Abstract: A method of welding alloys having directionally-solidified grain structure. The methods improve the weldability of these alloys by creating a localized region of fine grain structure, wherein the welding occurs in these localized regions. The localized regions are formed by applying strain energy using a variety of different methods, such as by hammer peening, laser peening or sand blasting. Then, a heat treatment step may be used to create recrystallized grains having the fine grain structure. The region of fine grain structure provides better weldability.

Abstract: An improved method of heat treating superalloys prior to welding includes subjecting only the portion of the component to be repaired to a localized heat treatment, leaving the remainder of the component untreated. The localized heat treatment permits the use of higher hold temperatures that are near, at, or above the Ni3(Al,Ti) solution temperature of the alloy. Such heat treatment prevents strain age cracking and also prevents recrystallization in areas that are not heat treated. Such localized heat treatment can be applied before and/or after welding, for material rejuvenation, pre-brazing, and post-brazing.

Abstract: A consumable insert (10) formed of material particles (14) contained within a sheath (12). The particles may be a melting point depressant that has a concentration that is greater in a center region (16) of the insert than in the surface region (18) of the insert, thereby facilitating complete melting of the insert during a transient liquid phase bonding process. Alternatively, the particles may be a low-ductility material, such as a superalloy or an MCrAlY alloy, contained within a high ductility sheath material formed into a ribbon shape, thereby allowing the low-ductility material to be delivered in ribbon form during a coating process.

Abstract: A method of repairing a combustion turbine component having damage located at or near a cooling hole or hollow or geometrically complex portion of the component is provided. The method comprises forming a preparatory groove that extends from a surface of the component to the damaged area but does not extend to the cooling hole or hollow or geometrically complex portion of the component, the groove extending 40–90% the distance from the component to the damaged area; spraying a filler material into the groove with a micro-plasma torch at a current of less than 50 amperes; and filling the groove with the filler material such that the heated filler material substantially extends from the cooling hole or hollow or geometrically complex portion of the component to a surface of the component.

Abstract: A weld preparation process that translates a consumable or nonconsumable tool over an area that is subsequently to be welded to impart friction heating to the surface. Rotary or linearly oscillated motion between the tool and the workpiece is used to generate heat and produce deformation in the surface, resulting in recrystallization of the area being processed and a compressive residual stress.

Abstract: Method for welding objects having limited backside access to a cavity behind a region to be welded. The method includes inserting a fugitive backing material in an installation state into a first portion of the cavity proximate the region to be welded and then transforming the fugitive backing material to a rigid state. The method further includes forming a weld in the region and then transforming the fugitive backing material to a removable state and removing the fugitive backing material from the cavity. The method may also include placing a pre-formed weld backing in the cavity and filling the cavity with a fugitive backing material. The method further includes transforming the fugitive backing material to a rigid state, forming a weld, and transforming the fugitive backing material to a removable state. The method may further include removing the fugitive backing material and removing the pre-formed weld backing from the cavity.

Abstract: A turbine blade closure system composed of a closure member capable of being friction welded in an aperture in a hollow-cast turbine blade to prevent the escape of cooling fluids from an internal cavity in the turbine blade. In one embodiment, the aperture is formed in the turbine blade during the manufacturing process as a result of one or more support projections used to position a core block in a turbine blade mold.

Abstract: A weld preparation process that translates a consumable or nonconsumable tool over an area that is subsequently to be welded to impart friction heating to the surface. Rotary or linearly oscillated motion between the tool and the workpiece is used to generate heat and produce deformation in the surface, resulting in recrystallization of the area being processed and a compressive residual stress.

Abstract: A turbine blade closure system composed of a closure member capable of being friction welded in an aperture in a hollow-cast turbine blade to prevent the escape of cooling fluids from an internal cavity in the turbine blade. In one embodiment, the aperture is formed in the turbine blade during the manufacturing process as a result of one or more support projections used to position a core block in a turbine blade mold.