Abstract: A rivet having improved formability is provided. The rivet has a shank having a head at one end. The shank and the head have a refined grain structure. The rivet is manufactured from the region of the workpiece having a refined grain structure by first forming a region having a refined grain structure in a workpiece and then forming the rivet. The refined grain structure results in improved mechanical properties, such as formability, strength, toughness, ductility, corrosion resistance, and fatigue resistance. The improved formability of the rivet reduces the formation and propagation of cracks during the manufacture and installation of the rivets.

Abstract: A fastener component is formed from aluminum or aluminum-alloy material having a head portion and an elongate shank portion, the shank portion having an end and intermediate or transition region. At least the shank portion of the fastener is cold-worked or heat-treated to an intermediate hardness stage, typically to a T6 condition. The intermediate region of the shank portion is further cold-worked to harden or strengthen the intermediate region of the shank portion with respect to the end of the shank, typically to a T8 condition. The aluminum or aluminum-alloy material of the component advantageously has ultra-fine grain size of less than about 5 microns. The ultra-fine grain size is advantageously obtained by friction stir processing (FSP) or equal angle extrusion (EAE).

Abstract: The apparatus for operating on a workpiece includes a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The interior of the die can be structured to shape the workpiece into a predetermined configuration. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.

Abstract: A rivet having improved formability is provided. The rivet has a shank having a head at one end. The shank and the head have a refined grain structure. The rivet is manufactured from the region of the workpiece having a refined grain structure by first forming a region having a refined grain structure in a workpiece and then forming the rivet. The refined grain structure results in improved mechanical properties, such as formability, strength, toughness, ductility, corrosion resistance, and fatigue resistance. The improved formability of the rivet reduces the formation and propagation of cracks during the manufacture and installation of the rivets.

Abstract: A rivet having improved formability is provided. The rivet has a shank having a head at one end. The shank and the head have a refined grain structure. The rivet is manufactured from the region of the workpiece having a refined grain structure by first forming a region having a refined grain structure in a workpiece and then forming the rivet. The refined grain structure results in improved mechanical properties, such as formability, strength, toughness, ductility, corrosion resistance, and fatigue resistance. The improved formability of the rivet reduces the formation and propagation of cracks during the manufacture and installation of the rivets.

Abstract: A precipitation hardened structural assembly is provided, including a first structural member and a second structural member positioned adjacent to the first structural member such that the first and second structural members define an interface therebetween. At least one friction stir weld joint joins the first structural member to the second structural member at least partially along the interface. The first and second structural members and the friction stir weld joint are solution heat treated at a first predetermined temperature schedule and precipitation heat treated at a second predetermined temperature schedule and wherein the friction stir weld joint comprises a refined grain structure having grain size of less than about 5 microns.

Abstract: The apparatus for operating on a workpiece includes a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The interior of the die can be structured to shape the workpiece into a predetermined configuration. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.

Abstract: A rivet having improved formability is provided. The rivet has a shank having a head at one end. The shank and the head have a refined grain structure. The rivet is manufactured from the region of the workpiece having a refined grain structure by first forming a region having a refined grain structure in a workpiece and then forming the rivet. The refined grain structure results in improved mechanical properties, such as formability, strength, toughness, ductility, corrosion resistance, and fatigue resistance. The improved formability of the rivet reduces the formation and propagation of cracks during the manufacture and installation of the rivets.

Abstract: A rivet having improved formability is provided. The rivet has a shank having a head at one end. The shank and the head have a refined grain structure. The rivet is manufactured from the region of the workpiece having a refined grain structure by first forming a region having a refined grain structure in a workpiece and then forming the rivet. The refined grain structure results in improved mechanical properties, such as formability, strength, toughness, ductility, corrosion resistance, and fatigue resistance. The improved formability of the rivet reduces the formation and propagation of cracks during the manufacture and installation of the rivets.

Abstract: The apparatus for operating on a workpiece includes a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The interior of the die can be structured to shape the workpiece into a predetermined configuration. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.

Abstract: The apparatus for operating on a workpiece includes a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The interior of the die can be structured to shape the workpiece into a predetermined configuration. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.

Abstract: The apparatus for operating on a workpiece includes a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The interior of the die can be structured to shape the workpiece into a predetermined configuration. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.

Abstract: A rivet having improved formability is provided. The rivet has a shank having a head at one end. The shank and the head have a refined grain structure. The rivet is manufactured from the region of the workpiece having a refined grain structure by first forming a region having a refined grain structure in a workpiece and then forming the rivet. The refined grain structure results in improved mechanical properties, such as formability, strength, toughness, ductility, corrosion resistance, and fatigue resistance. The improved formability of the rivet reduces the formation and propagation of cracks during the manufacture and installation of the rivets.

