DE112018001845T5 - Aluminum brazing sheet material that is suitable for flux-free soldering in a protective gas atmosphere - Google Patents

Abstract

The invention relates to an aluminum alloy brazing sheet product comprising a covering aluminum material layer comprising 0.5% to -5% Zn, an aluminum core material layer and an Al-Si alloy brazing material layer as an intermediate material which is between the covering aluminum material layer and the aluminum. Core material layer is arranged, wherein the aluminum core material layer comprises an aluminum alloy with a solidus temperature that is higher than the liquidus temperature of the Al-Si alloy brazing material layer, and wherein the Al-Si alloy brazing material layer contains 0.01% to 1% Mg ,

Description

FIELD OF THE INVENTION

The present invention relates to a rolled aluminum alloy brazing sheet product comprising a covering material layer, a core material layer and further an Al-Si alloy brazing material layer as an intermediate material which is arranged between the covering material layer and the core material layer.

The invention further relates to a solder assembly that is manufactured in a soldering process, ideally in a CAB process without using a brazing flux material, wherein the soldering assembly comprises different components and at least one component is made from the aluminum alloy brazing sheet product according to this invention.

BACKGROUND OF THE INVENTION

Substrates made of aluminum or an aluminum alloy in the form of a sheet or an extrusion are used to produce designed or shaped products. In some of these processes, parts of (designed) aluminum substrates are bonded together. One end of a substrate can be connected to the other end, or a substrate can be joined with one or more other substrates. This is usually done by soldering. In a soldering process, a hard solder metal or a hard solder alloy or a composition that generates a hard solder alloy when heated is applied to at least a part of the substrate to be soldered. After the substrate parts are assembled, they are heated until the solder or braze alloy melts. The melting point of the brazing material is lower than the melting point of the aluminum substrate or the aluminum core sheet.

Brazing sheet products are widely used in heat exchangers and other similar devices. Conventional brazing products have a core of rolled sheet metal, typically but not exclusively, of an aluminum alloy of the 3xxx series, which has an aluminum plating layer on at least one surface of the core sheet. The aluminum plating layer consists of an alloy from the 4xxx series, which contains silicon in an amount in the range from 4% to 20%. The aluminum plating layer can be coupled or bonded to the core alloy in various ways known in the art, for example by roll plating, spray molding, or semi-continuous or continuous casting processes. These 4xxx series aluminum cladding layers have a liquidus temperature that is typically in the range of approximately 540 ° C to 610 ° C.

Various soldering processes are used to manufacture soldering assemblies such as heat exchangers on an industrial scale.

Vacuum soldering is carried out, for example, at very low atmospheric pressure. In order to obtain the optimal conditions for the assembly, Al-Si brazing alloys, which are usually used for vacuum brazing, contain appropriate additives of about 1% Mg or more. The mechanism, it is believed, is that Mg destroys the hard oxide film of the braze alloy as it evaporates from the braze sheet during brazing, and further, the evaporated Mg plays a role in reducing the oxygen and moisture that remain in the vacuum braze furnace.

The patent document US 3,917,151 (Kaiser Aluminum) discloses a method for vacuum brazing aluminum parts using a vacuum brazing sheet comprising an aluminum alloy core, wherein a hard braze alloy consisting essentially of 5 to 15% Si, 0.5 to 5% Mg, is plated on the core 0.8% Fe, up to 0.25% Cu, up to 0.20% Zn, up to 0.20% Mn, other elements each up to 0.1%, the remainder aluminum, and a Mg to this solder alloy -free aluminum alloy, ie no more than 0.1% Mg with a melting point of at least 1100 ° F (593 ° C) is plated. The Mg in the braze alloy acts as a Mg source to facilitate the vacuum brazing process. The Mg-free alloy and the core alloy should contain less than 5% Zn, 0.8% Fe, 1% Si, 3% Mn, 0.5% Cr, 0.05% Ti and 0.10% other elements each. Suitable alloys disclosed for the core and Mg-free alloy are the aluminum alloys 1100 and 3003 , aluminum alloys 6951 and 7005 can also be used as core alloys. Intermediate layers of thin, relatively pure aluminum, e.g. B. 1100 alloy, between the different layers.

