Abstract: A method of finishing a fan blade includes bonding a sheath and a cover to an aluminum fan blade with an airfoil, a root, a leading edge and a tip; imparting residual stresses onto the blade; coating the blade to protect exposed areas of the blade; and curing the blade in low-temperature cure cycles to preserve residual stresses imparted.

Abstract: A method for protecting a fan blade with an airfoil, a tip, a root and a sheath, the root to be inserted into a hub includes peening the airfoil of the blade; inserting a scrim cloth between the fan blade and the sheath to galvanically isolate the fan blade from the sheath; bonding the sheath to the blade with an epoxy adhesive; peening the blade root; bonding wear pads to the root with epoxy adhesive to galvanically isolate the root from the hub; applying a protective cover to the tip of the blade; and applying a coating to all exposed areas of the blade to inhibit corrosion.

Abstract: An airfoil for a gas turbine engine includes a substrate and a sheath providing an edge. A cured adhesive secures the sheath to the substrate. The cured adhesive has a fillet that extends beyond the edge that includes a mechanically worked finished surface. A method of manufacturing the airfoil includes the steps of securing a sheath to a substrate with adhesive, curing the adhesive, and mechanically removing a portion of the adhesive extending beyond the sheath.

Abstract: An apparatus and method for repairing defects in composite materials using a tapered disk sized to fit the part being repaired. Also included is a bolt sized to fit through a central hole in the disk. A spring is positioned on the bolt with a washer. A nut is attached to the end of the bolt and tightened to place pressure on the washer to compress the biasing device. An adhesive is applied to the tapered disk prior to engaging the composite material. A threaded bushing is used to fixedly attach a second bolt completely in the hole.

Abstract: A method of forming a fan blade includes the steps of applying an adhesive to an inner surface of a cover and moving a toothed instrument along the inner surface of the cover to spread the adhesive over the inner surface of the cover to form a plurality of rows of adhesive on the inner surface of the cover. The method further includes the steps of applying the inner surface of the cover to a fan blade body and curing the adhesive to secure the cover to the fan blade body.

Abstract: A rotary blade is provided that includes a root, an airfoil, and a tip insert. The airfoil is attached to the root, and has a suction side surface, a pressure side surface, a leading edge, a trailing edge, a tip, and a slot disposed within the tip. The slot extends in a chordwise direction between the leading edge and trailing edge. The tip insert has a base end and a rub end. The base end of the tip insert is disposed within the slot. The rub end of the tip insert extends radially outward from the airfoil tip.

Abstract: A method for bonding a sheath made of a first metallic material to an airfoil made of a second metallic material includes treating the bonding surface of the airfoil; treating the bonding surface of the sheath; placing an adhesive between the bonding surfaces of the airfoil and the sheath; and pressing the airfoil and sheath together so that the adhesive bonds the sheath to the airfoil.

Abstract: A method of finishing a fan blade includes bonding a sheath and a cover to an aluminum fan blade with an airfoil, a root, a leading edge and a tip; imparting residual stresses onto the blade; coating the blade to protect exposed areas of the blade; and curing the blade in low-temperature cure cycles to preserve residual stresses imparted.

Abstract: A method for protecting a fan blade with an airfoil, a tip, a root and a sheath, the root to be inserted into a hub includes peening the airfoil of the blade; inserting a scrim cloth between the fan blade and the sheath to galvanically isolate the fan blade from the sheath; bonding the sheath to the blade with an epoxy adhesive; peening the blade root; bonding wear pads to the root with epoxy adhesive to galvanically isolate the root from the hub; applying a protective cover to the tip of the blade; and applying a coating to all exposed areas of the blade to inhibit corrosion.

Abstract: A method of debulking a fiber preform includes debulking a three-dimensional fiber preform from a first size to a second, smaller size. A solvent may be infiltrated into the preform to distribute a tackifier material therein. The solvent is then removed and the dried preform is compressed to the smaller size such that, upon removal of the pressure, the tackifier material causes the preform to substantially remain at the smaller size.

Abstract: A method for bonding a sheath made of a first metallic material to an airfoil made of a second metallic material includes treating the bonding surface of the airfoil; treating the bonding surface of the sheath; placing an adhesive between the bonding surfaces of the airfoil and the sheath; and pressing the airfoil and sheath together so that the adhesive bonds the sheath to the airfoil.

