Abstract: Fuel nozzles including a fuel conduit supply having at least one pilot cavity and at least one main cavity, and a distributor ring having at least one injection post extending outwardly therefrom, the distributor ring operably coupled to each of the at least one pilot cavity and at least one main cavity wherein the nozzle is fabricated using metal injection molding.

Abstract: A process for heating a braze alloy by microwave radiation so that heating of the alloy is selective and sufficient to cause complete melting of the alloy and permit metallurgical bonding to a substrate on which the alloy is melted, but without excessively heating the substrate so as not to degrade the properties of the substrate. The process entails providing metallic powder particles having essentially the same metallic composition, with at least some of the particles being sufficiently small to be highly susceptible to microwave radiation. A mass of the particles is then applied to a surface of a substrate, after which the mass is subjected to microwave radiation so that the particles within the mass couple with the microwave radiation and sufficiently melt to metallurgically bond to the substrate. The microwave radiation is then interrupted and the mass is allowed to cool, solidify, and form a solid brazement.

Abstract: Disclosed is a method for selectively removing a coating from a substrate. Aluminum is diffused into the coating. The coating is contacted with an aqueous composition including at least one of an acid having the formula HxAF6, and precursors to the acid, A being selected from the group consisting of Si, Ge, Ti, Zr, Al, and Ga, and x being 1-6. The coating being removed is often an McrAl(X) material. The substrate is a metal, usually a superalloy.

Abstract: The pulsed partial pressure hydrogen cleaning of cobalt-based alloys in turbine components is achieved by disposing the component within a vacuum furnace and heating the component. Upon heating to about 1400° F., a partial pressure hydrogen gas and a vacuum are repetitively cycled within the furnace by supplying in each cycle a fresh supply of hydrogen gas, followed by removal of reaction products between the hydrogen gas and surface contaminants and substantially all residual hydrogen gas from within the furnace. The repetitious cycling renders the surfaces clean, enabling refurbishment thereof by activated diffusion healing repair.

Abstract: A method for assembling a vane sector for a gas turbine engine, the vane sector including an airfoil vane and a platform includes depositing a wear coating material onto a selected area of the platform, positioning the platform adjacent to the airfoil vane, and executing a brazing operation such that the airfoil vane is permanently coupled to the platform portion and such that the wear coating material is bonded across a predefined area of the platform.

Abstract: A brazing material including about 40 to about 60 percent by weight gold, about 5 to about 16 percent by weight nickel and about 35 to about 55 percent by weight copper.

Abstract: A process for heating a powder material by microwave radiation so that heating of the powder material is selective and sufficient to cause complete melting of the particles. The process entails providing a mass of powder comprising a quantity of filler particles of a metallic composition, and subjecting the mass to microwave radiation so that the filler particles within the mass couple with the microwave radiation and are completely melted. According to one aspect, the mass further contains at least one constituent that is more highly susceptible to microwave radiation than the filler particles, and the filler particles are melted as a result of heating by microwave radiation and thermal contact with the at least one constituent. According to another aspect, the powder mass is thermally pretreated to induce an irreversible increase in its dielectric loss factor prior to melting by microwave irradiation.

Abstract: A method of making a braze preform includes: providing a mixture of a brazing alloy in metallic powder form and a binder; melting the binder and forming the mixture into a preform having a preselected shape; removing a majority of the binder from the preform; and heating the preform to remove the remainder of the binder and to sinter the metallic powder together. The preform may include a wear-resistant material therein. Such preforms may be used to form a braze joint between two metallic components, or to produce a metallic component with a wearcoated surface.

Abstract: A nickel-base braze material suitable for closing holes in a high temperature component, such as a tip cap hole in a turbine blade. The braze material comprises first and second filler materials and a binder. The first filler material comprises particles of a first alloy, and the second filler material comprises particles of at least a second alloy having a lower melting temperature than the first alloy. The second alloy consists essentially of, by weight, about 8 to about 23 percent chromium, about 4 to about 18 percent cobalt, about 1.5 to about 6.0 percent tantalum, about 1.0 to about 6.0 percent aluminum, about 0.3 to about 1.5 percent boron, about 2.0 to about 6.0 percent silicon, up to 0.2 percent carbon, the balance being nickel and incidental impurities.

Abstract: A nickel-base superalloy article, such as a gas turbine stationary flowpath shroud that has previously been in service, is repaired by applying a restoration coating to a surface of the article. The restoration coating is applied by providing a precursor mixture, wherein the precursor mixture has no more than about 15 weight percent chromium and no more than about 0.01 percent yttrium, and wherein the precursor mixture includes a higher-melting-point alloy component and a lower-melting-point alloy component. The precursor mixture is applied to the surface of the article, in a form such as a preform of the alloy components. The article with the precursor mixture applied to the surface thereof is heated to a sufficiently high temperature to melt the lower-melting-point alloy component, thereby forming the restoration coating on the surface of the article.

