Abstract: 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.

Abstract: One embodiment includes an electrode dressing apparatus having a rotatable dressing blade including a first cutting face, an electrode comprising an electrode body and a weld face, and an electrode guide positioned absolutely relative to the rotatable dressing blade to position the weld face of the electrode at a designated location over the first cutting face.

Abstract: The workpiece-contacting surface of the spot welding electrode may be suitably modified to incorporate a desired shape or form, generally comprising a depressed region outlining a recognizable shape, to form aesthetically-pleasing or functional features in the surface of a workpiece during resistance spot welding. Methods for creating the desired form in the spot welding electrode including abrasion, upsetting, and electrical discharge machining are disclosed. Preferably the electrode face is shaped and subsequently redressed during welding operations at the welding station.

Abstract: A copper tube with copper end pieces for a water-cooled secondary winding of a welding transformer is an example of a brazed assembly having a potentially corrodible side, the water-cooled side, and a low-exposure side, the air side or dry side, of the joined pieces. By shaping contacting surfaces of the parts at the brazed joint it is useful to form a barrier, for example, between a special braze material required for the corrosive side and a conventional, easy to apply, braze material for use on the air side of the joint.

Abstract: The present invention is directed to improved weldable metal composites and methods. A metal composite structure (10) features two metal members (12) (14) sandwiching a viscoelastic layer (26) where the viscoelastic layer entrains electrically conductive particles (28) and a carbon extracting attractant layers (32) (34) to inhibit and/or prevent carbon migration and carbide formation during welding.

Abstract: 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.

Abstract: A method is disclosed for using welding electrodes with a spherically-domed welding face having concentric contoured features formed into the face for better contact with workpiece surfaces. The concentric contoured features may be initially formed by rotating a cutting tool with a contoured cutting edge, the cutting edge being in engagement with the electrode face. A similar practice may be followed to re-create the weld face surface geometry if it becomes eroded or malformed during welding use. A suitable tool may have a blade-like geometry, with a mounting portion for supporting and positioning the tool in a rotating holder and a cutting edge. The cutting edge may have a contour complementary to that of the weld face and extend at least from the center of the weld face to at least the radial extent of the concentric contoured features.

Abstract: Outer steel sheet-viscoelastic core laminates are often subject to corrosion in moisture-containing environments. Zinc-based alloys of aluminum, or of aluminum and magnesium, may be beneficially applied to the inner faces of the steel sheets or to both the inner and outer sheet faces. Substantially pure zinc coatings may be applied over the zinc-based alloys or over an otherwise bare outer steel sheet surface. Combinations of such zinc-based alloy coatings and substantially pure zinc coatings improve the corrosion resistance of the steel sheet-polymer core laminates while maximizing weldability and paintability.

Abstract: Spot welding electrodes with generally dome shaped welding faces are provided with surface features for welding both aluminum alloy sheet assemblies and steel sheet assemblies. A raised circular plateau is formed on the central axis of the dome and, in one embodiment, a suitable number of round bumps are formed in concentric spacing from adjacent the circumference of the plateau toward the circular edge of the welding face. For welding steel workpieces the plateau mainly serves as the engaging feature of the electrode. Both the plateau and concentric bumps are used in penetrating light metal surfaces for suitable current passage. In another embodiment, the domed surface is shaped with concentric terraces for engagement with the workpieces.

Abstract: Weld faces of electrodes for resistance spot welding are formed with a suitable area of protrusions and/or intrusions. The size, shape, and elevation or depths of the protrusions or intrusions are determined for the formation of suitable spot welds in and between metal workpieces such as aluminum or steel panels for vehicle bodies. The protrusions or intrusions are also conceived and used to form an image on at least a visible surface of the welded article to produce an attractive appearance on the surface of the welded sheet.

Abstract: Steel sheet-viscoelastic core laminates are often subject to corrosion in moisture-containing environments. Zinc-based alloys of iron may be beneficially applied to the inner faces of the steel sheets or to both the inner and outer sheet faces. Substantially pure zinc coatings may be applied over the zinc-iron alloys or over an otherwise base outer steel sheet surface. Combinations of such zinc-iron alloy coatings and substantially pure zinc coatings improve the corrosion resistance of the steel sheet-polymer core laminates while supporting weldability and paintability.

