A seal system for a gas turbine engine includes a seal runner manufactured of a Molybdenum alloy material that provides a first coefficient of thermal expansion and a seal ring manufactured of a graphitic material that provides a second coefficient of thermal expansion greater than the first coefficient of thermal expansion.

A seal assembly includes a carbon seal that has a sealing surface. A seal seat has a sealing surface and is positioned for rotation relative to the carbon seal. A diamond-like carbon coating at least partially forms the sealing surface on the seal seat.

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.

The invention relates to a guide vane assembly for a turbomachine, comprising a guide vane, which has a guide vane airfoil; and a guide vane holder. The guide vane is mounted in the guide vane holder such that the guide vane can be moved about an axis of rotation. For this purpose, the guide vane has at least one axle element, which is inserted into the guide vane holder in such a way that an outer lateral surface of the axle element faces an inner lateral surface of the guide vane holder. A protective coating is applied to at least parts of the guide vane airfoil. A protective coating is applied to at least one of the lateral surfaces. The invention also relates to a compressor module, a turbomachine, and a method for producing a guide vane assembly.

A method of operating a variable vane for a gas turbine includes the step of locating a first bushing at least partially surrounding a first trunnion that extends from a first end of the variable vane. The first trunnion includes an outer surface that has a plurality of troughs. The first bushing includes a plurality of peaks that extend inward from an inner surface. Relative movement is produced between the first bushing and the first trunnion to form a carbon transfer film between the first bushing and the first trunnion.

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.

A method for processing a component is provided and includes masking a first portion of the component with a maskant. The maskant includes a slurry having a plurality of particles in a fluid carrier. The plurality of particles comprises at least one of silicon, carbon, one or more rare earth disilicates, monosilicates or oxides, and combinations thereof. The method includes depositing a silicon-based coating on a second portion of the component via a chemical vapor deposition process and removing the maskant and any overlying silicon-based coating from the first portion of the component.

A seal assembly includes a housing at least partially defining a seal opening and at least partially surrounding a rotatable shaft. A carbon seal is located at least partially in the seal opening and includes a sealing surface. The rotatable shaft includes a radially facing surface that has a carbide based coating and a diamond-like carbon coating in engagement with the sealing surface on the carbon seal.

A gas turbine engine is provided. The gas turbine engine includes a fan; a turbomachine operably coupled to the fan for driving the fan, the turbomachine comprising a compressor section, a combustion section, and a turbine section in serial flow order and together defining a core air flowpath; a static fluid passageway in thermal communication with a portion of the turbomachine; and one or more graphene layers coupled to a portion of the static fluid passageway. The one or more graphene layers include graphene or an allotrope thereof

This disclosure is directed to seal assemblies for a turbomachine. The seal assemblies include stationary and rotating components and at least one interface between the stationary and rotating components. The seal assembly further includes a self-lubricating lattice element made of carbon or a carbon-based material. The self-lubricating lattice element may have a porous and compressible microstructure capable of retaining a liquid substance. During engine operation, the self-lubricating lattice element can compress and expel some portion of the liquid substance to form a liquid-containing layer between the rotating and stationary components of the seal assembly. Also described herein are self-lubricating wear sleeves for use in other portions of the turbomachine.