Another method of soldering is controlled atmosphere ("CAB") soldering, which is carried out in a dry oxygen-restricted atmosphere, preferably using an inert one Environment, for example nitrogen or argon can be used. To facilitate soldering, a non-corrosive braze flux, e.g. B. a fluoride-based flux, as is known in the art, applied. This braze flux removes or interferes with the oxide layer during the soldering process so that the molten filler contacts the bare metal to form the bond. The aluminum alloys used for CAB should be Mg minimized as Mg can inhibit the brazing flux effect. In the case of complexly designed assemblies, the application of the non-corrosive brazing flux before soldering inside the assemblies is often seen as problematic.

Yet another brazing technique is CAB without the use of a brazing flux, and this technique is used in particular to join surfaces within a heat exchanger that are very difficult to flux and are cheaper on an industrial scale than vacuum brazing because vacuum brazing is a batch process and requires significant equipment investment costs ,

There is a need for further improved brazing sheet materials and soldering methods in which at least the inside of an assembly need not be provided with a non-corrosive brazing flux.

DESCRIPTION OF THE INVENTION

As will be seen hereinafter, aluminum alloy designations and condition designations, unless otherwise noted, refer to the aluminum association designations in the aluminum standards and dates and registration records as provided by the Aluminum Association in the year 2016 have been published and are known to those skilled in the art.

For any description of alloy compositions or preferred alloy compositions, references to percentages are by weight unless otherwise specified. The terms "up to" and "up to about" as used herein explicitly include, but are not limited to, the possibility of zero weight percent of the particular alloy component to which it refers. For example, up to 0.3% Cu can be an alloy that has no Cu, and therefore such an element may be missing.

And for the purpose of this invention and as used below, the term "controlled atmosphere soldering" or "CAB" refers to a soldering process that uses an inert atmosphere, such as nitrogen or argon, when soldering the various alloy articles and differs from vacuum soldering distinguishes in particular in that in CAB the soldering atmosphere in the furnace during the soldering process is approximately atmospheric pressure, although a slight negative pressure (for example working at a pressure of 0.1 bar or more) or a slight positive pressure can be used to reduce the To facilitate control of the internal atmosphere and to prevent oxygen from flowing into the soldering furnace. “Core” means an aluminum alloy, which is the structural support for the aluminum alloy used as a filler. “Filler” means an aluminum-silicon alloy that is used to solder the core or other aluminum item. "Rounding" means a concave connection between two surfaces.

It is an object of the invention to provide an aluminum alloy brazing sheet material that can be used in a CAB process without applying a non-corrosive brazing flux.

These and other objects and other advantages are achieved or exceeded by the present invention, which provides an aluminum alloy brazing sheet product comprising an aluminum covering layer comprising 0.5% to 5% Zn, an aluminum core material layer and an Al-Si alloy layer. Brazing material layer as an intermediate material which is arranged between the covering aluminum material layer and the aluminum core material layer, the aluminum core material layer comprising an aluminum alloy with a solidus temperature which is higher than the liquidus temperature of the Al-Si alloy brazing material layer, and wherein the Al- Si alloy brazing material layer contains from 0.01% to 1% Mg.

In one embodiment, the covering aluminum material layer is a thin covering material layer that is free of Mg, and the Al-Si alloy brazing material layer is arranged as an intermediate material between the thin covering material layer and the core material layer, and wherein the thin covering material layer and the core material layer are made of Aluminum alloys exist, have a solidus temperature that is higher than a liquidus temperature of the Al-Si alloy brazing material, so that Braze material interacts with the cover material layer when the braze material is melted in one soldering operation.

According to the invention, it was found that a Harlot metal sheet product with a multilayer structure with an aluminum cover material layer, which has a targeted addition of Zn on an Al-Si braze material layer, can be used very successfully in a flux-free CAB process. Since the thickness of the cover layer is preferably relatively small with respect to the Al-Si alloy brazing material layer, the total amount of Zn in the fillet formed is still small and has no adverse effects on the soldering and the result of the soldering component. The presence of a small amount of Zn in this layer construction can even help provide sacrificial protection to the core alloy by increasing corrosion resistance.

In one embodiment of the brazing sheet product, the cover aluminum material layer or coating layer contains at least 0.7% Zn. In one embodiment of the brazing sheet product, the coating layer contains at most 3.0% Zn and preferably at most 2.5% Zn.

