The present disclosure provides a method of manufacturing a composite material. The method can include compacting a copper alloy powder into a plurality of substantially uniform compressed sub-assemblies such that the copper alloy powder has a density that is greater than 50%. The plurality of compressed sub-assemblies can be layered relative one another within an aperture of a shell, the plurality of compressed sub-assemblies to form a consecutive assembly of compacted copper alloy. The shell may include one of the following: a precipitation hardened copper alloy, copper alloy, and carbon steel. The consecutive assembly can be sealed within the shell to form a billet. The billet can be hot-extruded to form a rod, and the extruded rod can be further drawn to form a composite wire of a desired diameter. The composite wire may be used to create a composite welding electrode.

A welding electrode and a method of using the welding electrode for resistance spot welding are disclosed. The welding electrode includes a body and a weld face. The weld face includes a central dome portion and a shoulder portion that surrounds the central dome portion and extends from an outer circumference of the weld face upwardly and radially inwardly to the central dome portion. The central dome portion has a series of radially-spaced ringed ridges that project outwardly from a base dome face surface. The series of radially-spaced ringed ridges on the central dome portion includes an innermost ringed ridge and an outermost ringed ridge. The outermost ringed ridge on the central dome portion has a radial inner side surface and a radial outer side surface. The radial outer side surface extends below the base dome face surface down to the shoulder portion of the weld face.

A welding torch assembly includes a mounting plate. A welding torch is mounted to the mounting plate. The welding torch includes an adjustment track fixed to the mounting plate, an adjustment body slidable relative to the adjustment track, a torch body, an electrode holder having a longitudinal axis. An electrode includes an elongated body defining a longitudinal axis. A seating end portion includes a first truncated cone. A working end portion includes a second truncated cone. The elongated body is located between the seating portion and the working portion. A retaining nut secures the electrode in the electrode holder. The electrode retaining nut contacts the angled surface of the seating end portion. A shield gas cup is secured to the torch body that forms a welding arc to melt filler wire.

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.

The present disclosure provides a welding electrode and methods of manufacturing the same. The welding electrode can include a composite body having a tip portion and an end portion. The composite body can include a shell defining a cavity through the end portion, the shell comprising a first metal that includes one or more of the following: a precipitation hardened copper alloy, copper alloy, and carbon steel. The composite body can also include a core within the shell, the core extending through the shell from the tip portion to the cavity, the core comprising a second metal that includes dispersion strengthened copper. The core and the shell have a metallurgical bond formed from co-extrusion.

An oval nugget can reliably be obtained with this indirect spot welding method. In this indirect spot welding method, an electrode end portion of a welding electrode includes a tip of the welding electrode, and as viewed from the tip, the electrode end portion has a two-step dome shape formed by a first curved surface with a curvature radius r.sub.1 (mm) located within a range of a circle of radius R (mm) centering on the tip and a second curved surface with a curvature radius r.sub.2 (mm). 2tR6t (1), 30r.sub.1 (2), and 6r.sub.212 (3), where t is the sheet thickness (mm) of a thinner metal sheet.

A bonding sheet according to the present invention contains a matrix resin; solder particles; and a fluxing agent. In the bonding sheet, the solder particles are dispersed in the matrix resin, and the fluxing agent is unevenly distributed around the solder particles in the matrix resin. The method for producing the bonding sheet of the present invention includes a first step of dissolving a fluxing agent in a first solvent to prepare a fluxing agent solution; a second step of mixing a second solvent, a matrix resin component, solder particles, and the fluxing agent solution to prepare a mixed composition; and a third step of applying the mixed composition onto a substrate to form a coated film, and then drying the coated film to form a bonding sheet.

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.

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.

This bonding sheet (10, 20) with a preform layer (13) is a bonding sheet (10, 20) for bonding a substrate (16) and an electronic component (17), the bonding sheet (10, 20) includes a copper sheet (11) and a porous preform layer (13) including copper particles (12) provided on one surface or both surfaces of the copper sheet (11), in which surfaces of the copper particles (12) are coated with copper nanoparticles (12a) having an average particle diameter smaller than an average particle diameter of the copper particles (12), the average particle diameter of the copper nanoparticles (12a) calculated from a BET value is 9.59 nm or more and 850 nm or less, and an average porosity of the preform layer (13) is 11% or more and 78% or less.