A cutting tool comprises a coating on a substrate. The coating comprises a first layer element having an overall composition comprising the metal or metalloid elements aluminum, chromium, titanium, and silicon. The first layer element comprises at least 2 N.sub.lay first layer element layers. Each of the first layer element layers comprises a nitride layer comprising the metal or metalloid elements aluminum, chromium, titanium and silicon. The N.sub.lay first layer element layers comprise at least two different types of layers that at least differ in a silicon content. A first type of the layers has a highest silicon content C.sub.Si,H, (in at. %) and a second type of the layers has a lowest silicon content C.sub.Si,L (in at. %), both relative to a total of the metal and metalloid elements, and with a ratio of the lowest silicon content C.sub.Si,L to the highest silicon content C.sub.Si,H in the range of 0.25≤C.sub.Si,L/C.sub.Si,H≤0.9.

Provided are a friction reduced and wear resistant coating, a preparation method thereof and a piston ring. The coating includes an adhesive layer, a transition layer, a gradient layer and a function layer in sequence. The gradient layer is a CrMo.sub.xN layer in which Mo content progressively increases. The function layer includes at least one cyclical layer. Each cyclical layer includes a first CrMo.sub.xN layer and a second CrMo.sub.xN layer in sequence from bottom to top. The Mo content of the first CrMo.sub.xN layer is lower than the Mo content of the second CrMo.sub.xN layer. The coating provided by the present invention has a friction coefficient of 0.3 to 0.45, 10% to 30% lower than a CrN coating, and has an overall hardness of up to 1400 HV to 2600 HV and a thickness of 80 μm, satisfying the required durability for the full lifecycle of the piston ring. The preparation process of the coating is simple and highly operable, and thus is convenient for industrialization.

The present disclosure relates to a laminate and a method for preparing the same. The laminate comprises a substrate, a coating layer, and a water-repellent layer sequentially laminated, the coating layer comprises a first coating layer and a second coating layer laminated one or more times alternately, the first coating layer comprises at least one metal oxide selected from a group consisting of a lanthanide metal oxide, a transition metal oxide, and a composite metal oxide comprising lanthanum metal and transition metal, the second coating layer comprises an alkaline earth metal fluoride and a transition metal oxide.

A cutting tool comprising a base material and a coating arranged on the base material; wherein: the coating comprises an α-Al.sub.2O.sub.3 layer composed of a plurality of α-Al.sub.2O.sub.3 particles; the average particle diameter a of the α-Al.sub.2O.sub.3 particles in a first region of the α-Al.sub.2O.sub.3 layer is 0.10 μm or more and 0.30 μm or less; the average particle diameter b of the α-Al.sub.2O.sub.3 particles in a second region of the α-Al.sub.2O.sub.3 layer is 0.30 μm or more and 0.50 μm or less; the average particle diameter c of the α-Al.sub.2O.sub.3 particles in a third region of the α-Al.sub.2O.sub.3 layer is 0.10 μm or more and 0.30 μm or less; and the ratio b/a is 1.5 or more and 5.0 or less.

A method includes casting a metallic material (56) in a mold (20) containing a core, the core having a substrate (40, 44) coated with a coating (42). A removing of the metallic material from the mold and decoring leaves a casting having a layer formed by the coating. The coating has a ceramic having a porosity in a zone (50) near the substrate less than a porosity in a zone (52) away from the substrate.

A coated cutting tool includes a substrate and a coating. The coating has an inner layer of 4-14 μm thick Ti.sub.1-xAl.sub.xN, an intermediate layer of 0.05-1 μm TiCN and at least one outer layer of 1-9 μm α-Al.sub.2O.sub.3. The α-Al.sub.2O.sub.3 layer exhibits an X-ray diffraction pattern, as measured using CuKα radiation and theta-2theta scan. A texture coefficient TC(hkl) is defined according to Harris formula, wherein the (hkl) reflections used are (0 2 4), (1 1 6), (3 0 0) and (0 0 12), I(hkl)=measured intensity (peak intensity) of the (hkl) reflection, I0(hkl)=standard intensity according to ICDD's PDF-card No. 00-042-1468, n=number of reflections used in the calculation, and 3<TC(0 0 12)<4.

