High recovery content aluminum alloys, aluminum alloy products and methods of producing brazed products

Abstract

Disclosed herein are aluminum alloys useful in core alloys. The aluminum alloy may be produced from 50% or more of recycled aluminum alloy materials and exhibit good strength and corrosion resistance for use in heat exchangers. The aluminum alloy is resistant to higher amounts of recovered aluminum alloy material while maintaining corrosion resistance and suitability for controlled atmosphere brazing processes. The present disclosure also provides uncoated aluminum alloy products and coated aluminum alloy products including an aluminum alloy as a core layer and / or one or more coating layers.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 481,252, filed January 24, 2023, which is incorporated herein by reference in its entirety for all intents and purposes. Technical Field

[0003] The present disclosure relates to the fields of materials science, materials chemistry, metallurgy, aluminum alloys, aluminum alloy products, aluminum manufacturing, and related fields. More specifically, the present disclosure provides a novel aluminum alloy that can be used in a variety of applications, including, for example, as a core alloy for clad aluminum alloy products that can be produced from recycled aluminum alloy material. Background Art

[0004] People have long been interested in using recycled aluminum alloy materials to produce aluminum alloys. Incorporating recycled aluminum alloy materials results in a reduction in cost and time associated with producing primary aluminum, as well as a reduction in carbon emissions (e.g., global impact and specific carbon footprint reduction). However, recycled aluminum alloy materials may not be suitable for preparing high-performance aluminum alloys because recycled aluminum alloy materials may contain higher levels of certain undesirable elements. For example, the aluminum alloy components used in heat exchangers require, among other properties, high corrosion resistance. Therefore, the aluminum alloy components used in heat exchangers have strict composition restrictions. The strict boundaries of many high-performance aluminum alloy products severely limit the amount and type of recycled aluminum alloy materials and process-related waste materials that can be used to form and process. For example, recycled waste materials may contain a certain amount of certain elements that adversely affect the mechanical properties and corrosion resistance of the aluminum alloy. For these reasons, it is impractical to use a large amount of recycled waste materials in producing certain aluminum alloys, particularly for heat exchangers that require strictly controlled aluminum alloy composition and material properties. Summary of the Invention

[0005] The embodiments encompassed by the present invention are defined by the claims, not by this Summary. This Summary is a high-level overview of various aspects of the invention and introduces some of the concepts further described in the Detailed Description below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used alone to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification, any or all of the drawings, and each claim.

[0006] Provided herein are recycling-friendly aluminum alloys for a variety of applications. The aluminum alloys described herein include 0.7–1.3 wt% Si, up to 0.6 wt% Fe, 0.1–0.6 wt% Cu, 0.9–2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al. In some embodiments, the aluminum alloy includes 0.7–1.3 wt% Si, up to 0.6 wt% Fe, 0.1–0.6 wt% Cu, 0.9–2 wt% Mn, up to 0.2 wt% Mg, up to 0.25 wt% Cr, up to 0.4 wt% Zn, up to 0.2 wt% Ti, up to 0.25 wt% Zr, up to 0.15 wt% impurities, and the remainder Al. In some embodiments, the aluminum alloy comprises 0.8-1.3 wt% Si, up to 0.4 wt% Fe, 0.1-0.5 wt% Cu, 0.9-2 wt% Mn, up to 0.1 wt% Mg, up to 0.2 wt% Cr, up to 0.3 wt% Zn, up to 0.2 wt% Ti, up to 0.2 wt% Zr, up to 0.15 wt% impurities, and the balance Al. In some embodiments, the aluminum alloy comprises 0.85-1.3 wt% Si, up to 0.55 wt% Fe, 0.1-0.55 wt% Cu, 1-2 wt% Mn, up to 0.2 wt% Mg, up to 0.15 wt% Cr, up to 0.2 wt% Zn, up to 0.15 wt% Ti, up to 0.15 wt% Zr, up to 0.15 wt% impurities, and the balance Al. In some embodiments, the aluminum alloy comprises 0.85-1.25 wt% Si, up to 0.5 wt% Fe, 0.2-0.5 wt% Cu, 1.2-1.8 wt% Mn, up to 0.15 wt% Mg, up to 0.10 wt% Cr, up to 0.10 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr, up to 0.15 wt% impurities, and the balance Al. In some embodiments, the aluminum alloy comprises 0.85-1.15 wt% Si, up to 0.38 wt% Fe, 0.23-0.43 wt% Cu, 1.4-1.6 wt% Mn, up to 0.1 wt% Mg, up to 0.05 wt% Cr, up to 0.05 wt% Zn, up to 0.1 wt% Ti, up to 0.05 wt% Zr, up to 0.15 wt% impurities, and the balance Al.

[0007] In some embodiments, the aluminum alloy comprises 0.9–1.1 wt % Si, up to 0.35 wt % Fe, 0.23–0.43 wt % Cu, 1.4–1.6 wt % Mn, up to 0.05 wt % Mg, up to 0.03 wt % Cr, up to 0.04 wt % Zn, up to 0.1 wt % Ti, up to 0.01 wt % Zr, up to 0.15 wt % impurities, and the remainder Al. In some embodiments, the aluminum alloy comprises greater than 50% recycled aluminum alloy material. In some embodiments, the recycled aluminum alloy material comprises used clad aluminum alloy products, including a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys. In some embodiments, the solidus temperature of the aluminum alloy is 600° C. or higher. In some embodiments, the ultimate tensile strength of the aluminum alloy is 125 MPa to 200 MPa. In some embodiments, the yield strength of the aluminum alloy is 35 MPa to 80 MPa. In some embodiments, the aluminum alloy comprises 0.85–1.25 wt. % Si, up to 0.50 wt. % Fe, 0.2–0.55 wt. % Cu, 1.2–1.8 wt. % Mn, up to 0.15 wt. % Mg, up to 0.1 wt. % Cr, up to 0.1 wt. % Zn, up to 0.1 wt. % Ti, up to 0.05 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al, wherein the aluminum alloy comprises greater than 50% recycled aluminum alloy material, the recycled aluminum alloy material comprising a used clad aluminum alloy product comprising a mixture of a 3xxx series aluminum alloy and a 4xxx series aluminum alloy; and wherein the aluminum alloy has a solidus temperature of 600° C. or greater. Provided herein are unclad aluminum alloy products comprising the aluminum alloys described herein. Provided herein are clad aluminum alloy products comprising a core layer comprising the aluminum alloys described herein.

[0008] Provided herein is a clad aluminum alloy product comprising: a core layer, wherein the core layer has a first side and a second side; at least one cladding layer on the first side or the second side; wherein the core layer and / or the cladding layer comprises 0.7-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al. In some embodiments, the at least one cladding layer comprises a 1xxx, 3xxx, 4xxx, or 7xxx series aluminum alloy. In some embodiments, a heat exchanger comprises the clad aluminum alloy product described herein.

[0009] Provided herein is a method for forming a brazed product, the method comprising the steps of providing one or more metal parts; providing a clad aluminum alloy product on or between the one or more metal parts to form an assembly, wherein the clad aluminum alloy product comprises a core layer; brazing the assembly to join the clad aluminum alloy product and the one or more metal parts to produce a brazed assembly; optionally applying a flux load prior to brazing; and cooling the brazed assembly, wherein the core layer comprises 0.7-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al. In some embodiments, brazing comprises controlled atmosphere brazing. In some embodiments, the assembly is brazed at a brazing temperature of 560°C to 620°C.

[0010] Other aspects, objects and advantages will become apparent upon consideration of the following detailed description of the invention, given by way of non-limiting examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A graph showing the effect of alloying elements on the solidus temperature of aluminum alloys as a function of silicon concentration in the aluminum alloy is provided. Typical CAB brazing temperatures are also shown.

[0012] Figure 2 A graph showing the effect of the amount of primary aluminum on the carbon footprint of an aluminum alloy product is provided. DETAILED DESCRIPTION

[0013] This paper describes a novel aluminum alloy that can be used as, for example, a core aluminum alloy, a clad aluminum alloy product, a non-clad aluminum alloy product (fin blank, bracket, etc.), and a related method for producing a brazed product using the novel aluminum alloy. Aluminum alloy as described herein is a "recycling-friendly" aluminum alloy that can be used for a variety of applications, including, for example, as a core alloy in a clad aluminum product (e.g., brazing sheet), which can replace the core aluminum alloy produced by high-content raw aluminum. Aluminum alloy as described herein can tolerate higher amounts of silicon (Si) and copper (Cu) than conventional 3xxx series aluminum alloys (e.g., for brazing sheet), thereby allowing the use of recycled aluminum alloy materials. Specifically, aluminum alloy scrap containing high Si can be used to produce aluminum alloy as described herein. For example, clad aluminum alloy products can be produced by a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys. 4xxx series aluminum alloys include Si as a primary alloying element. Aluminum alloy as described herein can be produced by aluminum alloy scrap containing high Si (such as clad aluminum alloy products), and still maintains desired performance. Despite having relatively high Si and Cu contents, the aluminum alloys described herein maintain a solidus temperature of 600° C. or above for use as core alloys or non-clad alloys. The aluminum alloys described herein include a careful balance of alloying elements to provide aluminum alloy products having a sufficient solidus temperature for standard controlled atmosphere brazing (CAB) with relatively low flux loadings while having good corrosion resistance and providing increased strength compared to AA3003 aluminum alloy.

[0014] Conventional aluminum alloys used as core alloys for heat exchanger products (e.g., 3xxx series aluminum alloys) cannot be produced with high-content recycled aluminum alloy materials (with a higher amount of Si) without sacrificing aluminum alloy performance. However, in order to reduce carbon footprint, the market demand for aluminum alloys produced from recycled aluminum alloy materials is huge. In addition to factors such as price and material properties, the recycled content of specific aluminum alloys is also increasingly important for the automotive and non-automotive industries. Although aluminum alloys that can be incorporated with a large amount of recycled aluminum alloy materials with a wide range of alloying elements (e.g., Mg, Si, Cu, and Mn) chemical windows are available on the market, these aluminum alloys cannot be considered for key components (e.g., corrosion-critical components in heat exchangers). For these key components, the aluminum alloy composition can have more stringent composition restrictions to achieve the desired performance. For example, the aluminum alloys used in heat exchangers require a balance of alloying elements to obtain good brazing performance and corrosion resistance. For example, Si and Cu can reduce the solidus temperature of the aluminum alloy, which is crucial for brazing at about 600°C. Aluminum alloys with a solidus temperature below 600°C may be prone to local melting during brazing, thereby limiting the use of recycled aluminum alloy materials containing higher amounts of Si and Cu. In addition, the Mg content in the aluminum alloy used as the core alloy may affect the amount of flux required for the CAB process. Aluminum alloys containing a large amount of Mg (e.g., greater than 0.2 wt%) require a higher flux load. However, a higher flux load may result in a higher amount of flux residue on the surface of the material after brazing. This may have functional effects, for example, if necessary, the flux residue may lead to uneven painting and / or poor adhesion during the painting process.

