Abstract: A thermal barrier coating and deposition process for a component intended for use in a hostile thermal environment, such as the turbine, combustor and augmentor components of a gas turbine engine. The TBC has a first coating portion on at least a first surface portion of the component. The first coating portion is formed of a ceramic material to have at least an inner region, at least an outer region overlying the inner region, and a columnar microstructure whereby the inner and outer regions comprise columns of the ceramic material. The columns of the inner region are more closely spaced than the columns of the outer region so that the inner region of the first coating portion is denser than the outer region of the first coating portion, wherein the higher density of the inner region promotes the impact resistance of the first coating portion.

Abstract: An environmental barrier coating for a component including silicon that has a first coefficient of thermal expansion is provided. The environmental coating includes a silicon bondcoat that is bonded to at least a portion of an outer surface of the component. An intermediate layer is bonded to the silicon bondcoat and has a second coefficient of thermal expansion matched to the first coefficient of thermal expansion. The intermediate layer has a general composition of RE2Si2O7. A protective layer is bonded to the intermediate layer and has a general composition of RE2SiO5. A surface layer is bonded to the protective layer. The surface layer includes RE and has a ratio of RE to oxygen of at least 2:3.

Abstract: An environmental barrier coating for a component including silicon that has a first coefficient of thermal expansion is provided. The environmental coating includes a silicon bondcoat that is bonded to at least a portion of an outer surface of the component. An intermediate layer is bonded to the silicon bondcoat and has a second coefficient of thermal expansion matched to the first coefficient of thermal expansion. The intermediate layer has a general composition of RE2Si2O7. A protective layer is bonded to the intermediate layer and has a general composition of RE2SiO5. A surface layer is bonded to the protective layer. The surface layer includes RE and has a ratio of RE to oxygen of at least 2:3.

Abstract: An article resistant to recession in high temperature environments, and methods for making the article, are presented herein. The article comprises a substrate, an intermediate coating system disposed over the substrate, and a topcoat disposed over the intermediate coating system. The intermediate coating system comprises a separator layer comprising an oxygen getter material, and a barrier layer disposed over the separator layer, the barrier layer comprising a ceramic composition. The topcoat also comprises this ceramic composition. Moreover, at least about 50% by volume of the ceramic composition present in the barrier layer is a metastable precursor material that tends to transform over time into a product material. At least about 75% by volume of the ceramic composition present in the topcoat is the product material, and up to about 25% by volume of the ceramic composition present in the topcoat is the metastable precursor material.

Abstract: In accordance with an embodiment of the invention, an article is provided. The article comprises a substrate comprised of silicon containing material, an environmental barrier coating (EBC) overlying the substrate and a thermal barrier coating (TBC) on the environmental barrier coating. The thermal barrier coating comprising a compound having a rhombohedral phase.

Abstract: In accordance with an embodiment of the invention, a thermal barrier coating for inclusion in a thermal barrier coating system is provided. The thermal barrier coating comprises a compound having a rhombohedral phase. In accordance with another embodiment of the invention, a thermal barrier coating is provided that comprises a compound having the formula of: A4B3O12, wherein A is at least one rare earth element; and B is selected from the group consisting of Zr, Hf and mixtures thereof.

Abstract: A support apparatus for a gas turbine shroud is disclosed. The apparatus includes an outer shroud block having a coupling connectable to a casing of the gas turbine and a shroud component having a forward flange and an aft flange. The shroud component is attached to the outer shroud block via the forward flange and the aft flange. The apparatus further includes a damper disposed between the outer shroud block and the shroud component and a biasing element disposed within the outer shroud block. A translational degree of freedom between the damper and the outer shroud block defines a direction of motion of the damper. The biasing element is in operable connection between the outer shroud block and the shroud component via the damper, a bias force of the biasing element directed along the direction of motion of the damper.

Abstract: In accordance with an embodiment of the invention, a thermal barrier coating for inclusion in a thermal barrier coating system is provided. The thermal barrier coating comprises a compound having a rhombohedral phase. In accordance with another embodiment of the invention, a thermal barrier coating is provided that comprises a compound having the formula of: A4B3O12, wherein A is at least one rare earth element; and B is selected from the group consisting of Zr, Hf and mixtures thereof.

Abstract: An article for use in aggressive environments is presented. In one embodiment, the article comprises a substrate and a self-sealing and substantially hermetic sealing layer disposed over the bondcoat. The substrate may be any high-temperature material, including, for instance, silicon-bearing ceramics and ceramic matrix composites. A method for making such articles is also presented. The method comprises providing a substrate; disposing a self-sealing layer over the substrate; and heating the sealing layer to a sealing temperature at which at least a portion of the sealing layer will flow.

