High-recycle content aluminum alloy, aluminum alloy product, and method for manufacturing brazed product

Abstract

Disclosed herein are aluminum alloys that can be used for the core alloy. The aluminum alloys can be manufactured from 50% or more recycled aluminum alloy material and can exhibit good strength and corrosion resistance for use in heat exchangers. The aluminum alloys allow for greater amounts of recycled aluminum alloy material while maintaining corrosion resistance and suitability for controlled atmosphere brazing processes. The present disclosure also provides unclad and clad aluminum alloy products that include an aluminum alloy as the core layer and / or one or more cladding layers.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS 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.

[0002] 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 novel aluminum alloys that can be used in a variety of applications, including, for example, as core alloys for clad aluminum alloy products that can be produced from recycled aluminum alloy materials. [Background technology]

[0003] There has long been interest in using recycled aluminum alloy materials in the production of aluminum alloys. The incorporation of recycled aluminum alloy materials leads to reduced costs and time associated with the production of primary aluminum, as well as reduced carbon emissions (e.g., reduced overall impact and specific carbon footprint). However, recycled materials may contain higher levels of certain unwanted elements, making them unsuitable for use in the preparation of high-performance aluminum alloys. For example, aluminum alloy components used in heat exchangers require, among other properties, high corrosion resistance. Therefore, aluminum alloy components used in heat exchangers have strict compositional restrictions. Strict restrictions on the composition and processing of many high-performance aluminum alloy products significantly limit the amount and type of recycled aluminum alloy material and process-related scrap that can be used. For example, recycled scrap may contain certain elements in amounts that adversely affect the mechanical properties of the aluminum alloy and its corrosion resistance. For these reasons, it is impractical to use large amounts of recycled scrap in the production of certain aluminum alloys, especially for heat exchangers that require tightly controlled aluminum alloy composition and material properties. Summary of the Invention

[0004] The encompassed embodiments of the invention are defined by the claims, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some concepts that are further described in the Detailed Description section below. This summary is not intended to identify key features or important features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to the entire specification, any or all drawings, and appropriate portions of each claim.

[0005] Provided herein are recyclable aluminum alloys for many applications. The aluminum alloys described herein 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 balance Al. In some embodiments, the aluminum alloy contains 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. In some embodiments, the aluminum alloy comprises 0.8-1.3 wt% Si, max. 0.4 wt% Fe, 0.1-0.5 wt% Cu, 0.9-2 wt% Mn, max. 0.1 wt% Mg, max. 0.2 wt% Cr, max. 0.3 wt% Zn, max. 0.2 wt% Ti, max. 0.2 wt% Zr, max. 0.15 wt% impurities, and balance Al. In some embodiments, the aluminum alloy comprises 0.85-1.3 wt% Si, max. 0.55 wt% Fe, 0.1-0.55 wt% Cu, 1-2 wt% Mn, max. 0.2 wt% Mg, max. 0.15 wt% Cr, max. 0.2 wt% Zn, max. 0.15 wt% Ti, max. 0.15 wt% Zr, max. 0.15 wt% impurities, and 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 includes 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.% Z, up to 0.1 wt.% Ti, up to 0.05 wt.% Zr, up to 0.15 wt.% impurities, and the balance Al.

[0006] 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 balance Al. In some embodiments, the aluminum alloy comprises more than 50% recycled aluminum alloy material. In some embodiments, the recycled aluminum alloy material comprises post-consumer clad aluminum alloy products comprising a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys. In some embodiments, the aluminum alloy has a solidus temperature of 600°C or greater. In some embodiments, the aluminum alloy has an ultimate tensile strength of 125 MPa to 200 MPa. In some embodiments, the aluminum alloy has a yield strength of 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 balance Al, and comprises more than 50% recycled aluminum alloy material, including post-consumer clad aluminum alloy products comprising mixtures of 3xxx series aluminum alloys and 4xxx series aluminum alloys, and 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.

[0007] Provided herein is a clad aluminum alloy product comprising: a core layer having a first side and a second side; and 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 balance Al. In some embodiments, 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.

[0008] Provided herein is a method of forming a brazed product, the method comprising the steps of providing one or more metal components, disposing a clad aluminum alloy product on or between the one or more metal components to form an assembly, the clad aluminum alloy product comprising 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 an amount of flux prior to brazing, and cooling the brazed assembly, wherein the core layer comprises 0.7-1.3 wt% Si, max 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, max 0.2 wt% Mg, max 0.3 wt% Cr, max 0.5 wt% Zn, max 0.2 wt% Ti, max 0.3 wt% Zr, max 0.15 wt% impurities, and balance Al. In some embodiments, the brazing comprises controlled atmosphere brazing. In some embodiments, the assembly is brazed at a brazing temperature of 560°C to 620°C.