[0015] The aluminum alloys described herein incorporate higher amounts of recycled aluminum alloy materials (e.g., high Si-containing aluminum alloy scrap) than conventional core aluminum alloys and still maintain good mechanical properties, such as for brazing applications. Specifically, the aluminum alloys described herein include carefully balanced alloying elements, thereby surprisingly providing aluminum alloy products that have sufficient temperature resistance to perform brazing with relatively low flux loadings (e.g., less than 5 g / m 2) brazing, while having good corrosion resistance (although produced by a large amount of recycled aluminum alloy materials). In some embodiments, the aluminum alloy described herein is a modified 3xxx series aluminum alloy, which includes a balance of silicon (Si), copper (Cu), magnesium (Mg) and manganese (Mn), which can be used for brazing applications with relatively low flux loads. Without being bound by theory, adding Mn (e.g., 0.9 wt % to 2 wt %) improves the solidus temperature of the aluminum alloy, thereby allowing, for example, a higher amount of Si and Cu from recycled aluminum alloy materials. In addition, the aluminum alloy can include 0.2 wt % or less Mg to braze with a lower flux load, to minimize or reduce the amount of flux residue, and thereby avoid or at least minimize the rinsing and cleaning operations after CAB. The combination of performance provides an aluminum alloy that can be used as the core alloy of a clad aluminum alloy product. Aluminum alloy compositions as described herein provide a more environmentally friendly alternative to using existing 3xxx series aluminum alloys for clad aluminum products.

[0016] The aluminum alloys described herein have a combination of properties suitable for the heat exchanger market (e.g., including vehicle electrification). In summary, the aluminum alloys described herein have a combination of a relatively high relative recycled content (e.g., 50 wt. % to 70 wt. %), which can be derived from materials containing high Si to reduce the carbon footprint of the aluminum alloy, the aluminum alloys have a higher Mn content (e.g., 0.9 wt. % to 2 wt. %) to compensate for Si and Cu that lower the solidus temperature of the aluminum alloy, and the aluminum alloys have a Mg content (e.g., 0.2 wt. % or less) that allows for relatively low flux loadings, for example, to support lower electrical conductivity of standard coolants, with little or no need for post-braze cleaning and / or rinsing operations. The newly developed aluminum alloys can be produced at high recycling rates and can be brazed with smaller amounts of flux, thereby ensuring uniform painting without the need to clean the brazed parts.

[0017] Definition and Explanation:

[0018] As used herein, the terms "invention," "described invention," "this invention," and "the present invention" are intended to refer broadly to the entire subject matter of this patent application and the claims that follow. Statements containing these terms should not be construed to limit the subject matter described herein or to limit the meaning or scope of the patent claims that follow.

[0019] In this specification, reference is made to alloys identified by aluminum industry designations, such as "Series" or "3xxx." For information on the numerical designation systems most commonly used to name and identify aluminum and its alloys, see "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys" or "Registration Record of Aluminum Association Alloy Designations and Chemical Compositions Limits for Aluminum Alloys in the Form of Castings and Ingots," published by The Aluminum Association.

[0020] As used herein, the meaning of "a," "an," or "the" includes both singular and plural referents unless the context clearly indicates otherwise.

[0021] As used herein, plate generally has a thickness greater than about 15 mm. For example, plate can refer to an aluminum product having a thickness greater than about 15 mm, greater than about 20 mm, greater than about 25 mm, greater than about 30 mm, greater than about 35 mm, greater than about 40 mm, greater than about 45 mm, greater than about 50 mm, or greater than about 100 mm.

[0022] As used herein, shate board (also referred to as sheet board) typically has a thickness of about 4 mm to about 15 mm. For example, shate board can have a thickness of about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, or about 15 mm.

[0023] As used herein, sheet generally refers to an aluminum product having a thickness of less than about 4 mm. For example, the sheet can have a thickness of less than about 4 mm, less than about 3 mm, less than about 2 mm, less than about 1 mm, less than about 0.5 mm, less than about 0.3 mm, or less than about 0.1 mm.

[0024] As used herein, the "solidus temperature" of an aluminum alloy refers to the highest temperature at which the aluminum alloy is completely in the solid state before partial melting begins.

[0025] Reference is made throughout this application to alloy tempers or conditions. For descriptions of the most commonly used alloy tempers, see "American National Standard (ANSI) H35 on Alloy and Temper Designation System." The F temper or temper refers to the aluminum alloy as manufactured. The O temper or temper refers to the aluminum alloy after annealing. The Hxx temper or temper, also referred to herein as the H temper, refers to the aluminum alloy with or without heat treatment (e.g., annealing) after cold rolling. Suitable H tempers include HX1, HX2, HX3, HX4, HX5, HX6, HX7, HX8, or HX9 tempers. For example, aluminum alloys can be strain hardened to various tempers, such as H16, H18, or other H1X tempers.

[0026] Reference is made to recycled content throughout this application. The term "recycled content" includes, but is not limited to, what is commonly referred to as internal process waste or scrap, and also includes different types of external scrap, such as post-consumer scrap, remelt scrap ingot (RSI), etc. Since primary aluminum (excluding alloying elements and hardeners) is the primary source of Scope 3 emissions (as described below), all types of recycled content input (whether internal or external scrap) contribute to more sustainable aluminum alloy products and support possible closed-loop material circulation (production) processes.

[0027] The following aluminum alloys are described in terms of elemental composition in weight percent (wt%) based on the total weight of the alloy. In certain examples of each alloy, the remainder is aluminum, with a maximum wt% of the sum of impurities of 0.15%.

[0028] As used herein, "controlled atmosphere brazing" or "CAB" refers to a brazing process that utilizes an inert gas atmosphere (eg, nitrogen or argon) in the brazing of various alloy articles.

[0029] As used herein, "electrochemical potential" refers to a material's amenability to redox reactions. Electrochemical potential can be used to assess the corrosion resistance of the aluminum alloys described herein. Negative values ​​can describe a material that is more easily oxidized (e.g., loses electrons or has an increased oxidation state) when compared to a material having a positive electrochemical potential or a less negative electrochemical potential. Positive values ​​can describe a material that is more easily reduced (e.g., gains electrons or has a decreased oxidation state) when compared to a material having a negative electrochemical potential or a less positive electrochemical potential. As used herein, electrochemical potential is a vector quantity representing both magnitude and direction.

[0030] As used herein, "room temperature" may include temperatures from about 15°C to about 30°C, for example, about 15°C, about 16°C, about 17°C, about 18°C, about 19°C, about 20°C, about 21°C, about 22°C, about 23°C, about 24°C, about 25°C, about 26°C, about 27°C, about 28°C, about 29°C or about 30°C.

[0031] All ranges disclosed herein should be understood to encompass any and all subranges subsumed therein. For example, the specified range "1 to 10" should be considered to include any and all subranges between (and including) a minimum of 1 and a maximum of 10; that is, all subranges begin with a minimum of 1 or greater, such as 1 to 6.1, and end with a maximum of 10 or less, such as 5.5 to 10.

[0032] Clad aluminum alloy products

[0033] The terms "cladding," "clad," "cladding layer," "clad layer," and related terms are generally used to refer to a relatively thin surface layer of a clad aluminum alloy product. The terms "core," "core layer," and related terms are used to refer to a relatively thicker layer of a clad aluminum alloy product. In some instances, a clad aluminum alloy product (e.g., a clad sheet aluminum alloy) may have cladding layers on both sides of the core layer, in which case the core layer is the inner layer of the aluminum material. However, a clad aluminum alloy product (e.g., a clad sheet aluminum alloy) may also have a cladding layer on only one side of the core layer, in which case the core layer may also be the surface. The core layer and the cladding layer typically have different chemical compositions. In some cases, a clad aluminum alloy product may have two cladding layers having different compositions and properties.

[0034] It should be understood that a clad aluminum alloy product suitable for brazing applications does not necessarily contain only a core layer and one or two cladding layers. The clad aluminum alloy product may contain other layers (e.g., to form a multi-layer aluminum material), some of which may be referred to as "sandwiches," "outer layers," "linings," and other related terms. For example, a clad aluminum alloy product may have 2, 3, 4, 5, 6, or more different layers, each having a certain function. More generally, a clad aluminum alloy product may have as many stackable layers as possible and be bonded together in one or more operations. In a commercial context, a possible limiting factor may be the production cost and / or waste generated in the process of producing the clad aluminum alloy product, which may become too high to be commercially viable as the number of layers of the clad aluminum alloy product increases. In the context of a clad aluminum alloy product suitable for brazing applications, one or more cladding layers may be part of the product that melts during the brazing cycle. A liner may be a layer that is not expected to melt during the brazing cycle and which may impart some other benefits to the clad aluminum alloy product, such as corrosion resistance or increased strength. The core may also include multiple layers, such as one or more interlayers on one or both sides of the main core layer.

[0035] In some embodiments, the coated aluminum alloy product includes a core layer and at least one cladding layer. In some cases, the coated aluminum alloy product includes a core layer, a first cladding layer and a second cladding layer. In these aspects, the first cladding layer may be adjacent to and contact with the first side of the core layer to form a first interface (that is, no layer intervenes between the first cladding layer and the first side of the core layer). The second cladding layer may be adjacent to and contact with the second side of the core layer to form a first interface (that is, no layer intervenes between the second cladding layer and the second side of the core layer). The first cladding layer and the second cladding layer may each comprise an alloy composition as described herein. In some embodiments, the core layer is coated only on one side. In other embodiments, the core layer is coated on both sides. In other embodiments, the core layer is coated on one side of the core layer, and a water side lining or other layers are placed on the other side of the core layer. In other embodiments, the core layer is not coated and is intended to be used together with other coated aluminum alloy products.

