A method of resistance spot welding a workpiece stack-up that includes an aluminum workpiece and an adjacent overlapping steel workpiece is disclosed. The method uses a first welding electrode positioned proximate the aluminum workpiece and a second welding electrode positioned proximate the steel workpiece to effectuate the spot welding process. In an effort to positively affect the strength of the ultimately-formed weld joint, external heat may be supplied to the first welding electrode by an external heating source disposed in heat transfer relation with the first welding electrode either before or after, or both before or after, an electrical current is passed between the first and second welding electrodes to create a molten aluminum weld pool within the aluminum workpiece.

A method of resistance spot welding workpiece stack-ups of different combinations of metal workpieces with a single weld gun using the same set of welding electrodes is disclosed. In this method, a set of opposed welding electrodes that include an original shape and oxide-disrupting structural features are used to resistance spot weld at least two of the following types of workpiece stack-ups in a particular sequence: (1) a workpiece stack-up of two or more aluminum workpieces; (2) a workpiece stack-up that includes an aluminum workpiece and an adjacent steel workpiece; and (3) a workpiece stack-up of two or more steel workpieces. The spot welding sequence calls for completing all of the aluminum-to-aluminum spot welds and/or all of the steel-to-steel spot welds last.

A welded assembly includes a first component including an aluminum material, a second component including a stainless steel, and a third component including a steel material. An ultrasonic weld is formed between the first and second components to join them and form a stack. A sealant and/or adhesive may be applied to the stack. A resistance spot weld is used to join the third component to the stack to form the welded assembly. The resistance spot weld encompasses a portion of the first, second, and third components, and a portion of the ultrasonic weld. The resistance spot weld is completely encompassed in the welded assembly, and thus is sealed from electrolyte in a surrounding environment.

A welded assembly includes a first component including an aluminum material, a second component including a stainless steel, and a third component including a steel material. An ultrasonic weld is formed between the first and second components to join them and form a stack. A sealant and/or adhesive may be applied to the stack. A resistance spot weld is used to join the third component to the stack to form the welded assembly. The resistance spot weld encompasses a portion of the first, second, and third components, and a portion of the ultrasonic weld. The resistance spot weld is completely encompassed in the welded assembly, and thus is sealed from electrolyte in a surrounding environment.

A combination component handling and connecting device connectable to a multi-axis robot for use in moving and connecting components and subassemblies includes a housing and an actuator fixedly connected to the housing. The actuator includes an actuating link movable from a first position to a second position. Connected to the actuating link is an end effector for concurrent movement with the actuating link. The component handling and connecting device includes a clamp having a first jaw and a second jaw. The second jaw is connected to the actuating link for selectively moving the second jaw toward the first jaw operative to engage a component.

A method of resistance spot welding a steel workpiece and an aluminum or aluminum alloy workpiece, and a welding electrode used therein. In one step of the method a workpiece stack-up is provided. The workpiece stack-up includes a steel workpiece and an aluminum or aluminum alloy workpiece. Another step of the method involves contacting the aluminum or aluminum alloy workpiece with a weld face of the welding electrode. The welding electrode has a body and an insert. The insert is composed of a material having an electrical resistivity that is greater than an electrical resistivity of the material of the body. The weld face has a first section defined by a surface of the insert and has a second section defined by a surface of the body. Both the first and second sections make surface-to-surface contact with the aluminum or aluminum alloy workpiece amid resistance spot welding.

A method of resistance spot welding a workpiece stack-up that includes an aluminum workpiece and an overlapping adjacent steel workpiece so as to minimize the thickness of an intermetallic layer comprising Fe—Al intermetallic compounds involves providing reaction-slowing elements at the faying interface of the aluminum and steel workpieces. The reaction-slowing elements may include at least one of carbon, copper, silicon, nickel, manganese, cobalt, or chromium. Various ways are available for making the one or more reaction-slowing elements available at the faying interface of the aluminum and steel workpieces including being dissolved in a high strength steel or being present in an interlayer that may take on a variety of forms including a rigid shim, a flexible foil, a deposited layer adhered to and metallurgically bonded with a faying surface of the steel workpiece, or an interadjacent organic material layer that includes particles containing the reaction-slowing elements.

A method of resistance spot welding a workpiece stack-up that that includes an aluminum workpiece and an adjacent overlapping steel workpiece involves assembling the workpiece stack-up so that an intermediate metallurgical additive is positioned between the faying surfaces of the aluminum and steel workpieces. The intermediate metallurgical additive includes at least one of carbon, silicon, nickel, manganese, chromium, cobalt, or copper, and has the capability to counteract the growth and formation of Fe—Al intermetallic compounds within a molten metal weld pool created within the aluminum workpiece during resistance spot welding of the workpiece stack-up. In certain aspects of the disclosed method, the intermediate metallurgical additive may be one or more metallurgical additive deposits that are deposited onto the faying surface of the aluminum workpiece or the faying surface of the steel workpiece by an oscillating wire arc welding process.

A series of many electrical resistance spot welds is to be formed in members of an assembled, but un-joined, body that presents workpiece stack-ups of various combinations of metal workpieces including all aluminum workpieces, all steel workpieces, and a combination of aluminum and steel workpieces. A pair of spot welding electrodes, each with a specified weld face that includes oxide-disrupting features, is used to form the required numbers of aluminum-to-aluminum spot welds, aluminum-to-steel spot welds, and steel-to-steel spot welds. A predetermined sequence of forming the various spot welds may be specified for extending the number of spot welds that can be made before the weld faces must be restored. And, during at least one of the aluminum-to-steel spot welds, a cover is inserted between the weld face of one of the welding electrodes and a side of a workpiece stack-up that includes the adjacent aluminum and steel workpieces.

A steel plate frame and a thin plate are made of different materials. A plurality of through holes are formed in a portion of the thin plate to be placed on the steel plate frame. A plurality of projections 6c are formed on a support plate, each of the projections being allowed to be inserted into a corresponding one of the through holes. An adhesive is applied to a portion of the steel plate frame on which the thin plate is placed. The thin plate is placed on the steel plate frame, and the steel plate frame and the thin plate are bonded together by the adhesive. The support plate is placed on the thin plate to insert the projections into the through holes. The projections and the steel plate frame are welded to form a plurality of welded spots.