Abstract: A doubler assembly repairs at least one damaged aperture of a composite flange. The doubler assembly includes an insert, an adhesive, and a support. The insert is positioned in the damaged aperture to provide compressive load transfer through the composite flange. The adhesive is positioned directly on at least a portion of the composite flange proximate the damaged aperture. The support is positioned over the adhesive.

Abstract: An assembly includes a composite flange, an insert, an adhesive and a support. The composite flange has at least one damaged aperture. The insert is positioned in the damaged aperture and extends therefrom to provide compressive load transfer through the composite flange. The adhesive is positioned directly on at least a portion of the composite flange proximate the damaged aperture. The support is positioned over the adhesive and contacts the insert.

Abstract: A component to be repaired includes a relatively rigid plate. On a surface that may have been subject to fracture, a resin material is first laid down, then a relatively flexible material is positioned outwardly of the resin material to repair the barrier. A part may also be formed initially with the flexible material. In another feature of this application, a method of forming a barrier includes providing a composite material, and applying a relatively flexible material on a surface of the composite material, and concurrently molding the relatively flexible material with the composite material using a composite mold.

Abstract: A method and system is described herein for repairing a part used in a gas turbine engine, which has a damaged or worn lubricant layer bonded to a surface of the part. After removing the damaged or worn lubricant layer, a polymeric adhesive may be used to attach a replacement lubricant layer to the metal surface. The polymeric adhesive may be a film or a paste. In some embodiments, the adhesive includes a non-metallic filler. The polymeric adhesive is stable at an operating temperature of the part to which it is attached. In one embodiment, the adhesive is polyimide, which is well-suited for use in a high pressure compressor of the gas turbine engine that operates at high temperatures. In other embodiments, the adhesive is bismaleimide (BMI) or cyanate ester.

Abstract: A process for applying erosion resistant coatings includes the steps of applying a fluoroelastomer based solution to at least a portion of at least one perforated surface of an article, at least one perforated surface includes a plurality of perforations, and each of the perforations has a pre-coating diameter of no less than about 0.025 inches and no greater than about 0.075 inches; drying at least one perforated surface coated with the fluoroelastomer based solution; and curing at least one perforated surface coated with the fluoroelastomer based solution to form an erosion resistant coating.

Abstract: The invention is a porous carbon body for a fuel cell having an electronically conductive hydrophilic agent and method of manufacture of the body. The porous carbon body comprises an electronically conductive graphite powder in an amount of between 60%-80% by weight of the body; a carbon fiber in an amount of between 5%-15% by weight of the body; a thermoset binder in an amount of between 6%-18% by weight of the body; and, a modified carbon black electronically conductive hydrophilic agent in an amount of between 2%-20% by weight of the body. The body provides for increased wettability without any decrease in electrical conductivity, and also provides for an efficient manufacture without any need for high temperature, costly steps to graphitize the body, or to incorporate post molding hydrophilic agents into pores of the body.

Abstract: The invention is a porous carbon body for a fuel cell having an electronically conductive hydrophilic agent and method of manufacture of the body. The porous carbon body comprises an electronically conductive graphite powder in an amount of between 60%-80% by weight of the body; a carbon fiber in an amount of between 5%-15% by weight of the body; a thermoset binder in an amount of between 6%-18% by weight of the body; and, a modified carbon black electronically conductive hydrophilic agent in an amount of between 2%-20% by weight of the body. The body provides for increased wettability without any decrease in electrical conductivity, and also provides for an efficient manufacture without any need for high temperature, costly steps to graphitize the body, or to incorporate post molding hydrophilic agents into pores of the body.

Abstract: A composite article comprising of a non-metallic composite core, a fluoroelastomer adhesive layer which has a curing temperature substantially similar to the composite core, and a metallic structure which overlays the fluoroelastomer adhesive layer, wherein the composite article can be formed by co-curing the core and the fluoroelastomer adhesive layer.

Abstract: The present invention related to a method for providing a composite structure and the composite structure formed thereby. The method broadly comprises the steps of: providing a core structure formed from a non-metallic composite material in a substantially uncured state; applying a fluoroelastomer film in a substantially uncured state over surface portions of said core structure; placing a metallic structure over a portion of said core structure, said metallic structure having inner surfaces which contacts said fluoroelastomer film; and molding said composite structure under conditions of heat and pressure for a time sufficient to co-cure said fluoroelastomer film and said non-metallic core structure material and to form a bond between said fluoroelastomer film and said inner surfaces of said metallic structure. The method of the present invention may be used to manufacture original metal/composite structures as well as to refurbish metal/composite structures such as fan exit guide vanes for jet engines.