In the patent EP 1 306 207 B1 it is reported that in order to achieve successful CAB soldering without the use of a brazing flux, both the coating layer and the aluminum core material layer should have a solidus temperature above the liquidus temperature of the intermediate brazing material layer. In this way, during a subsequent soldering operation at a temperature between the liquidus temperature and the solidus temperature, the molten brazing material is intended to cause the Al-Si alloy brazing material layer to melt while the thin covering material layer remains solid to prevent oxidation of the melting brazing material, and then cause the Al-Si alloy braze material to seep onto a surface of the thin cover material layer due to the volume expansion through separation areas of the thin cover material layer and to spread over the surface of the thin cover material to form an exiting surface that results in a solder joint , In the EP-1306207-B1 however, there is no disclosure of the appropriate addition of Zn to the coating layer to facilitate the flux-free CAB process.

In the brazing sheet material according to the invention, the core material layer is made of an aluminum alloy. The core alloys preferably originate from the aluminum alloys of the 2xxx, 3xxx, 5xxx or 6xxx series, in particular from an alloy of the 3xxx or 6xxx series, such as an alloy of the type AA3003, AA3103, AA3005, AA3105, AA6060, AA6063 or AA6951 or Modifications thereof.

The Al-Si alloy brazing material layer preferably consists of an Al-Si alloy with 5% to 15% Si and an appropriate addition of Mg in a range of 0.01% to 1% in order to do the CAB soldering in the absence of a To facilitate flux. Preferably there is at least 0.02% Mg, more preferably at least about 0.05% and more preferably at least about 0.09%. The Mg content is at most 1.0% and preferably at most about 0.25%.

In one embodiment, the Al-Si alloy braze material layer further contains a convenient addition of Zn in a range from about 0.05% to 2%.

In one embodiment of the invention, the Al-Si brazing filler layer has the following composition, consisting of Si 5% to 15%, preferably 6% to 14% mg 0.01% to 1%, preferably 0.05% to 1.0% Fe up to 0.8%, Cu up to 0.3%, Mn up to 0.8%, preferably up to 0.2% Zn up to 2%, Ti up to 0.3%,

Rest of aluminum and unavoidable impurities each <0.05%, total <0.2%.

In one embodiment, the Al-Si alloy braze material layer further includes one or more wetting elements or elements that control the surface tension of a molten Al-Si Modify filling material. Preferably, the elements are selected from the group comprising Bi, Y, Pb, Li, Na, Sb, Sr and Th, and the total amount of the wetting element (s) is in a range from about 0.01% to 0.8 % lies. In a preferred embodiment, the upper limit for the total amount of wetting element (s) is 0.5%.

In a preferred embodiment, the element Bi is selected from the defined group of wetting elements and is in a range from approximately 0.01% to 0.8% and preferably in a range from approximately 0.01% to 0.5%, since it is the most effective wetting element for this purpose in this alloy system during a soldering process.

The brazing sheet product according to the invention has a typical final gauge in the range of about 0.1 mm to 10 mm, preferably in the range of about 0.1 mm to 5 mm.

In one embodiment, the thin cover material layer has a thickness that is about 0.1% to 10% of the total thickness of the aluminum alloy brazing sheet, and the Al-Si alloy brazing material layer has a thickness that is about 3% to 30%, preferably about 4% to 20% of the total thickness of the aluminum alloy brazing sheet.

Furthermore, in a preferred embodiment, the thickness ratio of the Al-Si alloy brazing material layer and the thin cover material layer is 3 or more to 1, preferably 4 or more to 1, for example the thickness ratio is 3 to 1 or 3.5 to 1 or 4 to 1.

In one embodiment, the cover material layer is free of wetting elements or elements which modify the surface tension of a molten Al-Si filler material, which are selected from the group consisting of Ag, Be, Bi, Ce, La, Li, Na, Pb, Se, Sb , Sr, Th and Y. By "free" it is meant that there is no appropriate addition of Ag, Be, Bi, Ce, La, Li, Na, Pb, Se, Sb, Sr, Th or Y to the chemical composition, that trace amounts nevertheless find their way into the cover material layer due to contamination and / or leaks when in contact with manufacturing plants. In practice, this means that the amount present, if any, is up to about 0.005%, typically less than about 0.001%.

The cover material layer is preferably free of Mg, which means that the proportion is less than 0.05% and preferably less than about 0.03% and more preferably less than about 0.01%. By "free" it is meant that there is no appropriate addition of Mg to the chemical composition, but that trace amounts nevertheless find their way into the cover material layer due to contamination and / or leaks from contact with manufacturing plants.

