A transmission X-ray diffraction on a cross section of a boron nitride sintered body perpendicular to a first surface provides X-ray intensities at a top of a 111 diffraction peak of cubic boron nitride and X-ray intensities at a top of a 002 diffraction peak of compressed boron nitride, in a direction perpendicular to the first surface and a direction parallel to the first surface. A compressed boron nitride content value obtained from these X-ray intensities is greater than 0.002 and smaller than 0.01. A cubic orientation value is greater than 0.5, and a compressed boron nitride orientation value is greater than the cubic orientation value. An insert has a coating layer on at least a part of a surface of the boron nitride sintered body.

A transmission X-ray diffraction on a cross section of a boron nitride sintered body perpendicular to a first surface provides X-ray intensities at a top of a 111 diffraction peak of cubic boron nitride and X-ray intensities at a top of a 002 diffraction peak of compressed boron nitride, in a direction perpendicular to the first surface and a direction parallel to the first surface. A compressed boron nitride content value obtained from these X-ray intensities is greater than 0.002 and smaller than 0.01. A cubic orientation value is greater than 0.5, and a compressed boron nitride orientation value is greater than the cubic orientation value. An insert has a coating layer on at least a part of a surface of the boron nitride sintered body.

According to the present disclosure, a coated member is provided with a base material and a diamond layer located on the base material. When a ratio (SP3/SP2) obtainable from an SP3 peak derived from diamond crystals measurable by Raman spectroscopy and an SP2 peak derived from a graphite phase is referred to as an SP3 ratio, an SP3 ratio at a first measuring point with a thickness up to 1 m extending from an interface of the base material and the diamond layer toward the diamond layer is higher than an SP3 ratio at a second measuring point that is intermediate in a thickness direction of the diamond layer.

According to the present disclosure, a coated member is provided with a base material and a diamond layer located on the base material. When a ratio (SP3/SP2) obtainable from an SP3 peak derived from diamond crystals measurable by Raman spectroscopy and an SP2 peak derived from a graphite phase is referred to as an SP3 ratio, an SP3 ratio at a first measuring point with a thickness up to 1 m extending from an interface of the base material and the diamond layer toward the diamond layer is higher than an SP3 ratio at a second measuring point that is intermediate in a thickness direction of the diamond layer.

A composite diamond body includes a diamond base material and a stable layer disposed on the diamond base material. The stable layer may have a thickness of 0.001 m or more and less than 10 m, and may include a plurality of layers. A composite diamond tool includes the composite diamond body. There are thus provided highly wear-resistant composite diamond body and composite diamond tool that are even applicable to mirror-finish planarization of a workpiece which reacts with diamond to cause the diamond to wear.

A composite diamond body includes a diamond base material and a stable layer disposed on the diamond base material. The stable layer may have a thickness of 0.001 m or more and less than 10 m, and may include a plurality of layers. A composite diamond tool includes the composite diamond body. There are thus provided highly wear-resistant composite diamond body and composite diamond tool that are even applicable to mirror-finish planarization of a workpiece which reacts with diamond to cause the diamond to wear.

A cutting tool according to an aspect of the present disclosure includes a cutting edge portion which contains at least one of cubic boron nitride and polycrystalline diamond. The cutting edge portion includes a flank face, a negative land contiguous to the flank face, and a cutting edge formed by a ridgeline between the flank face and the negative land. At least one of the negative land and the flank face is provided with a plurality of recesses and a projection. The projection is formed by arranging the edges of adjacent recesses in contact with each other.

A cutting tool according to an aspect of the present disclosure includes a cutting edge portion which contains at least one of cubic boron nitride and polycrystalline diamond. The cutting edge portion includes a flank face, a negative land contiguous to the flank face, and a cutting edge formed by a ridgeline between the flank face and the negative land. At least one of the negative land and the flank face is provided with a plurality of recesses and a projection. The projection is formed by arranging the edges of adjacent recesses in contact with each other.

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.

A bonded diamond body having a high bonded strength is provided. The bonded diamond body includes a sintered polycrystalline diamond body, a hard substrate, and a hard layer provided between the sintered polycrystalline diamond body and the hard substrate, the sintered polycrystalline diamond body containing a diamond grain and a sintering aid, the hard substrate containing tungsten carbide and cobalt, and the hard layer containing cobalt and a hard grain made of a carbide, a nitride, or a carbonitride having a Vickers hardness of 1100 Hv or more.