US 2017/0320170 A1 · BRAZING METHOD

Abstract

A hollow aluminum structure that will be brazed includes at least one brazing sheet having a filler metal layer clad onto a core layer. The core layer is composed of aluminum or an aluminum alloy containing less than 0.2 mass % Mg. The filler metal layer is composed of an aluminum alloy that contains Si: 4.0-13.0 mass % and Bi: 0.01-0.3 mass %, and further contains Li: 0.004-0.08 mass % and/or Be: 0.006-0.12 mass %, the filler metal layer containing less than 0.1 mass % Mg. The hollow aluminum structure is assembled such that the filler metal layer is present at locations that will form both an interior-facing brazed joint and an exterior-facing brazed joint. Then, flux is applied onto the filler metal layer at the location that will form the exterior brazed joint, and the hollow aluminum structure heated in an inert gas atmosphere to form the interior brazed joint and the exterior brazed joint.

Claims20

Dependent claims

A brazing method for brazing an object to be processed, which is composed of an aluminum material and has a hollow portion, to form an inner join part that faces the hollow portion and also an outer join part that faces an external space, the brazing method comprising:

preparing the object to be processed that comprises a brazing sheet including:
a core layer having a chemical composition in which the content of Mg is less than 0.2% (mass %, likewise hereinbelow), the remainder being composed of Al and unavoidable impurities;
and
a filler metal layer having a chemical composition that indispensably contains Si:
4.0 to 13.0% and Bi:
0.01 to 0.3%, and further contains at least one element selected from the group consisting of Li:
0.004 to 0.08% and Be:
0.006 to 0.12%, the Mg content being less than 0.1% and the remainder being composed of Al and unavoidable impurities, the filler metal layer being clad onto at least one side of the core layer;
assembling the object to be processed such that the filler metal layer is present at locations that will form both the inner join part and the outer join part;
next, applying a flux onto the filler metal layer that is present at the location that will form the outer join part;
and
subsequently, heating and brazing the object to be processed in an inert gas atmosphere.

9 more elements

A method for brazing a hollow aluminum structure to form both an interior brazed joint that faces an interior hollow space of the hollow aluminum structure and an exterior brazed joint that faces a space external to the interior hollow space,

wherein, prior to brazing, the hollow aluminum structure includes at least one brazing sheet having a filler metal layer clad onto at least one side of a core layer, the core layer being composed of aluminum or an aluminum alloy containing less than 0.2 mass % Mg (mass %, likewise hereinbelow), and the filler metal layer being composed of an aluminum alloy that contains Si:
4.0-13.0 mass % and Bi:
0.01-0.3 mass %, and further contains at least one element selected from the group consisting of Li:
0.004-0.08 mass % and Be:
0.006-0.12 mass %, the filler metal layer containing less than 0.1 mass % Mg,
the method comprising:
assembling the hollow aluminum structure such that the filler metal layer of the at least one brazing sheet is present at locations that will form both the interior brazed joint and the exterior brazed joint;
thereafter, applying a flux onto the filler metal layer at the location that will form the exterior brazed joint;
and
subsequently, heating and brazing the hollow aluminum structure in an inert gas atmosphere to form the interior brazed joint and the exterior brazed joint.

7 more elements

Dependencies are inferred from the claim text.

Brazing method

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Brazing method

Life of this patent

Abstract

Claims20