A boundary layer turbine (BLT) engine has a housing formed by an outer cylinder a first and a second faceplate, a turbine shaft through the faceplates, a stack of alternating disks and spacers with central holes joined to the turbine shaft leaving an outer combustion zone, an air inlet through the first faceplate, an exhaust port through the second faceplate, a fuel port through the outer cylinder, and an ignition device communicating with the combustion zone. The disks and spacers have openings forming separate intake and exhaust channels parallel to the turbine shaft, one channel channeling air from the air inlet port to spaces between disks, and the other channel channeling exhaust from the combustion zone through the exhaust channel to the exhaust port. Fuel is injected into the combustion zone, the air fuel mixture is ignited, and exhaust products impart torque to the turbine shaft by boundary layer friction.

This disclosure provides a method of pressure sintering an environmental barrier coating on a surface of a ceramic substrate to form an article. The method includes the steps of etching the surface of the ceramic substrate to texture the surface, disposing an environmental barrier coating on the etched surface of the ceramic substrate wherein the environmental barrier coating includes a rare earth silicate, and pressure sintering the environmental barrier coating on the etched surface of the ceramic substrate in an inert or nitrogen atmosphere at a pressure of greater than atmospheric pressure such that at least a portion of the environmental barrier coating is disposed in the texture of the surface of the ceramic substrate thereby forming the article.

A method of providing a self-healing coating includes providing substrate, applying a layer of an aluminum-containing MAX phase material and another material to the substrate. The method includes exposing the layer to a temperature greater than 2000° F. to form alpha aluminum.

A gas turbine engine with a rotor having a shaft mounted to the engine with a plurality of electrically insulating bearings is provided. The electrically insulating bearings are coupled to the shaft to support the rotor in the engine. There is at least one electrically conductive bearing coupled to the shaft and that further support the rotor in the engine. An electrically conductive path is defined between the rotor and an electrical ground of the engine. The electrically conductive path is defined through the electrically conductive bearing to reach the electrical ground of the engine. A method for electrostatically discharging a rotor supported in the gas turbine engine is also provided.

A coated substrate comprising a metal or metal alloy such as a high speed steel, TiAl based alloy or Ni based alloy or an electrically conductive ceramic material, wherein the coating comprises a hard material protective coating comprising alternating layers of different compositions, wherein a first composition of the alternating layers comprises silicon, Si, and/or a second composition of the alternating layers comprises boron, B.

A method of pressure sintering an environmental barrier coating on a surface of a ceramic substrate to form an article includes the steps of etching the surface of the ceramic substrate to texture the surface, disposing an environmental barrier coating on the etched surface of the ceramic substrate wherein the environmental barrier coating includes a rare earth silicate, and pressure sintering the environmental barrier coating on the etched surface of the ceramic substrate in an inert or nitrogen atmosphere at a pressure of greater than atmospheric pressure such that at least a portion of the environmental barrier coating is disposed in the texture of the surface of the ceramic substrate thereby forming the article.

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 blade for a gas turbine engine includes a fiber reinforced ceramic matrix composite structure that provides an airfoil with an exposed exterior airfoil surface and a refractory structure that provides at least an outer portion of a root secured relative to the airfoil.

An airfoil includes an airfoil section that has a ceramic airfoil wall that defines a suction side and a pressure side. There is an interior cavity in the airfoil section. A rib spans across the interior cavity and connects the suction side and the pressure side. The rib has a thermal conductance element that is configured to conduct heat away from the suction side and the pressure side.

The present disclosure relates generally to blades used in gas turbine engines. More specifically designs in accordance with the present disclosure include turbine blades comprising ceramic matrix composite materials with abrasive tips coupled thereto.