Abstract: Two steel sheets joined face-to-face with a core layer form a laminated workpiece that may be shaped, for example, into automotive components. Depending on the nature of the core layer the laminated workpieces may be used for sound and vibration damping or as light weight structural panels. Before joining of the steel sheets, their facing surfaces may each be provided with a polymeric (organic or inorganic) corrosion resistant film that resists physical degradation such as tearing or scratching as the laminate is formed into a desired component shape. The pre-applied protective layer may also provide a bonding layer for the viscoelastic core or a structural core material. Conductive particles may be incorporated into the viscoelastic layer to assist in electrical resistance welding involving the laminated steel workpiece.

Abstract: Weld faces of electrodes for resistance spot welding are formed with a suitable area of protrusions and/or intrusions. The size, shape, and elevation or depths of the protrusions or intrusions are determined for the formation of suitable spot welds in and between metal workpieces such as aluminum or steel panels for vehicle bodies. The protrusions or intrusions are also conceived and used to form an image on at least a visible surface of the welded article to produce an attractive appearance on the surface of the welded sheet.

Abstract: A copper tube with copper end pieces for a water-cooled secondary winding of a welding transformer is an example of a brazed assembly having a potentially corrodible side, the water-cooled side, and a low-exposure side, the air side or dry side, of the joined pieces. By shaping contacting surfaces of the parts at the brazed joint it is useful to form a barrier, for example, between a special braze material required for the corrosive side and a conventional, easy to apply, braze material for use on the air side of the joint.

Abstract: Electrically conductive workpieces with facing surfaces are bonded with an adhesive that is filled with conductive metal particles that are reactive with the surfaces of the workpieces. In the bonding process the surfaces are coated with the adhesive, pressed together and an electric current passed between them to momentarily melt the conductive particles. The molten droplets agglomerate and wet the facing surfaces. When the molten clusters re-solidify, electrically conductive paths are formed between the workpieces. For example, the practice is useful for bonding ferrous-based or aluminum-based alloy sheets, strips or plates in making products such as bipolar plates for fuel cells.

Abstract: A current collector plate, also called a bipolar plate, for a fuel cell includes two facing metal sheets with fluid channels for the fuel (often hydrogen) on the non-facing side of one sheet and fluid channels for air on the non-facing side of the other sheet. Such a plate is made by applying a patterned coating of particles of a soft and reactive metal to at least one of the sheets and rolling them together so that the soft metal particles deform and interact with the facing sheets to selectively join them at the patterned areas. Pressurized fluid is introduced between the sheets to expand non-bonded portions and define the fluid channels.

Abstract: 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.

Abstract: Welding electrodes with a welding face for contact with a metal surface for electrical resistance welding are provided with concentric contoured rings formed into the face. The rings may, for example, be ridges upstanding in the face or grooves depressed into the face. The contoured rings may be radially spaced with relatively flat (depending on the curvature of the face) intervening rings. When the electrode is pressed into contact with the surface of the workpiece for delivery of a welding current, the features of the concentric rings penetrate surface oxides or other conductivity barriers. When ongoing welding operations have eroded the contoured rings they may be rapidly reformed in the weld face in a surface re-dressing operation.

Abstract: Laminated steel panels which are subjected to forming and assembly operations such as welding that subject the composite construction to high temperatures in localized regions. The metal laminate structure has metal skins sandwiching one or more layers of polymeric material. The polymeric material incorporates cavity structures which are designed to accommodate the gaseous components liberated during welding and other high temperature processes.

Abstract: A method for making a current collector plate includes providing a first sheet of material having a first bonding face and a first outer face. A second sheet of material is provided having a second bonding face and a second outer face. A work area is defined on at least one of the first bonding face and the second bonding face. The first and second sheets are bonded together at a bonding area which is different from the work area. The bonded first and second sheet is placed into a die having a pattern defining at least one flow channel. Fluid is injected between the first and second sheets thereby causing at least one of the first and second sheets to project outward at the work area causing at least one flow channel to be formed in the work area as defined by the die pattern.