A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 80 volume % or less; a content of the binder phase is 20 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.5 μm or more and 4.0 μm or less; the binder phase contains TiC and TiB.sub.2 and contains substantially no AlN and/or Al.sub.2O.sub.3; a (101) plane of TiB.sub.2 in the binder phase shows a maximum peak position (2θ) in X-ray diffraction of 44.2° or more; and a (200) plane of TiC in the binder phase shows a maximum peak position (2θ) in X-ray diffraction of less than 42.1°.

A coated tool may include a base member and a coating layer located on the base member. The coating layer may include a first section located on the base member and a second section located on the first section. The first section may include an AlTi portion including aluminum and titanium, and an AlCr portion including aluminum and chromium, and each of the AlTi portion and the AlCr portion may be in contact with the base member. The second section may include a plurality of AlTi layers including aluminum and titanium, and a plurality of AlCr layers including aluminum and chromium, and the AlTi layers and the AlCr layers may be located alternately one upon another.

This disclosure relates to a high cBN content polycrystalline cubic boron nitride, PCBN, material. The binder matrix material comprises 2 to 15 wt. % titanium diboride (TiB2).

Provided is a cutting tool comprising a base body and a hard carbon film arranged on the base body, in which, when the cross section of the hard carbon film is observed using a high angle annular dark field scanning transmission electron microscope, the area proportion of black regions with an equivalent circle diameter of 10 nm or more is 0.7% or less, and the hard carbon film has a hydrogen content of 5 atom% or less.

A coated cutting tool having a substrate and a coating is provided. The coating includes an inner α-Al.sub.2O.sub.3-multilayer and an outer α-Al.sub.2O.sub.3-single-layer. The thickness of the inner α-Al.sub.2O.sub.3-multilayer is less than or equal to 35% of the sum of the thickness of the inner α-Al.sub.2O.sub.3-multilayer and the thickness of the outer α-Al.sub.2O.sub.3-single-layer. The sum of the thickness of the inner α-Al.sub.2O.sub.3-multilayer and the outer α-Al.sub.2O.sub.3-single-layer is 2-15 μm. The inner α-Al.sub.2O.sub.3-multilayer consists of alternating sublayers of α-Al.sub.2O.sub.3 and sublayers of TiCO, TiCNO, AlTiCO or AlTiCNO. The inner α-Al.sub.2O.sub.3-multilayer can include at least 5 sublayers of α-Al.sub.2O.sub.3.

A coated cutting tool comprises a substrate and a coating layer formed on a surface of the substrate, and has a rake face and a flank. The coating layer comprises an alternating laminate structure in which first compound layers containing AlN and second compound layers containing a compound are laminated in an alternating manner, the compound having a composition represented by formula (1) below:
(Ti.sub.1-xAl.sub.x)N  (1)
(wherein x satisfies 0.40≤x≤0.70). An average thickness T.sub.1 per first compound layer is 5 nm or more to 160 nm or less, and an average thickness T.sub.2 per second compound layer is 8 nm or more to 200 nm or less. A ratio of T.sub.1 to T.sub.2 is 0.10 or more to 0.80 or less. An average thickness T.sub.3 of the alternating laminate structure is 2.5 μm or more to 7.0 μm or less. A ratio (H/E) of hardness H to elastic modulus E is 0.065 or more to 0.085 or less at the rake face or the flank.

A coated tool includes a base and a coating film on the base. The coating film includes an Al.sub.2O.sub.3 layer, and a surface layer on the Al.sub.2O.sub.3 layer. The surface layer has a first erosion rate of 0.1 μm/min or less. The first erosion rate is obtained from measurement by causing a liquid A, in which 3 mass % of amorphous Al.sub.2O.sub.3 particles having a mean particle diameter of 1.1-1.3 μm is dispersed in purified water, to collide with the surface layer. The surface layer has a second erosion rate of 2.0 μm/min or more. The second erosion rate is obtained from measurement by causing a liquid B, in which 3 mass % of spherical Al.sub.2O.sub.3 particles having a mean particle diameter of 2.8-3.2 μm is dispersed in purified water, to collide with the surface layer.

A coated tool according to the present disclosure comprises a base body and a coating film. The base body contains a plurality of boron nitride particles. The coating film is located on the base body. In addition, in a case where a hardness is measured by pressing an indenter from a surface of the coating film to a depth of 20% of the coating film while changing an indentation load of the indenter, a maximum hardness difference, which is a difference between a maximum hardness and a minimum hardness of the hardness, is 4 GPa or more.

A cutting tool is made of a cemented carbide including a first hard phase and a binder phase. The first hard phase is composed of WC particles. The binder phase contains Co and/or Ni. The cutting tool includes a main body part and a surface layer part. A thickness of the surface layer part is equal to or less than an average particle diameter of the first hard phase. On a surface of a plain part in a rake face, 1.0 GPa or more of a compressive residual stress is applied to the first hard phase. A ratio (B/A) of the average particle diameter (B) of the first hard phase on the surface of the plain part in the rake face to an average particle diameter (A) of the first hard phase on a cross section of the main body part is 0.7 or more and less than 1.

The present invention discloses a coated cutting tool having a hard coating film on a surface of the tool. The hard coating film is a nitride, the content ratio of titanium (Ti) with respect to a total amount of metal elements (including semimetal elements) is in a range of 70 at % to 95 at %, the content ratio of silicon (Si) with respect to the total amount of metal elements (including semimetal elements) is in a range of 5 at % to 30 at %, and the content ratio of argon (Ar) with respect to the total amount of metal elements (including semimetal elements) and non-metal elements is 0.1 at % or less. The hard coating film has a NaCl type crystal structure and has an average crystal grain size in a range of 5 nm to 30 nm.