Abstract: A turbine engine component includes a substrate and a wear coating on the substrate. The wear coating includes wear-resistant particles in a matrix phase, the wear-resistant particles being formed of chrome carbide or a cobalt alloy. Methods for forming a turbine engine component are also disclosed.

Abstract: A final throat area of a gas turbine nozzle circumferential structure is established by providing at least two gas turbine nozzle vanes, and determining a pairwise initial throat area between each pair of gas turbine nozzle vanes. For each pair of gas turbine nozzle vanes whose pairwise initial throat area is not within the final pairwise throat area target range, a trailing edge of at least one of the gas turbine nozzle vanes is extended responsive to the step of determining the initial pairwise throat area, so that a final pairwise throat area is within a final pairwise throat area target range. A nozzle plurality of pairs of gas turbine nozzle vanes that together comprise the gas turbine nozzle circumferential structure may be selected so that a sum of their final pairwise throat areas is within a final total throat area target range.

Abstract: A method for coating a substrate is presented. The method comprises providing a substrate; attaching a preform to the substrate, the preform comprising braze alloy and wear-resistant particles; and bonding the preform to the substrate to form a wear-resistant coating.

Abstract: Apparatus for controlled-atmosphere brazing of parts or components having cross-sectional dimensions of up to twenty-four inches. The apparatus maintains the components or parts at a uniform temperature during the brazing cycle. The apparatus includes a susceptor having a physical boundary that separates an interior of the susceptor from its exterior. While there is no limitation upon the length of the parts or components that can be brazed, the wall of the susceptor formed as a physical boundary has an internal diameter that limits the maximum cross-sectional dimension of the parts or components that are to be brazed, so that the parts or components reside within the interior of the susceptor. A heating source for heating the susceptor is provided. The heating source is capable of heating the susceptor sufficiently so that the interior of the susceptor can reach a temperature sufficient to braze the components inside the susceptor.

Abstract: A final throat area of a gas turbine nozzle circumferential structure is established by providing at least two gas turbine nozzle vanes, and determining a pairwise initial throat area between each pair of gas turbine nozzle vanes. For each pair of gas turbine nozzle vanes whose pairwise initial throat area is not within the final pairwise throat area target range, a trailing edge of at least one of the gas turbine nozzle vanes is extended responsive to the step of determining the initial pairwise throat area, so that a final pairwise throat area is within a final pairwise throat area target range. A nozzle plurality of pairs of gas turbine nozzle vanes that together comprise the gas turbine nozzle circumferential structure may be selected so that a sum of their final pairwise throat areas is within a final total throat area target range.

Abstract: A method for restoring thickness to load-bearing components of gas turbine engines, and for repairing a honeycomb structured gas turbine engine component. A surface of the component such as the backing surface of a honeycomb component after honeycomb removal is roughened and cleaned. A selected build-up material is deposited onto the substrate by high velocity oxy-fuel deposition or low pressure plasma spray. The component is heat treated to enhance the bond between the deposited material particles, and between the deposited material and the substrate by diffusion.

Abstract: A braze material and method for repairing an article, such as a gas turbine engine combustor liner formed from a nickel-base or cobalt-base superalloy. The braze material is composed of a nickel-base braze alloy that is preferably in powder form and may be dispersed in a suitable vehicle to yield a slurry, putty or solid tape. The braze alloy is formulated to be capable of withstanding the high temperature operating environment of a combustor liner, and to have a melting temperature below the grain growth or incipient melting temperature of the superalloy to be repaired. A preferred braze alloy is formed by combining at least two nickel-base powders. A suitable composition for the braze alloy is, in weight percent, about 10 to about 19 chromium, about 3 to about 10.5 cobalt, about 1.75 to about 4.9 titanium, about 0.75 to about 3.4 aluminum, about 1.25 to about 4.1 tungsten, about 1.25 to about 4.1 molybdenum, about 0.025 to about 0.225 carbon, about 0.005 to about 0.15 zirconium, about 0.50 to about 2.

Abstract: A method for restoring thickness to load-bearing components of gas turbine engines, and for repairing a honeycomb structured gas turbine engine component. A surface of the component such as the backing surface of a honeycomb component after honeycomb removal is roughened and cleaned. A selected build-up material is deposited onto the substrate by high velocity oxy-fuel deposition or low pressure plasma spray. The component is heat treated to enhance the bond between the deposited material particles, and between the deposited material and the substrate by diffusion.

Abstract: A turbine engine component includes a substrate and a wear coating on the substrate. The wear coating includes wear-resistant particles in a matrix phase, the wear-resistant particles being formed of chrome carbide or a cobalt alloy. Methods for forming a turbine engine component are also disclosed.

Abstract: An undersize repair region of a gas turbine engine stationary shroud is repaired with a sufficient mass of a repair material. The repair material includes a first fraction of a first powder of a first alloy component, and a second fraction of a second powder of a second alloy component. The first alloy component and the second alloy component have different solidus temperatures. The repair material is placed in the repair region. The repair material and the repair region are heated to melt the repair material but not the repair region, and thereafter the repair material and the repair region are cooled to solidify the repair material.