[0009] Further aspects, objects, and advantages will become apparent in view of the detailed description of the non-limiting examples that follow. [Brief explanation of the drawings]

[0010] [Figure 1] 1 provides a graph showing the effect of alloying elements on the solidus temperature of an aluminum alloy as a function of silicon concentration in the aluminum alloy. Typical CAB brazing temperatures are also shown. [Figure 2] 1 provides a graph showing the effect of the amount of primary aluminum on the carbon footprint of an aluminum alloy product. DETAILED DESCRIPTION OF THE INVENTION

[0011] Described herein are novel aluminum alloys that can be used, for example, as core aluminum alloys, clad aluminum alloy products, and unclad aluminum alloy products (finstock, brackets, etc.), as well as related methods for producing brazable products using the novel aluminum alloys. The aluminum alloys described herein are "recyclable" aluminum alloys that can be used in a variety of applications, including, for example, as core alloys in clad aluminum products (e.g., brazing sheets), which can replace core aluminum alloys produced from high-content primary aluminum. The aluminum alloys described herein can tolerate higher amounts of silicon (Si) and copper (Cu) than conventional 3xxx-series aluminum alloys (e.g., used in brazing sheets), enabling the use of recycled aluminum alloy materials. Specifically, high-Si-content aluminum alloy scrap can be used to produce the aluminum alloys described herein. For example, clad aluminum alloy products can be produced from a mixture of 3xxx-series and 4xxx-series aluminum alloys. 4xxx-series aluminum alloys contain Si as a primary alloying element. The aluminum alloys described herein can be produced from high-Si-content aluminum alloy scrap, such as clad aluminum alloy products, while still maintaining desirable properties. Despite the higher Si and Cu contents, the aluminum alloys described herein maintain a solidus temperature above 600°C for use as core or unclad alloys. The aluminum alloys described herein contain a careful balance of alloying elements that provide aluminum alloy products with solidus temperatures suitable for standard controlled atmosphere brazing (CAB) with relatively small amounts of flux, while having good corrosion resistance properties and providing improved strength compared to AA3003 aluminum alloy.

[0012] Conventional aluminum alloys (e.g., 3xxx series aluminum alloys) for use as core alloys in heat exchanger products have a high recycled aluminum alloy content and a high amount of Si, making it impossible to produce recycled aluminum alloy materials without compromising the aluminum alloy's properties. However, there is a significant market need for aluminum alloys produced from recycled aluminum alloy materials to reduce carbon footprints. In addition to factors such as price and material properties, the recycled content of certain aluminum alloys is becoming increasingly important for the automotive and non-automotive industries. While there are commercially available aluminum alloys that can incorporate large amounts of recycled aluminum alloy materials with a wide range of chemical compositions of alloying elements (e.g., Mg, Si, Cu, and Mn), these aluminum alloys cannot be considered for critical components (e.g., parts in heat exchangers where corrosion is critical). For these critical components, the aluminum alloy composition may be more restrictive to achieve the desired properties. As an example, aluminum alloys used in heat exchangers require a balance of alloying elements for good brazing properties and corrosion resistance. For example, Si and Cu can lower the solidus temperature of the aluminum alloy, which is essential for brazing at approximately 600°C. Aluminum alloys with solidus temperatures below 600°C may be prone to localized melting during brazing, which limits the use of recycled aluminum alloy materials containing higher amounts of Si and Cu. Furthermore, the Mg content of aluminum alloys intended for use as core alloys can affect the amount of flux required for the CAB process. Aluminum alloys containing higher amounts of Mg (e.g., greater than 0.2 wt%) require higher amounts of flux. However, higher flux amounts can result in higher amounts of flux residue on the material surface after brazing. This can have functional implications; for example, flux residue can cause uneven painting and / or poor adhesion during lacquering (if required).

[0013] The aluminum alloys described herein incorporate higher amounts of recycled aluminum alloy material (e.g., high Si content aluminum alloy scrap) compared to conventional core aluminum alloys, and still maintain good mechanical properties, for example, for brazing applications. Specifically, the aluminum alloys described herein surprisingly have good corrosion resistance properties despite being made from a high amount of recycled aluminum alloy material, while requiring relatively small amounts of flux (e.g., 5 g / m 2 This involves a careful balance of alloying elements that provides an aluminum alloy product with a temperature suitable for brazing at temperatures below 1000 K (less than 1000 K). In some embodiments, the aluminum alloys described herein are modified 3xxx series aluminum alloys that contain a balance of silicon (Si), copper (Cu), magnesium (Mg), and manganese (Mn) that can be used for brazing applications with relatively low amounts of flux. Without being bound by theory, the addition of Mn (e.g., 0.9 wt.% to 2 wt.%) increases the solidus temperature of the aluminum alloy, thereby allowing for higher amounts of Si and Cu to be derived, for example, from recycled aluminum alloy materials. Furthermore, the aluminum alloy may contain up to 0.2 wt.% Mg for brazing with lower amounts of flux to minimize or reduce the amount of flux residue, thereby avoiding or at least minimizing post-CAB flushing and cleaning steps. This combination of properties provides an aluminum alloy that can be used as a core alloy for clad aluminum alloy products. The aluminum alloy compositions described herein provide a more environmentally friendly alternative to the use of existing 3xxx series aluminum alloys for clad aluminum products.