[0036] The aluminum alloy compositions described herein can be used as the core layer of a clad aluminum alloy product. The aluminum alloy can tolerate higher amounts of Si than some of the standard 3xxx series aluminum alloys (e.g., AA3003 aluminum alloy). Therefore, the aluminum alloy used for the core layer can be produced from a higher amount of recycled aluminum alloy containing relatively high Si. For example, a clad aluminum alloy product may include a core layer comprising a 3xxx series aluminum alloy and one or more cladding layers comprising a 4xxx series aluminum alloy. The 4xxx series aluminum alloy contains Si as the main alloying element. The higher concentration of Si in the clad aluminum alloy product limits its use as a core alloy for the production of brazing sheets from recycled aluminum. The aluminum alloys described herein can tolerate higher amounts of Si, and therefore the clad aluminum alloy products can be utilized as recycled material. In particular, the aluminum alloys described herein can be produced from more than 50% recycled aluminum alloy material (e.g., mixed 3xxx / 4xxx series aluminum alloy process scrap).

[0037] Figure 1 A graph is provided showing the effect of alloying elements on the solidus temperature of an aluminum alloy. Concentrations of Si and Cu both reduce the solidus temperature of the aluminum alloy, while Mn increases the solidus temperature of the aluminum alloy. Recycled aluminum alloy materials (e.g., clad aluminum alloy products) containing higher amounts of Si can reduce the solidus temperature of the aluminum alloy. Specifically, core alloys having a solidus temperature below 600°C may be susceptible to local melting during brazing. The aluminum alloy composition of the core alloy described herein includes a balance of Si, Cu, and Mn, thereby providing a solidus temperature of 600°C or higher. The Mn in the aluminum alloy composition compensates for Si and Cu to produce an aluminum alloy having a desired solidus temperature for brazing applications.

[0038] In addition, the aluminum alloy described herein comprises at most 0.2 wt % Mg. The amount of Mg in the aluminum alloy used for the core layer is carefully balanced to provide good brazing performance (e.g., by CAB process). Aluminum alloys comprising more than 0.2 wt % Mg may require higher flux loadings during the CAB process. However, using higher flux loadings may result in increased flux residues after brazing. During heat exchanger operation, flux residues may cause certain coolants to form gels, which may reduce the efficiency of the heat exchanger. Therefore, in the case of the CAB process, strong rinsing and cleaning may be required to remove excessive flux residues. For this reason, vacuum brazing is also an alternative processing option. The aluminum alloy described herein comprises at most 0.2 wt % Mg, which makes it possible to use lower flux loadings during brazing. Lower flux loadings can limit the amount of flux residues to avoid the need to rinse and clean the brazed heat exchanger.

[0039] The clad aluminum alloy products and methods described herein can be used in industrial applications including sacrificial parts, filler parts, heat dissipation, packaging, and building materials. In some embodiments, the clad aluminum alloy products described herein can be used in aluminum alloy components for heat exchangers, including use with dissimilar metals and as or with extruded components. Specifically, the clad aluminum alloy products described herein can be formed into brazed products. Suitable cladding layers and core layers for such clad aluminum alloy products are described below.

[0040] Core layer

[0041] Described below are novel aluminum alloy compositions that can be produced using relatively high levels of recycled aluminum alloy material. In some embodiments, the aluminum alloys described herein can be used as a core layer, combined with a cladding layer to produce the clad aluminum alloy products described herein, or without a cladding layer to produce a bare, unclad core alloy. The resulting clad aluminum alloy products are suitable for a variety of applications, including, for example, use as corrosion-resistant brazing sheet packaging in cold plates (e.g., cooling plates or battery cooling plates) for manufacturing electric vehicle batteries.

[0042] In some embodiments, the aluminum alloy is a modified 3xxx series aluminum alloy. For example, the aluminum alloy can be a modified AA3003 aluminum alloy. Compared to unmodified 3xxx series aluminum alloys, although the aluminum alloys described herein are produced from relatively high amounts of recycled aluminum alloys (e.g., aluminum materials containing Si), they still exhibit good brazing properties and corrosion resistance. The performance of the alloy is achieved in part due to the elemental composition of the alloy.

[0043] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 1.

[0044] Table 1

[0045]

[0046] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 2.

[0047] Table 2

[0048]

[0049] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 3.

[0050] Table 3

[0051]

[0052] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 4.

[0053] Table 4

[0054]

[0055] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 5.

[0056] Table 5

[0057]

[0058]

[0059] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 6.

[0060] Table 6

[0061]

[0062] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 7.

[0063] Table 7

[0064]

[0065]

[0066] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 8.

[0067] Table 8

[0068]

[0069] In some examples, the aluminum alloy optionally used as the core layer can have the following elemental composition as provided in Table 9.

[0070] Table 9

[0071]

[0072]

[0073] Silicon (Si)

[0074] In some examples, the aluminum alloy includes silicon (Si) in an amount of 0.70% to 1.35% (e.g., 0.70% to 1.3%, 0.8% to 1.3%, 0.85% to 1.3%, 0.85% to 1.25%, 0.85% to 1.2%, 0.85% to 1.15%, or 0.9% to 1.1%), based on the total weight of the alloy. For example, the aluminum alloy may include 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.00%, 1.01%, 1.02%, 1.03%, 1.04%, 1.05%, 1.06%, 1.07%, 1.08%, 1.09%, 1.10%, 1.11%, 1.12%, 1.13%, 1.14%, 1.15%, 1.16%, 1.17%, 1.18%, 1.19%, 1.20%, 1.21%, 1.22%, 1.23%, 1.24%, 1.25%, 1.26%, 1.27%, 1.28%, 1.29%, %. 1.02%, 1.03%, 1.04%, 1.05%, 1.06%, 1.07%, 1.08%, 1.09%, 1.10%, 1.11%, 1.12%, 1.13%, 1.14%, 1.15%, 1.16%, 1.17%, 1.18%, 1.19%, 1.20%, 1.21%, 1.22%, 1.23%, 1.24%, 1.25%, 1.26%, 1.27%, 1.28%, 1.29%, 1.30%, 1.31%, 1.32%, 1.33%, or 1.35% Si. All percentages are expressed in weight %. As mentioned above, Si can lower the solidus temperature of the aluminum alloy. The amounts of Si and Mn are carefully balanced to provide an adequate solidus temperature for the aluminum alloy used in the brazing process. Furthermore, aluminum alloys having Si contents of 0.7% to 1.3% can utilize recycled aluminum alloy scrap containing higher amounts of Si. For example, the aluminum alloys described herein can be produced from aluminum alloy process scrap containing higher amounts of Si, such as used clad aluminum alloy products containing a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys. However, higher levels of Si (e.g., greater than 1.3 wt. %) can increase the risk of corrosion during brazing.

[0075] Iron (Fe)

[0076] In some examples, the alloy further includes up to 0.6% (e.g., up to 0.6, up to 0.55, up to 0.5, up to 0.45, up to 0.4, up to 0.38%, up to 0.35%, up to 0.3%, up to 0.25%, or up to 0.2%) iron (Fe), based on the total weight of the alloy. For example, the alloy may include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.60%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0. 39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, or 0.60% Fe. In some cases, Fe is absent from the alloy (i.e., 0%). All percentages are expressed in weight %.

[0077] Copper (Cu)

[0078] In some examples, the disclosed alloys include copper (Cu) in an amount of 0.1% to 0.6% (e.g., 0.1% to 0.55%, 0.1% to 0.5%, 0.1% to 0.4%, 0.15% to 0.45%, 0.2% to 0.45%, 0.2% to 0.4%, or 0.23% to 0.43%) based on the total weight of the alloy. For example, the alloy may contain 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%. %, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, or 0.60% Cu. All percentages are expressed in weight %. Adding Cu can increase the electrochemical potential of the aluminum alloy (e.g., the core aluminum alloy) and thereby improve the corrosion resistance.

[0079] Manganese (Mn)

[0080] In some examples, the alloy can include manganese (Mn) in an amount of 0.9% to 2% (e.g., 1% to 2%, 1% to 1.9%, 1.2% to 1.8%, or 1.4% to 1.6%), based on the total weight of the alloy. For example, the alloy can include 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.00%, 1.01%, 1.02%, 1.03%, 1.04%, 1.05%, 1.06%, 1.07%, 1.08%, 1.09%, 1.10%, 1.11%, 1.12%, 1.13%, 1.14%, 1.15%, 1.16%, 1.17%, 1.18%, 1.19%, 2.20%, 2.21%, 2.22%, 2.23%, 2.24%, 2.25%, 2.26%, 2.27%, 2.28%, 2.29%, 3.30%, 3.31%, 3.32%, 3.33%, 3.34%, 3.35%, 3.36%, 3.37%, 3.38%, 3.39%, 3.40%, 3.41%, 3.42%, 3.43%, 3.44%, 3.45%, 3.46%, 3.47%, 3.48%, 3.49%, 3.50%, 3.51%, 3.52%, 3.53%, 3.54%, 3.55%, 3.56%, 3.57%, 3.58%, 3.59%, %, 1.17%, 1.18%, 1.19%, 1.20%, 1.21%, 1.22%, 1.23%, 1.24%, 1.25%, 1.26%, 1.27%, 1.28%, 1.29%, 1.30%, 1.31%, 1.32%, 1.33%, 1.34%, 1.35%, 1.36%, 1.37%, 1.38%, 1.39%, 1.40%, 1.41%, 1.42%, 1.43%, 1.44% , 1.45%, 1.46%, 1.47%, 1.48%, 1.49%, 1.50%, 1.51%, 1.52%, 1.53%, 1.54%, 1.55%, 1.56%, 1.57%, 1.58%, 1.59%, 1.60%, 1.61%, 1.62%, 1.63%, 1.64%, 1.65%, 1.66%, 1.67%, 1.68%, 1.69%, 1.70%, 1.71%, 1.72% %, 1.73%, 1.74%, 1.75%, 1.76%, 1.77%, 1.78%, 1.79%, 1.80%, 1.81%, 1.82%, 1.83%, 1.84%, 1.85%, 1.86%, 1.87%, 1.88%, 1.89%, 1.90%, 1.91%, 1.92%, 1.93%, 1.94%, 1.95%, 1.96%, 1.97%, 1.98%, 1.99%, or 2.00% Mn. All percentages are expressed in weight %. As mentioned above, Mn can increase the solidus temperature of the aluminum alloy. Mn is added to the aluminum alloy composition to compensate for the higher amounts of Si and Cu in the aluminum alloy composition. In addition, most of the Mn remains in solid solution, while a small amount precipitates as fine dispersions during hot rolling and intermediate annealing. The effect of this microstructure is that when the material is heated to 600°C during the brazing operation, the material maintains strength due to the solid solution strengthening effect of Mn. In this way, the addition of Mn is optimized to provide a useful balance of properties. Another positive effect of Mn is the formation of fine dispersions that control the grain structure of the brazed heat exchanger or brazing sheet itself.

