Abstract: An aluminum filler alloy, particularly useful in fluxless controlled atmosphere brazing (CAB), contains from about 4% to 20% wt. % silicon (Si) and about 0.0008% to 0.06% sodium (Na). In addition to the sodium, the alloy may also contain bismuth (Bi) and/or potassium (K) in the ranges of about 0.0005% to 0.03% K, and from about 0.03% to 0.133% Bi. The filler metals can be clad to aluminum core alloys preferably from the 3XXX, 5XXX, or 6XXX alloys series.

Abstract: Minor additions of calcium (Ca) to Al--(1% to 14%) Si filler metals result in larger fillets than conventional Al--Si alloys normally used in the NOCOLOK brazing process. This new filler metal can be clad to 2XXX, 3XXX, 6XXX, and 7XXX series alloys and brazed with a fluoride flux. The filler metal contains between 0.005% Ca to 0.3% Ca. The new filler metal could have up to 0.3% Mg and up to 0.3% Li. Additionally, the brazing process can optionally include an aqueous treatment with a fluoride salt to reduce the need for NOCOLOK fluxing.

Abstract: The present invention provides a method of joining aluminum parts by brazing, comprising the steps of (a) providing a composite sheet having an aluminum core alloy material and a filler alloy cladding, applied to the core alloy material, the cladding including about filler alloy for brazing, which includes about 4 to 18 wt. % silicon, about 0.001 to 0.4 wt. % magnesium, about 0.01 to 0.3 wt. % lithium, not more than about 2 wt. % zinc, not more than about 1.25 wt. % manganese, not more than about 0.30 wt. % iron, not more than about 0.10 wt. % copper, not more than 0.15 wt. % impurities, balance aluminum; (b) contacting an aluminum part with the filler alloy cladding; and (c) brazing the aluminum part and the composite sheet to produce a brazed assembly.

Abstract: A process for improving the fillet-forming capability of brazeable aluminum articles includes providing a brazeable aluminum article, having at least one surface; and contacting the surface with a dilute, aqueous solution of fluoridic compounds, for at least 5 seconds at a temperature ranging from about 150.degree. to 212.degree. F. to produce an oxide-free surface which can be readily brazed with a minimal drip loss.

Abstract: The present invention provides a filler alloy for brazing, which includes about 4 to 18 wt. % silicon; about 0.001 to 0.4 wt. % magnesium; about 0.01 to 0.3 wt. % lithium; not more than about 2 wt. % zinc; not more than about 1.25 wt. % manganese; not more than about 0.30 wt. % iron; not more than about 0.10 wt. % copper; not more than 0.15 wt. % impurities; balance aluminum.

Abstract: An aluminum brazing alloy composite sheet is provided which can be utilized in both the vacuum brazing process and the controlled atmosphere brazing process for the brazing of aluminum parts, The brazing alloy composite sheet consists of an aluminum core alloy of the 3XXX, 5XXX or 6XXX type clad at least on one major surface with a lithium-containing aluminum filler alloy containing from about 0.01% to about 0.

Abstract: An aluminum brazing alloy composite sheet is provided which can be utilized in both the vacuum brazing process and the controlled atmosphere brazing process for the brazing of aluminum parts. The brazing alloy composite sheet consists of an aluminum core alloy of the 3XXX, 5XXX or 6XXX type clad at least on one major surface with a lithium-containing aluminum filler alloy containing from about 0.01% to about 0.30% by weight lithium. The core alloy may contain up to about 2% by weight magnesium and is suitable for producing aluminum alloy heat exchanger assemblies, such as radiators or evaporators.

Abstract: An aluminum brazing alloy composite sheet is provided which can be utilized in both the vacuum brazing process and the controlled atmosphere brazing process for the brazing of aluminum parts. The brazing alloy composite sheet consists of an aluminum core alloy of the 3XXX, 5XXX or 6XXX type clad at least on one major surface with a lithium-containing aluminum filler alloy containing from about 0.01% to about 0.30% by weight lithium. The core alloy may contain up to about 2% by weight magnesium and is suitable for producing aluminum alloy heat exchanger assemblies, such as radiators or evaporators.

Abstract: An aluminum brazing alloy composite sheet is provided which can be utilized in both the vacuum brazing process and the controlled atmosphere brazing process for the brazing of aluminum parts. The brazing alloy composite sheet consists of an aluminum core alloy of the 3XXX, 5XXX or 6XXX type clad at least on one major surface with a lithium-containing aluminum filler alloy containing from about 0.01% to about 0.30% by weight lithium. The core alloy may contain up to about 2% by weight magnesium and is suitable for producing aluminum alloy heat exchanger assemblies, such as radiators or evaporators.