A coated cutting tool of a cemented carbide substrate made of WC, a metallic binder phase and a gamma phase has a well distributed gamma phase and a reduced amount of abnormal WC grains. Further, the coated cutting tool is provided with a CVD coating of TiCN and an α-Al.sub.2O.sub.3 layer, wherein the α-Al.sub.2O.sub.3 layer exhibits a texture coefficient TC(0 0 12)≥7.2 and wherein in the ratio I(0 0 12)/I(0 1 14)≥1. The coated cutting tool has an increased resistance against plastic deformation. whilst maintaining toughness.

The present invention relates to a tap drill comprising a substrate and a coating, wherein the coating is deposited on at least a portion of the substrate comprising the head of the drill, the coating comprising a first layer deposited directly on the substrate and a second layer deposited atop the first layer, wherein the first layer is a wear resistant layer of (Al,Cr)N deposited by Hi PIMS and the second layer is a friction reduction layer, wherein the second layer is a metal carbide layer or a metal-carbide comprising layer deposited by using a physical vapor deposition (PVD) process of the type magnetron sputtering, preferably of the type HiPIMS.

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 cutting tool including a rake face, a flank face, and a cutting edge portion, comprising a substrate and an AlTiN layer, the AlTiN layer including cubic Al.sub.xTi.sub.1-xN crystal grains, Al having an atomic ratio x of 0.7 or more and less than 0.95, the AlTiN layer including a central portion, the central portion at the rake face being occupied in area by (200) oriented crystal grains at a ratio of 80% or more, the central portion at the cutting edge portion being occupied in area by (200) oriented crystal grains at a ratio of 50% or more and less than 80%.

A coated tool may include a base member and a coating layer located on the base member. The coating layer may include an alternating layer having first layers and second layers. The first layers may contain (Ti.sub.bNb.sub.dM.sub.e)C.sub.xN.sub.1-x (where M is one or more kinds selected from metals of Groups 4, 5 and 6 in the periodic table except for Ti and Nb, and Al, 0.2≤b≤0.8, 0.01≤d≤0.2, 0≤e≤0.7, b+d+e=1 and 0<x<1). The second layers may contain M′N (where M′ is metal of Groups 4, 5 and 6 in the periodic table except for Nb).

A method for preparing a super-lubricative multi-layer composite fullerene-like carbon layer/graphene-like boron nitride thin film is provided. A substrate is ultrasonically cleaned in absolute ethyl alcohol and acetone sequentially for 15 min. The substrate is cleaned by argon plasma bombardment for 15 min. A fullerene-like carbon layer A having an onion-like structure is prepared by high-vacuum medium-frequency magnetron sputtering for 30 s. A graphene-like boron nitride layer B is prepared by high-vacuum medium-frequency magnetron sputtering and coating device to sputter the elemental boron target for 30 s. Steps (3) and (4) are repeated 80 times to overlay the fullerene-like carbon layer A and the graphene-like boron nitride layer B in an alternate way. The super-lubricative multi-layer composite fullerene-like carbon layer/graphene-like boron nitride thin film has a large load capacity, and excellent wear resistance, high temperature resistance and super lubrication.

Provided is a coated cutting tool that has a nitride hard coating that contains Ti at 70 at % to 95 at % and Si at 5 at % to 30 at % with respect to the total amount of metallic elements, and Ar at 0.05 at % to 0.20 at % with respect to the total amount of metallic and non-metallic elements, has a NaCl-type crystalline structure, exhibits maximum diffraction peak intensity in the (200) plane, and has an average grain size of 5 nm to 30 nm. When 100 at % is defined as the total of content rates of the metallic elements, nitrogen, oxygen, and carbon in a composition at intervals of 20 nm from a depth of 20 nm to 200 nm from a surface of the hard coating, the content rate of nitrogen is 50.0 at % or more.

A coated cutting tool includes a substrate and a hard film on coated on the substrate. The hard film contains a complex nitride of Al and Cr. The hard film includes aggregates of columnar grains grown on the substrate along the thickness of the film. The nitride has an Al content of 60 atom % or more, a Cr content of 10 atom % or more, and a total content of Al and Cr of 90 atom % or more relative to the total amount of metal and metalloid elements. The complex nitride has the highest peak intensity assigned to crystal plane (311) of an fcc structure in X-ray diffractometry. In the hard film, the ratio of an X-ray diffraction intensity of plane (311) to the intensities of the other planes is 1.30 or more. A method and a system are also provided for manufacturing the coated cutting tool by chemical vapor deposition.

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 a 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 to a total length 100% of a total grain boundary is 20% or more and 60% or less.

To improve the adhesion resistance and wear resistance of a surface-coated cutting tool. The surface-coated cutting tool includes a tool substrate, and a single-component coating layer composed of a composite nitride of Cr (chromium), Al (aluminum), and V (vanadium) and disposed on the surface of the tool substrate. The composite nitride is characterized by being represented by a compositional formula: Cr.sub.aAl.sub.bV.sub.cN satisfying the following relations:
0.11≤a≤0.26;
0.73≤b≤0.85;
0<c≤0.04; and
a+b+c≤1
(wherein a, b, and c each represent an atomic proportion). The single-component coating layer has both a hexagonal phase and a cubic phase.