Honeywell International Inc.

Alliedsignal Inc.

Other

United States of America As Represented by the Secretary of the Air Force

Drexel University

Chien-Wei Li

Derek Raybould

Thomas E Strangman

Bjoern Schenk

Jean Yamanis

Thirumalai G Palanisamy

Michel W Barsoum

Liang A Xue

Jeffrey A Goldacker

Surojit Gupta

James Vincent Guiheen

Mohammad Behi

Paul Chipko

Milton Ortiz

Alexander S Kozlov

Lee Poandl

John P Pollinger

Gilbert Carrasquillo

Maria Melanie Matic

Jeffery A Goldacker

John Pollinger

A protective coating for a component comprising a ceramic based substrate, and methods for protecting the component, the protective coating adapted for withstanding repeated thermal cycling. The substrate may comprise silicon nitride or silicon carbide, and the protective coating may comprise at least one tantalate of scandium, yttrium, or a rare earth element. The protective coating may further comprise one or more metal oxides. The coating protects the substrate from combustion gases in the high temperature turbine engine environment. The coating may be multi-layered and exhibits strong bonding to Si-based substrate materials and composites.

Protective coating for ceramic components

A turbomachinery component includes a substrate having a surface, the surface consisting essentially of at least one composite of at least one metal and at least one compound having the chemical formula MAX, wherein M is at least one early transition metal selected from groups IIIB, IVB, VB, and VIB, A is at least one element selected from groups IIIA, IVA, VA, VIA, and VIIA, X is one or both of carbon and nitrogen, and n is an integer between 1 and 3. The component is made by compressing a powdered material to form a substrate that consists essentially of the composite and sintering the substrate, or by coating a substrate with the composite.

Ternary carbide and nitride composites having tribological applications and methods of making same

A turbomachinery component includes a substrate having a surface, the surface being a material consisting essentially of at least one compound having the chemical formula MAX, wherein M is at least one early transition metal selected from groups IIIB, IVB, VB, and VIB, A is at least one element selected from groups IIIA, IVA, VA, VIA, and VIIA, X is one or both of carbon and nitrogen, and n is an integer between 1 and 3. The component is made by forming a compact and sintered substrate with the material, or by coating a substrate with the material.

Ternary carbide and nitride materials having tribological applications and methods of making same

A protective barrier coating system including a diffusion barrier coating and an oxidation barrier coating and method for use in protecting silicon-based ceramic turbine engine components. A complete barrier coating system includes a thermal barrier coating of stabilized zirconia and an environmental barrier coating of an alloyed tantalum oxide. The oxidation barrier coating includes a layer of metallic silicates formed on a substrate of silicon nitride or silicon carbide to be protected. The oxidation barrier coating can include silicates of scandium, ytterbia or yttrium. The oxidation barrier coating may also include an inner layer of SiONbetween the diffusion barrier and the metallic silicate layer. The oxidation barrier coating can be applied to the substrate by spraying, slurry dipping and sintering, by a sol-gel process followed by sintering, by plasma spray, or by electron beam-physical vapor deposition. The diffusion layer of essentially pure SiNcan be applied to the substrate to prevent the migration of damaging cations from the protective layers to the substrate and is preferably formed by chemical vapor deposition. A method for protecting silicon based substrates can comprise a step of forming an oxidation barrier coating on a substrate, where a step of forming the oxidation barrier includes a step of sintering the oxidation barrier and substrate in a wet gas containing hydrogen.

Oxidation barrier coatings for silicon based ceramics

A component comprising a silicon-based substrate and a diffusion barrier coating disposed on the silicon-based substrate. The diffusion barrier coating comprises an isolation layer disposed directly on the silicon-based substrate and at least one oxygen barrier layer disposed on the isolation layer. The oxygen barrier layer prevents the diffusion of oxygen therethrough, and prevents excessive oxidation of the silicon-based substrate. The isolation layer(s) prevent contaminants and impurities from reacting with the oxygen barrier layer. An environmental barrier coating may be disposed on the diffusion barrier coating, and a thermal barrier coating may be disposed on the environmental barrier coating. Methods for making a component having a diffusion barrier coating are also disclosed.