[0081] Magnesium (Mg)

[0082] In some examples, the alloy can include magnesium (Mg) in an amount of up to 0.2% (eg, up to 0.15%, up to 0.1%, up to 0.08%, up to 0.05%, or up to 0.03%) based on the total weight of the alloy. For example, the alloy may contain 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.20% Mg. In some cases, Mg is absent from the alloy (i.e., 0%). All percentages are expressed in weight %. The Mg content in the aluminum alloy may affect the amount of flux required during the CAB process. Aluminum alloys containing large amounts of Mg (e.g., greater than 0.2 wt. %) require higher flux loadings. However, higher flux loadings result in higher amounts of flux residue after brazing. Flux residues can also lead to uneven painting and / or poor adhesion during the painting process. Advantageously, aluminum alloys containing 0.2 wt. % or less of Mg allow brazing with lower flux loadings to minimize or reduce the amount of flux residue.

[0083] Chromium (Cr)

[0084] In some examples, the alloy includes chromium (Cr) in an amount of up to 0.3% (e.g., 0.001% to 0.3%, 0.01% to 0.25%, 0.05% to 0.2%, 0.001% to 0.04%, 0% to 0.05%, 0.001% to 0.04%, or 0.01% to 0.03%) based on the total weight of the alloy. For example, the alloy may include 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0. ... %, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, or 0.30% Cr. In some cases, Cr is absent from the alloy (i.e., 0%). All percentages are expressed in weight %.

[0085] Zinc (Zn)

[0086] In some examples, the alloy includes zinc (Zn) in an amount of up to 0.5% (e.g., 0.001% to 0.5%, 0.001% to 0.4%, 0.001% to 0.3%, 0.01% to 0.2%, 0% to 0.15%, 0% to 0.1%, or 0% to 0.03%) based on the total weight of the alloy. For example, the alloy may contain 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 48%, 0.49%, or 0.50% Zn. In some cases, Zn is not present in the alloy (i.e., 0%).

[0087] Titanium (Ti)

[0088] In some examples, the alloy includes titanium (Ti) in an amount up to 0.2% (e.g., 0% to 0.15%, 0.001% to 0.1%, 0% to 0.05%, 0.001% to 0.04%, or 0.01% to 0.03%) based on the total weight of the alloy. For example, the alloy may contain 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.20% Ti. In some cases, Ti is absent from the alloy (i.e., 0%). All percentages are expressed in weight %.

[0089] Zirconium (Zr)

[0090] In some examples, the alloy includes zirconium (Zr) in an amount of up to 0.3% (e.g., 0% to 0.25%, 0.001% to 0.2%, 0.01% to 0.15%, 0.01% to 0.1%, 0% to 0.05%, 0.001% to 0.04%, or 0.01% to 0.03%) based on the total weight of the alloy. For example, the alloy may include 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0. ... %.

[0091] Optionally, the alloy composition may also include other trace elements, sometimes referred to as impurities, each in an amount of 0.05% or less, 0.04% or less, 0.03% or less, 0.02% or less, or 0.01% or less. These impurities may include, but are not limited to, Na, Ga, V, Ni, Sc, Ag, B, Bi, Li, Pb, Sn, Ca, Hf, Sr, or a combination thereof. Thus, Na, Ga, V, Ni, Sc, Ag, B, Bi, Li, Pb, Sn, Ca, Hf, or Sr may be present in the alloy in an amount of 0.05% or less, 0.04% or less, 0.03% or less, 0.02% or less, or 0.01% or less. In certain aspects, the sum of all impurities does not exceed 0.15% (e.g., 0.1%). All percentages are expressed in weight %. In certain aspects, the remainder of the alloy is aluminum.

[0092] In some embodiments, exemplary alloys include 0.85%-1.15% Si, up to 0.38% Fe, 0.23%-0.43% Cu, 1.40%-1.60% Mn, up to 0.1% Mg, up to 0.03% Cr, up to 0.04% Zn, up to 0.1% Ti, up to 0.01% Zr, and up to 0.15% total impurities, with the remainder being Al. All percentages are expressed in weight %.

[0093] In some embodiments, exemplary alloys include 0.7-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0094] In some embodiments, exemplary alloys include 0.7-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.25 wt% Cr, up to 0.4 wt% Zn, up to 0.2 wt% Ti, up to 0.25 wt% Zr, up to 0.15 wt% impurities, and the balance Al.

[0095] In some embodiments, exemplary alloys include 0.7-1.3 wt% Si, up to 0.4 wt% Fe, 0.1-0.5 wt% Cu, 0.9-2 wt% Mn, up to 0.1 wt% Mg, up to 0.2 wt% Cr, up to 0.3 wt% Zn, up to 0.2 wt% Ti, up to 0.2 wt% Zr, up to 0.15 wt% impurities, and the balance Al.

[0096] In some embodiments, exemplary alloys include 0.7-1.3 wt% Si, up to 0.55 wt% Fe, 0.1-0.55 wt% Cu, 1-2 wt% Mn, up to 0.2 wt% Mg, up to 0.15 wt% Cr, up to 0.2 wt% Zn, up to 0.15 wt% Ti, up to 0.15 wt% Zr, up to 0.15 wt% impurities, and the balance Al.

[0097] In some embodiments, exemplary alloys include 0.7-1.25 wt% Si, up to 0.5 wt% Fe, 0.2-0.5 wt% Cu, 1.2-1.8 wt% Mn, up to 0.15 wt% Mg, up to 0.10 wt% Cr, up to 0.10 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr, up to 0.15 wt% impurities, and the balance Al.

[0098] In some embodiments, exemplary alloys include 0.7-1.15 wt% Si, up to 0.38 wt% Fe, 0.23-0.43 wt% Cu, 1.4-1.6 wt% Mn, up to 0.1 wt% Mg, up to 0.05 wt% Cr, up to 0.05 wt% Zn, up to 0.1 wt% Ti, up to 0.05 wt% Zr, up to 0.15 wt% impurities, and the balance Al.

[0099] cladding

[0100] In some embodiments, the cladding layer is a 1xxx, 3xxx, 4xxx, or 7xxx series aluminum alloy.

[0101] In some embodiments, the cladding layer is a 4xxx series aluminum alloy.The 4xxx series aluminum alloy may contain 1 wt. % to 15 wt. % Si. Suitable 4xxx series aluminum alloys for use in the cladding layers described herein include, for example, AA4004, AA4104, AA4006, AA4007, AA4008, AA4009, AA4010, AA4013, AA4014, AA4015, AA4015A, AA4115, AA4016, AA4017, AA4018, AA4019, AA4020, AA4021, AA4026, AA4032, AA4043, AA4043A, AA4143, AA4343, AA4643, AA4943, AA4044, AA4045, AA4145, AA4145A, AA4046, AA4047, AA4047A, AA4147, and variations thereof.

[0102] Aluminum alloy materials for core alloy recycling

[0103] The aluminum alloys described herein can tolerate large amounts of recycled aluminum alloy material and significantly reduce Scope 3 emissions, as further defined below. The effects of impurities and / or alloying elements (from recycled aluminum alloy material) on the mechanical properties of the aluminum alloy are reduced by providing a customized aluminum alloy composition to compensate for the impurities. This enables recycled aluminum alloy material with higher impurities (e.g., used clad aluminum alloy products, including 3xxx / 4xxx series aluminum alloys) to be used to produce aluminum alloys that still exhibit desired properties.

[0104] An entity's net greenhouse gas emissions are typically measured in units of CO2 equivalents and are referred to as the entity's "carbon footprint." An entity's carbon footprint is considered a representative measure of the entity's impact on the environment relative to the concentration of greenhouse gases in the atmosphere. Entities that take steps to reduce their carbon footprint are often considered socially responsible and, as such, are often labeled "green" or environmentally friendly. As used herein, the term CO2 means and is intended to include all types of greenhouse gas emissions.

[0105] When determining or attempting to measure an entity's carbon footprint, there are a number of fundamental elements to consider. The primary focus is on operational effects, which account for emissions from the entity's own activities (and those of other emitting entities it owns or controls). Upstream and downstream impacts also need to be considered when determining an entity's net emissions. For accurate "carbon accounting," an entity's operational activities can be further broken down into direct and indirect GHG emissions.

[0106] Direct operational emissions are defined as emissions from sources owned or controlled by an entity, including, for example, emissions from combustion in its own boilers or vehicles. For the purpose of reporting emissions data for carbon audits and regulatory filings, those skilled in the art typically refer to an entity's direct emissions as Scope 1 emissions. These emissions can be precisely measured using equations, which may require knowledge of, for example, the mass / volume of fuel burned per unit time and how the fuel is burned.

[0107] An entity's Scope 1 emissions can be affected by many factors, including factors such as how its factories operate or how goods are transported within and across the company. For example, a company that uses hybrid vehicles rather than traditional internal combustion engine vehicles to transport goods might be considered to have reduced its carbon footprint to some extent. Similarly, companies that take measures to reduce emissions from their factories (for example, by using on-site renewable heat sources such as solar thermal panels) will also have a smaller carbon footprint than companies that do not take such measures.

