A method of forming an additively manufactured aluminum part includes establishing an arc between a metal-cored aluminum wire and the additively manufactured aluminum part, wherein the metal-cored aluminum wire includes a metallic sheath and a granular core disposed within the metallic sheath. The granular core comprises aluminum metal matrix nano-composites (Al-MMNCs) that comprise an aluminum metal matrix and ceramic nanoparticles. The method includes melting a portion of the metal-cored aluminum wire using the heat of the arc to form molten droplets. The method includes transferring the molten droplets to the additively manufactured aluminum part under an inert gas flow, and solidifying the molten droplets under the inert gas flow to form deposits of the additively manufactured aluminum part.

An aluminum alloy brazing sheet used for brazing in an inert gas atmosphere without using a flux includes a brazing material cladded onto at least one side surface of a core material. An oxide is formed on a surface of the aluminum alloy brazing sheet by brazing heating, the oxide including any one or two or more of Mg, Li, and Ca and having a volume change ratio of 0.990 or less to a surface oxide film formed before brazing heating, and an atomic molar ratio of Mg, Li, and Ca to Al in the oxide formed on the surface of the aluminum alloy brazing sheet before brazing heating is 0.50 or less. The present invention provides an aluminum alloy brazing sheet having excellent brazability in brazing in an inert gas atmosphere without using a flux, and a method for manufacturing the same.

The invention relates to a method of manufacturing a brazing sheet product having a core layer of a 3xxx-series aluminium alloy clad on one or both sides with a 4xxx-series aluminium alloy brazing layer, the method comprising the steps of: (i) casting a rolling ingot of the core layer of a 3xxx-series aluminium alloy having the following composition, in wt. %: Mn 0.5-1.8, Si≤1.5, Fe≤0.7, Cu≤1.5, Mg≤1.0, Cr≤0.25, Zr≤0.25, Ti≤0.25, Zn≤0.5, balance impurities and aluminium; (ii) hot rolling of the rolling ingot to a hot rolled sheet having thickness of 2.5-10 mm; (iii) cold rolling of the hot rolled sheet to a gauge of 0.1-4 mm, optionally with an intermediate annealing step during the cold rolling operation; (iv) soft annealing to recrystallize the microstructure of the aluminium sheet, preferably at a temperature in the range of 250° C.-450° C.; (v) further cold rolling of the soft annealed sheet with a cold rolling reduction in the range of 5% to <10% to a final cold rolling thickness; and (vi) recovery annealing at 200° C.-420° C. of the cold rolled aluminium sheet at final cold rolling thickness.

An apparatus, material and method for forming a reliably roll-bonded, multi-layer aluminum alloy brazing sheet has a core of 2XXX, 3XXX, 5XXX or 6XXX alloy, a braze liner of 4XXX alloy and an interliner with Mn in the range of 0.2 to 1.0 wt. % and Si in the range of 0.31-1.0 wt. %. Alternatively, Mg in the range of 0.1 to 0.5 wt. % may be present in the interliner. Additional layers such as a second braze liner may be present for providing an inner surface of a heat exchanger. An additional interliner may optionally be used between the core the inner surface layer. The material may be used for highly corrosive environments like an EGR cooler.

A scandium-containing aluminium powder alloy, wires and materials including said alloy, and a method for producing the scandium-containing aluminium powder alloy, the wires and materials, the proportion of scandium in the scandium-containing aluminium powder alloy being elevated, are disclosed. At least one element is selected from the group consisting of the lanthanum group except for Ce, Y, Ga, Nb, Ta, W, V, Ni, Co, Mo, Li, Th, Ag.

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 aluminum alloy for flux-free brazing provided for brazing performed via an Al—Si-based brazing material without a flux in a non-oxidizing atmosphere without depressurization, includes: by mass %, 0.01% to 2.0% of Mg; and 0.005% to 1.5% of Bi, wherein in the aluminum alloy, there are more than 10 Mg—Bi-based compounds having a diameter of 0.01 μm or more and less than 5.0 μm in terms of equivalent circle diameter per 10,000-μm.sup.2 visual field and there are less than 2 Mg—Bi-based compounds having a diameter of 5.0 μm or more per 10,000-μm.sup.2 visual field in a cross section parallel to a rolling direction, and in the aluminum alloy, there are less than 5 Bi particles having a diameter of 5.0 μm or more in terms of equivalent circle diameter per 10,000-μm.sup.2 visual field in the cross section parallel to the rolling direction.

An aluminum alloy brazing sheet used for brazing of an aluminum material in an inert gas atmosphere or in vacuum is formed of a two-layer material in which a brazing material and a core material are stacked in this order. The core material is formed of an aluminum alloy and has a grain size of 20 to 300 μm, and the aluminum alloy contains Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of 1.00 mass % or less, with the balance being aluminum and inevitable impurities. The brazing material is formed of an aluminum alloy containing Si of 4.00 to 13.00 mass % with the balance being aluminum and inevitable impurities, and, in a drop-type fluidity test, a ratio α (α=K.sub.a/K.sub.b) of a fluid coefficient K.sub.a is 0.50 or more.

An aluminum alloy brazing sheet may include a sacrificial material having a function of a brazing material on at least one surface of a core material, wherein the sacrificial material has a composition containing: in a mass %, 2% to 5% of Si; 3% to 5% of Zn; and an Al balance with inevitable impurities the core material is made of an Al—Mn-based alloy, an in the core material before brazing, Al—Mn based secondary particles having an equivalent circle diameter of 100 to 400 nm are distributed with a number density of 0.3 to 5 particles/μm.sup.2.

A strip intended for the manufacture of brazed heat exchangers, having a core made of an alloy with the composition (weight %):

Si: 0.10-0.30%, preferably 0.15-0.25%
Fe<0.25%, preferably 0.1-0.2%
Cu: 0.85-1.1%, preferably 0.9-1.0%
Mn: 1.2-1.7%, preferably 1.2-1.4%
Mg: 0.1-0.3%, preferably 0.1-0.21%
Zn<0.1%
Ti 0.05-0.20%, preferably 0.06-0.15%, more preferably 0.06-0.1%
optionally up to 0.15% of Bi and/or Y
other elements <0.05% each and <0.15% in total,
remainder aluminium.