Abstract: A method for repairing a gas turbine stationary flowpath shroud. The method comprises providing a superalloy gas turbine stationary flowpath shroud that has previously been in service. The method further comprises preparing a restoration coating for application to the flowpath surface of the shroud by the steps of providing a precursor mixture comprising a higher-melting-point alloy component, a lower-melting-point alloy component, and a fugitive binder. A perform is prepared from the components and pre-sintered into a mildly curved form. The partially densified perform is applied to the flowpath surface and thermally bonded to the flowpath surface, forming a restoration coating.

Abstract: Methods and apparatus of fabricating a gas turbine engine component are provided. The method includes selecting a surface of a component to apply a wear-resistant material, applying a formed wear pad fabricated from a wear-resistant alloy and a braze material, and vacuum brazing the component and applied wear pad wherein the wear-resistant alloy is bonded to the component surface using the braze material.

Abstract: Methods and apparatus of fabricating a gas turbine engine component are provided. The method includes selecting a surface of a component to apply a wear-resistant material, applying a formed wear pad fabricated from a wear-resistant alloy and a braze material, and vacuum brazing the component and applied wear pad wherein the wear-resistant alloy is bonded to the component surface using the braze material.

Abstract: A method enables a nozzle assembly for a gas turbine engine rotor assembly to be fabricated. The rotor assembly includes at least two adjacent rows of rotor blades coupled together by a disk spacer arm. The method includes providing a nozzle assembly that includes at least one nozzle including a vane that extends outwardly from a radially outer side of an inner band, coupling the nozzle assembly into the rotor assembly between the two adjacent rows of rotor blades, and coupling a seal assembly that includes a backing piece to the nozzle assembly such that the backing piece is substantially parallel to the rotor assembly disk spacer arm.

Abstract: A method enables a nozzle assembly for a gas turbine engine rotor assembly to be fabricated. The rotor assembly includes at least two adjacent rows of rotor blades coupled together by a disk spacer arm. The method includes providing a nozzle assembly that includes at least one nozzle including a vane that extends outwardly from a radially outer side of an inner band, coupling the nozzle assembly into the rotor assembly between the two adjacent rows of rotor blades, and coupling a seal assembly that includes a backing piece to the nozzle assembly such that the backing piece is substantially parallel to the rotor assembly disk spacer arm.

Abstract: A built-up gas turbine component is prepared by providing a gas turbine component having a component surface and being made of a component base metal having a component base metal composition. A buildup tape is supplied having a net metallic buildup composition different from the component base metal composition. The buildup tape includes a first metallic constituent having a first melting point, and a second metallic constituent having a second melting point. The first metallic constituent and second metallic constituent together have the net metallic buildup composition. A nonmetallic binder binds together the first metallic constituent and the second metallic constituent. The buildup tape is applied to the component surface and heated to a brazing temperature greater than the first melting point and less than the second melting point.

Abstract: A built-up gas turbine component is prepared by providing a gas turbine component having a component surface and being made of a component base metal having a component base metal composition. A buildup tape is supplied having a net metallic buildup composition different from the component base metal composition. The buildup tape includes a first metallic constituent having a first melting point, and a second metallic constituent having a second melting point. The first metallic constituent and second metallic constituent together have the net metallic buildup composition. A nonmetallic binder binds together the first metallic constituent and the second metallic constituent. The buildup tape is applied to the component surface and heated to a brazing temperature greater than the first melting point and less than the second melting point.

Abstract: A method is provided for making, from a plurality of members brazed together, an article including an environmental resistant surface coating and a wear resistant surface portion. Prior to brazing, the members are assembled with at least one preform including the wear resistant material in a matrix including a first brazing alloy having a brazing temperature in a brazing temperature range. The assembly of members includes a second brazing alloy having a brazing temperature in the brazing temperature range. The assembly of members and wear resistant preform is heated in the brazing temperature range to provide a brazed article preform. Then the article preform is machined to a selected geometry and can be coated with the environmental coating.

Abstract: A tip cap hole is loaded with a first composition comprising particles of a first alloy having a solidus temperature above the brazing temperature. The first composition is covered with a second composition comprising particles of a second alloy having a liquidus temperature below the brazing temperature. The second composition is heated to the brazing temperature to cause particles of the second alloy to melt to form a liquid of the second alloy which is carried into spaces between the particles of the first alloy by capillarity. The liquid of the second alloy is cooled to form a solid securely bonding the particles of the first alloy. By weight, the second alloy has no more than 1% B and from 3% to 11% Si. The first alloy has Cr and at least about 5% Al, at least about 0.5% Hf, no more than 0.5% Ti.

