The Boeing Company

Mcdonnell Douglas Corporation

The United States of America As Represented by the Administrator

Lambda Research, Inc.

Advanced Joining Technologies, Inc.

Douglas J Waldron

Keith McTernan

Robert Scott Forrest

Ray Miryekta

William F Bozich

Henry W Babel

R Scott Forrest

Ronaldo Reyes De Jesus

Murray W Mahoney

Paul S Prevey, Iii

Richard G Pettit

Daniel J Rybicki

William F McGee

Michael Royston James

Ray F Toosky

Scott Forrest

Paul S Prevey

Paul S Iii Prevey

Raymond Miryekta

Keith R Mcternan

A method for making a riser component includes: positioning a coupler adjacent and end of a tube such that a region of the coupler forms an interface with the tube's end, wherein the region includes a material (in some embodiments an aluminum alloy), and the tube's end includes a groove and another material (in some embodiments a steel alloy) that is different than the region's material; heating the region of the coupler to increase the region's malleability; and exerting pressure on the region of the coupler to plastically deform the region to insert some of the region's material into the groove in the tube's end. By fixing the coupler to the tube in this manner, the coupler may be strongly secured to the tube, and thus able to withstand high, dynamic loads frequently experienced in service. Also, the material of the coupler may be different than the material of the tube, and thus the material of the coupler may be lighter than the material of the tube. This allows one to design a riser component that is lighter than a conventional steel riser component having a steel tube and steel flanges, but that can withstand the high, dynamic loads frequently experienced in service.

Riser components and methods for making the same

An apparatus for forming a workpiece to a desired, non-planar configuration are provided. At least one friction stir forming tool, having a shoulder and a pin, is used to urge the workpiece to the desired configuration and friction stir form the workpiece. The forming tool can urge the workpiece against a contour surface of a die or a shoulder that is opposite the structural member from the tool. Thus, the forming tool plasticizes a portion of the workpiece and urges the workpiece to the desired configuration. In addition, the material properties of the workpiece can be improved by the friction stir processing.

Stir forming apparatus

The present invention provides a tool for forming a friction stir weld joint in a workpiece. According to one embodiment, the tool includes a rotatable pin having first and second ends and defining a stirring portion therebetween structured to frictionally engage the workpiece so as to at least partially form the friction stir weld joint. The tool includes a rotatable first shoulder defining an aperture therethrough structured to slidably receive the first end of the pin. The tool also includes a second shoulder defining an aperture structured to receive the second end of the pin such that the pin extends between the first and second shoulders and such that the second shoulder is in rotatable communication with the pin. The first shoulder is structured to rotate independently of the pin and the second shoulder.

Method and apparatus for friction stir welding

An apparatus and method for forming a workpiece to a desired, non-planar configuration are provided. At least one friction stir forming tool, having a shoulder and a pin, is used to urge the workpiece to the desired configuration and friction stir form the workpiece. The forming tool can urge the workpiece against a contour surface of a die or a shoulder that is opposite the structural member from the tool. Thus, the forming tool plasticizes a portion of the workpiece and urges the workpiece to the desired configuration. In addition, the material properties of the workpiece can be improved by the friction stir processing.

Stir forming apparatus and method

The present invention relates to methods of making large spin blanks out of pieces of aluminum sheet or plate joined by friction stir welding to provide plate blank sizes greater than 156 inch (396 cm) in diameter. Blank sizes greater than 209 inch diameter enable manufacturing possibilities for large one-piece spun parts instead of constructing large structures from pieces. This also applies to sheet, except that the maximum width obtainable is 139 inches (353 cm). The availability of large blank sizes, particularly for sheet, permits the use of traditional spinning where bending is the predominant method of metal movement rather than stretching and spinning. As the present invention is a very cost effective approach, it provides a method for producing significantly more economical spin blanks between 156 and 209 inches in diameter than are obtainable for a single piece blank.

