Abstract: A method of repairing an airfoil is provided. The method includes providing an airfoil with a damaged section and removing the damaged section by machining or cutting an upper section of the airfoil. A replacement section is configured to mate with an upper surface of the airfoil. A presintered preform is provided to join the airfoil and the replacement sections through a resistance brazing process. The presintered preform is configured to mate with the upper surface of the airfoil and a lower surface of the replacement section and inserted between this upper surface and lower surface, creating a stacked airfoil comprising three mated sections in abutting contact. The stacked airfoil is resistance brazed such that only the braze material of the presintered preform melts and the upper surface of the airfoil and the lower surface of the replacement section remain below the grain boundary temperature of the material of the airfoil.

Abstract: A method of repairing an airfoil is provided. The method includes providing an airfoil with a damaged section and removing the damaged section by machining or cutting an upper section of the airfoil. A replacement section is configured to mate with an upper surface of the airfoil. A presintered preform is provided to join the airfoil and the replacement sections through a resistance brazing process. The presintered preform is configured to mate with the upper surface of the airfoil and a lower surface of the replacement section and inserted between this upper surface and lower surface, creating a stacked airfoil comprising three mated sections in abutting contact. The stacked airfoil is resistance brazed such that only the braze material of the presintered preform melts and the upper surface of the airfoil and the lower surface of the replacement section remain below the grain boundary temperature of the material of the airfoil.

Abstract: A method of braze repair for a superalloy material component. Following a brazing operation on the superalloy material, the component is subjected to an isostatic solution treatment, followed by a rapid cool down to ambient temperature under pressure The conditions of the isostatic solution treatment combined with the cool down at pressure function to both reduce porosity in the component and to solution treat the superalloy material, thereby optimizing superalloy properties without reintroducing porosity in the braze.

Abstract: A braze tape (12) useful with superalloy materials. In one embodiment, the tape includes a layer (14) containing superalloy powder (22) in a binder (24), and a layer (16) containing boron and silicon free braze material powder (32) in a binder, joined together by a layer (18) of double-sided adhesive fluorocarbon polymer tape, such as a double-sided adhesive polytetrafluoroethylene or Teflon® tape (46).

Abstract: A system for manufacturing of a sintered wire and in-situ feeding to a laser wire welding system is presented. The system includes a pressure vessel connected to a powder feed system for delivering at least two powders to a powder mixing zone of the pressure vessel. The at least two powders are mixed via a rotating cone in the pressure vessel. After mixing, a heating device contained within the pressure vessel heats the mixture so that liquid phase sintering occurs and a sintered rod is created. The sintered wire is continuously fed to a laser metal deposition system for depositing a layer of additive material on a base material. A method of additively manufacturing or repairing a superalloy component is also presented.

Abstract: A method of manufacturing a hard-to-weld material by a beam-assisted additive manufacturing process is presented. The method includes depositing a first layer for the material onto the substrate, the first layer including a major fraction of a base material for the component and a minor fraction of a solder, depositing a second layer of the base material for the component and a thermal treatment of the layer arrangement. The thermal treatment includes a first thermal cycle at a first temperature above 1200° C. for a duration of more than 3 hours, a subsequent second thermal cycle at a second temperature above 1000° C. for more than 2 hours, and a subsequent third thermal cycle and a third temperature above 700° C. for more than 12 hours. A manufactured component is also presented.

Abstract: System (10) and methods (1000) for structural braze repair of high gamma prime nickel base gas turbine components (1). The system may include a controller (200) operably connected to a heating system (100), e.g., a vacuum furnace, for controlling heat temperatures of the furnace for a specified or predetermined time period. A damaged component is placed in the furnace and heated to a first temperature, which is held for the specified time period before being cooled to about room temperature. The component is then heated to a second temperature higher than the first temperature, which is held for a second time period before being cooled again to about room temperature. After cooling the component may be braze repaired at a third temperature equal to or higher than the previous temperatures for a third time period.

Abstract: System (10) and methods (1000) for structural braze repair of high gamma prime nickel base gas turbine components (1). The system may include a controller (200) operably connected to a heating system (100), e.g., a vacuum furnace, for controlling heat temperatures of the furnace for a specified or predetermined time period. A damaged component is placed in the furnace and heated to a first temperature, which is held for the specified time period before being cooled to about room temperature. The component is then heated to a second temperature higher than the first temperature, which is held for a second time period before being cooled again to about room temperature. After cooling the component may be braze repaired at a third temperature equal to or higher than the previous temperatures for a third time period.

Abstract: A process is disclosed comprising heating a powder mixture (212) with an energy beam (304) to melt only a portion of a first powder (202) of the mixture and to melt all or most of a second powder (204) of the mixture, wherein the second powder includes a gamma prime forming constituent and the first powder includes elements of a desired precipitation strengthened superalloy composition less the gamma prime forming constituent; allowing the melted portions to mix and to cool to form a deposit layer (208) including a beta phase alloy surrounding unmelted first powder of the mixture. The process may further include heat treating the deposit layer to transform it into a gamma plus gamma prime layer (210) of the desired precipitation strengthened superalloy composition.

