Gm Global Technolgoy Operations, Inc.

Yen-Lung Chen

Xiaohong Gayden

David R Sigler

Mark William Verbrugge

Peter H Foss

Robert T Szymanski

Mark T Hall

James Gregory Schroth

Sri Krishna Chimbli

Alan L Browne

Nilesh D Mankame

Paul Edward Krajewski

Thomas Arthur Perry

Yang-Tse Cheng

John E Carsley

Peter M Parlow

Anita Miriam Weiner

John D Fickes

Douglas L Faulkner

Matthew D Scrase

Robert L Totten

Gregory A Fischer

Steven J Wesoloski

Corey C Holupko

Aluminum alloy workpieces and/or magnesium alloy workpieces are joined in a solid state weld by use of a reactive material placed, in a suitable form, at the joining surfaces. Joining surfaces of the workpieces are pressed against the interposed reactive material and heated. The reactive material alloys or reacts with the workpiece surfaces consuming some of the surface material in forming a reaction product comprising a low melting liquid that removes oxide films and other surface impediments to a welded bond across the interface. Further pressure is applied to expel the reaction product and to join the workpiece surfaces in a solid state weld bond.

Welding light metal workpieces by reaction metallurgy

A method is provided for welding together a tubular member of a first metal and a tubular member of a second metal that is dissimilar to the first metal. The method includes making a transition attachment by friction welding together end-to-end a first end of a rod of the first metal with a first end of a rod of the second metal. An arc weld welds together a second end of the rod of the first metal with the tubular member of the first metal. And another arc weld welds together a second end of the rod of the second metal to the tubular member of the second metal.

Transition joint and method for attaching dissimilar metal tubes

When a friction stir weld tool penetrates the interface of two workpieces of dissimilar metal alloy materials, the resultant weld of the different alloy materials may produce a weak weld joint. Such weak joints are often experienced, for example, when attempting to form spot welds or other friction stir welds between a magnesium alloy sheet or strip and an aluminum alloy sheet or strip. It is discovered that suitable coating compositions including an adhesive placed at the interface of assembled workpieces can alter the composition of the friction stir weld material and strengthen the resulting bond. In the example of friction stir welds between magnesium alloy and aluminum alloy workpieces, it is found that combinations of an adhesive with copper, tin, zinc, and/or other powders can strengthen the magnesium-containing and aluminum-containing friction stir weld material.

Friction stir welding of dissimilar metals

A shape memory polymer workpiece is attached to a second workpiece. A face of the SMP workpiece is placed against an attachment surface of the second workpiece. The second workpiece has an attachment hole(s). The SMP workpiece is activated (e.g., heated) to a softening temperature and a portion extruded into the attachment hole of the facing surface of the second workpiece. The SMP piece is held while still heated against the second workpiece, the material flowing as result of the shape memory effect to form an attachment. As the SMP material cools while still under load its modulus increases fixing the attachment geometry. Reheating the attached parts without pushing them together reverses the process.

Joining polymer workpieces to other components

A procedure for incorporating particles to a predetermined depth in a body to develop a composite surface layer using friction stir processing is described. The process comprises; preparing the surface of the body; applying particulate matter to the prepared surface; selecting a friction stir tool with a pin length substantially equal to the desired composite layer thickness; using a friction stir process to frictionally heat, stir and intermix the particulate matter with the matrix of the article; and traversing the friction stir tool across the body.

Modified surfaces using friction stir processing

A device for use with a welding apparatus, such as a friction stir spot welding (FSSW) apparatus, that maintains work pieces in a generally flat or flush orientation during a welding operation. The device can be mounted to the operable end of an FSSW apparatus so that it exerts a stabilizing force against an upper work piece. The stabilizing force exerted by the device prevents the upper work piece from deflecting when the rotating tool of the FSSW apparatus passes through the upper work piece and penetrates into the lower work piece. In an exemplary embodiment, the device includes a housing component that slidably receives a movable component under the force of a biasing component.

Device for use with a friction stir spot welding (FSSW) apparatus

In a Friction Stir Welding process a load, applied through a rotating tool, frictionally heats, plasticizes and commingles selected regions of the workpieces while translating along the length of the joint. The load is supported by an anvil. The applied load inhibits relative motion of the workpiece and conventional anvils due to friction which requires application of higher translation forces and could lead to undesired surface blemishes. Thus conventional practice is to employ bulky, stationary anvils. Compact, moveable anvils comprising freely-rotating or freely moving elements in contact with the workpieces and capable of reducing workpiece-anvil friction are described. Particular benefits of this anvil design are illustrated for the process of assembling inner and outer sheet metal components into an automobile assembly, a portion of which is visible to a vehicle customer.

Anvil with rolling elements for friction stir welding

An apparatus and method is provided for hemming together a pair of panels and immediately sealing the hemmed joint against the intrusion of moisture. A tool mount is attached to a multi-axis manipulator such as a robot for moving the tool mount along the edge portions of the panels. A hemming roller is mounted on the tool mount and adapted to be moved along the edge portions of the panels by the multi axis manipulator to fold the flanged edge portion of the outer panel onto the edge portion of inner panel as the tool mount traverses the edge portions of the panels. A sealing mechanism is mounted on the tool mount adjacent to the hemming roller to seal the hemmed joint immediately after the flanged edge portion is folded onto the inner panel. The sealing mechanism may be a dispenser of adhesive sealer or a friction stir welder.

Method and apparatus for hemming and sealing a joint

The present invention provides an apparatus and improved method of friction stir spot welding that assures a predetermined bottom thickness and a reduction in variation in a series of resultant spot welds. The advantage of the present invention lies in that the plunge distance is controlled from the top plane of the anvil against which the bottom thickness is specified, and systematically adjusted to account for changing system parameters, such as, but not limited to, deflection and thermal expansion of the weld gun. The present invention also provides for improved and controlled weld quality through implementation of a dwell operation or dwell operations, whereby weld heat input is manipulated by causing the weld tool to dwell in a dwell region or at a desired depth or depths within the workpiece(s) for a predetermined time interval to achieve desired mechanical properties of the resultant weld joint.

Apparatus and method of solid-state welding

Friction stir welding using an adhesive, copper, tin and zinc interlayer

One side of a metal sheet is joined to a polymer layer by applying heat to a joining area on the opposite side of the metal. The heat flows through the thin metal to activate a thermoplastic material or heat setting polymer into a bond with the metal. The method can be used to bond the metal sheet to a plastic body or another metal member. It is preferred to use a friction or friction stir tool to heat the metal surface.

Friction heating for joining dissimilar materials

The present invention is directed to improved weldable metal composites and methods. A metal composite structure () features two metal members () () sandwiching a viscoelastic layer () where the viscoelastic layer entrains electrically conductive particles () and a carbon extracting attractant layers () () to inhibit and/or prevent carbon migration and carbide formation during welding.

Weldable metal composites and methods

In an assembly of facing metal sheets separated by a polymer layer, welded metallurgical bonds are formed between the metal sheets by use of a friction stir weld tool. A rotating tool penetrates the first sheet, locally displaces the encountered portion of polymer film and penetrates into the second sheet. The affected metal of the two sheets is momentarily plasticized and stirred, and the plasticized metal of the two sheets combines to form a weld between the metal sheets. The interposed polymer film may be intended to serve as an adhesive or a vibration damping medium or the like. The facing metal sheets can be layers of facing laminated metal sheet structures that each comprise two metal sheets bonded by an adhesive interlayer.

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Troy, MI, United States of America

Yen-Lung Chen