In one embodiment, the thin cover material layer is a Mg-free aluminum alloy comprising Fe 0 to 0.6%, Si 0 to 4%, preferably 0 to 2%, more preferably 0 to 1%, Mn 0 to 1.0%, preferably 0 to 0.4% Cu 0 to 0.5%, preferably 0 to 0.15%, more preferably 0 to 0.05%, Zn 0.5% to 5%, preferably 0.7% to 3.0%, Ti 0 to 0.1%, unavoidable impurities, each <0.05%, total <0.15%,
Balance aluminum and with preferred narrower composition ranges as described and claimed herein.

In one embodiment, the thin cover material layer is a Mg-free aluminum alloy Fe 0 to 0.6%, Si 0 to 4%, preferably 0 to 2%, more preferably 0 to 1%, Mn 0 to 1.0%, preferably 0 to 0.4% Cu 0 to 0.5%, preferably 0 to 0.15%, more preferably 0 to 0.05%, Zn 0.5% to 5%, preferably 0.7% to 3.0%, Ti 0 to 0.1%, Rest of aluminum and unavoidable impurities, each <0.05%, total <0.15%.
Balance aluminum and with preferred narrower composition ranges as described and claimed herein.

In another embodiment, the thin cover material layer is a Mg-free aluminum alloy and, in addition to the appropriate addition of Zn, has a composition in the range of aluminum alloys of the AA1000 series and preferably an aluminum alloy selected from the group comprising AA1050, AA1070, AA1100, AA1145 and AA1230 on.

In a further aspect of the invention there is provided an article comprising at least two shaped elements joined together by brazing, for example a heat exchanger, comprising at least the aluminum alloy brazing product according to this invention as one of the shaped elements. The aluminum alloy brazing sheet product can be used in all known automotive heat exchanger types, e.g. B. Powertrain cooling and HVAC designs. A typical example of a heat exchanger that is beneficial for the aluminum alloy brazing material according to this invention is an oil cooler, and ideally at least the aluminum facing layer and the Al-Si alloy brazing material layer join a cavity formed in the article , Another typical example is a crimped tube, the configurations of which are well known to those skilled in the art, having an inner surface that cannot be fluxed, whereas fins should be added to the tube on the outer surface.

1. (a) Bereitstellen oder Bilden der Komponenten, von denen mindestens eine aus einem Aluminiumlegierungs-Hartlotblechprodukt wie oben dargelegt oder beansprucht hergestellt ist;
2. (b) Zusammenfügen der Komponenten zu einer Baugruppe; und vorzugsweise wird eine Seite des Hartlotblechprodukts der Erfindung, welche die Deckmaterialschicht aufweist, im Inneren der Baugruppe gehalten, die das Hartlotblech bildet, um eine Struktur, vorzugsweise eine hohle Struktur, zu bilden;
3. (c) Löten der Baugruppe ohne Auftragen von Lötflussmittel in einer Inertgasatmosphäre bei einer Löttemperatur, typischerweise bei einer Temperatur in einem Bereich von ungefähr 540 °C bis 615 °C, zum Beispiel bei etwa 590 °C oder bei etwa 600 °C, für eine ausreichend lange Zeit zum Schmelzen und Verteilen des Aluminiumhartlot-Füllmaterials, zum Beispiel mit einer Verweilzeit von etwa 1 bis 10 Minuten, vorzugsweise 1 bis 6 Minuten, typischerweise für etwa 2 oder 4 Minuten, um eine Verrundung zwischen dem Füllmaterial und mindestens einer anderen Komponente zu bilden; und wobei der Sauerstoffgehalt der trockenen Inertgasatmosphäre auf einem so geringen Pegel wie möglich gesteuert wird, vorzugsweise unter 200 ppm, und mehr bevorzugt unter 100 ppm, und mehr bevorzugt unter 40 ppm; und
4. (d) Kühlen der Lötbaugruppe, typischerweise auf unter 100 °C; z. B. auf Umgebungstemperatur.

