A welding electrode for an electric resistance welding process. The welding electrode includes a body extending along a center axis and terminating axially at a weld face for contacting a work face. The weld face defines a center along the axis and defines an outer edge spaced radially from the center. A plurality of senates are defined along the weld face. Each of the serrates projects axially away from the weld face and extends radially from the center axis to the outer edge of the weld face. A higher density of the plurality of serrates is formed proximate to the center axis than proximate to the outer circumference of the weld face. Methods for using the welding electrode and forming the senates on the welding electrode are also provided.

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.

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.

An apparatus for making three-dimensional physical objects of a predetermined shape includes a printing header having a least one arc welding torch. The arc welding torch includes an axially extending first nozzle and an axially extending non-consumable electrode, which is disposed substantially coaxially within the first nozzle and having a tip disposed at a distal end thereof and/or outside the first nozzle; means for supplying electricity to the electrode; means for supplying a protecting gas to the first nozzle for shielding the electrode from oxidising conditions; an axially extending through-hole formed through the electrode; an elongated non-electrified guide portion disposed within the through-hole terminating inwardly of the tip; and a consumable material wire that is fed through the guide portion relatively to the electrode so that the material wire is not electrified by the guide portion or by the electrode.

The present invention provides a spot resistance welding electrode cap for welding two or more work-pieces together, including a substantially cylindrical body having an interior surface, an exterior surface, and a tapered interior cavity for frictionally fitting over an electrode shank. The exterior surface of the body includes a plurality of longitudinally extending depressions or flutes formed therein which provide an increased external surface area to the electrode cap, thus increasing the ability to transfer additional amounts of heat. The electrode cap further includes a plurality of fins disposed on the interior surface of the body within the interior cavity. The free ends of the fins are chamfered in order to ease the transition of coolant flowing throughout the shank proximate the electrode cap.

A solder alloy substantially consists of tin, silver, indium, bismuth, and antimony. With respect to the total amount of the solder alloy, the content ratio of the silver is 2.8 mass % or more and 4 mass % or less; the content ratio of the indium is 6.2 mass % or more and 9.0 mass % or less; the content ratio of the bismuth is 0.7 mass % or more and 5.0 mass % or less; the content ratio of the antimony is 0.3 mass % or more and 5.0 mass % or less; and the content ratio of the tin is the remaining ratio and the value of A is 4.36 or less wherein A=0.87[In content ratio (mass %)]0.41[Ag content ratio (mass %)]0.82[Sb content ratio (mass %)].

Solder particles containing an oxidized film on the surface thereof, wherein the average film thickness of the oxidized film is 3 nm or greater, and the average surface roughness Ra of the solder particles is 10 nm or greater are provided.

A solder alloy is a tin-silver-copper solder alloy substantially consisting of tin, silver, copper, bismuth, nickel, cobalt, and indium. With respect to the total amount of the solder alloy, the content ratio of the silver is 2 mass % or more and 5 mass % or less; the content ratio of the copper is 0.1 mass % or more and 1 mass % or less; the content ratio of the bismuth is 0.5 mass % or more and 4.8 mass % or less; the content ratio of the nickel is 0.01 mass % or more and 0.15 mass % or less; the content ratio of the cobalt is 0.001 mass % or more and 0.008 mass % or less; the content ratio of the indium is above 6.2 mass % and 10 mass % or less; and the content ratio of the tin is the remaining ratio.

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.

The present disclosure relates generally to welding alloys and, more specifically, to welding consumables (e.g., welding wires and rods) for welding, such as Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), Shielded Metal Arc Welding (SMAW), and Flux Core Arc Welding (FCAW). In an embodiment, a welding alloy includes less than approximately 1 wt % manganese as well as one or more strengthening agents selected from the group: nickel, cobalt, copper, carbon, molybdenum, chromium, vanadium, silicon, and boron. Additionally, the welding alloy has a carbon equivalence (CE) value that is less than approximately 0.23, according to the Ito and Bessyo carbon equivalence equation. The welding alloy also includes one or more grain control agents selected from the group: niobium, tantalum, titanium, zirconium, and boron, wherein the welding alloy includes less than approximately 0.6 wt % grain control agents.