Large diameter domes and methods of manufacturing same

The present invention provides an improved structural assembly constructed of a plurality of structural members secured together. At least one of the plurality of structural members defines a first region characterized by comparatively high operational stress and a second region having a locally refined grain structure positioned such that the second region at least partially encompasses the first region to thereby enhance the strength, toughness and fatigue resistance of the at least one structural member in the first region. The present invention also provides a method for selectively improving the strength, toughness and fatigue resistance of a structural member in a region of high operational stress including the steps of casting the structural member in a pre-selected configuration. Regions of the structural member having comparatively high operational stress are identified. The structural member is secured to prevent movement. The region of the structural member having comparatively high operational stress is then mixed with a rotating friction stir welding probe to locally refine the grain structure of the structural member within the region of high operational stress to thereby improve the strength, toughness and fatigue resistance of the structural member in the region. The structural member can be secured to other structural members to form the frame of an aircraft. The improved structural assembly will have an increased operational life, as well as require less stock material with a corresponding decrease in the overall weight of the assembly.

Friction stir grain refinement of structural members

The welding apparatus and associated method are provided. The welding apparatus includes a welding tool for forming a weld joint along the surface of at least one workpiece. The welding apparatus also includes a compression tool for selectively inducing a layer of residual compressive stress in at least a portion of the surface of the weld joint and the surface of the at least one workpiece to thereby improve the material properties of the workpiece, including corrosion resistance and fatigue strength.

Apparatus and method for forming weld joints having compressive residual stress patterns

The method of manufacturing a structural assembly includes positioning a first structural member at least partially adjacent a second structural member to define an interface therebetween and inserting a rotating plug into the first and second structural members at the interface to thereby join the first structural member to the second structural member. The resulting friction plug weld provides a relatively strong joint between the structural members, requires less forming and machining time, and is compatible with single-sided tooling. Additionally, the friction plug weld is compatible with other joining methods, such as friction stir welding.

Joining of structural members by friction plug welding

Large diameter dome tanks made of a plurality of plates friction stir welded together to form a blank and spun and/or stretched into form. The dome tanks may be for holding liquid rocket fuel. Methods of forming include friction stir welding two or more flat blanks together and spinning the combined workpiece into a hemisphere. The blanks may be sufficiently thick to enable stretching as well as spinning. Aluminum alloys may be used, and filler material may be included in thee friction stir welds to reduce grain growth and problems associated therewith in the spinning process.

Methods of manufacture of spin-forming blanks, particularly for fabrication of rocket domes

A backing member for a friction stir butt welding apparatus includes a groove in the working surface of the backing member which supports the workpieces being butt welded. The backing member is positioned with the groove aligned directly beneath the butt joint between the workpieces. A rotating friction stir welding pin is introduced at the joint so as to plasticize the material of the workpieces on either side of the joint, and pressure is applied between the stir pin and the workpieces to create a forging pressure which forces plasticized material downward through the root zone of the weld and into the groove in the backing member. A visible bead is thus produced on the lower surfaces of the workpieces indicating total penetration of the weld. Lack of a bead indicates probable failure of the weld to totally penetrate through the root zone.

Method of friction stir welding with grooved backing member

A friction stir welding apparatus includes a C-shaped frame having two opposing jaws which are spaced apart to define a space for receiving workpieces which are to be welded together. One of the jaws supports a rotatably driven friction stir welding spindle, and the other jaw supports a back-up tool. The spindle is supported in a polycrystalline thrust bearing disposed in the one jaw for absorbing thrust forces exerted on the spindle during a welding operation. The C-shaped frame may be an integral one-piece structure, in which case the apparatus and workpieces are relatively advanced to cause the spindle to penetrate the workpieces at an edge thereof and to carry the welding tools along a weld path to a second edge of the workpieces, where the spindle exits and disengages the workpieces. Alternatively, the C-shaped frame may comprise a pair of separate jaws which are pivotally connected in scissor fashion, in which case the jaws may be pivotally urged toward one another to carry the welding tools into engagement with the workpieces for performing a welding operation. The C-shaped frame balances and absorbs the large thrust loads imposed on friction stir welding tools.

Friction stir welding apparatus and method

A process for joining two or more overlapping metal workpieces includes providing a fastener which is made of metal having a melting point temperature at least as great as that of the workpieces. The fastener is rotated about its central axis and is axially advanced at a predetermined advance rate into engagement with the workpieces so as to cause plasticization of the workpieces at the interface with the fastener, and to cause the fastener to axially penetrate through substantially the entire thickness of the workpieces. The rotation of the fastener is then stopped, and the plastic zone which surrounds the fastener cools to form a metallurgical bond with the fastener. The resulting fastened joint is mechanically superior to conventional mechanically fastened joints made by rivets and the like.

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Fountain Valley, CA, United States of America

Douglas J Waldron