[0108] Indirect operational emissions are defined as emissions resulting from the electricity consumed by an entity. These emissions occur at the entity's supplier's facilities, where the electricity is generated, and are generally referred to by those skilled in the art as Scope 2 emissions. These emissions can also be calculated with high accuracy using knowledge of electricity consumption (e.g., in megawatt-hours) over a specific time period, using an "emission factor" associated with a specific electricity supplier and designated tariff.

[0109] If an entity chooses to pay for electricity supplied with a renewable energy component, its Scope 2 emissions will be reduced proportionately. Similarly, if an entity is able to reduce the need to source electricity from external suppliers, for example through energy efficiency improvements or the development of on-site renewable power sources such as solar photovoltaic panels, emissions can also be reduced.

[0110] When calculating a net carbon footprint, a range of other emissions associated with an entity's activities can also be considered. These will vary by industry sector and sub-sector and are generally referred to as Scope 3 emissions. These emissions may include emissions from activities such as employee travel and downstream consumer visits to the entity's premises. When estimating Scope 3 emissions, both upstream and downstream suppliers in the entity's value chain may be considered. This can be important, for example, because "carbon-intensive" parts of the value chain may be performed by third parties other than the entity under consideration, yet still result from the entity's operations. An example of this is an online mail-order company with a small warehouse and office, which may itself result in low direct / indirect emissions, but which subcontracts to a delivery company with a large fleet of trucks and high emissions. Downstream effects can also be influenced by a plethora of other factors, which may vary across industries.

[0111] The aluminum alloys described herein contain less primary aluminum than conventional 3xxx series aluminum alloys, thereby reducing scope 3 emissions during the aluminum alloy production process to reduce the overall carbon footprint. In order to reduce the amount of primary aluminum and include a large amount of recycled aluminum alloy materials, the aluminum alloy composition is carefully tailored to provide balanced mechanical properties. For example, Figure 1 An example of a phase diagram of the solidus temperature of an aluminum alloy as a function of the Si concentration in the aluminum alloy is provided. Si is one of the common alloying elements in some recycled aluminum alloy materials, which may affect the mechanical properties if used to produce new aluminum alloys. Figure 1 As shown, if aluminum alloys are produced from recycled aluminum materials containing a high concentration of Si, the solidus temperature of the aluminum alloys produced from these recycled materials may be significantly lower than 600° C. Aluminum alloys with a solidus temperature lower than 600° C. may be susceptible to partial melting and cannot be used to produce core aluminum alloys. Therefore, the type and amount of recycled aluminum alloy materials that can be used to produce core aluminum alloys are limited based on the amount of Si.

[0112] Compared to conventional 3xxx series aluminum alloys, the aluminum alloy compositions described herein may contain a higher amount of recycled aluminum alloy materials to reduce the overall carbon footprint of the aluminum alloy. Aluminum alloys produced from recycled aluminum alloys that contain little to no primary aluminum minimize potential environmental impacts. Although primary aluminum may only account for a small portion of the raw material inputs for many aluminum alloys, its contribution to the environmental impact of many aluminum alloy products is significant. In view of the significant impact of primary aluminum on carbon footprint, one way to reduce scope 3 emissions (as defined above) in the aluminum alloy production process is to reduce the use of primary aluminum and increase the use of recycled aluminum alloy materials. For example, Figure 2It is shown that a 1% increase in primary aluminum increases the carbon footprint of the aluminum alloy by 117 kg CO₂e / 1,000 kg of product produced. Therefore, a 1% increase in recycled aluminum alloy material used to produce the aluminum alloy will result in a reduction in the carbon footprint by the same amount. Although aluminum alloys are available on the market that can incorporate larger amounts of recycled aluminum alloy material that allow higher levels of certain key elements (e.g., Mg, Si, Cu, and Mn), these aluminum alloys cannot be considered for use in critical components (e.g., corrosion-critical components) in heat exchangers. For these critical components, more stringent chemical resistance may be required to achieve the desired performance.

[0113] In some embodiments, the aluminum alloys described herein provide a composition well-suited for utilizing post-consumer clad aluminum alloy products as recycled material. Specifically, the aluminum alloys described herein can be produced from a significant portion of post-consumer clad aluminum alloy products, including a mixture of 3xxx and 4xxx series aluminum alloys. The aluminum alloy composition of the core alloys described herein includes a balance of Si, Cu, and Mn to provide a solidus temperature above 600°C. The Mn in the aluminum alloy composition compensates for Si and Cu to produce an aluminum alloy having a desired solidus temperature for brazing applications.

[0114] In some embodiments, the used clad aluminum alloy product including the 3xxx and 4xxx series aluminum alloy mixture can be used as recycled material. As described herein, the aluminum alloy composition can utilize recycled aluminum alloy materials (e.g., used clad aluminum alloy products) to produce aluminum alloys from the aluminum alloy composition. A larger volume of recycled aluminum alloy materials and reduced raw aluminum amounts can be used to produce aluminum alloys. In some embodiments, the aluminum alloy composition described herein can be produced by a mixture of 3xxx series and 4xxx series aluminum alloys. In some aspects, the aluminum alloy described herein comprises an amount of recycled aluminum alloy materials equal to or greater than 50% (e.g., equal to or greater than 52%, equal to or greater than 54%, equal to or greater than 56%, equal to or greater than 58%, equal to or greater than 60%, equal to or greater than 62%, equal to or greater than 64%, or equal to or greater than 65%). As discussed above, in some aspects, the aluminum alloy described herein is particularly suitable for utilizing a mixture of 3xxx series aluminum alloy scrap and 4xxx series aluminum alloy scrap.

[0115] In some aspects, the aluminum alloys described herein include less than 50% primary aluminum, e.g., less than 45%, less than 40%, less than 35%, less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, or less than 20%, all expressed in weight percent.

[0116] Alloy properties of core alloy

[0117] In some embodiments, the solidus temperature of the aluminum alloy used as the core alloy is important for controlling the properties of the brazed product. The solidus temperature refers to the temperature at which the aluminum alloy (in this case, the core layer) begins to melt (i.e., the beginning of melting). The core layer described herein has a solidus temperature that avoids local melting during the brazing process. If the solidus temperature of the core layer is low (e.g., below 600°C), the core alloy may be prone to local melting. In some embodiments, the solidus temperature of the core layer is 600°C or higher (e.g., 602°C or higher, 604°C or higher, 606°C or higher, 608°C or higher, or 610°C or higher).

[0118] In certain aspects, the aluminum alloys described herein can have a yield strength in the O temper of 30 MPa to 150 MPa (e.g., 30 MPa to 125 MPa, 30 MPa to 100 MPa, 35 MPa to 80 MPa, 40 MPa to 80 MPa, or 50 MPa to 80 MPa). In certain aspects, the aluminum alloys described herein can have a yield strength in the O temper of 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, or any value therebetween.

[0119] In certain aspects, the aluminum alloys described herein can have an ultimate tensile strength in the O temper of 100 MPa to 250 MPa (e.g., 110 MPa to 240 MPa, 120 MPa to 225 MPa, 125 MPa to 200 MPa, 130 MPa to 200 MPa, or 150 MPa to 200 MPa). In some aspects, the aluminum alloys described herein can have a yield strength in the O temper of 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, or any value therebetween.

[0120] In certain aspects, the aluminum alloys described herein can have sufficient formability to meet an elongation of at least 15% in the O-temper (e.g., at least 16%, at least 17%, at least 18%, at least 19%, or at least 20%).

[0121] Preparation and processing methods

[0122] In some aspects, the disclosed alloy compositions are products of the disclosed methods. Without limiting the present disclosure, aluminum alloy properties are determined in part by the formation of microstructure during alloy preparation. In some aspects, the method of preparing the alloy composition can influence or even determine whether the alloy will have properties suitable for a desired application.

[0123] Casting

[0124] The alloys described herein can be cast using casting methods known to those skilled in the art. For example, the casting process can include a direct chill (DC) casting process. The DC casting process is performed according to conventional standards in the aluminum industry known to those skilled in the art. The DC process can provide ingots. Optionally, the casting process can be a continuous casting (CC) process or an electromagnetic casting (EMC) process. In some embodiments, the ingot surface can be stripped after casting and before downstream processing. In some embodiments, the casting process can include an electromagnetic casting (EMC) process.

[0125] The cast aluminum alloy may then be subjected to further processing steps. For example, the processing method as described herein may include the following steps: optional homogenization, preheating, hot rolling, cold rolling, slitting and / or annealing.

[0126] Homogenization

[0127] In some embodiments, the method may include an optional homogenization step. In some embodiments, the homogenization step may be used in place of the preheating step. In some embodiments, the homogenization step may replace the preheating step. For example, the cast aluminum alloy may be homogenized and then preheated.

[0128] The homogenization step may include heating the cast aluminum alloy as described herein to a homogenization temperature of at least 500° C. (e.g., 500° C., 510° C., 520° C., 530° C., 540° C., 550° C., 560° C., 570° C., 580° C., 580° C., 590° C., 600° C., 610° C., 620° C., 630° C., or any value therebetween). For example, the cast aluminum alloy may be heated to a temperature of 500° C. to 630° C., 510° C. to 615° C., 500° C. to 575° C., 510° C. to 600° C., or 525° C. to 625° C. In some cases, the rate of heating to the homogenization temperature may be 10° C. / hour or greater, 20° C. / hour or greater, 30° C. / hour or greater, 40° C. / hour or greater, 50° C. / hour or greater, 60° C. / hour or greater, or 70° C. / hour or greater. In other cases, the rate of heating to the homogenization temperature can be from 10°C / min to 100°C / min (e.g., from 10°C / min to 90°C / min, from 20°C / min to 80°C / min, from 30°C / min to 70°C / min, from 40°C / min to 65°C / min, from 45°C / min to 60°C / min, or from 50°C / min to 60°C / min).

[0129] The cast aluminum alloy is then soaked (i.e., maintained at a specified temperature) for a period of time at the homogenization temperature range. According to a non-limiting example, the cast aluminum alloy is soaked for up to 30 hours (e.g., 10 minutes to 30 hours, inclusive). For example, the cast aluminum alloy may be soaked at 500° C. to 630° C. for 10 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, or any value therebetween.

