This disclosure relates to a high cBN content polycrystalline cubic boron nitride, PCBN, material. The binder matrix material comprises 19 to 50 wt. % chromium, or a compound thereof.

A cutting tool includes a substrate; and a coating film, wherein the coating film includes a multilayer structure layer having first unit layer(s) and second unit layer(s), the first unit layer(s) and the second unit layer(s) are alternately layered, under a condition X-ray diffraction intensities of different planes in the multilayer structure layer are respectively represented by I.sub.(200), I.sub.(111), and I.sub.(220), the following formula 0.6≤I.sub.(200)/{I.sub.(200)+I.sub.(111)+I.sub.(220)}, the first unit layer(s) has a NaCl-like structure in which an interplanar spacing d.sub.1c in a c-axis direction is larger than an interplanar spacing d.sub.1a in an a-axis direction, the second unit layer(s) has a NaCl-like structure in which an interplanar spacing d.sub.2c in the c-axis direction is smaller than an interplanar spacing d.sub.2a in the a-axis direction, and the following formulas are satisfied as well 1≤d.sub.1a/d.sub.2a≤1.02, 1.01≤d.sub.1c/d.sub.2c≤1.05, and d.sub.1a/d.sub.2a<d.sub.1c/d.sub.2c.

An object of the invention is to provide a coated cutting tool whose tool life can be extended by having excellent wear resistance and fracture resistance. The coated cutting tool includes: a substrate; and a coating layer formed on a surface of the substrate, in which the coating layer includes a lower layer, an intermediate layer, and an upper layer in this order from a substrate side to a surface side of the coating layer, the lower layer includes one or more Ti compound layers formed of a specific Ti compound, the intermediate layer contains TiCNO, TiCO, or TiAlCNO, the upper layer contains α-type Al.sub.2O.sub.3, an average thickness of the lower layer is 2.0 μm or more and 8.0 μm or less, an average thickness of the intermediate layer is 0.5 μm or more and 2.0 μm or less and is 10% or more and 20% or less of an average thickness of the entire coating layer, an average thickness of the upper layer is 0.8 μm or more and 6.0 μm or less, and in the intermediate layer, a ratio of a length of CSL grain boundaries and a ratio of a length of Σ3 grain boundaries are in specific ranges.

A cutting tool includes a cemented carbide substrate. The cemented carbide consists of hard constituents in a metallic binder. The hard constituents include WC. The WC content in the cemented carbide is 80-93 wt %. The cemented carbide has Ni and Al, and a Ni content of 3-13 wt %, a weight ratio of Co/Ni<0.33, a weight ratio of Fe/Ni<0.25, a weight ratio of Cr/Ni<0.25 and a weight ratio of 0.02<Al/(Ni+Co+Fe)<0.1. The crack resistance W is defined as the ratio of the load applied on a Vickers hardness indentation and the total crack length of the cracks formed at the corners of the Vickers hardness indentation. The product of the hardness H(rake) at the rake face and the crack resistance W(rake) at the rake face is H(rake)*W(rake)>5000 HV100*N/μm.

A cutting tool includes a substrate of cemented carbide having hard constituents in a metallic binder. The hard constituents include WC. The WC content in the cemented carbide is 80-95 wt %. The cemented carbide has a Fe+Ni+Co+Cr content of 3-13 wt %, an atomic ratio of 0.05<Fe/(Fe+Ni+Co+Cr)<0.35, an atomic ratio of 0.05<Ni/(Fe+Ni+Co+Cr)<0.35, an atomic ratio of 0.05<Co/(Fe+Ni+Co+Cr)<0.35 and an atomic ratio of 0.05<Cr/(Fe+Ni+Co+Cr)<0.35. The crack resistance W measured on the rake face of the cutting tool is at least 25% higher than the W measured on a cross section of the bulk area of the cutting tool.

A hard film formed on/above a substrate has a composition represented by the following formula (1): Cr.sub.1−aMg.sub.a(B.sub.xC.sub.yN.sub.1−x−y) (1). In the formula (1), a is the atomic ratio of Mg, x is the atomic ratio of B, and y is the atomic ratio of C; and a, x, and y satisfy the following relationships: 0.05≦a≦0.30, 0≦x≦0.20, and 0≦y≦0.30.

A coated tool in a non-limiting embodiment of the present disclosure includes a base and a coating layer located on the base. The coated tool includes a first surface, a second surface adjacent to the first surface, and a cutting edge located on at least a part of a ridge part of the first surface and the second surface. The coating layer includes a Ti-based coating layer. If a fracture toughness value of the Ti-based coating layer is measured on a surface of the coating layer parallel to a surface of the base, the Ti-based coating layer includes a first region where the fracture toughness value is 10 MPa.Math.m.sup.0.5 or more.

A cutting tool includes a substrate and a coating film, wherein the coating film has a first layer formed from a plurality of hard grains, the hard grains are made of TiSiCN having a cubic crystal structure, the hard grains have a lamellar structure in which a layer having a relatively high silicon concentration and a layer having a relatively low silicon concentration are alternately stacked, and a maximum value of percentage of number A.sub.Si of silicon atoms to a sum of the number A.sub.Si of silicon atoms and number A.sub.Ti of titanium atoms in a grain boundary region between the hard grains, {A.sub.Si/(A.sub.Si+A.sub.Ti)}×100, is larger than an average value of percentage of number B.sub.Si of silicon atoms to a sum of the number B.sub.Si of silicon atoms and number B.sub.Ti of titanium atoms in the first layer, {B.sub.Si/(B.sub.Si+B.sub.Ti)}×100.

Provided is a coated cutting tool in which a surface of a substrate is coated with a hard coating film. The hard coating film includes: a layer (A) disposed on the surface of the substrate, and having a face-centered cubic lattice structure, in which the total content ratio of W and Ti is at least 85 atomic %, and which contains W as the most abundant element and Ti as the next most abundant element among metal (including metalloid) elements; and a layer (B) disposed on the layer (A) and having a face-centered cubic lattice structure, which is composed of nitrides or carbonitrides containing Al, Cr, and Si, and in which, among metal (including metalloid) elements, the Al content ratio is at least 50 atomic %, the total content ratio of Al and Cr is at least 85 atomic %, and the Si content ratio is 4 to 15 atomic %.

A coated cutting tool includes a substrate and a coating layer formed on the substrate, wherein the coating layer comprises a compound layer containing a compound having a composition represented by (Al.sub.xCr.sub.yTi.sub.1−x−y)N (in the formula (1), x represents an atomic ratio of an Al element to a total of the Al element, a Cr element and a Ti element and satisfies 0.70≤x≤0.95, and y represents an atomic ratio of a Cr element to a total of an Al element, the Cr element and a Ti element and satisfies 0.04≤y≤0.21, and 1−x−y>0); a ratio (Cr/Ti) of the Cr element and the Ti element in the compound layer is 1.0 or more and 2.5 or less; and an average thickness of the compound layer is 2.0 μm or more and 10.0 μm or less.