Abstract: A resistive welding electrode includes at least a weld face constructed of a refractory-based material that exhibits an electrical conductivity that is less than or equal to 65% of the electrical conductivity of commercially pure annealed copper as defined by the International Annealed Copper Standard (IACS). A method of using the resistive welding electrode to resistance spot weld a workpiece stack-up that includes an aluminum alloy workpiece and steel workpiece that overlap and contact each other at a faying interface is also disclosed.

Abstract: A resistance spot welding method may involve spot welding a workpiece stack-up that includes a steel workpiece and an aluminum alloy workpiece. A pair of opposed welding electrodes are pressed against opposite sides of the workpiece stack-up with one welding electrode contacting the aluminum alloy workpiece and the other welding electrode contacting the steel workpiece. The welding electrodes are constructed so that, when an electrical current is passed between the electrodes and through the workpiece stack-up, the electrical current has a greater current density in the steel workpiece than in the aluminum alloy workpiece to thereby concentrate heat within a smaller zone in the steel workpiece. Concentrating heat within a smaller zone in the steel workpiece is believed to modify the solidification behavior of the resultant molten aluminum alloy weld pool in a desirable way.

Abstract: A workpiece stack-up that includes at least a steel workpiece and an aluminum-based workpiece can be resistance spot welded by a spot welding method in which the welding current is controlled to perform one or more stages of weld joint development. When it is desired to terminate weld current flow and to solidify a liquid weld pool into a weld nugget (of mostly aluminum-based composition), additional cooling is applied to the outer surface of the aluminum-based workpiece around the contact area of the spot welding electrode engaging the surface of the aluminum-based workpiece surface. The additional cooling is applied and controlled so as to increase the rate of solidification of the liquid aluminum-based material and to control the direction of solidification of the weld nugget to better confine impurities, and the like, originally in the melt, at the surface of the steel workpiece.

Abstract: A workpiece stack-up that includes at least a steel workpiece and an adjacent and overlapping aluminum workpiece can be resistance spot welded by a multi-stage spot welding method. The multi-stage spot welding method involves initially forming a weld joint between the steel and aluminum workpieces. The weld joint extends into the aluminum workpiece from the faying interface of the two workpieces and includes an interfacial weld bond area adjacent to and joined with the faying surface of the steel workpiece. After the weld joint is initially formed, the multi-stage spot welding method calls for remelting and resolidifying at least a portion of the weld joint that includes some or all of the interfacial weld bond area. At least a portion of the resultant refined weld joint may then be subjected to the same remelting and resolidifying practice, if desired. Multiple additional practices of remelting and resolidifying may be carried out.

Abstract: A bobbin tool is disclosed that includes a top shoulder, a bottom shoulder, and an axial pin that extends between the top and bottom shoulders. The bottom shoulder has an annular shoulder end surface, a back surface opposite the annular shoulder end surface, and a side surface that joins the annular shoulder end surface and the back surface. One or more and radially-extending blades may be disposed on the side surface of the bottom shoulder and/or one or more axially-extending blades may be disposed on the back surface. The one or more blades provide the bobbin tool with an ability to friction stir weld a variable thickness workpiece assembly, axially plunged through the workpiece assembly along an axis of rotation of the bobbin tool, and/or be extracted through the workpiece assembly along an axis of rotation of the bobbin tool.

Abstract: A welding electrode includes a weld face that has a convex base weld face surface and a plurality of ringed ridges that are radially spaced apart on the base weld face surface and surround a central weld face axis. The plurality of ringed ridges including an innermost ringed ridge and an outermost ringed ridge. The innermost ringed ridge is located closest to the central weld face axis and rises above a central portion of the base weld face surface, and the outermost ringed ridge is located farthest from the central weld face axis and rises above an outer peripheral portion of the base weld face surface. At least one of the plurality of ringed ridges is a discontinuous ringed ridge.

Abstract: An aperture plate for a welding apparatus includes a body defining an aperture. The body of the aperture plate includes a first end and a second end that is opposite the first end. In addition, the body includes a first surface intersecting the first and second ends. Moreover, the body includes a second surface formed opposite the first surface. The second surface is nonparallel to the first surface.

Abstract: A panel assembly is formed by a plurality of bonds between two sheet materials in a face to face relationship to form a preform. The plurality of bonds define a closed perimeter region between the two sheet materials and an open perimeter region between the two sheet materials. The preform may be formed into a predefined shape. Pressurized fluid is applied through an inlet into the open perimeter region to expand the preform. The pressurized fluid expands the open perimeter region such that the two sheet materials expand in an opposing direction, thereby defining an expanded open perimeter region. The closed perimeter region between the two sheet materials remains vacant of the pressurized fluid such that the closed perimeter region is not expanded. The expanded open perimeter region is filled with a filler material for improving a performance characteristic of the panel assembly, e.g., strength, sound absorption, or stiffness.

Abstract: Friction stir blind rivet systems and methods are provided for joining workpieces. A FSBR joining system includes a mandrel with a head forming a tip. A stem extends from the head and has a narrowed section forming a notch. A tail section of the mandrel is configured to break off at the notch forming a broken end. A shank also has a head and a body, with a through-hole defined through the shank. The shank head includes a shoulder forming a surface contacting one workpiece. The head has an outermost point opposite the surface. A range is defined between the outermost point of the head and the surface. A wall projects from another workpiece and is formed around the body. The wall has a size formed by the mandrel and that is controlled to enable the body to deform.