[0130] Preheat

[0131] The preheating step may include heating the cast aluminum alloy as described herein to a preheat temperature of at least 350°C (e.g., 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, 580°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, or any value therebetween). For example, the cast aluminum alloy may be heated to a temperature of 350° C. to 630° C., 360° C. to 620° C., 375° C. to 610° C., 400° C. to 600° C., 410° C. to 575° C., 420° C. to 550° C., 440° C. to 540° C., 450° C. to 530° C., or 450° C. to 480° C. In some cases, the rate of heating to the preheat temperature may be 10° C. / hour or greater, 20° C. / hour or greater, 30° C. / hour or greater, 40° C. / hour or greater, 50° C. / hour or greater, 60° C. / hour or greater, or 70° C. / hour or greater. In other cases, the rate of heating to the preheat temperature may be 10°C / min to 100°C / min (e.g., 10°C / min to 90°C / min, 20°C / min to 80°C / min, 30°C / min to 70°C / min, 40°C / min to 65°C / min, 45°C / min to 60°C / min, or 50°C / min to 60°C / min).

[0132] The cast aluminum alloy is then soaked (i.e., maintained at a specified temperature) for a period of time at a preheat temperature range. According to a non-limiting example, the cast aluminum alloy is soaked for up to 30 hours (e.g., 10 minutes to 30 hours, inclusive). For example, the cast aluminum alloy can be soaked at 450°C to 560°C for 10 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, or any value therebetween. In some embodiments, the cast aluminum alloy is soaked at a preheat temperature of 480°C to 560°C for 5 to 7 hours.

[0133] Hot Rolling

[0134] After the homogenization step and / or the preheating step, a hot rolling step may be performed. The cast aluminum alloy may be hot rolled at a temperature of 350°C to 560°C (e.g., 375°C to 550°C, 400°C to 540°C, 425°C to 530°C, 450°C to 530°C, or 475°C to 520°C). In some examples, the hot rolling temperature is 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, or 560°C. If the hot rolling temperature is too low (e.g., below 350°C), the hot rolling load is too high and may be prone to cracking. If the hot rolling temperature is too high (eg, above 560°C), the aluminum alloy may be too soft and fracture in the hot rolling mill. In some embodiments, the cast aluminum alloy may be hot rolled at a temperature of 350°C to 500°C.

[0135] In some cases, the cast aluminum alloy can be hot rolled to a thickness of 2 mm to 15 mm (e.g., a thickness of 2.5 mm to 12 mm). For example, the cast aluminum alloy can be hot rolled to a thickness of 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm. In some cases, the cast aluminum alloy can be hot rolled to a thickness greater than 15 mm (i.e., plate). In other cases, the cast aluminum alloy can be hot rolled to a thickness less than 4 mm (i.e., sheet).

[0136] Cold Rolling

[0137] After the hot rolling step, an optional cold rolling step can be carried out. The cold rolling step can include one or more cold rolling passes. In certain embodiments, the hot-rolled product from the hot rolling step can be cold rolled to produce, for example, thin gauge saturate plate or sheet. In some embodiments, thin gauge saturate plate or sheet are cold rolled to have a final gauge thickness (that is, first thickness) within the scope of 0.02mm to 10.0mm (for example, 0.2mm to 3mm). In some embodiments, the cold rolling step can include two other cold rolling steps. Two or more cold rolling steps can reduce thickness to the final gauge thickness in succession.

[0138] Slitting and / or annealing

[0139] Optionally, the method may also include an intermittent and / or final annealing step between or after the cold rolling step. In some embodiments, the thin gauge saturate plate or sheet may be subjected to final annealing. In some embodiments, the final annealing step is a continuous annealing and solution heat treatment step. The thin gauge saturate plate or sheet may be heated to a peak metal temperature in the range of about 500°C to 580°C (e.g., 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, or 580°C) and soaked (i.e., maintained at a specified temperature) for a period of time (higher than a predetermined temperature). In some instances, the thin gauge saturate plate or sheet is soaked for up to about 10 minutes (e.g., 1 second to 10 minutes, inclusive). For example, the sheet may be soaked for about 5 seconds or less, 10 seconds or less, 15 seconds or less, 30 seconds or less, 45 seconds or less, 1 minute or less, 2 minutes or less, 3 minutes or less, 4 minutes or less, 5 minutes or less, 6 minutes or less, 7 minutes or less, 8 minutes or less, 9 minutes or less, or 10 minutes or less.

[0140] In some embodiments, the method may optionally include a slitting step. The thin gauge shaving plate or sheet may be slit after cold rolling or final annealing. In some embodiments, the thin gauge shaving plate or sheet may be slit to final thickness or slit to provide multiple narrower widths / rings / loops before or after final annealing.

[0141] Brazing method

[0142] The clad aluminum alloy products described herein are suitable for brazing applications. Therefore, various brazing processes and technical steps can be suitably adopted in the embodiments of the present disclosure. The clad aluminum alloy products can be brazed in an inert gas atmosphere. Any suitable inert gas can be used, including, for example, argon, helium, nitrogen, etc. The clad aluminum alloy products described herein are suitable for CAB. For the brazing cycle, the clad aluminum alloy products can be heated in a CAB furnace. In some embodiments, the aluminum alloy can be used for other joining processes, such as vacuum brazing, flame brazing, flux braze rings / gaskets, induction heating, laser brazing, welding, gluing, etc.

[0143] In some embodiments, the surface of the metal parts to be connected to the coated aluminum alloy product is prepared (for example, pre-treatment) before brazing. In some embodiments, the metal parts to be connected are carried out one or more pre-treatments, which can be used to promote the adhesion of the coated aluminum alloy product and the metal parts. The outer surface of the metal parts coated with the aluminum alloy product can be deposited with the pre-treatment to improve the adhesion of the coated aluminum alloy product and the metal parts (for example, the coating of the aluminum alloy product), to produce a good brazing joint. In some embodiments, pre-treatment comprises a preliminary cleaning step, in which the surface of the metal parts is processed to remove grease, oil, polishing compound, rolling lubricant or slitting oil during this step. This can be achieved in many ways, for example, by thermal degreasing, solvent washing, solvent emulsification cleaning, mechanical grinding or by this mild etching.

[0144] In some embodiments, the surfaces of the metal parts to be joined are etched to remove residual oil and grease from the rolling process and to thin the oxide film. For example, the preparation process includes etching the surfaces of the metal parts using a corrosive cleaner (e.g., 10% NaOH) to remove all traces of oil or grease. In some embodiments, etching the surface can produce surface features that are important for forming a good brazed joint.

[0145] In some embodiments, the brazing process is performed in a dry atmosphere with little or no oxygen. In some embodiments, the brazing process is performed in an inert atmosphere of nitrogen, argon, or helium. The brazing process may include heating the clad aluminum alloy product as described herein to a brazing temperature of about or at least about 560°C (e.g., at least 570°C, at least 580°C, at least 590°C, at least 600°C, or any value therebetween). For example, the clad aluminum alloy product may be heated to a temperature of 560°C to 620°C, 570°C to 615°C, 580°C to 610°C, or 590°C to 605°C. In some cases, the rate of heating to the brazing temperature may be 200°C / hour or less, 180°C / hour or less, 160°C / hour or less, 140°C / hour or less, 120°C / hour or less, 100°C / hour or less, 75°C / hour or less, 50°C / hour or less, 40°C / hour or less, 30°C / hour or less, 25°C / hour or less, 20°C / hour or less, 15°C / hour or less, or 10°C / hour or less. In other cases, the rate of heating to the brazing temperature may be 10° C. / min to 200° C. / min (e.g., 10° C. / min to 175° C. / min, 10° C. / min to 150° C. / min, 10° C. / min to 100° C. / min, 20° C. / min to 90° C. / min, 30° C. / min to 80° C. / min, 40° C. / min to 70° C. / min, or 50° C. / min to 60° C. / min). In some embodiments, the rate of heating to the peak temperature in the CAB furnace is less than 3 minutes.

[0146] In some embodiments, the clad aluminum alloy product may be heated in a CAB furnace at a rate of 100°C per minute until a temperature of 520°C is reached. The clad aluminum alloy product may then be heated at a rate of 25°C per minute until a temperature of 605°C is reached, and then hot dipped at 605°C for 3 minutes. The clad aluminum alloy product may then be cooled to 570°C and removed from the furnace to cool at room temperature. In some embodiments, the clad aluminum alloy product is heated in a CAB furnace at 600°C for 3 minutes in a brazing atmosphere having an oxygen concentration of less than 100 ppm and a dew point of less than -40°C (in a nitrogen atmosphere).

[0147] In some embodiments, a method for manufacturing an article (such as a heat exchanger) connected by brazing or assembly of brazed parts is provided. The method may include providing a component at least one of which is made of a clad aluminum alloy product as described herein. The method may include assembling components such as corrugated fin blanks and other components such as tubes into an assembly. The method may also include brazing the assembly without applying a brazing flux when assembling the assembly. The entire assembly is brazed in a controlled inert gas atmosphere at a brazing temperature (typically at a temperature in the range of 560°C to 620°C) for a time long enough to allow the fillers connecting the various components to melt and diffuse, for example, a residence time of 1 to 5 minutes. The oxygen content in the brazing atmosphere should be as low as reasonably possible, and preferably less than 100 ppm, and more preferably less than 50 ppm, for example 25 ppm or less. The method also includes cooling the brazed assembly using, for example, air blowing or any other suitable cooling medium, typically cooling to less than 100°C, for example, cooling to room temperature.

[0148] Although metal parts such as aluminum alloy articles are described throughout, the methods and articles are applicable to any metal. In some examples, the metal part is aluminum, an aluminum alloy, magnesium, a magnesium-based material, titanium, a titanium-based material, copper, a copper-based material, steel, a steel-based material, bronze, a bronze-based material, brass, a brass-based material, a composite, a sheet used in a composite, or any other suitable metal or combination of materials.