Coated tool for hot stamping of coated or uncoated sheet metals, in particular for hot stamping of AlSi- or Zn-coated sheet metals.sub.[KM2], comprising a coated substrate surface to be in contact with the coated or uncoated metal sheet, wherein the coating in the coated substrate surface is a multi-layer coating comprising one or more inferior layers and one or more superior layers, where the inferior layers are deposited closer to the substrate surface than the superior layers, whereas: —the inferior layers are designed for providing load bearing capacity, —the superior layers are designed for providing galling resistance, —at least one superior layer (layer 5) is deposited having a multi-nanolayer structure formed by sublayers of the type A, B and C, said three kind of sublayers being nanolayers deposited alternate one on each other forming a sequence of the type . . . A/B/C/A/B/C/A . . . , wherein at least two sequences of one A nanolayer, one B nanolayer and one C nanolayer are deposited forming the multi-nanolayer structure wherein: —the nanolayer of type A is composed in at least 90 at.-% of chromium and nitrogen, —the nanolayer of type B is composed in at least 90 at.-% of titanium, aluminum and nitrogen, —the nanolayer of type C is composed I at least 90 at.-% of vanadium carbon and nitrogen, and —the layer thickness of the at least one superior layer (layer 5) is not lower than 0.5 μm and not higher than 15 μm.

A surface-coated cutting tool has a hard coating layer including an upper layer α, an adhesion layer β, and a lower layer γ. The upper layer α is formed of an α-Al.sub.2O.sub.3 layer formed under low temperature conditions. The adhesion layer β includes a TiCN layer having a thickness of 0.5 μm or more in an outermost layer and contains 0.5 to 3 μm to a maximum depth of 0.5 μm toward the inside in a layer thickness direction of the TiCN layer from the interface between the TiCN layer and the upper layer α. The lower layer γ is formed of (Ti.sub.1-XAl.sub.X)(C.sub.YN.sub.1-Y) of a single phase of a NaCl type face-centered cubic structure, in which an average content ratio X.sub.avg of Al and an average content ratio Y.sub.avg of C in this composition formula satisfy 0.60≤X.sub.avg≤0.95 and 0≤Y.sub.avg≤0.005.

A surface-coated cutting tool includes a tool body and a hard coating layer, where one TiAlCN layer α (1) containing 70 area % or more of a wurtzite type hexagonal structure on a tool surface side (S) and one TiAlCN layer β (2) containing 70 area % or more of a NaCl type face-centered cubic structure on the tool body side (B), when a composition of the TiAlCN layer α (1) is represented by (Ti.sub.(1-xα)Al.sub.xα)(C.sub.yαN.sub.(1-yα)) satisfying 0.70≤xα≤0.95 and 0.000≤yα≤0.010, when a composition of the TiAlCN layer β (2) is represented by (Ti.sub.(1-xβ)Al.sub.xβ)(C.sub.yβN.sub.(1-yβ)) satisfying 0.65≤xβ≤0.95 and 0.000≤yβ≤0.010, and when average layer thicknesses of the TiAlCN layer α (1) and the TiAlCN layer β (2) are defined as Lα and Lβ satisfying 0.5 μm≤Lα≤10.0 μm and 1.0 μm≤Lβ≤20.0 μm.

A coated tool includes a base and a coating layer located on the base. The coating layer includes a first layer having a thickness of 1 μm or more located near the base, and a second layer including Al.sub.2O.sub.3 particles which is in contact with the first layer and is located more away from the base than the first layer. A difference (A2−A1) between an erosion ratio A2 in the second layer and an erosion ratio A1 in the first layer is 0.60 to −0.30 μm/g. The erosion ratio is obtained by collision of a liquid A in which 3 mass % of spherical Al.sub.2O.sub.3 particles having a mean particle diameter of 1.1-1.3 μm is dispersed in pure water. A cutting tool includes a holder which includes a pocket, and the coated tool located in the pocket.