Methods of machining a body to produce a chip wherein the body is formed of a material and in a state such that the material exhibits sinuous flow during a machining operation. The methods include providing a layer located on a surface of the body, and machining the body by causing engagement between a cutting tool and the body in a contact region below an area of the surface having the coating layer thereon and moving the cutting tool relative to the body to produce the chip having the layer thereon. The layer reduces sinuous flow in the material of the body.

A cutting tool made by an additive manufacturing process is disclosed. The cutting tool has an exterior surface and an enclosed interior cavity defined by one or more inwardly facing surfaces. The interior cavity may have internal supports such as a lattice or a honeycomb structure. The cutting tool may be an insert, drill or endmill with coolant holes.

A coated cutting tool includes a substrate of cemented carbide, cermet, cBN, ceramics or HSS and a coating of a nitride layer, which is a High Power Impulse Magnetron Sputtering (HIPIMS) deposited layer of a nitride of one or more of Ti, Zr, Hf, V, Ta, Nb, Cr, Si and Al, and a HIPIMS-deposited oxide layer being an (Al.sub.aMe.sub.1−a).sub.2O.sub.3 layer, 0.05≤a≤1, wherein Me is one or more of Ti, Mg, Ag, Zr, Si, V, Fe, Hf, B and Cr. The oxide layer is situated above the nitride layer. Also, a method is disclosed for producing a coated cutting tool having the nitride layer and oxide layer, the nitride layer and the oxide layer being deposited by a HIPIMS process.

A surface-coated cutting tool includes a substrate and a coating formed on a surface of the substrate, the coating including one or two or more layers, at least one of the layers being an Al-rich layer including hard particles, the hard particle having a sodium chloride type crystal structure, and including a first unit phase in a form of a plurality of lumps and a second unit phase interposed between the lumps of the first unit phase, the first unit phase being composed of a nitride or carbonitride of Al.sub.xTi.sub.1-x, the first unit phase having an atomic ratio x of Al of 0.7 or more and 0.96 or less, the second unit phase being composed of a nitride or carbonitride of Al.sub.yTi.sub.1-y, the second unit phase having an atomic ratio y of Al exceeding 0.5 and less than 0.7.

A small-diameter drill in which is a double margin having a diameter of 2 mm or less and a ratio of a margin length to a diameter of 3 or more, in which the margin length L in an axial direction from an outer peripheral end of a cutting edge to the rear ends of first and second margin parts and a ratio L/D to a diameter D are 3 or more, in which at least a surface of a chip discharge groove is provided with a hard coating made of nitride, in which a surface of the hard coating in the chip discharge groove has skewness (Ssk) defined in ISO25178 of less than 0, and in which the number of droplets having an equivalent circle diameter of 1.0 μm or more is 5 or less per 100 μm.sup.2 in cross-section observation of the hard coating.

A diamond-coated tool includes: a substrate; and a diamond layer that coats the substrate, wherein the diamond layer includes a first region that is in contact with the substrate, the first region includes a region S1 surrounded by an interface P between the substrate and the diamond layer and an imaginary plane V1 separated from the interface P by a distance of 2 μm, and the region S1 has crystal grains grown in random directions.

A coated tool may include a base member having a first surface and a coating layer located on the first surface. The coating layer may have a first layer and a second layer. The first layer may be located on the first surface, and the first layer may include aluminum oxide. The second layer may be contactedly located on the first layer, and the second layer may include a titanium compound. In a cross section orthogonal to the first surface, the first layer may include a first projection protruding toward the second layer and a first recess located on the first projection. The second layer may include a second recess engaged with the first projection and a second projection engaged with the first recess.

[Problem]

To provide a coated cutting tool having excellent fracture resistance and thus allowing for the extension of tool life.

[Means for Resolution]

A covered cutting tool having a cemented carbide and a covering layer formed on the cemented carbide. The covered cutting tool includes a rake face, a flank face, and a cutting edge line part located between the rake face and the flank face. The coating layer includes a compound layer containing a compound having a composition represented by (Al.sub.xTi.sub.1-x)N. The average thickness T.sub.1 of the covering layer in the cutting edge line part and the average thickness T.sub.2 of the coating layer in the rake face at a position 2 mm or more away from the cutting edge line part toward the rake face are within specific ranges and satisfy T.sub.2 <T.sub.1. The residual stress S.sub.1 of the cemented carbide in the cutting edge line part and the residual stress S2 of the cemented carbide in the rake face at a position 2 mm or more away from the cutting edge line part toward the rake face satisfy S.sub.2 <S.sub.1.

A coated cutting tool including a substrate and a single layer or multi-layer hard material coating is provided. The substrate is selected from cemented carbide, cermet, ceramics, cubic boron nitride (cBN), polycrystalline diamond, steel or high-speed steel. The hard material coating includes at least one layer of gamma-Al.sub.2O.sub.3, exhibiting particularly high hardness and reduced Young's modulus. The gamma-Al.sub.2O.sub.3 layer of the coated cutting tool is obtainable by means of a reactive magnetron sputtering process using at least one Al target, wherein the deposition is carried out using a reaction gas composition of argon (Ar) and oxygen (O.sub.2) at a total reaction gas pressure within the range from at least 1 Pa to at most 5 Pa, at an O.sub.2 partial pressure within the range from 0.001 Pa to 0.1 Pa, and at a temperature within the range from 400° C. to 600° C.

A hard coating includes a three kinds of layers that are alternately laminated. The three kinds of layers consist of a single composition layer and two kinds of nanolayer-alternated layers. The single composition layer is constituted by one of an A composition (nitride of AlCrα), a B composition (nitride of AlTiCrβ) and a C composition (nitride of AlCr(SiC)γ). The two kinds of nanolayer-alternated layers include nanolayers which are alternately laminated and which are constituted by two of three combinations consisting of a combination of the A composition and B composition, a combination of the A composition and C composition and a combination of the B composition and C composition. The single composition layer has a thickness of 0.5-1000 nm. Each of the nanolayers constituting the two kinds of nanolayer-alternated layers has a thickness of 0.5-500 nm, and each of the two kinds of nanolayer-alternated layers has a thickness of 1-1000 nm.