[0149] How to use

[0150] The aluminum alloys and methods described herein can be used in industrial applications, including sacrificial parts, heat dissipation, heating, ventilation, air conditioning and refrigeration, packaging, and building materials. The aluminum alloys described herein can be used in various applications, such as for making fins for heat exchangers. In one example, the improved aluminum alloys described herein can be used for high-performance, lightweight automotive heat exchangers. More generally, the aluminum alloys described herein can be used in motor vehicle heat exchangers, such as radiators, condensers, heaters, intercoolers, charge air coolers, oil coolers, exhaust coolers, fuel coolers, cold plates (also referred to as, for example, cooling plates or battery cooling plates), and evaporators. Cold plates are typically produced by brazing bare aluminum flat sheets to formed sheets, one side of the formed sheet having a cladding lining and the other side (e.g., the coolant channel side) possibly having a 1xxx or 7xxx sacrificial lining. The aluminum alloys can be used for bare flat sheets and / or as core alloys for formed sheets. As discussed above, the compositions and processes for producing the improved aluminum alloys described herein yield materials having a combination of advantageous characteristics and properties that make them suitable for use in the manufacture of cold plates, base plates, tubes, headers, manifolds, side supports, or other components of automotive or industrial heat exchangers. However, the uses and applications of the improved aluminum alloys described herein are not limited to automotive or industrial heat exchangers, and other uses are also contemplated. The improved aluminum alloys described herein can be used to manufacture various devices that employ heat exchangers and are produced by brazing, such as devices for heating, ventilation, and air conditioning (HVAC).

[0151] Aluminum alloy disclosed herein is a suitable substitute for the metal conventionally used in indoor and outdoor HVAC devices. As used herein, the implication of "indoor" refers to the position included in any structure manufactured by people under controlled environmental conditions. As used herein, the implication of "outdoor" refers to the position not fully included in any structure manufactured by people and exposed to geological and meteorological environmental conditions, which include air, solar radiation, wind, rain, sleet, snow, freezing rain, ice, hail, dust storms, humidity, drought, smog (for example, tobacco smoke, house fire smoke, industrial incinerator smoke and wildfire smoke), haze, fossil fuel exhaust, biofuel exhaust, salt (for example, high salt content air in areas near salt water bodies), radiation, electromagnetic waves, corrosive gases, corrosive liquids, electroplated metals, electroplated alloys, corrosive solids, plasma, fire, electrostatic discharge (for example, lightning), biomaterials (for example, animal feces, saliva, discharged oil, vegetation), wind-blown particulate matter, air pressure changes and diurnal temperature changes. Compared with currently adopted alloys, aluminum alloy as described herein provides better corrosion performance and higher strength.

[0152] The following examples will be used to further illustrate the present invention, but do not constitute any limitation of the present invention. On the contrary, it should be clearly understood that after reading the description herein, those skilled in the art may conceive of making various embodiments, modifications and equivalents thereof without departing from the spirit of the present invention. In the research process described in the following examples, unless otherwise stated, conventional procedures are followed. Some procedures are described below for illustrative purposes.

[0153] illustration

[0154] Example 1: An aluminum alloy comprising 0.8-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0155] Example 2: An example as described in any preceding or subsequent example, which contains 0.8-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.25 wt% Cr, up to 0.4 wt% Zn, up to 0.2 wt% Ti, up to 0.25 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0156] Example 3: An example as described in any preceding or subsequent example, which contains 0.8-1.3 wt% Si, up to 0.4 wt% Fe, 0.1-0.5 wt% Cu, 0.9-2 wt% Mn, up to 0.1 wt% Mg, up to 0.2 wt% Cr, up to 0.3 wt% Zn, up to 0.2 wt% Ti, up to 0.2 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0157] Example 4: An example as described in any preceding or subsequent example, which contains 0.85-1.3 wt% Si, up to 0.55 wt% Fe, 0.1-0.55 wt% Cu, 1-2 wt% Mn, up to 0.2 wt% Mg, up to 0.15 wt% Cr, up to 0.2 wt% Zn, up to 0.15 wt% Ti, up to 0.15 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0158] Example 5: An example as described in any preceding or subsequent example, which contains 0.85-1.25 wt% Si, up to 0.5 wt% Fe, 0.2-0.5 wt% Cu, 1.2-1.8 wt% Mn, up to 0.15 wt% Mg, up to 0.10 wt% Cr, up to 0.10 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0159] Example 6: An example as described in any preceding or subsequent example, comprising 0.85-1.15 wt% Si, up to 0.38 wt% Fe, 0.23-0.43 wt% Cu, 1.4-1.6 wt% Mn, up to 0.1 wt% Mg, up to 0.05 wt% Cr, up to 0.05 wt% Zn, up to 0.1 wt% Ti, up to 0.05 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0160] Example 7: An example as described in any preceding or subsequent example, which contains 0.9-1.1 wt% Si, up to 0.35 wt% Fe, 0.23-0.43 wt% Cu, 1.4-1.6 wt% Mn, up to 0.05 wt% Mg, up to 0.03 wt% Cr, up to 0.04 wt% Zn, up to 0.1 wt% Ti, up to 0.01 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0161] Example 8: An example of any preceding or subsequent example, wherein the aluminum alloy comprises greater than 50% recycled aluminum alloy material.

[0162] Example 9: An example as in any preceding or subsequent example, wherein the recycled aluminum alloy material comprises a used clad aluminum alloy product comprising a mixture of a 3xxx series aluminum alloy and a 4xxx series aluminum alloy.

[0163] Example 10: The example of any preceding or subsequent example, wherein the aluminum alloy has a solidus temperature of 600°C or higher.

[0164] Example 11: The example of any preceding or subsequent example, wherein the aluminum alloy has an ultimate tensile strength of 125 MPa to 200 MPa.

[0165] Example 12: The example of any preceding or subsequent example, wherein the aluminum alloy has a yield strength of 35 MPa to 80 MPa.

[0166] Example 13: An example as described in any preceding or subsequent example, wherein the aluminum alloy comprises 0.85–1.25 wt. % Si, up to 0.50 wt. % Fe, 0.2–0.55 wt. % Cu, 1.2–1.8 wt. % Mn, up to 0.15 wt. % Mg, up to 0.1 wt. % Cr, up to 0.1 wt. % Zn, up to 0.1 wt. % Ti, up to 0.05 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al, wherein the aluminum alloy comprises greater than 50% recycled aluminum alloy material, the recycled aluminum alloy material comprising used clad aluminum alloy products comprising a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys; and wherein the aluminum alloy has a solidus temperature of 600°C or greater.

[0167] Example 14: An unclad aluminum alloy product comprising the aluminum alloy of any preceding or subsequent example.

[0168] Example 15: An unclad aluminum alloy product comprising a core layer, the unclad aluminum alloy product comprising the aluminum alloy of any preceding or subsequent example.

[0169] Example 16: A clad aluminum alloy product, comprising: a core layer, wherein the core layer has a first side and a second side; at least one cladding layer on the first side or the second side; wherein the core layer and / or the cladding layer contains 0.8–1.3 wt% Si, up to 0.6 wt% Fe, 0.1–0.6 wt% Cu, 0.9–2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0170] Example 17: An example of any preceding or subsequent example, wherein the at least one cladding layer comprises a 1xxx, 3xxx, 4xxx, or 7xxx series aluminum alloy.

[0171] Example 18: A heat exchanger comprising the clad aluminum alloy product of any preceding or subsequent example.

[0172] Example 19: A method of forming a brazed product, the method comprising the steps of: providing one or more metal parts; providing a clad aluminum alloy product on or between the one or more metal parts to form an assembly, wherein the clad aluminum alloy product includes a core layer; brazing the assembly to connect the clad aluminum alloy product and the one or more metal parts to produce a brazed assembly; optionally applying a flux load before brazing; and cooling the brazed assembly, wherein the core layer comprises 0.8–1.3 wt% Si, up to 0.6 wt% Fe, 0.1–0.6 wt% Cu, 0.9–2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

[0173] Example 20: An example of any preceding or subsequent example, wherein the brazing comprises controlled atmosphere brazing.

[0174] Example 21: An example of any preceding or subsequent example, wherein the assembly is brazed at a brazing temperature of 560°C to 620°C.

[0175] Example 22: As described in any preceding or subsequent example, the aluminum alloy comprises 0.7–1.3 wt. % Si, up to 0.6 wt. % Fe, 0.1–0.6 wt. % Cu, 0.9–2 wt. % Mn, up to 0.2 wt. % Mg, up to 0.3 wt. % Cr, up to 0.5 wt. % Zn, up to 0.2 wt. % Ti, up to 0.3 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al.

[0176] Example 22: As described in any preceding or subsequent example, the aluminum alloy comprises 0.7–1.3 wt. % Si, up to 0.6 wt. % Fe, 0.1–0.6 wt. % Cu, 0.9–2 wt. % Mn, up to 0.25 wt. % Mg, up to 0.25 wt. % Cr, up to 0.4 wt. % Zn, up to 0.2 wt. % Ti, up to 0.25 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al.

[0177] Example 23: As described in any preceding or subsequent example, the aluminum alloy comprises 0.7–1.3 wt. % Si, up to 0.4 wt. % Fe, 0.1–0.5 wt. % Cu, 0.9–2 wt. % Mn, up to 0.1 wt. % Mg, up to 0.2 wt. % Cr, up to 0.3 wt. % Zn, up to 0.2 wt. % Ti, up to 0.2 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al.

[0178] Example 24: As described in any preceding or subsequent example, the aluminum alloy comprises 0.7–1.3 wt. % Si, up to 0.55 wt. % Fe, 0.1–0.55 wt. % Cu, 1–2 wt. % Mn, up to 0.2 wt. % Mg, up to 0.15 wt. % Cr, up to 0.2 wt. % Zn, up to 0.15 wt. % Ti, up to 0.15 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al.

[0179] Example 25: As described in any preceding or subsequent example, the aluminum alloy comprises 0.7–1.25 wt. % Si, up to 0.5 wt. % Fe, 0.2–0.5 wt. % Cu, 1.2–1.8 wt. % Mn, up to 0.15 wt. % Mg, up to 0.10 wt. % Cr, up to 0.10 wt. % Zn, up to 0.1 wt. % Ti, up to 0.1 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al.

[0180] Example 26: As described in any preceding or subsequent example, the aluminum alloy comprises 0.7–1.15 wt. % Si, up to 0.38 wt. % Fe, 0.23–0.43 wt. % Cu, 1.4–1.6 wt. % Mn, up to 0.1 wt. % Mg, up to 0.05 wt. % Cr, up to 0.05 wt. % Zn, up to 0.1 wt. % Ti, up to 0.05 wt. % Zr, up to 0.15 wt. % impurities, and the remainder Al.