Abstract: A tip cap hole is loaded with a first composition comprising particles of a first alloy having a solidus temperature above the brazing temperature. The first composition is covered with a second composition comprising particles of a second alloy having a liquidus temperature below the brazing temperature. The second composition is heated to the brazing temperature to cause particles of the second alloy to melt to form a liquid of the second alloy which is carried into spaces between the particles of the first alloy by capillarity. The liquid of the second alloy is cooled to form a solid securely bonding the particles of the first alloy. By weight, the second alloy has no more than 1% B and from 3% to 11% Si. The first alloy has Cr and at least about 5% Al, at least about 0.5% Hf, no more than 0.5% Ti.

Abstract: A nickel-base superalloy article has a coating having a composition, in weight percent, of from about 10 to about 20 percent cobalt, from about 14 to about 25 percent chromium, from about 2 to about 12 percent aluminum, from 0 to about 0.2 percent yttrium, from about 0.001 to about 3 percent boron, from about 1 to about 10 percent silicon, balance nickel and incidental impurities. The coating is preferably applied by mixing together two powders, one with a higher solidus temperature and one with a lower solidus temperature, whose net composition is that of the coating. The powder mixture is compacted with a binder, applied to a surface of the article, and heated to a temperature above the lower solidus temperature.

Abstract: A braze material is provided for repairing an article, and particularly components formed from cobalt and nickel-base superalloys, such as gas turbine engine components. The braze material is composed of high melt particles distributed within a braze alloy. The braze alloy can be any suitable bonding material of the type used to repair components that must operate at high temperatures. The particles are single crystal, directionally solidified or equiaxed particles formed from a superalloy or ceramic material, or mixtures thereof. Importantly, the particles have an aspect ratio (length to width) of at least 4:1. The braze material can be provided and used in the form of a slurry, a presintered preform, a plasticized tape, or in a powdered form.

Abstract: A nickel-base superalloy article has a coating having a composition, in weight percent, of from about 10 to about 20 percent cobalt, from about 14 to about 25 percent chromium, from about 2 to about 12 percent aluminum, from 0 to about 0.2 percent yttrium, from about 0.001 to about 3 percent boron, from about 1 to about 10 percent silicon, balance nickel and incidental impurities. The coating is preferably applied by mixing together two powders, one with a higher solidus temperature and one with a lower solidus temperature, whose net composition is that of the coating. The powder mixture is compacted with a binder, applied to a surface of the article, and heated to a temperature above the lower solidus temperature.

Abstract: A nickel-base superalloy article has a coating having a composition, in weight percent, of from about 10 to about 20 percent cobalt, from about 14 to about 25 percent chromium, from about 2 to about 12 percent aluminum, from 0 to about 0.2 percent yttrium, from about 0.001 to about 3 percent boron, from about 1 to about 10 percent silicon, balance nickel and incidental impurities. The coating is preferably applied by mixing together two powders, one with a higher solidus temperature and one with a lower solidus temperature, whose net composition is that of the coating. The powder mixture is compacted with a binder, applied to a surface of the article, and heated to a temperature above the lower solidus temperature.

Abstract: An article with a high temperature superalloy body having a directionally oriented microsuucture and a structural discontinuity, such as a crack, or surface erosion or wear portion, is repaired, to provide a repaired article, using a mixture of Ni base ahoy powders. One powder includes a careful balance of the temperature depressants Si and B. In the one powder, Si is included in the range of about 0.05-2.2 wt. % to provide about 0.02-1.3 wt. % Si in a repaired portion as bonded with the article. In that same powder, B is include in the range of about 0.2-1.2 wt. % to provide about 0.08-0.7 wt. % in that repaired portion. In the repair method, the repaired portion can be provided, when shorter brazing times are used, with improved mechanical properties by diffusing the brazed alloy and aging the repaired structure in the range of about 1600.degree.-1700.degree. F. for a time in the range of about 1-16 hours.

Abstract: A series of braze materials for brazing superalloy substrates at effective brazing temperatures above about 2300.degree. F. is described. The braze materials are formulated as mixtures of cobalt- and nickel-base alloy powders. Each such braze material contains at least two components, one of which is predominantly liquid at the effective brazing temperature, and one of which remains substantially solid at that temperature. The brazing materials solidify by an isothermal solidification process. Unless otherwise limited by the temperature capability of the superalloy substrate being joined, these brazing alloys provide joints that have useful strength at temperatures significantly higher than joints made with prior art brazing alloys.