Diffusion barrier coating for Si-based components

A method and superalloy component for depositing a layer of material onto gas turbine engine components by atomic layer deposition. A superalloy component may have a ceramic thermal barrier coating on at least a portion of its surface, comprising a superalloy substrate and a bonding coat; and aluminum oxide (AlO) layer may be deposited on top of an yttria-stabilized zirconia layer and form a bonding coat by atomic layer deposition. The yttria-stabilized zirconia layer may have a plurality of micron sized gaps extending from the top surface of the ceramic coating towards the substrate and defining a plurality of columns of the yttria-stabilized zirconia layer. Also, atomic layer deposition may be used to lay an aluminum oxide (AlO) layer over a tantalum oxide (TaO) layer on a silicon-based substrate. Using atomic layer deposition to coat the gas turbine engine components permits conformal coating of the columnar surface to permit gap expansion and contraction without sintering of the columnar surface or spalling of the coating, and form an oxidation resistant bonding coat.

Atomic layer deposition for turbine components

A component comprising a silicon-based substrate and a braze-based protective coating disposed on the silicon-based substrate. The braze-based coating comprises a brazed layer, wherein the brazed layer comprises at least one intermetallic compound. A scale layer may be formed on the brazed layer. An environmental barrier coating may be disposed directly on the brazed layer or directly on the scale layer. A thermal barrier coating may be disposed on the environmental barrier coating. Methods for making a Si-based component having a braze-based protective coating are also disclosed.

Braze-based protective coating for silicon nitride

Sintered silicon nitride products comprising predominantly &#x3b2;-silicon nitride grains in combination with from about 0.1 to 30 mole % silicon carbide, and grain boundary secondary phases of scandium oxide and scandium disilicate. Such products have high fracture toughness, resistance to recession, and resistance to oxidation at temperatures of at least 1500&#xb0; C. Methods for preparing sintered silicon nitride products are also disclosed.

Sintered silicon nitride

A component comprises a silicon-based substrate; and a protective coating for the substrate. The protective coating includes tantalum oxide (TaO) and an additive for suppressing transformation from beta TaOto alpha TaO.

Environmental and thermal barrier coating for ceramic components

A turbomachine component includes a silicon nitride substrate and a protective coating on the substrate. The protective coating includes a porous silicon nitride matrix and a noble metal infiltrated in the porous silicon nitride matrix.

Protective coating including porous silicon nitride matrix and noble metal

A turbomachine component includes a silicon nitride substrate and a multi-layer coating bonded to the substrate. The coating includes an interlayer of porous fibrous silicon nitride having a density of between 85-98%. The coating also includes an outer layer formed of an oxide compound, preferably tantalum oxide, that is applied by Electron Beam-Physical Vapor Deposition. The combination of the silicon nitride interlayer and tantalum oxide outer layer serves to protect the substrate from the adverse affects of oxidation, impact by foreign objects and extreme operating temperatures.

Silicon nitride components with protective coating

A method for forming a ceramic part with an internal structure includes aqueous slip-casting and a polystyrene foam insert. An aqueous slurry is poured over the insert to form a green body. The insert is shaped to produce the desired internal structure upon being encased by the slurry. The insert is then removed from the green body by dissolving it in trichloroethylene. Because the polystyrene foam does not expand when exposed to trichloroethylene and rapidly dissolves, build up of shrinkage stress in the green body is avoided. The green body is then sintered to produce the ceramic part with an internal structure.

Method for producing a ceramic part with an internal structure

A coating of whisker shaped beta silicon nitride grains are formed upon a silicon nitride substrate by sintering over a period of several hours, and the resulting product has a porous reaction bond coating strongly adhered to the silicon nitride substrate.

Thermal barrier coating for silicon nitride

A silicon nitride sintered body has a composition consisting essentially of 80 to 93% by weight .beta. silicon nitride, 7 to 20% by weight grain boundary phases consisting essentially of (i) at least two rare earth elements, wherein yttrium is considered a rare earth, and strontium which, calculated as SrO, is 0.5 to 5% by weight, and (ii) at least two of Si, N, O and C; and (c) silicon carbide particulate present in the amount of about 5 to 35 parts by weight per 100 parts by weight of components (a) and (b), said SiC being substantially homogeneously dispersed within said sintered body. Such a ceramic has high strength and long term durability, and is especially suited for industrial applications such as components for gas turbine and automotive engines.

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Livingston, NJ, United States of America

Chien-Wei Li