[0181] All patents, publications, and abstracts cited above are incorporated herein by reference in their entirety. The present invention has described various embodiments to achieve the various objectives of the present invention. It should be understood that these embodiments are merely illustrative of the principles of the present invention. Various modifications and alterations will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined in the following claims.

[0182] Example

[0183] Sample alloy 1 and sample alloy 2 as herein described are modified 3xxx series aluminum alloys, and although produced by a large amount of aluminum alloy materials recovered, they are still prepared to have good brazing properties, while having good corrosion resistance. Sample alloy 1 and 2 have high Mn content (e.g., 0.9 wt % to 2 wt %) to improve the solidus temperature of the aluminum alloy, to compensate for the higher amount of Si and Cu brought by the aluminum alloy materials recycled. In addition, sample alloy 1 to 2 includes less than 0.2 wt % Mg to promote controlled atmosphere brazing (CAB), e.g., by enabling relatively low flux loading. Therefore, modified aluminum alloy provides a recycling-friendly alternative for conventional 3xxx series aluminum alloys (e.g., AA3003 aluminum alloy) used as the core alloy in heat exchanger products. The composition of sample alloy 1 to 2 is provided in table 10 below.

[0184]

[0185] Sample Alloys 1 and 2 were used as core layers to produce individual clad aluminum alloy samples. Sample Alloy 1 had a thickness of 0.6 mm. One side of Sample Alloy 1 was clad with AA4343 aluminum alloy to produce the first clad aluminum alloy product. The thickness ratio of the clad layer to the entire sheet before brazing was 10%. Sample Alloy 2 had a thickness of 1.14 mm. One side of Sample Alloy 2 was clad with AA4045 aluminum alloy to produce the second clad aluminum alloy product. The thickness ratio of the clad layer to the entire sheet before brazing was 6.5%.

[0186] Two clad aluminum alloy samples were tested to determine the mechanical properties. The tensile properties of each clad aluminum alloy sample were determined using the ISO 6892-1B standard (sample type E12.5). The bending properties were determined using the DIN EN 1396:2015 standard, and the grain size was determined using ASTM E112. The mechanical properties of each clad aluminum alloy product were tested before and after brazing at 600°C for three minutes. The yield strength of the first clad aluminum alloy product before brazing was 52.8 MPa, and the tensile strength was 149.8 MPa. In addition, the first clad aluminum alloy product exhibited a tensile elongation of 22.9% before brazing. After brazing under the above conditions, the yield strength and tensile strength of the first clad aluminum alloy product were tested again. The yield strength of the first clad aluminum alloy sample after brazing was 53.3 MPa, and the tensile strength was 158.8 MPa. The yield strength of the first clad aluminum alloy sample was similar before and after brazing. In addition, the tensile strength of the first clad aluminum alloy sample increased after brazing.

[0187] In addition to determining the mechanical properties of the first clad aluminum alloy sample, the first clad aluminum alloy sample was also tested to observe the bending performance before brazing. The first clad aluminum alloy sample did not crack when bent at an angle of 180° and a radius of zero relative to the longitudinal direction (e.g., grain orientation parallel to the core layer) and the long transverse direction (e.g., maximum dimension perpendicular to the longitudinal direction). In addition, the grain size of the core alloy of the first clad aluminum alloy sample was characterized before and after brazing. The grain size (average) of the first clad aluminum alloy sample was ASTM size 6 or finer before and after brazing, indicating that the grain size was essentially unchanged after brazing.

[0188] The mechanical properties of the second clad aluminum alloy sample were tested before and after brazing at 600°C for five minutes. The 0.2% offset yield strength of the second clad aluminum alloy sample before brazing was 52 MPa, and the tensile strength was 153 MPa. In addition, the second clad aluminum alloy sample exhibited a tensile elongation of 26.4% before brazing. After brazing, the yield strength and tensile strength of the second clad aluminum alloy sample were tested again. The yield strength of the second clad aluminum alloy sample after brazing was 52.8 MPa, and the tensile strength was 163.5 MPa. Like the first clad aluminum alloy sample, the corresponding yield strengths of the second clad aluminum alloy sample before and after brazing were similar. In addition, the tensile strength of the second clad aluminum alloy sample after brazing was higher, indicating that although sample alloy 2 was produced from a large amount of recycled aluminum alloy material, it still exhibited suitable brazing performance.

[0189] The second clad aluminum alloy sample was also tested to determine its bending properties before brazing. The second clad aluminum alloy sample exhibited no cracking when bent at a 180° angle and a zero radius relative to both the longitudinal and transverse directions. The grain size of the second clad aluminum alloy sample was ASTM grain size 7 or finer both before and after brazing. Similar to the first clad aluminum alloy sample, the grain size of the second clad aluminum alloy sample remained essentially unchanged after brazing.

Claims

1. An aluminum alloy comprising 0.7-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder being Al.

2. The aluminum alloy of claim 1 , comprising 0.7-1.3 wt. % Si, up to 0.6 wt. % Fe, 0.1-0.6 wt. % Cu, 0.9-2 wt. % Mn, up to 0.2 wt. % Mg, up to 0.25 wt. % Cr, up to 0.4 wt. % Zn, up to 0.2 wt. % Ti, up to 0.25 wt. % Zr, up to 0.15 wt. % impurities, and the remainder being Al.

3. The aluminum alloy of claim 1 , comprising 0.8-1.3 wt % Si, up to 0.4 wt % Fe, 0.1-0.5 wt % Cu, 0.9-2 wt % Mn, up to 0.1 wt % Mg, up to 0.2 wt % Cr, up to 0.3 wt % Zn, up to 0.2 wt % Ti, up to 0.2 wt % Zr, up to 0.15 wt % impurities, and the remainder being Al.

4. The aluminum alloy of claim 1 , comprising 0.85-1.3 wt % Si, up to 0.55 wt % Fe, 0.1-0.55 wt % Cu, 1-2 wt % Mn, up to 0.2 wt % Mg, up to 0.15 wt % Cr, up to 0.2 wt % Zn, up to 0.15 wt % Ti, up to 0.15 wt % Zr, up to 0.15 wt % impurities, and the remainder being Al.

5. The aluminum alloy of claim 1 , comprising 0.85-1.25 wt % Si, up to 0.5 wt % Fe, 0.2-0.5 wt % Cu, 1.2-1.8 wt % Mn, up to 0.15 wt % Mg, up to 0.10 wt % Cr, up to 0.10 wt % Zn, up to 0.1 wt % Ti, up to 0.1 wt % Zr, up to 0.15 wt % impurities, and the balance being Al.

6. The aluminum alloy of claim 1 , comprising 0.85-1.15 wt % Si, up to 0.38 wt % Fe, 0.23-0.43 wt % Cu, 1.4-1.6 wt % Mn, up to 0.1 wt % Mg, up to 0.05 wt % Cr, up to 0.05 wt % Zn, up to 0.1 wt % Ti, up to 0.05 wt % Zr, up to 0.15 wt % impurities, and the balance being Al.

7. The aluminum alloy of claim 1 , comprising 0.9-1.1 wt % Si, up to 0.35 wt % Fe, 0.23-0.43 wt % Cu, 1.4-1.6 wt % Mn, up to 0.05 wt % Mg, up to 0.03 wt % Cr, up to 0.04 wt % Zn, up to 0.1 wt % Ti, up to 0.01 wt % Zr, up to 0.15 wt % impurities, and the balance being Al.

8. The aluminum alloy of claim 1, wherein the aluminum alloy comprises greater than 50% recycled aluminum alloy material.

9. The aluminum alloy of claim 8, wherein the recycled aluminum alloy material comprises a used clad aluminum alloy product comprising a mixture of a 3xxx series aluminum alloy and a 4xxx series aluminum alloy.

10. The aluminum alloy of claim 1, wherein the aluminum alloy has a solidus temperature of 600°C or higher.

11. The aluminum alloy of claim 1, wherein the ultimate tensile strength of the aluminum alloy is 125 MPa to 200 MPa. 12 . The aluminum alloy of claim 1 , wherein the aluminum alloy has a yield strength of 35 MPa to 80 MPa.

13. The aluminum alloy of claim 1 , wherein the aluminum alloy comprises 0.85-1.25 wt% Si, up to 0.50 wt% Fe, 0.2-0.55 wt% Cu, 1.2-1.8 wt% Mn, up to 0.15 wt% Mg, up to 0.1 wt% Cr, up to 0.1 wt% Zn, up to 0.1 wt% Ti, up to 0.05 wt% Zr, up to 0.15 wt% impurities, and the remainder Al, wherein the aluminum alloy comprises greater than 50% recycled aluminum alloy material, the recycled aluminum alloy material comprising used clad aluminum alloy products including a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys; and The aluminum alloy has a solidus temperature of 600° C. or higher.

14. An unclad aluminum alloy product, comprising the aluminum alloy of claim 1.

15. A clad aluminum alloy product comprising a core layer, the clad aluminum alloy product comprising the aluminum alloy of claim 1.

16. A clad aluminum alloy product, comprising: a core layer, wherein the core layer has a first side and a second side; at least one cladding layer on the first side or the second side; The core layer and / or the cladding layer contain 0.7-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

17. The clad aluminum alloy product of claim 16, wherein the at least one cladding layer comprises a 1xxx, 3xxx, 4xxx, or 7xxx series aluminum alloy.

18. A heat exchanger comprising the clad aluminum alloy product according to claim 16.

19. A method of forming a brazed product, the method comprising the steps of: providing one or more metal parts; providing a clad aluminum alloy product on or between the one or more metal components to form an assembly, wherein the clad aluminum alloy product includes a core layer; brazing the assembly to join the clad aluminum alloy product and the one or more metal components to produce a brazed assembly; optionally applying a flux load prior to brazing; and The brazed assembly is cooled, wherein the core layer comprises 0.7-1.3 wt% Si, up to 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, up to 0.2 wt% Mg, up to 0.3 wt% Cr, up to 0.5 wt% Zn, up to 0.2 wt% Ti, up to 0.3 wt% Zr, up to 0.15 wt% impurities, and the remainder Al.

20. The method of claim 19, wherein the brazing comprises controlled atmosphere brazing.

21. The method of claim 19, wherein the assembly is brazed at a brazing temperature of 560°C to 620°C.

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