A rocket engine has a combustion chamber having an inlet and an outlet, the inlet fluidly connectable to a source of oxidizer, the outlet in fluid communication with an environment outside the combustion chamber for expelling combustion gases, a first fuel having a first solid propellant and a second fuel having a second solid propellant, the first and second fuels located within the combustion chamber and configured to be exposed to the oxidizer injected in the combustion chamber via the inlet, the first solid propellant having a regression rate greater than that of the second solid propellant.

Using the systems and methods discussed herein, CMAS corrosion is inhibited via CMAS interception in an engine environment and/or is prevented or reduced by the formation of a metal oxide protective coating on a hot engine section component. The CMAS interception can occur while the engine is in operation in flight or in a testing or quality control environment. The metal oxide protective coating can be applied over other coatings, including Gd-zirconates (GZO) or yttria-stabilized zirconia (YSZ). The metal oxide protective coating is applied at original equipment manufacturers (OEM) and can also be applied in-situ using a gas injection system during engine use in-flight or during maintenance or quality testing. The metal oxide protective coating contains a rare earth element, aluminum, zirconium, chromium, or combinations thereof, and is from 1 nm to 3 microns in thickness.

Embodiments of the present disclosure generally relate to protective coatings on an aerospace component and methods for depositing the protective coatings. In one or more embodiments, a method for depositing a coating on an aerospace component 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 chemical vapor deposition (CVD) process or a first atomic layer deposition (ALD) process 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 ALD process, where the first deposited layer and the second deposited layer have different compositions from each other.

Embodiments of the present disclosure generally relate to protective coatings on an aerospace component and methods for depositing the protective coatings. In one or more embodiments, a method for depositing a protective coating on an aerospace component includes sequentially exposing the aerospace component to a chromium precursor and a reactant to form a chromium-containing layer on a surface the aerospace component by an atomic layer deposition process. The chromium-containing layer contains metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium silicide, or any combination thereof.

A method of coating a component including aluminizing an array of internal passageways within the component; and chromizing a portion of the array of internal passageways within the component. A component, including an airfoil having an array of aluminized internal passageways, the array of aluminized internal passageways chromized up to a demarcation.

A composite blade includes a composite blade body including reinforced fibers and resin; a metal layer provided on an outer side of a leading edge section including a leading edge that is a part of the composite blade body on an upstream side of an air stream, the metal layer having a thickness of equal to or larger than 5 micrometers and equal to or smaller than 100 micrometers; an adhesive layer provided between the composite blade body and the metal layer to bond the metal layer to the composite blade body; and an electric insulating layer provided in contact with a surface of the leading edge section of the composite blade body, the surface being on the side on which the metal layer is provided, the electric insulating layer having an electric insulating property.

The present invention relates to a method for producing a blade or blade arrangement of a turbomachine, which features the following steps: producing a blade (4) from at least one blade material, machining the blade in at least one region of the blade by a surface machining process, cleaning the surface of the blade depositing an erosion protection coating (10) of at least two layers of different hardness by physical vapor deposition in the at least one region, machining the erosion protection coating (10) by a coating smoothing process in order to establish a defined surface roughness. Furthermore, the invention relates to correspondingly produced blades or blade arrangements.

Described herein a bucket for use in the last stage of a steam turbine engine. The bucket includes a titanium-based alloy having a leading edge wherein the leading edge includes titania having a plurality of pores and a top sealing layer filling the plurality of pores, the sealing layer selected from the group consisting of: chromium, cobalt, nickel, polyimide, polytetrafluoroethylene and polyester.

A method of applying a protective coating to an article comprises the steps of a) depositing aluminum in a surface region of an article, and b) depositing chromium is the surface region of the article subsequent to step a), whereby at least a portion of the chromium replaces at least a portion of the aluminum. Another method and an article are also disclosed.

A piston seal assembly for a gas turbine engine includes a seal composed of a nickel-based superalloy; a component in contact with the seal and defining a seal-counterface; and a coating on the seal at the seal-counterface, wherein the coating is a metal alloy binder phase and a hard particle phase distributed through the binder phase.