Provided is a cutting tool that can have a long tool life even when used to cut soft metals in particular. The cutting tool comprises a base body and a hard carbon film arranged on the base body, the hard carbon film includes an amorphous phase and a graphite phase, the density of the hard carbon film is no less than 2.5 g/cm.sup.3 and no more than 3.5 g/cm.sup.3, the degree of crystallinity of the hard carbon film is no more than 6.5%, and the average coordination number of the amorphous phase is no less than 2.5 and no more than 4.

A substrate is coated with a multi-layer coating, comprising in order: (i) a first functional layer comprising ta-C, (ii) a second functional layer comprising ta-C, (iii) (a) a third functional layer comprising ta-C and a first intermediate layer comprising a carbide of a first element, or (b) a first intermediate layer comprising a carbide of a first element, and a second intermediate layer comprising the first element, wherein the ta-C has a hydrogen content less than 10% and an sp2 content less than 30%; wherein (i) the Young's modulus or (ii) the hardness or (iii) both the Young's modulus and the hardness independently stay the same or increase from layer to layer in (iii) (a) from the first intermediate layer to the first functional layer, or in (iii) (b) from the second intermediate layer to the first functional layer.

A method of manufacturing a device includes thermally spraying tungsten carbine in feedstock that does not include Cobalt but that includes Nickel, Copper, or a Nickel-Copper alloy, the method improves the base coating toughness, anticorrosion, and antifouling properties for high load application in sea water and brackish water environments. Additionally, a Cobalt-free material lowers material costs and reduces the global demand of Cobalt. Providing a topcoat of a Silicon-doped DLC significantly reduces the topcoat brittleness of common DLC failures such as “egg shell” in high stress applications. Thus, high hardness, low friction applications may be tailored in high stress applications.

A jet-black coating that resists wear; first, at least one DLC layer with a high degree of hardness is applied to a component and then a gradient layer, whose density decreases in the direction toward the surface, is applied to this DLC layer. By means of the refraction index progression that this produces in the gradient layer, the gradient layer functions as a reflection-reducing layer.

A method for preparing thin double-structured composite corrosion resistant and/or passivating coatings that consist of a thin metal oxide-hydroxide subcoating prepared by anodizing the metal substrate materials near-surface part and then provided with an atomic layer deposition (ALD) topmost nanocoating, of e.g. oxide, nitride, carbonate, carbide etc. or their mixes or laminates, or laminates with ceramic and metallic layers, or laminates with inorganic or organic polymers and ceramic layers.

A polycrystalline diamond is formed on a substrate to form a polycrystalline diamond compact (PDC) cutter for a tool. The polycrystalline diamond has a cross-sectional dimension of at least 4 millimeters. The substrate includes tungsten carbide. An outer surface of the PDC cutter is at least partially surrounded with at least a single layer of coating by atomic layer deposition. The single layer of coating is configured to protect the PDC cutter from thermal degradation in response to exposure to a temperature greater than 700 degrees Celsius (° C.) and less than about 1050° C.

The purpose of the invention is to provide technology, which, in addition to being capable of forming thick hard carbon films of excellent durability even using PVD, is able to establish both chipping resistance and wear resistance in the formed hard carbon film and able to improve low friction properties and peeling resistance. Provided is a coating film to be coated on the surface of a substrate, the coating film having a total film thickness of greater than 1 μm to 50 μm wherein: when a cross-section is observed using bright field TEM images, white hard carbon layers that are shown as relatively white and black hard carbon layers that are shown as black are alternately laminated in the thickness direction; and the white hard carbon layers have regions that have grown in a fan-shape in the thickness direction.

A sliding member includes a carbon transfer layer and can superiorly effectively decrease friction and reduce wear. A method produces the sliding member. The sliding member includes a substrate and a carbon transfer layer. The carbon transfer layer is disposed on the surface of the substrate and includes both sp.sup.2 bonded carbon and sp.sup.3 bonded carbon. The carbon transfer layer preferably has a ratio sp.sup.3/(sp.sup.2+sp.sup.3) of the sp.sup.3 bonded carbon to the totality of the sp.sup.2 bonded carbon and the sp.sup.3 bonded carbon of 0.1 or more.

The invention provides a gate valve (1) for control of petroleum production or water injection, distinctive in that at least one surface subject to sliding in operation of the valve comprises a top layer coating of diamond like carbon (DLC). The DLC contains hydrogen, preferably more than 16 atom-% and more preferred more than 17 atom-%. It is further directed to a method of commissioning or operating a gate valve according to the invention, and use of a diamond like carbon (DLC) top layer coating on at least one surface subject to sliding in operation of the gate valve. Valve parts have a tendency of sticking, adhering or cold welding together, which result in high friction. The aim of the invention is to reduce or eliminate friction problems occurring with time or operation cycles, when using a full scale gate valve.

The present invention addresses the problem of providing a piston ring covered with a DLC coating that has excellent wear resistance and shows a low attacking property on a cylinder bore sliding surface. The problem is solved by a piston ring which is used in the presence of an engine lubricating oil and includes a DLC coating on an outer peripheral sliding surface. The DLC coating has an sp.sup.2 component ratio of 0.5 to 0.85 as determined from a TEM-EELS spectrum obtained by a combination of a transmission electron microscope (TEM) and electron energy loss spectroscopy (EELS), as well as a coating hardness of 12 GPa to 26 GPa and a Young's modulus of 250 GPa or less as measured by a nanoindentation method.