A flux-free brazing aluminum alloy brazing sheet includes: a core material formed of aluminum alloy comprising Si of 0.50 to 0.90 mass %, Cu of 0.30 to 2.50 mass %, and Mn of 1.40 to 1.80 mass %, with a Mg content limited to 0.05 mass % or less, and with the balance being Al and inevitable impurities; an intermediate material being formed of aluminum alloy comprising Mg of 0.40 to 1.00 mass %, and Zn of 2.00 to 6.00 mass %, with the balance being Al and inevitable impurities; and a brazing material being formed of aluminum alloy comprising Si of 6.00 to 13.00 mass %, Mg of 0.05 to 0.40 mass %, and Bi of 0.010 to 0.050 mass %, with the balance being Al and inevitable impurities.

In a brazing sheet manufacturing method, a cladding slab is prepared by overlaying at least a core-material slab composed of an aluminum material and a filler-material slab composed of an AlSi series alloy, in which a metal element that oxidizes more readily than Al is included in at least one of the slabs. A clad sheet is prepared by hot rolling this cladding slab, which then has at least a core material layer composed of the core-material slab and a filler material layer composed of the filler-material slab and disposed on at least one side of the core material. Then, a surface of the clad sheet is etched using a liquid etchant that contains an acid. Subsequently, the clad sheet is cold rolled to a desired thickness. In flux-free brazing, such a brazing sheet is capable of curtailing degradation in brazeability caused by fluctuations in dew point and oxygen concentration.

An aluminum alloy heat exchanger for an exhaust gas recirculation system, the heat exchanger obtained by brazing: a tube material comprising a core material comprising 0.05 mass % to 1.50 mass % of Si, 0.05 mass % to 3.00 mass % of Cu, and 0.40 mass % to 2.00 mass % of Mn, and a sacrificial anticorrosion material comprising 2.00 mass % to 6.00 mass % of Zn, clad on an inner side surface of the core material; and a fin material comprising a core material comprising 0.05 mass to 1.50 mass % of Si, and 0.40 mass % to 2.00 mass % of Mn, and a brazing material comprising 3.00 mass % to 13.00 mass % of Si, clad on both surfaces of the core material; the heat exchanger having a ratio of a surface area S.sub.b (mm.sup.2) of the fin material to a surface area S.sub.a (mm.sup.2) of the sacrificial anticorrosion material of less than 200%.

A method of making a semiconductor including soldering a conductor to an aluminum metallization is disclosed. In one example, the method includes substituting an aluminum oxide layer on the aluminum metallization by a substitute metal oxide layer or a substitute metal alloy oxide layer. Then, substitute metal oxides in the substitute metal oxide layer or the substitute metal alloy oxide layer are at least partly reduced. The conductor is soldered to the aluminum metallization using a solder material.

Some variations provide a method of making an additively manufactured metal component, comprising: providing a feedstock that includes a high-vapor-pressure metal; exposing a first amount of the feedstock to an energy source for melting; and solidifying the melt layer, thereby generating a solid layer of an additively manufactured metal component. The metal-containing feedstock is enriched with a higher concentration of the high-vapor-pressure metal compared to its concentration in the additively manufactured metal component. The high-vapor-pressure metal may be selected from Mg, Zn, Li, Al, Cd, Hg, K, Na, Rb, Cs, Mn, Be, Ca, Sr, or Ba, for example. Additively manufactured metal components are provided. Metal-containing feedstocks for additive manufacturing are also disclosed, wherein concentration of at least one high-vapor-pressure metal in the feedstock is selected based on a desired concentration of the high-vapor-pressure metal in an additively manufactured metal component derived from the metal-containing feedstock. Various feedstock compositions are disclosed.

A method of making a semiconductor including soldering a conductor to an aluminum metallization is disclosed. In one example, the method includes substituting an aluminum oxide layer on the aluminum metallization by a substitute metal oxide layer or a substitute metal alloy oxide layer. Then, substitute metal oxides in the substitute metal oxide layer or the substitute metal alloy oxide layer are at least partly reduced. The conductor is soldered to the aluminum metallization using a solder material.

An aluminum alloy brazing sheet is disclosed including a core material made of pure aluminum or aluminum alloy, one side or both sides of the core material, being clad with a brazing material, with an intermediate material interposed between the core material and the brazing material, the intermediate material including 0.4 to 6 mass % of Mg, further including at least one of Mn, Cr, and Zr, and the balance being Al and inevitable impurities, having the Mn content not more than 2.0 mass %, the Cr content not more than 0.3 mass %, and the Zr content not more than 0.3 mass %, with the total content of Mn, Cr, and Zr being at least 0.1 mass %, the brazing material including 4 to 13 mass % of Si, and the balance being Al and inevitable.

The present disclosure relates to a metal-cored welding wire, and, more specifically, to a metal-cored aluminum welding wire for arc welding, such as Gas Metal Arc Welding (GMAW) and Gas Tungsten Arc Welding (GTAW). A disclosed metal-cored aluminum welding wire includes a metallic sheath and a granular core disposed within the metallic sheath. The granular core includes a first alloy having a plurality of elements, wherein the first alloy has a solidus that is lower than each of the respective melting points of the plurality of elements of the first alloy.

A method for manufacturing a heat exchanger (1) includes joining an inner fin (3) to a hollow structure (20) formed from at least two clad plates (200a, 200b) by heating and brazing a filler metal layer (B). Each clad plate has a core layer (A) composed of an aluminum alloy that contains Mg: 0.40-1.0 mass %. The filler metal layer is composed of an aluminum alloy that contains Si: 4.0-13.0 mass %, and further contains Li: 0.0040-0.10 mass %, Be: 0.0040-0.10 mass %, and/or Bi: 0.01-0.30 mass %. The inner fin is composed of an aluminum alloy that contains Si: 0.30-0.70 mass % and Mg: 0.35-0.80 mass %. A flux (F) that contains cesium (Cs) is applied along a contact part (201), and the vicinity thereof, of the at least two clad plates prior to the heating. A heat exchanger (1) may be manufactured according to this method.

An apparatus, material and method for forming a brazing sheet has a composite braze liner layer of low melting point aluminum alloy and 4000 series braze liner. The low melting point layer of the composite braze liner facilitates low temperature brazing and decrease of the diffusion of magnesium from the core into the composite braze liner. The reduction of magnesium diffusion also lowers the formation of associated magnesium oxides at the braze joint interface that are resistant to removal by Nocolok flux, thereby facilitating the formation of good brazing joints through the use of low temperature controlled atmosphere brazing (CAB) and Nocolok flux. The apparatus also enables the production of brazing sheet materials with high strength and good corrosion property.