nitride sintered body, which achieves both of superior chipping resistance and wear resistance. In accordance with a first aspect of the present invention, a cubic boron nitride (cBN) sintered body contains cubic boron nitride particles and a bonding material used for bonding the cBN particles to one another. This sintered body is constituted by cBN particles in a range from 70 vol % to 98 vol % and a residual bonding material made from a Co compound, an Al compound and WC and a solid solution of these. Moreover, the cBN particles in the sintered body contain 0.03 wt % or less of Mg and 0.001 wt % or more to 0.05 wt % or less of Li. In accordance with a second aspect of the present invention, the cubic boron nitride sintered body has a composition in which the bonding material of the first aspect is changed to an Al compound.

Abstract: The present invention provides a cubic boron nitride sintered body, which achieves both of superior chipping resistance and wear resistance. In accordance with a first aspect of the present invention, a cubic boron nitride (cBN) sintered body contains cubic boron nitride particles and a bonding material used for bonding the cBN particles to one another. This sintered body is constituted by cBN particles in a range from 70 vol % to 98 vol % and a residual bonding material made from a Co compound, an Al compound and WC and a solid solution of these. Moreover, the cBN particles in the sintered body contain 0.03 wt % or less of Mg and 0.001 wt % or more to 0.05 wt % or less of Li. In accordance with a second aspect of the present invention, the cubic boron nitride sintered body has a composition in which the bonding material of the first aspect is changed to an Al compound.

Abstract: [Problems] It is an object of the invention to provide a tool for precision finishing and grooving of quenched steel by thinning a coating film of a CBN sintered compact tool. [Means to Solve the Problem] The invention provides a surface-coated high hardness material for tool comprising a cubic boron nitride sintered compact (CBN sintered compact, hereinafter) as a substrate and at least one coating film layer formed on the surface of the substrate wherein said coating film layer has thickness of 0.1 ?m or more and less than 1 ?m and comprises, as main component, a compound having at least one kind of element selected from C, N and O, and Ti and Al. If this material is used as a grooving tool, excellent performance is exhibited. Examples of the coating film are an intermediate layer, a wear-resistant film, a surface layer and the like.