An apparatus and method are provided for manufacturing an orthopedic prosthesis by resistance welding a porous metal layer of the orthopedic prosthesis onto an underlying metal substrate of the orthopedic prosthesis. The resistance welding process involves directing an electrical current through the porous layer and the substrate, which dissipates as heat to cause softening and/or melting of the materials, especially along the interface between the porous layer and the substrate. The softened and/or melted materials undergo metallurgical bonding at points of contact between the porous layer and the substrate to fixedly secure the porous layer onto the substrate.

The exposed metal tip of the strike end of an SMAW welding electrode is covered with a protective coating formed from a binder and metal particles. Because metal particles rather than graphite particles are used to provide electrical conductivity to this protective coating, flare-up of the arc when initially struck is eliminated substantially completely. In addition, the potential for weld porosity problems is also eliminated, because the metal particles of the inventive electrode do not produce CO.sub.2 as a reaction by-product which can ultimately lead to improper welding technique.

An arc welding/brazing process is disclosed that is useful to join together a first copper piece and a second copper piece without damaging more heat-sensitive materials that may be located nearby is disclosed. The arc welding/brazing process includes using a non-consumable electrode wire, which electrically communicates with a weld control in a straight polarity orientation, to strike an arc across a gap established between a leading tip end of the electrode wire and the first copper piece. The current that flows through the arc when the arc is established heats the first copper piece such that the first copper piece becomes joined to a second copper piece. The joint between the first copper piece and the second copper piece may be an autogenous weld joint or a braze joint.

A welding system includes a feeder that advances a self-shielded flux-cored welding electrode toward a weld puddle. A power supply provides a welding output to the electrode to generate an arc, and a controller controls the welding output. The controller controls the power supply to provide a background welding output to the electrode before a shorting event between the electrode and a workpiece is detected. The controller monitors the welding output to detect both the shorting event and the clearance thereof. Upon detecting clearance of the short, the controller automatically switches the welding output to a minimum magnitude fixed current welding output. After the predetermined duration, the controller automatically switches the welding output from the minimum magnitude fixed current welding output back to the background welding output until another shorting event is detected.

The invention described herein generally pertains to a system and method related to detecting a change in height during a welding operation and adjusting one or more welding parameters based on such detected change in height. In particular, a change in a height can be related to two or more revolutions on the workpiece in which the change is due to material being deposited onto the workpiece from the welding operation. Since the material deposited onto the workpiece changes the height of the electrode to the workpiece, one or more welding parameters can be adjusted for compensation. Specifically, an electrode speed can be adjusted to compensate for a change in the height, wherein the electrode speed is a rate that the electrode moves adjacent to the workpiece.

A welding torch with a welding electrode and a welding electrode holder is provided. One welding torch includes a securing mechanism and an insulated grip. The securing mechanism is configured to secure an exposed central portion of a welding rod bounded by flux covered first and second sides. The securing mechanism is also configured to make electrical contact with the central portion of the rod for arc welding with the first side. The insulated grip is configured to cover the second side of the welding rod.

A method and apparatus for welding include initiating a pulse welding process includes initiating a welding arc by providing CC type welding power, maintaining the arc by providing CV type power. Then, pulse type welding power is provided. The method and system can be used to start short circuit, or other welding processes by providing short circuit power, or welding power of a given mode, instead of providing pulse power. Also, in one alternative, a method and system of initiating a pulse, short circuit, or given welding process includes initiating a welding arc by providing CC type welding power at least until a pseudo-equilibrium for the arc is established. Then, providing welding power in a pulse, short circuit, or the given mode.