Abstract: A ternary near eutectic alloy of Ni, Ti, Cr is described having a relatively low melting temperature of approximately 1230 deg. C. or less, suitable for fusing cracks in turbine blades and vanes without substantial risk of cracking during the repair process. Such an alloy is suitable for low temperature joining or repair of turbine blades since it contains the same components as typical turbine blades and vanes without foreign elements to lower the melting point of the repaired material or adversely affect the mechanical properties of the repaired component. Exclusion of boron eliminates the formation of brittle boron compounds, detrimental to the properties of the repair or seam.

Abstract: A method of making pre-sintered preforms using a mixture of base superalloy particles and titanium-containing boron and silicon free braze alloy particles, such as for the repair of superalloy gas turbine engine components. Alloy particles as large as 2 mm provide reduced shrinkage when compared to prior art preforms. Braze material compositions disclosed herein are boron and silicon free and may have melting temperature ranges as low as 10° C., and they include no element not already present in the composition of the superalloy component.

Abstract: Boron and silicon free braze alloys useful for structural repairs of superalloy gas turbine engine components. The braze alloy composition may contain only elements that are contained in the superalloy material to be repaired, and may have melting temperature ranges as low as 10° C. to facilitate producing a high strength homogenized braze joint during a solution heat treatment of the superalloy substrate material.

Abstract: A process is disclosed comprising heating a powder mixture (212) with an energy beam (304) to melt only a portion of a first powder (202) of the mixture and to melt all or most of a second powder (204) of the mixture, wherein the second powder includes a gamma prime forming constituent and the first powder includes elements of a desired precipitation strengthened superalloy composition less the gamma prime forming constituent; allowing the melted portions to mix and to cool to form a deposit layer (208) including a beta phase alloy surrounding unmelted first powder of the mixture. The process may further include heat treating the deposit layer to transform it into a gamma plus gamma prime layer (210) of the desired precipitation strengthened superalloy composition.

Abstract: A superalloy component such as a gas turbine engine blade (40) having a ceramic thermal barrier coating (41) is repaired using a textured repair foil (30). A degraded region of the thermal barrier coating is removed (14) and the underlying superalloy material surface is prepared (16) for re-coating. The repair foil is includes a layer of boron-free braze material (34) and a layer of superalloy material (32) having a textured surface (36). The foil is brazed (18) to the prepared surface during a solution heat treatment effective to homogenize the braze (20). A new area of thermal barrier coating (46) is applied over the foil with a bond that is enhanced by the texturing of the foil surface.

Abstract: A ternary near eutectic alloy of Ni, Ti, Cr is described having a relatively low melting temperature of approximately 1230 deg. C. or less, suitable for fusing cracks in turbine blades and vanes without substantial risk of cracking during the repair process. Such an alloy is suitable for low temperature joining or repair of turbine blades since it contains the same components as typical turbine blades and vanes without foreign elements to lower the melting point of the repaired material or adversely affect the mechanical properties of the repaired component. Exclusion of boron eliminates the formation of brittle boron compounds, detrimental to the properties of the repair or seam.

Abstract: A spindle bolt structure is provided in a gas turbine engine, and includes a pilot region located within a bolt hole extending through a seal disk. The pilot region includes a circumferential pilot ridge located adjacent to a downstream axial face of the seal disk and a circumferential trough portion located between a bolt shoulder and the pilot ridge. The trough portion defines a trough diameter that is less than a diameter of the bolt shoulder and less than a diameter of the pilot ridge. The bolt shoulder and pilot ridge are formed with an applied compressive residual stress and are positioned for engagement with the seal disk.

Abstract: A braze tape (12) useful with superalloy materials. In one embodiment, the tape includes a layer (14) containing superalloy powder (22) in a binder (24), and a layer (16) containing boron and silicon free braze material powder (32) in a binder, joined together by a layer (18) of doubled-sided adhesive Teflon® tape (46).

Abstract: A ternary near eutectic alloy of Ni, Ti, Cr is described having a relatively low melting temperature of approximately 1230 deg. C. or less, suitable for fusing cracks in turbine blades and vanes without substantial risk of cracking during the repair process. Such an alloy is suitable for low temperature joining or repair of turbine blades since it contains the same components as typical turbine blades and vanes without foreign elements to lower the melting point of the repaired material or adversely affect the mechanical properties of the repaired component. Exclusion of boron eliminates the formation of brittle boron compounds, detrimental to the properties of the repair or seam.

Abstract: Ni base superalloy components containing relatively large amounts of Al and Ti are known to be difficult to build up by a weld build up process without cracking. As the Al and Ti content of the superalloy is increased to improve the strength, the susceptibility to cracking is increased. It is shown herein that reducing the ?? phase in the additive built up material improves robustness against cracking. A stepwise, controlled heating and cooling process is described to be used in cooperation with an additive build up process to reduce the ?? present and thereby reduce cracking.

Abstract: A method of braze repair for a superalloy material component. Following a brazing operation on the superalloy material, the component is subjected to an isostatic solution treatment, followed by a rapid cool down to ambient temperature under pressure The conditions of the isostatic solution treatment combined with the cool down at pressure function to both reduce porosity in the component and to solution treat the superalloy material, thereby optimizing superalloy properties without reintroducing porosity in the braze.