Abstract: A method of resistance spot welding a workpiece stack-up comprising overlapping first and second steel workpieces is disclosed, wherein at least one of the steel workpieces comprises an advanced high-strength steel substrate. The workpiece stack-up is positioned between a pair of opposed first and second welding electrodes. A cover is disposed between at least one of the first steel workpiece and the first welding electrode or the second steel workpiece and the second welding electrode at an intended weld site. The workpiece stack-up is clamped between the first and second welding electrodes at the weld site such that at least one of the weld faces of the first and second welding electrodes presses against the cover. The first and second steel workpieces are welded together by passing an electrical current between the first and second welding electrodes at the weld site.

Abstract: A resistance spot welding method may involve spot welding a workpiece stack-up that includes a steel workpiece and an aluminum alloy workpiece that overlap one another to provide a faying interface. A pair of opposed welding electrodes are pressed against opposite sides of the workpiece stack-up with one welding electrode contacting the aluminum alloy workpiece and the other welding electrode contacting the steel workpiece. The welding electrodes are constructed so that, when an electrical current is passed between the electrodes and through the workpiece stack-up, the electrical current has a greater current density in the steel workpiece than in the aluminum alloy workpiece to thereby concentrate heat within a smaller zone in the steel workpiece. Concentrating heat within a smaller zone in the steel workpiece is believed to modify the solidification behavior of the resultant molten aluminum alloy weld pool in a desirable way.

Abstract: The present disclosure relates a bonding system formed by a process that provides a first substrate and a second substrate. A flux coating is applied to the first contact surface, and a solder-adhesive mixture comprising an adhesive and a plurality of solder elements in at least a portion of the adhesive is applied to the first contact surface. The second substrate is positioned adjacent the solder-adhesive mixture much that a second contact surface of the second surface is opposite the first contact surface, and heat is applied to the solder-adhesive mixture by way of at least one of the first and second contact surfaces. The solder-adhesive mixture is heated to a temperature that is intended to at least partially melt or at least partially vaporize the flux coating upon contact to promote a bonding condition between the solder-adhesive mixture and the first substrate.

Abstract: An additive manufacturing system has a powder delivery system for presenting a powder material to a build chamber. A laser selectively sinters the powder material in the build chamber. The build chamber is presented in an annular configuration with the powder delivery system and laser arranged within a central portion thereof.

Abstract: The present disclosure relates to a bonding system comprising a first substrate, a second substrate, an adhesive, in contact with a first contact surface and a second contact surface, and a plurality of solder elements positioned in the adhesive. Each solder element has a plurality of indentations located on the perimeter of the solder element and the plurality of indentations receiving a portion of the adhesive. Also, the present disclosure relates to a bonding method to produce a solder-reinforced adhesive bond joining a first substrate and a second substrate.

Abstract: Additive manufacturing systems, area scanning laser systems, and methods for performing an additive manufacturing process are provided. An exemplary additive manufacturing system includes a laser generation device for producing a laser beam. Further, the additive manufacturing system includes an optic element for forming a first portion of the laser beam with a first polarization and a second portion of the laser beam with a second polarization different from the first polarization to encode an image in the laser beam. Also, the additive manufacturing system includes a selective beam separator configured to direct the first portion of the laser beam onto a material to be sintered or melted. The additive manufacturing system includes a recycling system for receiving the second portion of the laser beam.

Abstract: A method of manufacturing a battery module includes applying an adhesive solder to a tab of a battery cell. The adhesive solder includes a mixture of an adhesive composition and a plurality of solder elements. The adhesive solder is compressed between the tab of the first battery cell and an electrically conductive element, such as a tab of a second battery cell or a bus plate. The adhesive solder is then heated, whereby the adhesive composition is cured to fixedly attach the tab of the first battery cell and the electrically conductive element together, and the plurality of solder elements bond with the tab of the first battery cell and the electrically conductive element to connect them in electrical communication.

Abstract: A method of spot welding a workpiece stack-up that includes a steel workpiece and an aluminum alloy workpiece involves passing an electrical current through the workpieces and between welding electrodes that are constructed to affect the current density of the electrical current. The welding electrodes, more specifically, are constructed to render the density of the electrical current greater in the steel workpiece than in the aluminum alloy workpiece. This difference in current densities can be accomplished by passing, at least initially, the electrical current between a weld face of the welding electrode in contact with the steel workpiece and a perimeter region of a weld face of the welding electrode in contact with the aluminum alloy workpiece.

Abstract: A workpiece stack-up that includes at least a steel workpiece and an aluminum-based workpiece can be resistance spot welded by employing a multi-stage spot welding method in which the passage of electrical current is controlled to perform multiple stages of weld joint development.

Abstract: A method of resistance spot welding a steel workpiece and an aluminum or aluminum alloy workpiece together includes several steps. One step involves inserting a cover between the aluminum or aluminum alloy workpiece and an adjacent welding electrode. In another step, the adjacent welding electrode is pressed against cover, and another opposed welding electrode is pressed against the steel workpiece at a weld site. In yet another step, electrical current is passed between the welding electrodes, passed through the cover, and passed through the workpieces in order to initiate and grow a molten weld pool within the aluminum or aluminum alloy workpiece.

Abstract: A method of resistance spot welding a steel workpiece and an aluminum or aluminum alloy (“aluminum”) workpiece together includes several steps. One step involves providing a workpiece stack-up with a steel workpiece and an aluminum workpiece. Another step involves attaching a cover over a weld face of a welding electrode. The cover is made of a metal material with an electrical resistivity that is greater than an electrical resistivity of a material of the welding electrode. Yet another step involves performing multiple individual resistance spot welds to the workpiece stack-up. The cover abuts the aluminum workpiece while the individual resistance spot welds are performed. And another step involves removing the cover from the welding electrode after the individual spot welds are performed.