Abstract: A method for preparing ultra-fine grain titanium or titanium-alloy articles used for adjoining or assembling of detail components. Coarse-grained titanium or titanium-alloy materials typically are heated and forced under constant pressure through a friction stir processing tooling device containing a stirring chamber and a stirring rod. As the material is passed through the stirring chamber, the stirring rod solutionizes the titanium or titanium-alloy material and stirs the material to obtain a homogeneous or uniform material condition. As the processed material exits the stirring chamber of the friction stir process tooling device, it reconsolidates as an extremely homogeneous structure possessing ultra-fine grain structure. Titanium or titanium-alloy materials having been processed to achieve such ultra-fine grain material structure may then be manufactured into aerospace structural articles or components such as fasteners or articles that do not require a subsequent thermal or heat-treatment steps.

Abstract: A precipitation hardened structural assembly is provided, including a first structural member and a second structural member positioned adjacent to the first structural member such that the first and second structural members define an interface therebetween. At least one friction stir weld joint joins the first structural member to the second structural member at least partially along the interface. The first and second structural members and the friction stir weld joint are solution heat treated at a first predetermined temperature schedule and precipitation heat treated at a second predetermined temperature schedule and wherein the friction stir weld joint comprises a refined grain structure having grain size of less than about 5 microns.

Abstract: A method for preparing ultra-fine grain titanium or titanium-alloy articles used for adjoining or assembling of detail components. Coarse-grained titanium or titanium-alloy materials typically are heated and forced under constant pressure through a friction stir processing tooling device containing a stirring chamber and a stirring rod. As the material is passed through the stirring chamber, the stirring rod solutionizes the titanium or titanium-alloy material and stirs the material to obtain a homogeneous or uniform material condition. As the processed material exits the stirring chamber of the friction stir process tooling device, it reconsolidates as an extremely homogeneous structure possessing ultra-fine grain structure. Titanium or titanium-alloy materials having been processed to achieve such ultra-fine grain material structure may then be manufactured into aerospace structural articles or components such as fasteners or articles that do not require a subsequent thermal or heat-treatment steps.

Abstract: A back-up tooling apparatus for supporting the inner side of a hollow cylindrical workpiece during a circumferential friction stir weld includes a plurality of arcuate shoes configured to mate end-to-end to form a substantially continuous ring, and an expandable support for supporting the shoes and operable to retract and expand the shoes inward and outward. The expandable support includes at least one rotatable feed screw and central support members mounted on the feed screw or screws and pivotally connected to the shoes by support arms. The central support members are moved axially toward or away from each other for expanding or retracting the shoes. The shoes in one embodiment overlap in the circumferential direction, and a seal material is disposed between mating end faces of adjacent shoes. A restraining device is provided for clamping about the workpiece to reduce thermal expansion thereof. Cable-and-winch and geared drive devices are provided for rotatably driving the workpiece from its outer surface.

Abstract: A back-up tooling apparatus for supporting the inner side of a hollow cylindrical workpiece during a circumferential friction stir weld includes a plurality of arcuate shoes configured to mate end-to-end to form a substantially continuous ring, and an expandable support for supporting the shoes and operable to retract and expand the shoes inward and outward. The expandable support includes at least one rotatable feed screw and central support members mounted on the feed screw or screws and pivotally connected to the shoes by support arms. The central support members are moved axially toward or away from each other for expanding or retracting the shoes. The shoes in one embodiment overlap in the circumferential direction, and a seal material is disposed between mating end faces of adjacent shoes. A restraining device is provided for clamping about the workpiece to reduce thermal expansion thereof. Cable-and-winch and geared drive devices are provided for rotatably driving the workpiece from its outer surface.

Abstract: A back-up tooling apparatus for supporting the inner side of a hollow cylindrical workpiece during a circumferential friction stir weld includes a plurality of arcuate shoes configured to mate end-to-end to form a substantially continuous ring, and an expandable support for supporting the shoes and operable to retract and expand the shoes inward and outward. The expandable support includes at least one rotatable feed screw and central support members mounted on the feed screw or screws and pivotally connected to the shoes by support arms. The central support members are moved axially toward or away from each other for expanding or retracting the shoes. The shoes in one embodiment overlap in the circumferential direction, and a seal material is disposed between mating end faces of adjacent shoes. A restraining device is provided for clamping about the workpiece to reduce thermal expansion thereof. Cable-and-winch and geared drive devices are provided for rotatably driving the workpiece from its outer surface.

Abstract: The present invention provides a self-backing friction stir welding tool for backing up weld joints formed by friction stir welding large workpieces and workpieces having curvilinear geometries. The backing device includes a rotatable shoulder adapted to at least partially engage the weld joint and a probe having first and second ends and an intermediate portion therebetween. At least a portion of the intermediate portion of the probe frictionally engages the workpiece to form the weld joint. The first end of the probe defines a backing member, at least a portion of which engages the weld joint opposite the rotatable shoulder. The second end of the probe is adapted to rotatably and axial translatably communicate with the rotatable shoulder to thereby rotate the probe and urge the backing member toward the weld joint, thus constraining the plasticized material within the weld joint.