In various embodiments, three-dimensional layered metallic parts are substantially free of gaps between successive layers, are substantially free of cracks, and have densities no less than 97% of the theoretical density of the metallic material.

In various embodiments, wire composed at least partially of arc-melted refractory metal material is utilized to fabricate three-dimensional parts by additive manufacturing.

In various embodiments, wire composed at least partially of arc-melted refractory metal material is utilized to fabricate three-dimensional parts by additive manufacturing.

A contact tip assembly with a preheating tip comprises a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch; an electrode preheating circuit configured to provide preheating current through a first portion of the electrode via a second contact tip of the welding torch; and a preheat controller to: monitor a voltage drop across a second portion of the electrode; adjust at least one of the welding-type current or the preheating current based on the voltage drop, the second portion of the electrode comprising at least part of the first portion of the electrode; and control the preheating current based on a hydrogen reduction goal and based on stored parameters associated with a type of the electrode, a chemistry of the electrode, or a wire size.

A contact tip assembly with a preheating tip comprises a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch; an electrode preheating circuit configured to provide preheating current through a first portion of the electrode via a second contact tip of the welding torch; and a preheat controller to: monitor a voltage drop across a second portion of the electrode; adjust at least one of the welding-type current or the preheating current based on the voltage drop, the second portion of the electrode comprising at least part of the first portion of the electrode; and control the preheating current based on a hydrogen reduction goal and based on stored parameters associated with a type of the electrode, a chemistry of the electrode, or a wire size.

A welding electrode for resistance spot welding includes a weld face comprising rings of ridges that project outwardly from a base surface of the weld face. The rings of ridges are positioned on the weld face to contact and impress into a sheet metal workpiece surface during resistance spot welding. If the welding electrode is used during resistance spot welding of light metal alloy workpieces, such as those of aluminum alloy or magnesium alloy, the rings of ridges on the weld face can contribute to improved welding performance.

A contact tip assembly with a preheating tip comprises a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch. The assembly also includes an electrode preheating circuit configured to provide preheating current through a portion of the welding-type electrode via a second contact tip of the welding torch, and a voltage sense circuit to monitor a voltage drop across the two contact tips, and the electrode preheating circuit adjusts at least one of the first current or the preheating current based on the voltage drop.

A contact tip assembly with a preheating tip comprises a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch. The assembly also includes an electrode preheating circuit configured to provide preheating current through a portion of the welding-type electrode via a second contact tip of the welding torch, and a voltage sense circuit to monitor a voltage drop across the two contact tips, and the electrode preheating circuit adjusts at least one of the first current or the preheating current based on the voltage drop.

A composite wire for use with a wire arc spray system and related methods. The composite wire can include: a low melting point material at a core region thereof and a cladding including a metal surrounding the core region, the low metal point material having a melting point less than that of the metal, wherein the low melting point material includes a polymer in the form of a powder having particles having a size of from approximately 1 nanometer to approximately 100 nanometers.

A composite wire for use with a wire arc spray system and related methods. The composite wire can include: a low melting point material at a core region thereof and a cladding including a metal surrounding the core region, the low metal point material having a melting point less than that of the metal, wherein the low melting point material includes a polymer in the form of a powder having particles having a size of from approximately 1 nanometer to approximately 100 nanometers.