An arc welding apparatus and corresponding method includes a torch, a non-consumable electrode and a consumable electrode both disposed within the torch, a wire feeder configured to feed the consumable electrode in a vicinity of the non-consumable electrode, a first power source and a second power source that provide independent current, respectively, to the non-consumable electrode and the consumable electrode, and a weld process controller to control outputs of the first power source and the second power source such that a concentrated arc is formed, as a heat source, between the non-consumable electrode and a workpiece, and an inter-electrode arc is formed between the consumable electrode and the non-consumable electrode to melt the consumable electrode. The approach is characterized by low heat input, low distortion, low spatter, and the relative high speed or high deposition of laser and laser-MIG hybrid and other forms of multi-wire/multi-electrode welding, cladding, and additive manufacturing.

An aluminum alloy brazing sheet has a 3XXX, 1XXX or 6XXX core, an interliner and a 4XXX brazing layer without added Mg. The interliner has Bi and Mg, the magnesium migrating to the surface of the brazing sheet during brazing and reducing the aluminum oxide to facilitate brazing without flux in a controlled inert atmosphere with reduced oxygen.

A torch for performing TIG welding is disclosed. The torch includes an electrode for a TIG/GTAW welding operation with an inert gas and an active gas. In accordance with at least one embodiment of the present invention, the torch includes a torch body having a first fluid channel and a second fluid channel, an electrode assembly disposed in the torch body, a nozzle concentric with the electrode and a shield cap concentric with the nozzle. An angle between a longitudinal axis of the electrode assembly and an outer surface of at least one of the electrode holder and the electrode is about nine degrees.

A welded steel part with a very high mechanical strength is provided. The welded steel part is obtained by heating followed by hot forming, then cooling of at least one welded blank obtained by butt welding of at least one first and one second sheet. The at least one first and second sheets including, at least in part, a steel substrate and a pre-coating which includes an intermetallic alloy layer in contact with the steel substrate, topped by a metal alloy layer of aluminum or aluminum-based alloy. A method for the fabrication of a welded steel part and the fabrication of structural or safety parts for automotive vehicles are also provided.

A welded steel part with a very high mechanical strength is provided. The welded steel part is obtained by heating followed by hot forming, then cooling of at least one welded blank obtained by butt welding of at least one first and one second sheet. The at least one first and second sheets including, at least in part, a steel substrate and a pre-coating which includes an intermetallic alloy layer in contact with the steel substrate, topped by a metal alloy layer of aluminum or aluminum-based alloy. A method for the fabrication of a welded steel part and the fabrication of structural or safety parts for automotive vehicles are also provided.

The disclosed method relates to manufacturing a heat exchanger which causes no brazing defects, and a heat exchanger manufactured by the method. The method relates to manufacturing a heat exchanger having an aluminum alloy tube defining a cooling-medium flowing passage and a copper alloy tube defining a water flowing passage, wherein a heat exchange is carried out between a cooling medium flowing through the cooling-medium flowing passage and water flowing through the water flowing passage. The aluminum alloy tube and the copper alloy tube are brazed to each other at a temperature of less than 548° C.

An electrode (10) is presented including a sheath (14) formed of a ductile material, an outer coating (16) including a flux material, and a core (12) including at least one of flux material and alloying material. The ductile material may be an extrudable subset of elements of a desired superalloy material and the alloying material may include elements that complement the ductile material to form a desired superalloy material when the electrode is melted. The outer coating may be formed of a flexible bonding material or it may be segmented (18, 20) to facilitate bending the electrode onto a spool. Any hygroscopic material of the electrode may be included in the core to protect it from exposure to atmospheric moisture.

Properties and performance of weld material between metals in a weldment is controlled by modifying one or more of the nitrogen content and the carbon content to produce carbide (e.g. MC-type), nitride and/or complex carbide/nitride (e.g. MX-type) type precipitates. Fusion welding includes (i) adjusting shield gas composition to increase nitrogen/carbon gas and nitride/carbide species, (ii) adjusting composition of nitrogen/carbon in materials that participate in molten welding processes, (iii) direct addition of nitrides/carbides (e.g. powder form), controlled addition of nitride/carbide forming elements (e.g. Ti, Al), or addition of elements that increase/impede solubility of nitrogen/carbon or nitride/carbide promoting elements (e.g. Mn), and (iv) other processes, such as use of fluxes and additive materials. Weld materials have improved resistance to different cracking mechanisms (e.g., hot cracking mechanisms and solid state cracking mechanisms) and improved tensile related mechanical properties.

A welded steel part with a very high mechanical strength is provided. The welded steel part is obtained by heating followed by hot forming, then cooling of at least one welded blank obtained by butt welding of at least one first and one second sheet. The at least one first and second sheets including, at least in part, a steel substrate and a pre-coating which includes an intermetallic alloy layer in contact with the steel substrate, topped by a metal alloy layer of aluminum or aluminum-based alloy. A method for the fabrication of a welded steel part and the fabrication of structural or safety parts for automotive vehicles are also provided.

A composition for welding or brazing aluminum comprises silicon (Si) and magnesium (Mg) along with aluminum in an alloy suitable for use in welding and brazing. The Si content may vary between approximately 4.7 and 10.9 wt %, and the Mg content may vary between approximately 0.20 wt % and 0.50 wt %. The alloy is well suited for operations in which little or no dilution from the base metal affects the Si and/or Mg content of the filler metal. The Si content promotes fluidity and avoids stress concentrations and cracking The Mg content provides enhanced strength. Resulting joints may have a strength at least equal to that of the base metal with little or no dilution (e.g., draw of Mg). The joints may be both heat treated and artificially aged or naturally aged.