In a further aspect of the invention, a method for producing an assembly from soldering components is provided, comprising the steps:

1. (a) providing or forming the components, at least one of which is made from an aluminum alloy brazing sheet product as set forth or claimed above;
2. (b) assembling the components into an assembly; and preferably one side of the brazing sheet product of the invention having the cover material layer is held within the assembly that forms the brazing sheet to form a structure, preferably a hollow structure;
3. (c) Soldering the assembly without applying solder flux in an inert gas atmosphere at a soldering temperature, typically at a temperature in a range from about 540 ° C to 615 ° C, for example at about 590 ° C or at about 600 ° C for one sufficient time to melt and distribute the aluminum braze filler, for example with a residence time of about 1 to 10 minutes, preferably 1 to 6 minutes, typically for about 2 or 4 minutes, to cause a fillet to fillet and at least one other component form; and wherein the oxygen content of the dry inert gas atmosphere is controlled at as low a level as possible, preferably below 200 ppm, and more preferably below 100 ppm, and more preferably below 40 ppm; and
4. (d) cooling the solder assembly, typically below 100 ° C; z. B. to ambient temperature.

Ideally, when assembling the components into an assembly suitable for being joined by soldering, one side of the brazing sheet product of the invention, which has the relatively thin cover material layer, is held inside the assembly that forms the brazing sheet to form a structure. While using the brazing sheet product according to this invention, it is not necessary to apply a soldering flux in order to get a good connection after the soldering process.

In a preferred embodiment, the braze gas atmosphere should be dry during the soldering process, which means that the condensation point is less than minus 40 ° C and more preferably minus 45 ° C or even less.

Another aspect of the invention relates to the use or method of using the aluminum alloy brazing sheet product described and claimed herein in a flux-free CAB process as described and claimed herein, and preferably one side of the brazing sheet product of the invention having the cover material layer that is inside the assembly is held to the To build braze sheet to form a structure, preferably a hollow structure to make an assembly from solder components, preferably a heat exchanger, more preferably an oil cooler.

The invention will now be illustrated with reference to non-limiting figures and embodiments according to the invention.

Typical arrangements of the aluminum alloy brazing sheet product 4 according to the invention are in the 1A . 1B and 1C shown.

The aluminum covering material layer 2 and the intermediate Al-Si alloy brazing material layer 1 can be on both sides or only on one side of the core material layer 3 be applied, the cover material 2 forms the outer layer of the multilayer brazing sheet product. When both sides are plated, the braze sheet product has five layers, including the core alloy layer, as in FIG 1A shown. When one side is plated with the brazing material, the brazing sheet product has a three-layer configuration, as in FIG 1B shown.

In another embodiment, if one side is plated with the Al-Si alloy braze material layer, an outer layer may be on the other side of the core material layer 5 be applied as in 1C shown. The outer layer or shell would generally be made of an alloy tailored to provide high corrosion resistance or corrosion resistance in combination with an erosion resistance in the environment to which this surface of the sheet is exposed. An example of a suitable outer shell would be an aluminum alloy with a suitable addition of Zn, such as an alloy of the AA7072 series.

In another embodiment (not shown), a further aluminum alloy layer can be arranged between the core material layer and the brazing material layer coated with Al-Si alloy. For example, a further aluminum alloy layer can be applied, for example to limit the diffusion of alloy elements from the core layer to the Al-Si brazing layer or to further improve the corrosion performance of the brazing sheet product. Examples of a suitable further aluminum alloy layer include aluminum alloys of the series 1xxx, 3xxx or 5xxx. In a further embodiment, the alloys of the 1xxx series can have a suitable addition of Mg in a range from 0.1% to 1.5%, and in another embodiment the alloys of the 5xxx series can have 0.1% to 1, Have 5% Mg.

2 is an isometric view of a portion of a soldered heat exchanger assembly.

As in 2 shown, a soldered aluminum heat exchanger 12 according to the present invention a plurality of fluid-carrying pipes 6 which are made of the brazing sheet material according to this invention. The ends of the fluid-carrying pipes 6 are to a collector plate 8th and a tank 10 open towards one end of the fluid-carrying pipes 6 , a collector plate 8th and a tank 10 are in 2 shown). Coolant is drained from the tank 10 through the fluid-carrying pipes 6 and circulated to another tank (not shown). As shown, there are a variety of cooling fins 7 between the fluid-carrying pipes 6 arranged to conduct heat away therefrom, thereby facilitating heat exchange that cools the fluid therein.