Abstract: A thermal barrier coating and deposition process for a component intended for use in a hostile thermal environment, such as the turbine, combustor and augmentor components of a gas turbine engine. The TBC has a first coating portion on at least a first surface portion of the component. The first coating portion is formed of a ceramic material to have at least an inner region, at least an outer region overlying the inner region, and a columnar microstructure whereby the inner and outer regions comprise columns of the ceramic material. The columns of the inner region are more closely spaced than the columns of the outer region so that the inner region of the first coating portion is denser than the outer region of the first coating portion, wherein the higher density of the inner region promotes the impact resistance of the first coating portion.

Abstract: Method for joining wires using low resistivity joints is provided. More specifically, methods of joining one or more wires having superconductive filaments, such as magnesium diboride filaments, are provided. The wires are joined by a low resistivity joint to form wires of a desired length for applications, such in medical imaging applications.

Abstract: In accordance with an embodiment of the invention, a thermal barrier coating for inclusion in a thermal barrier coating system is provided. The thermal barrier coating comprises a compound having a rhombohedral phase. In accordance with another embodiment of the invention, a thermal barrier coating is provided that comprises a compound having the formula of: A4B3O12, wherein A is at least one rare earth element; and B is selected from the group consisting of Zr, Hf and mixtures thereof.

Abstract: In accordance with an embodiment of the invention, an article is provided. The article comprises a substrate comprised of silicon containing material, an environmental barrier coating (EBC) overlying the substrate and a thermal barrier coating (TBC) on the environmental barrier coating. The thermal barrier coating comprising a compound having a rhombohedral phase.

Abstract: In accordance with an embodiment of the invention, an article is provided. The article comprises a substrate comprised of silicon containing material, an environmental barrier coating (EBC) overlying the substrate and a thermal barrier coating (TBC) on the environmental barrier coating. The thermal barrier coating comprising a compound having a rhombohedral phase.

Abstract: Disclosed is a porous abradable coating including at least one abradable layer applicable to a substrate, said at least one abradable layer comprising coarsely cut powder pieces.

Abstract: A thermal barrier coating (TBC 26) and method for forming the TBC (26) on a component (10) characterized by a stabilized microstructure that resists grain growth, sintering and pore coarsening or coalescence during high temperature excursions. The TBC (26) contains elemental carbon and/or a carbon-containing gas that increase the amount of porosity (32) initially within the TBC (26) and form additional fine closed porosity (32) within the TBC (26) during subsequent exposures to high temperatures. A first method involves incorporating elemental carbon precipitates by evaporation into the TBC microstructure. A second method is to directly incorporate an insoluble gas, such as a carbon-containing gas, into an as-deposited TBC (26) and then partially sinter the TBC (26) to entrap the gas and produce fine stable porosity within the TBC (26).

Abstract: A thermal barrier coating (TBC) for a component intended for use in a hostile thermal environment. The TBC has an interior region and an outer surface region on and contacting the interior region. Both regions are formed of a ceramic material, with the interior region having a lower thermal conductivity than zirconia partially stabilized by about seven weight percent yttria. The interior region constitutes more than half of the thickness of the TBC, and the outer surface region constitutes less than half of the thickness of the TBC. The TBC has a columnar microstructure whereby the interior region and the outer surface region comprise columns of their ceramic materials. The outer surface region is more erosion and impact resistant than the interior region at least in part as a result of the columns thereof being more closely spaced than the columns of the interior region.

Abstract: A process for removing aluminosilicate-based material (e.g., “CMAS”) from a substrate is described. The material is treated with an aqueous composition containing at least one acid having the formula HxAF6, in which A is Si, Ge, Ti, Zr, Al, and Ga; and x is 1-6. Treatment of the substrate is often carried out by immersion in an aqueous bath. The process is also very effective for removing CMAS-type material from cavities in the substrate, e.g., cooling holes in a gas turbine component. Related compositions are also described.

Abstract: A fuel cell stack includes at least one fuel cell unit and a number of interconnects defining at least two openings and including at least one flow field for flowing a reagent. Each opening defines a respective fuel manifold, including at least one each of intake and exhaust fuel manifolds. The fuel cell unit includes an anode, a cathode, and an electrolyte disposed therebetween. The anode is adjacent to and in both electrical connection and fluid communication with one of the interconnects, which has a flow field that guides a fuel flow between the intake and exhaust fuel manifolds. The cathode is adjacent to and in both electrical connection and fluid communication with another interconnect with a flow field that guides an oxidant flow. The fuel cell stack includes a perimeter isolation seal and at least two interior isolation seals for sealing the electrolyte to the respective interconnects.

Abstract: A fuel cell and a method for manufacturing a fuel cell are presented. The method comprises providing at least one substrate and disposing a plurality of fuel cell component layers on the substrate by at least one physical vapor deposition process. Each layer of the plurality comprises an edge bordering the layer. The fuel cell unit comprises at least one substrate; a plurality of fuel cell component layers disposed on the substrate, wherein each layer of the plurality comprises an edge bordering the layer; and at least one dense layer of material disposed over at least a portion of the edge of at least one fuel cell component layer. The at least one dense layer seals at least the aforementioned portion of the edge.