A surface-coated cutting tool includes a base material and a coating formed on a surface of the base material. The coating includes a first hard coating layer including crystal grains having a sodium chloride-type crystal structure. The crystal grain has a layered structure in which a first layer composed of nitride or carbonitride of Al.sub.xTi.sub.1-x and a second layer composed of nitride or carbonitride of Al.sub.yTi.sub.1-y are stacked alternately into one or more layers. The first layer each has an atomic ratio x of Al varying in a range of 0.6 or more to less than 1. The second layer each has an atomic ratio y of Al varying in a range of 0.45 or more to less than 0.6. The largest value of difference between the atomic ratio x and the atomic ratio y is 0.05≤x−y≤0.5.

A surface-coated cutting tool includes a base material and a coating covering the base material. The base material includes a rake face and a flank face. The coating includes a TiCN layer. The TiCN layer has a (422) orientation in a region d1 in the rake face. The TiCN layer has a (311) orientation in a region d2 in the flank face.

A coated cutting tool comprising a substrate comprising a cubic boron nitride sintered body and a coating layer formed on the substrate, wherein the coating layer comprises a Ti carbonitride layer comprising Ti(C.sub.xN.sub.1-x); an average thickness of the Ti carbonitride layer is 0.5 μm or more and 5.0 μm or less; in the Ti carbonitride layer, R75 is higher than R25; in the Ti carbonitride layer, a texture coefficient TC (111) of a (111) plane is 1.0 or more and 2.0 or less; and in X-ray diffraction measurement of the Ti carbonitride layer, an absolute value of a difference between a maximum value and a minimum value of 2θ is 0.1° or less on the (111) plane when the measurement is performed at each of ψ angles of 0°, 30°, 50° and 70°.

A method of continuously depositing a coating on a substrate comprises (a) depositing a first layer of ta-C on a substrate via a CVA process, said first layer having a first hardness and a first thickness of 100 mm or greater; (b) adjusting the parameters of the CVA process and depositing a second layer of ta-C on a substrate via a CVA process, said second layer having a second hardness and a second thickness of 10 mm or less, and (c) repeating the above steps to provide a coating comprising at least 5 such first layers and at least 4 such second layers, wherein the first thickness is greater than the second thickness and the first hardness is greater than the second hardness.

A cutting tool comprising a substrate and a coating layer formed on the substrate, wherein the coating layer has, from a side closer to the substrate, a lower layer that contains a compound having a composition represented by (Al.sub.xTi.sub.1-x)N, and an upper layer that is formed on the lower layer and contains a compound having a composition represented by (Al.sub.yTi.sub.1-yN; the average thickness of the lower layer is 1.0 μm or more and 10.0 μm or less; the average thickness of the upper layer is 1.0 μm or more and 10.0 μm or less; and an area ratio GOS.sub.i of crystal grains having a GOS value of 1 degree or lower in the lower layer and an area ratio GOS.sub.s of crystal grains having a GOS value of 1 degree or lower in the upper layer satisfy GOS.sub.i<GOS.sub.s.

To provide a surface-coated cutting tool exhibiting excellent wear resistance in a high-speed cutting process and having prolonged service life. The surface-coated cutting tool includes a tool substrate containing WC crystal grains and insulating grains, and a coating layer composed of a multiple nitride of Ti, Al, and V and disposed on the surface of the tool substrate. The multiple nitride is represented by a compositional formula: Ti.sub.aAl.sub.bV.sub.cN satisfying the following relations:

0.25≤a≤0.35,

0.64≤b≤0.74,

0<c≤0.06, and

a+b+c=1

(wherein each of a, b, and c represents an atomic proportion). The coating layer is characterized by exhibiting a peak attributed to a hexagonal crystal phase and a peak attributed to a cubic crystal phase as observed through X-ray diffractometry.

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 0.95 or less, 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 flank 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 80% or more.

A component including a substrate surface coated with a coating including at least one MoN layer having a thickness not less than 40 nm. Between the substrate surface and the at least one MoN layer the component includes: i) a substrate surface hardened layer, which is a hardened, nitrogen-containing substrate surface layer that is the result of a nitriding treatment carried out at the substrate surface and has a thickness not less than 10 nm, preferably not less than 20 nm and not greater than 150 nm, and/or ii) a layer system composed of more than 2 MoN layers and more than 2 CrN layers, wherein the MoN and CrN layers forming the layer system are individual layers deposited alternatingly one on each other forming a multilayer MoN/CrN coating film.

A surface-coated cutting tool includes a substrate and a coating film. The coating film includes an alternate layer. The alternate layer includes a first layer having a first composition and a second layer having a second composition. The alternate layer is formed by alternately stacking at least one first layer and at least one second layer. The first layer and the second layer each have a thickness not smaller than 2 nm and not greater than 100 nm. The first composition is expressed as Ti.sub.aAl.sub.bSi.sub.cN (0.25≤a≤0.45, 0.55≤b≤0.75, 0≤c≤0.1, a+b+c=1). The second composition is expressed as Ti.sub.dAl.sub.eSi.sub.fN (0.35≤d≤0.55, 0.45≤e≤0.65, 0≤f≤0.1, d+e+f=1). The first composition and the second composition satisfy a condition of 0.05≤d−a≤0.2 and 0.05≤b−e≤0.2.

A coated tool may include a base member and a coating layer located on the base member. The coating layer may include a plurality of AlTi layers including aluminum and titanium as a main component, and a plurality of AlCr layers including aluminum and chromium as a main component. The AlTi layers and the AlCr layers may be located alternately one upon another. The plurality of AlTi layers may include a first AlTi layer and a second AlTi layer located farther away from the base member than the first AlTi layer. Each of the plurality of AlTi layers may further include chromium, and a content ratio of chromium in the second AlTi layer may be higher than a content ratio of chromium in the first AlTi layer.