A lead-free solder alloy includes Ag in an amount of 0.3 to 4.0% by mass, Cu in an amount of 0.1 to 2.0% by mass, Fe in an amount of 0.005 to 0.05% by mass, Ni in an amount of 0.01 to 0.5% by mass, Ga in an amount of 0.001 to 0.1% by mass, and Sn as the balance.

A hybrid electrode for resistance spot welding and a method of resistance welding are provided. The hybrid electrode comprises a pin and a collar member. The pin comprises an electrically conductive material and a pin contact surface. The collar member comprises a material that is at least one of less electrically conductive than the electrically conductive material of the pin and less thermally conductive than the electrically conductive material of the pin. The collar member comprises a collar member contact surface, and defines an inner cavity and a longitudinal axis. The pin is at least partially disposed in the inner cavity and the pin contact surface extends away from the collar member and is offset a distance along the longitudinal axis from the collar member contact surface.

A welding process used in a method of manufacturing a steel sheet assembly includes spot welding steel sheets performed for a heat time of 0.08 seconds or more using a convex electrode with a tip radius of curvature of 20 mm or more or a flat electrode such that the weld force F (kN) for initial 0.03 seconds of the heat time satisfies formula: F<0.00125×(1+0.75×t.sub.all)+3 where TS (MPa) denotes an average strength of the steel sheets and represents a weighted mean value of a thickness of each of the steel sheets, and t.sub.all (mm) denotes a total thickness of the steel sheets (the sum of the thicknesses of the steel sheets).

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.

A resistance spot welding electrode cap contains a groove at the center of the welding contact interface. During welding, because of the groove, the area of contact between the electrode cap and a metal workpiece to be soldered is reduced. In the initial stage, the overall heat generation is concentrated on the outer ring of the weld point and heat dissipation becomes slower, helping a weld nugget to form from the outside to the inside. Due to the presence of the groove, the metal workpiece expands toward the groove at the center of the electrode, thereby increasing the size of the weld nugget and reducing splash and deformation. In comparison with conventional electrode caps, the welding current required to form weld points of the same size is lower, saving on electricity costs, and weld points obtained using the same current have higher strength and stability with fewer welding defects.

A welding electrode apparatus has a base member and a locking ring for clamping a consumable electrode tip to the electrode base. The base and the tip are predominantly made of copper, or a copper alloy. The base member has a first end that is threaded to fit a welding head that supplies electric current; and an electrically conductive second end to which the electrode tip is mounted. The second portion has an externally facing, axially extending cylindrical wall. A circumferential groove is formed in the wall. The locking ring has a quick-disconnect feature in the form of an array of spring-loaded stainless steel ball bearing detents that deflect to ride upon the cylindrical wall, and spring inwardly to seat in the circumferential groove.

The present disclosure provides a system for printing a three-dimensional object. The system may comprise a support for holding a portion of the object and a wire(s) source configured to hold a wire(s) of substantially the same or different diameters. The system may also comprise a print head. The print head may comprise a guide for directing the wire to the support. The system may also comprise a driver roller comprising a groove configured to contact a portion of the wire and direct the wire to the guide, and a power source in electrical communication with the wire and the support. The system may also comprise a controller configured to direct the power source to supply electrical current to the wire and the support. The electrical current may be sufficient to melt the wire when the wire is in contact with the support or the portion of the object.

A welding apparatus includes a welding electrode, where the welding electrode has a concavely formed end-face region and where the welding electrode has a magnet such that a spherical dome-shaped portion of a magnetically attractable ball which is located in an effective range of the magnet is drawable against the concavely formed end-face region.

A welding electrode may comprise a welding electrode body and a welding electrode cap that is connected or connectable to the welding electrode body for making contact between the welding electrode and a component for producing a welded connection. The problem of achieving an efficient heating of the sandwich sheet to be welded in a compact layout with the fewest possible modifications of the welding electrodes used heretofore is solved in that an electrically conductive resistance element integrated, or which can be integrated, in the welding electrode and which is connected or connectable in an electrically-conductive manner to the welding electrode body and the welding electrode cap is provided for the heating of the component. Furthermore, a method and a device with the welding electrode and a use are disclosed.

Embodiments of the present invention include a plasma cutting torch and plasma cutting torch components, such as electrodes, cathodes, retainer caps, etc. having a unique physical features, including threads relationships. Embodiments include torch components having modified square thread with a specialized thread configuration including a particular relationship between thread crest and root, and included angles of thread sidewalls.