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.

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 substrate and a diamond layer that covers the substrate. The diamond layer includes a rake face and a flank continuous to the rake face. A ridgeline between the rake face and the flank forms a cutting edge. The substrate includes a top surface opposed to the rake face. When viewed in a direction perpendicular to the top surface, the rake face includes a plurality of protrusions. In a cross-section perpendicular to a direction of extension of the cutting edge, each of the plurality of protrusions includes an inclined portion and a curvature portion continuous to the inclined portion. In the cross-section, a height of the inclined portion in the direction perpendicular to the top surface increases as a distance from the cutting edge increases.

A cutting tool includes a substrate and a diamond layer that covers the substrate. The diamond layer includes a rake face and a flank continuous to the rake face. A ridgeline between the rake face and the flank forms a cutting edge. The substrate includes a top surface opposed to the rake face. When viewed in a direction perpendicular to the top surface, the rake face includes a plurality of protrusions. In a cross-section perpendicular to a direction of extension of the cutting edge, each of the plurality of protrusions includes an inclined portion and a curvature portion continuous to the inclined portion. In the cross-section, a height of the inclined portion in the direction perpendicular to the top surface increases as a distance from the cutting edge increases.

A coated tool includes a base body and a diamond coating. The coated tool has a cutting edge. The first surface comprises a first region close to the cutting edge and a second region further away from the cutting edge than the first region. The diamond coating comprises an outer surface having dome-shaped protrusions. The protrusions include first protrusions having an equivalent circle diameter of 6 .Math.m or more located in the first region, and second protrusions having an equivalent circle diameter of 6 .Math.m or more located in the second region. A number of the first protrusions per 1 mm.sup.2 is a first protrusion number. A number of the second protrusions per 1 mm.sup.2 is a second protrusion number. The first protrusion number is 30 or less, and the second protrusion number is larger than the first protrusion number.

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 cubic boron nitride sintered material tool contains a plurality of cBN grains. cBN grains located on a surface of the cutting edge contain a cubic boron nitride phase, and a hexagonal boron nitride phase. When a ratio I.sub.π*/I.sub.σ* between an intensity of a π* peak derived from a π bond of hBN in the hexagonal boron nitride phase and an intensity of a σ* peak derived from a σ bond of hBN in the hexagonal boron nitride phase and a σ bond of cBN in the cubic boron nitride phase is determined by measuring an energy loss associated with excitation of K-shell electrons of boron, the ratio I.sub.π*/I.sub.σ* of the cBN grain on the surface of the cutting edge is 0.1 to 2, and the ratio I.sub.π*/I.sub.σ* of the cBN grain at a depth position of 5 μm from the surface of the cutting edge is 0.001 to 0.1.

Provided is a coated cutting tool having improved wear resistance and fracture resistance and a prolonged tool life. The coated cutting tool includes a substrate and a coating layer formed on the substrate. The coating layer includes a first layer containing Ti(C.sub.x1N.sub.1-x1) and a second layer containing (Ti.sub.1-y1Al.sub.y1)N, particles in the first layer have an average particle size of 5 nm or more and less than 100 nm, 1.0≤I(111)/I(200)≤20.0 in the first layer, the first layer has an average thickness of 5 nm or more and 1.0 μm or less, 0.1≤I(111)/I(200)≤1.0 in the second layer, particles in the second layer have an average particle size of more than 100 nm and 300 nm or less, and the second layer has an average thickness of 5 nm or more and 2.0 μm or less.

Provided is a coated cutting tool having improved wear resistance and fracture resistance and a prolonged tool life. The coated cutting tool includes a substrate and a coating layer formed on the substrate. The coating layer includes a first layer containing Ti(C.sub.x1N.sub.1-x1) and a second layer containing (Ti.sub.1-y1Al.sub.y1)N, particles in the first layer have an average particle size of 5 nm or more and less than 100 nm, 1.0≤I(111)/I(200)≤20.0 in the first layer, the first layer has an average thickness of 5 nm or more and 1.0 μm or less, 0.1≤I(111)/I(200)≤1.0 in the second layer, particles in the second layer have an average particle size of more than 100 nm and 300 nm or less, and the second layer has an average thickness of 5 nm or more and 2.0 μm or less.

A coated tool of the present disclosure is provided with a base member and a coating layer located on a surface of the base member. The coating layer includes a TiCNO layer and an Al.sub.2O.sub.3 layer. The Al.sub.2O.sub.3 layer is located in contact with the TiCNO layer at a position farther from the base member than the TiCNO layer is. The TiCNO layer includes a plurality of first protrusions that project toward the Al.sub.2O.sub.3 layer, and a beam that extends in a direction intersecting a direction in which the first protrusions project, to connect the first protrusions. A cutting tool of the present disclosure is provided with: a holder extending from a first end toward a second end and including a pocket on a side of the first end; and the above-described coated tool located in the pocket.