A seal assembly includes a housing that includes a seal flange at least partially defining a seal opening. A carbon seal is located at least partially in the seal opening and includes a first axially facing surface. The seal flange includes an axially facing surface that has a carbide based coating and a diamond-like carbon coating in engagement with the first axially facing surface on the carbon seal.

An article has a cavity defined by an inner surface, the cavity having a size such that a largest sphere placeable in the cavity has a diameter of less than 7 cm and a smallest sphere placeable in the cavity has a diameter of 0.5 mm; and a hard coating on the inner surface, the hard coating having a hardness between 18 to 100 GPa, the hard coating distributed on the inner surface such that a ratio of a coating thickness at a first region of the hard coating to that at a second region of the hard coating ranges from 0.75 to 1.33.

A material composite is provided, wherein the material composite includes a first layer formed at least of a ceramic first material, and a second layer arranged on the first layer and formed at least of a ceramic second material that is different from the first material. In order to achieve a higher thermal and/or mechanical load capacity, the material composite further includes a connection layer arranged between the first layer and the second layer, and connects the first layer to the second layer. The connection layer is formed at least partially of a molybdenum-titanium carbide composite material.

A heterogeneous composition is disclosed, including an alloy mixture and a ceramic additive. The alloy mixture includes a first alloy having a first melting point of at least a first threshold temperature, and a second alloy having a second melting point of less than a second threshold temperature. The second threshold temperature is lower than the first threshold temperature. The first alloy, the second alloy, and the ceramic additive are intermixed with one another as distinct phases. An article is disclosed including a first portion including a material composition, and a second portion including the heterogeneous composition. A method for forming the article is disclosing, including applying the second portion to the first portion.

Coating systems for a cooled turbine blade tip, such as a metal turbine blade tip, are provided. The coating system includes an abrasive layer overlying the surface of the turbine blade tip. One or more buffer layers may additionally be disposed between an outer surface of the blade tip and the abrasive layer. The coated blade tip can be used with a ceramic matrix composite (CMC) shroud coated with an environmental barrier coating (EBC) to provide improved cooling to the tip so as to lengthen oxidation time of the abrasive layer and reduce blade tip wear. Methods are also provided for forming the cooled blade tip and applying the coating system onto the cooled turbine blade tip.

A bypass valve assembly for a turbine generator includes a valve body, bypass seats, valve stem, valve cap, bypass valve disc, bypass valves, and pressure seal head. The valve body defines a central bore and a plurality of passageways. Each passageway has an inlet smaller than its outlet. Each bypass seat is within the inlet of a corresponding passageway. The bypass seats have a higher wear resistance than the valve body. The valve stem is within the central bore. The valve cap is secured to the valve body. The bypass valve disc is secured to the valve stem. Each bypass valve has a base portion and a nose portion. Each nose portion defines a contoured surface area with a wear coating and extends into a corresponding passageway. The pressure seal head is disposed around the valve stem and defines steps having a wear coating.

The present disclosure relates to building very large gas turbines without changing rotor materials. The gas turbine part can include a structure composed of a metal and a ternary ceramic called MAX phase, having a formula Mn+1AXn, where n=1, 2, or 3, M is an early transition metal such as Ti, V, Cr, Zr, Nb, Mo, Hf, Sc, Ta, and A is an A-group element such as Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl, Pb, and X is C and/or N.

A bypass valve assembly for use in turbine generators includes a valve body defining a central bore and a plurality of passageways. Each passageway has a smaller area at an inlet portion and a larger area at an outlet portion to define a flared passageway. A plurality of bypass valves is disposed within the plurality of passageways within the valve body. Each bypass valve includes a base portion and a nose portion, with each nose portion defining a predefined contoured surface area. At least a portion of the contoured surface area includes a wear coating disposed thereon. Optionally, the wear coating includes a plasma enhanced magnetron sputtering nanocoating.

A composite bond coat may include a matrix and a reinforcing component. The matrix may be formed from silicon-based particles, and the reinforcing component includes silicon-based ceramic particles. The composite bond coat may be formed by introducing a precursor composition into a plume generated by a thermal spray gun to generate a thermal spray stream. The thermal spray stream may be directed at a major surface defined by a substrate of the component to form the composite bond coat. The precursor composition includes the matrix component and the reinforcing component.

A steam turbine rotor blade achieving both abrasion resistance and reliability, and a method for manufacturing a steam turbine rotor blade capable of obtaining such a steam turbine rotor blade are provided. A steam turbine rotor blade according to the invention is characterized by including a blade base material and an erosion shield formed on a surface of the blade base material, wherein the blade base material is composed of a titanium alloy, and the erosion shield is composed of a weld overlay layer including a parent phase composed of pure titanium in which a metal element is solid-dissolved or a titanium alloy in which a metal element is solid-dissolved, and a hard phase dispersed in the parent phase.