A chain component of a chain for power transmission coated with a layer of hard material includes a substrate based on steel and a layer of hard material on an outer surface of the substrate based on steel, with the layer of hard material containing metal nitrides and the C mass concentration in the layer of hard material decreasing in the direction toward the outer surface of the layer of hard material.

The invention concerns a turbine component, such as a turbine blade or a distributor fin, for example, comprising a substrate made from single-crystal nickel superalloy, and a metal sublayer covering the substrate, characterised in that the metal sublayer comprises at least two elementary layers, including a first elementary layer and a second elementary layer, the first elementary layer being arranged between the substrate and the second elementary layer, each elementary layer comprising a -Ni.sub.3Al phase, and optionally a -Ni phase, and in that the average atomic fraction of aluminum in the second elementary layer is strictly greater than the average atomic fraction of aluminum in the first elementary layer.

In one aspect, a calcium-magnesium alumino-silicate (CMAS)-resistant coating includes an outer coating having a plurality of columnar structures formed during material deposition due to preferential material accumulation and a plurality of generally vertically-oriented gaps separating adjacent columnar structures. The columnar structures include a plurality of randomly-oriented particle splats and a CMAS-reactive material and have a total porosity of less than five percent. The plurality of generally vertically-oriented gaps extend from an outermost surface of the outer coating to a first depth of the outer coating equal to or less than a total thickness of the outer coating. The vertically-oriented gaps have a median gap width of less than five micrometers.

Turbine engine components are provided that have a repaired thermal barrier coating, along with their methods of formation and repair. The turbine engine component includes a thermal barrier coating on a first portion of a surface of a substrate; a repaired thermal barrier coating on a second portion of the surface of the substrate; and a ceramic coat on the outer bond coat. The thermal barrier coating includes an inner bonding layer and a first ceramic layer, with the inner bonding layer being positioned between the substrate and the first ceramic layer. The repaired thermal barrier coating generally includes an inner bond coat on the surface of the substrate and an outer bond coat on the inner bond coat. The inner bond coat is formed from a cobalt-containing material, while the outer bond coat is substantially free from cobalt.

A metallic structure includes a first plurality of metal particles arranged in an amorphous structure; a second plurality of metal particles arranged in a crystalline structure having at least two grain sizes, wherein the crystalline structure is arranged to receive the amorphous structure deposited thereon; wherein the grain size is arranged in a gradient structure.

A sliding member includes a base material, and an amorphous hard carbon film formed on a surface of the base material, in which a sp.sup.2 ratio of the amorphous hard carbon film increases from an inner surface side corresponding to the base material side toward an outer surface side thereof to become a maximum value and further decreases toward the outer surface side.

The invention relates to an antiwear-coated metal component (1), in particular for a ball valve (6), the tribosurface of which component is at least partially provided with a multi-layer antiwear coating (2). The antiwear coating (2) has at least a metal adhesion layer (3a), an adhesion-promoting layer (3b) and at least one first cover layer (3c). The adhesion-promoting layer (3b) comprises a carbide-forming metal or a boride-forming metal. The at least first cover layer (3c) comprises a hydrogen-free tetrahedral carbon. The invention further relates to a method for applying an antiwear coating (2) to a metal substrate (9) in order to produce an antiwear-coated metal component (1) of this type. The invention further relates to a ball valve, comprising an antiwear-coated metal component (1) of this type and an antiwear coating (2).

A piston for an internal combustion engine is provided. The piston includes a thermal barrier coating applied to a crown formed of steel. According to one embodiment, a bond layer of a metal is applied to a combustion surface of the crown, followed by a mixed layer of metal and ceramic with a gradient structure, and then optionally a top layer of metal. The thermal barrier coating can also include a ceramic layer between the mixed layer and top layer, or as the outermost layer. The ceramic includes at least one of ceria, ceria stabilized zirconia, yttria, yttria stabilized zirconia, calcia stabilized zirconia, magnesia stabilized zirconia, and zirconia stabilized by another oxide. The thermal barrier coating is applied by thermal spray, HVOF, or wire arc spraying. The thermal barrier coating preferably has a thickness less than 200 microns and a surface roughness Ra of not greater than 3 microns.

A gripping tool for gripping oilfield tubulars includes a gripping element having a substrate, and at least one gripping surface configured to engage an oilfield tubular, the at least one gripping surface being formed on the gripping element. The at least one gripping surface includes a coating on an outer surface of the substrate, the coating includes a carrier and a plurality of particles at least partially embedded in the carrier. The particles each have a hardness that is greater than a hardness of the carrier and a base metal of the gripping element, and the particles extend outward from the carrier and are configured to engage a structure that is gripped by the gripping tool.

The object of the present invention is to produce a metal part equipped with a protection system, particularly for turbine blades for aircraft engines, having a thermal barrier that is improved in terms of thermal properties, adhesion to the part and resistance to oxidation/corrosion. In order to achieve this, the method according to the invention produces in a single step, from specific ceramics, coating layers using SPS technology. According to one embodiment, a metal part is produced according to an SPS flash sintering method and comprises a superalloy substrate (22), a metal sub-layer (21), a TGO oxide layer (25) and the thermal barrier (23) formed by said method from at least two chemically and thermally compatible ceramic layers (2a, 2b). A first ceramic (2a), referred to as the inner ceramic, is designed to have a substantially higher expansion coefficient. The outer ceramic (2b) is designed to have at least lower thermal conductivity, and a sintering temperature and/or maximum operating temperature that is substantially higher. The thermal barrier (23) has a composition and porosity gradient (3) from the metal sub-layer (21) to the outer ceramic (2b).