A ceramic heat shield for a gas turbine. The ceramic heat shield has a ceramic body containing aluminium oxide and has a surface layer of the ceramic body which contains yttrium aluminium garnet as reaction coating material. A gas turbine includes such a ceramic heat shield and a method produces such a ceramic heat shield.

Disclosed is a method of making a seal comprising fabricating a seal body that includes a first friction surface including nickel and cobalt. The first friction surface on the seal body is contacted with a metal counter-body surface including nickel. Pressure and heat is applied between the seal body and the counter-body, and motion is applied between the seal body and the counter-body with respect to each other in a direction parallel to the first friction surface, followed by separating the seal from the counter-body.

A method comprises inspecting a ceramic matrix composite component assembled in a gas turbine engine to determine an extent of damage to the ceramic matrix composite component, determining a repair technique to repair the damage to the ceramic matrix composite component based on the extent of damage to the ceramic matrix composite component, and repairing the ceramic matrix composite component using the repair technique.

A gas turbine engine component having a substrate; a thermal barrier coating on the substrate having a porous microstructure; and a reflective layer conforming to the porous microstructure of the thermal barrier coating, wherein the reflective layer comprises a conforming nanolaminate defined by alternating layers of platinum group metal materials selected from the group consisting of platinum group metal-based alloys, platinum group metal intermetallic compounds, mixtures of platinum group metal with metal oxides and combinations thereof. A capping layer can be added over the reflective layer. A supporting layer can be added between the reflective layer and the thermal barrier coating. A process is also disclosed.

A coating according to an exemplary embodiment of this disclosure, among other possible things includes a bond coat including gettering particles and diffusive particles dispersed in a matrix, a top coat disposed over the bond coat, and an intermediate layer between the bond coat and the top coat. The intermediate layer includes non-silicate oxide particles dispersed in a matrix. An article and a method of protecting a ceramic-based substrate are also disclosed.

A method includes predicting a composition of calcium-magnesium-aluminum-silicate (CMAS) to be encountered by a high temperature mechanical system during use of the high temperature mechanical system. The method further includes selecting a composition of a CMAS-resistant barrier coating layer based at least in part on the predicted composition of CMAS. The CMAS-resistant barrier coating layer includes a base composition and at least one secondary oxide selected based on the predicted composition of CMAS. The at least one secondary oxide includes at least one of an oxide of a divalent element, an oxide of a trivalent element, or an oxide of a tetravalent element. The CMAS-resistant barrier coating layer comprises greater than 0 mol. % and less than about 7 mol. % of the at least one secondary oxide.

A gas turbine engine includes a plurality of rotating components housed within a compressor section and a turbine section. A first tap is connected to the compressor section and configured to deliver air at a first pressure. A heat exchanger is connected downstream of the first tap. A flowpath is defined between a rotating surface and a non-rotating surface. The flowpath is connected downstream of the heat exchanger and is configured to deliver air to at least one of the plurality of rotating components. At least a portion of the non-rotating surface and the rotating surface includes a base metal. An insulation material is disposed on a surface along the flowpath.

Methods for forming protective coatings on aerospace components are provided. In one or more embodiments, the method includes exposing an aerospace component to a first precursor and a first reactant to form a first deposited layer on a surface of the aerospace component by a first deposition process (e.g., CVD or ALD), and exposing the aerospace component to a second precursor and a second reactant to form a second deposited layer on the first deposited layer by a second deposition process. The first deposited layer and the second deposited layer have different compositions from each other. The method also includes repeating the first deposition process and the second deposition process to form a nanolaminate film stack having from 2 pairs to about 1,000 pairs of the first deposited layer and the second deposited layer consecutively deposited on each other.

A coated substrate has a substrate and a coating system having one or more ceramic layers. At least a first layer of one of the one or more ceramic layers is a columnar layer having as-deposited columns and intercolumn gaps. The intercolumn gaps have a mean width at least one of: at least 4.0 micrometers; and at least 1.5% of a thickness of said first layer.

A superalloy workpiece includes a superalloy substrate and an interface layer (IF-1) of essentially the same superalloy composition directly on a surface of the superalloy substrate. A transition layer (TL) of essentially the same superalloy and superalloy oxides or a different metal composition and different metal oxides is on the interface layer (IF-1). The oxygen content of the transition layer increases from the interface layer (IF-1) towards a barrier layer (IF-2) of super alloy oxides or of different metal oxides.