A sliding member includes a base material and an amorphous hard carbon film formed on a surface of the base material, and the amorphous hard carbon film has a graded structure in which a sp.sup.2 ratio increases from an inner surface side corresponding to the base material side toward an outer surface side. A piston ring includes the sliding member.

A coated cutting tool and a process for the production thereof is provided. The coated cutting tool includes a substrate and a hard material coating, the substrate being selected from cemented carbide, cermet, ceramics, cubic boron nitride, polycrystalline diamond or high-speed steel. The hard material coating includes a (Ti,Al)N layer stack of alternately stacked (Ti,Al)N sub-layers. The layer stack has an overall atomic ratio of Ti:Al within the (Ti,Al)N layer stack within the range from 0.33:0.67 to 0.67:0.33, a total thickness of the (Ti,Al)N layer stack within the range from 1 m to 20 m, each of the individual (Ti,Al)N sub-layers within the (Ti,Al)N layer stack of alternately stacked (Ti,Al)N sub-layers having a thickness within the range from 0.5 nm to 50 nm, each of the individual (Ti,Al)N sub-layers within the (Ti,Al)N layer stack of alternately stacked (Ti,Al)N sub-layers being different in respect of the atomic ratio Ti:Al than an immediately adjacent (Ti,Al)N sub-layer, and other characteristics.

A process for producing a coated tool includes coating a base body of hard metal, cermet, ceramic, steel or high-speed steel with a multi-layer coating by a PVD process. The multi-layer coating includes a bonding layer and an anti-wear protective layer deposited directly thereon. The bonding layer is deposited by a reactive or non-reactive cathodic vacuum arc vapor deposition to have multi-layers, two layers of the bonding layer each being arranged directly one over the other and having different compositions. The anti-wear protective layer is deposited by high-power impulse magnetron sputtering to have a single or multi-layer design. The multiple layers of the multi-layer bonding layer and one or more layers of the anti-wear protective layer are each formed from carbides, nitrides, oxides, carbonitrides, oxicarbides, carboxinitrides of at least two different metals selected from Ti, V, Cr, Zr, Nb, Mo, Ru, Hf, Ta, W, Al, Si, Y, Li and B, and solid solutions thereof.

A valve component comprising a substrate with a sliding surface, the sliding surface being designed to be subjected to sliding against another surface during operation of the valve, wherein at least a portion of the sliding surface is coated with a coating comprising an under-layer comprising tungsten and an upper-layer deposited atop the under-layer, said upper-layer comprising diamond-like-carbon, wherein the under-layer comprises carbon and has a layer thickness of at least 11 micrometers, and the upper-layer has a lower coefficient of friction than the under-layer and has a layer thickness of at least 1.5 micrometers.

A PVD vacuum plating process for an aluminum alloy surface is provided. The process includes forming a bottom layer: bombarding with an arc power supply, with a bias voltage being controlled at 200-300 V, and the time being controlled at 3-5 minutes; forming an intermediate multi-layer: conducting multilayer transition with an oxide and a nitride, with the number of layers being controlled at 8-10, the time for an individual layer being controlled at 10-20 minutes, and a target current being controlled at 10-20 A. The process also includes forming a transitional engagement layer: conducting mixed sputtering of a transition layer and a color layer for the time of 15-25 minutes; forming the color layer: controlling the time for the color layer at 20-30 minutes; and forming a protective layer: using a high-frequency and large-energy power supply with the time controlled at 40-50 minutes, the process thereby eliminating water plating steps.

An ion source enhanced AlCrSiN coating for a cutting tool is provided. The ion source enhanced AlCrSiN coaling has gradient Si content and grain size, including sequentially an AlCrSiN working layer, an interlayer and an AlCrN bottom layer in order from a surface of the coating to a substrate, wherein from the AlCrN bottom layer to the AlCrSiN working layer, Si content in the interlayer is gradually increased, and the interlayer has a texture that changes from coarse columnar crystals to fine nanocrystals and amorphous body. A texture of the coating, in which the grain size is gradually decreased, sequentially includes coarse columnar crystals, fine columnar crystals and fine equiaxed crystals. A method for preparing the ion source enhanced AlCrSiN coating with the gradient Si content and grain size is provided as well as a cutting tool having the coating deposited thereon.

Articles containing metal, hard metal, cermet or ceramic and coated with a hard material, and a method for producing same. The hard material layers can be used as anti-wear layers for cutting tools, as protective layers for turbine blades, or as diffusion barriers in microelectronics. The hard material layers exhibit a high hardness, high oxidation resistance, and excellent wear resistance. The articles are coated with a single- or multi-layer layer system by a thermal CVD method without plasma excitation, where the single- or multi-layer layer system includes at least one nanocomposite layer with a first nanocrystalline phase of cubic titanium oxycarbonitride and a second, amorphous phase of silicon oxycarbonitride or silicon oxycarbide.

A coating including a bond layer deposited on a substrate. The bond layer includes a rare earth silicate and a second phase, the second phase including at least one of silicon, silicides, alkali metal oxides, alkali earth metal oxides, glass ceramics, Al.sub.2O.sub.3, TiO.sub.2, Ta.sub.2O.sub.5, HfO.sub.2, ZrO.sub.2, HfSiO.sub.4, ZrSiO.sub.4, HfTiO.sub.4, ZrTiO.sub.4, or mullite. The coating may provide thermal and/or environmental protection for the substrate, especially when the substrate is a component of a high-temperature mechanical system.

A sliding member (10) including a coating film (1) composed of a hard carbon layer on a sliding surface (16) of a base material (11). The coating film has, when a cross section thereof is observed by a bright-field TEM image, a thickness within a range of 1 m to 50 m, and is configured by repeating units including black hard carbon layers (B), relatively shown in black, and white hard carbon layers (W), relatively shown in white, and laminated in a thickness direction, and comprise an inclined region, provided on a base material side, where thicknesses of white hard carbon layers (W) of the repeating units gradually increase in a thickness direction, and a homogeneous region\, provided on a surface side of the sliding member, where thicknesses of the white hard carbon layers (W) of the repeating units are the same or substantially the same in the thickness direction.

At least one layer in a coating located on a surface of a substrate is a domain structure layer constituted of two or more domains different in composition. The average value of the size of each of first domains, defined as the diameter of a virtual circumcircle in contact with each first domain, is 1 nm to 10 nm. The average value of the nearest neighbor distance of each first domain, defined as the length of the shortest straight line connecting the center of the circumcircle with the center of another circumcircle adjacent to the circumcircle, is 1 nm to 12 nm. 95% or more of the first domains has a size within 25% of the average value of the size, and 95% or more of the first domains has a nearest neighbor distance within 25% of the average value of the nearest neighbor distance.