Now that the invention has been fully described, it will be apparent to those skilled in the art that many changes and modifications can be made without departing from the spirit or scope of the invention as described herein.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 3917151 [0007]
• EP 1306207 B1 [0019]

Claims (16)

Aluminum alloy brazing sheet product (4) comprising a covering aluminum material layer (2) comprising 0.5% to 5% Zn, an aluminum core material layer (3) and an Al-Si alloy brazing material layer (1) as an intermediate material between the covering aluminum material layer (2) and the aluminum core material layer (3) is arranged, the aluminum core material layer (3) comprising an aluminum alloy with a solidus temperature which is higher than the liquidus temperature of the Al-Si alloy brazing material layer (1), and wherein the Al-Si alloy brazing material layer (1) contains from 0.01% to 1% Mg. Aluminum alloy brazing sheet product after Claim 1 , wherein the covering aluminum material layer (2) is a thin covering material layer which is free of Mg, and the Al-Si alloy brazing material layer (1) is arranged as an intermediate material between the covering material layer (2) and the core material layer (3), and wherein the cover material layer (2) and the core material layer (3), which are made of aluminum alloys, have a solidus temperature that is higher than a liquidus temperature of the Al-Si alloy braze material, so that the molten braze material seeps onto a surface of the cover material layer when that Brazing material is melted in one soldering process. Aluminum alloy brazing sheet product after Claim 1 or 2 wherein the cover material layer (2) has a thickness which is 0.1% to 10% of the total thickness of the aluminum alloy brazing sheet product and wherein the Al-Si alloy brazing material layer (1) has a thickness which is 3% to 30% of the Total thickness of the aluminum alloy brazing sheet product. Aluminum alloy brazing sheet product according to one of the Claims 1 to 3 , wherein the thickness ratio between the Al-Si alloy brazing material layer (1) and the covering material layer (2) is 3 or more than 1 and preferably 4 or more than 1. Aluminum alloy brazing sheet product according to one of the Claims 1 to 4 , wherein the cover material layer (2) Mg has less than 0.05%, preferably less than 0.03%, more preferably less than 0.01% and is more preferably free of Mg. Aluminum alloy brazing sheet product according to one of the Claims 1 to 5 , wherein the covering aluminum layer (2) comprises: Fe 0 to 0.6%, Si 0 to 4%, preferably 0 to 2%, more preferably 0 to 1%, Mn 0 to 1.0%, Cu 0 to 0.5%, Zn 0.5% to 5%, Ti 0 to 0.1%, Impurities, each <0.05% total <0.15%, the rest aluminum. Aluminum alloy brazing sheet product according to one of the Claims 1 to 6 , wherein the covering aluminum alloy layer (2) is a Mg-free aluminum alloy which has a composition in the range of an aluminum alloy of the 1000 series. Aluminum alloy brazing sheet product according to one of the Claims 1 to 7 , wherein the covering aluminum alloy layer (2) has a Zn content of at least 0.7%, and preferably at most 3.0%. Aluminum alloy brazing sheet product according to one of the Claims 1 to 8th , wherein the Al-Si alloy brazing material layer (1) consists of the following: Si 5% to 15%, mg 0.01% to 1%, Fe up to 0.8%, Cu up to 0.3%, Mn up to 0.8%, Zn up to 2%, Ti up to 0.3%, Balance aluminum and unavoidable impurities. Aluminum alloy brazing sheet product according to one of the Claims 1 to 9 , wherein the Al-Si alloy brazing material layer (1) further contains one or more wetting elements selected from the group consisting of Bi, Y, Pb, Li, Na, Sb, Sr and Th, and wherein the total amount of Wetting element (of the wetting elements) is in a range of 0.01% to 0.8%. Aluminum alloy brazing sheet product according to one of the Claims 1 to 10 wherein the Al-Si alloy brazing material layer (1) has a Mg content in the range of 0.02% to 1.0% and preferably in the range of 0.05% to 1.0% and more preferably in the range of 0 , 09% to 0.25%. A method of making an assembly from solder components comprising the following steps: i. Providing the components, at least one of which is made from an aluminum alloy brazing sheet product according to one of the Claims 1 to 11 is manufactured; ii assembling the components into an assembly; iii. Soldering the assembly without applying flux in an inert gas atmosphere at a soldering temperature for a period of time long enough to melt and distribute the filler; iv. Cooling of the soldered assembly. Use of an aluminum alloy brazing sheet product according to one of the Claims 1 to 11 in the manufacture of an assembly from solder components in a flux-free soldering process under a controlled atmosphere. Solder assembly which is an aluminum alloy brazing sheet according to one of the Claims 1 to 11 integrated. Solder assembly after Claim 14 , wherein the solder assembly is a motor vehicle heat exchanger. Solder assembly after Claim 14 , the solder assembly being an oil cooler or a folded tube.

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