[0014] The aluminum alloys described herein possess a combination of properties suitable for the heat exchanger market (e.g., including vehicle electrification). In summary, the aluminum alloys described herein combine a higher relative recycled content (e.g., 50% to 70% by weight) that can be sourced from high-Si-containing materials to lower the aluminum alloy's carbon footprint; a higher Mn content (e.g., 0.9% to 2% by weight) to offset the Si and Cu that lower the aluminum alloy's solidus temperature; and a Mg content (e.g., 0.2% by weight or less) that allows for relatively low flux amounts, e.g., supports the lower conductivity of standard coolants with little or no post-braze cleaning and / or flushing steps. The newly developed aluminum alloys can be produced with high recycled content, can be brazed with less flux, and ensure uniform coating without the need for cleaning of the brazed parts.

[0015] Definitions and Explanations: As used herein, the terms "invention," "the invention," "this invention," and "the present invention" are intended to refer broadly to all of the subject matter of this patent application and the claims that follow. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the claims that follow.

[0016] This description refers to alloys identified by aluminum industry designations such as "series" or "3xxx." For an understanding of the numbering systems most commonly used in naming and identifying aluminum and its alloys, please refer to "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys" or "Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingots," both published by the Aluminum Association.

[0017] As used herein, the terms "a," "an," or "the" include singular and plural references unless the context clearly indicates otherwise.

[0018] As used herein, plate generally has a thickness of greater than about 15 mm. For example, plate may refer to an aluminum product having a thickness of 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.

[0019] As used herein, a sheet (also called a sheet plate) generally has a thickness of about 4 mm to about 15 mm. For example, the sheet may be 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 thick.

[0020] As used herein, sheet generally refers to an aluminum product that is less than about 4 mm in thickness. For example, the sheet may 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.

[0021] As used herein, the "solidus temperature" of an aluminum alloy refers to the highest temperature at which the aluminum alloy is in a completely solid state before partial melting begins.

[0022] Throughout this application, reference is made to alloy tempers or tempers. For an understanding of the most commonly used alloy temper descriptions, please refer to American National Standards (ANSI) H35 on Alloy and Temper Designation Systems. The F temper or temper refers to the aluminum alloy as produced. 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 after cold rolling, with or without heat treatment (e.g., annealing). Suitable H tempers include the HX1, HX2, HX3, HX4, HX5, HX6, HX7, HX8, or HX9 tempers. For example, aluminum alloys can be strain hardened to various tempers, such as the H16, H18, or other H1X tempers.

[0023] In this application, reference is made to recycled content. The term "recycled content" incorporates, but is not limited to, what is typically referred to as internal process waste or scrap, as well as different types of external scrap, such as post-consumer scrap, remelt scrap ingots (RSI), among others. Since primary aluminum (excluding alloying elements and hardeners) accounts for the majority of Scope 3 emissions (below), all types of recycled content material (whether internal scrap or external scrap) contributes to more sustainable aluminum alloy products and supports the envisioned closed-loop material circulation (manufacturing) process.

[0024] The following aluminum alloys are described in terms of their elemental composition in weight percent (wt%) based on the total weight of the alloy. In each alloy specific example, the balance is aluminum, and the maximum wt% of the total of impurities is 0.15%.

[0025] As used herein, "controlled atmosphere brazing" or "CAB" refers to a brazing process that utilizes an inert gas atmosphere, such as nitrogen or argon, in the brazing of various alloy articles.

[0026] As used herein, "electrochemical potential" refers to the susceptibility of a material to an oxidation-reduction reaction. Electrochemical potential can be used to evaluate the corrosion resistance of the aluminum alloys described herein. A negative value can describe a material that oxidizes easily (e.g., loses electrons or increases its oxidation state) when compared to a material with a positive or less negative electrochemical potential. A more positive value can describe a material that reduces easily (e.g., gains electrons or decreases its oxidation state) when compared to a material with a negative or less positive electrochemical potential. As used herein, electrochemical potential is a vector quantity that represents magnitude and direction.

[0027] As used herein, the meaning of "room temperature" can include temperatures of about 15°C to about 30°C, such as 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.

[0028] All ranges disclosed herein should be understood to encompass any and all subranges subsumed therein. For example, a range stated as "1 to 10" should be considered to include any and all subranges between the minimum value of 1 and the maximum value of 10, inclusive. That is, all subranges begin with a minimum value of 1 or greater, e.g., 1 to 6.1, and end with a maximum value of 10 or less, e.g., 5.5 to 10.

[0029] Clad aluminum alloy products 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 generally used to refer to a relatively thick layer of a clad aluminum alloy product. In some examples, a clad aluminum alloy product (e.g., a clad sheet aluminum alloy) may have cladding layers on both sides of a core layer, in which case the core layer is an inner layer of aluminum material. However, a clad aluminum alloy product (e.g., a clad sheet aluminum alloy) may alternatively have a cladding layer on only one side of the core layer, in which case the core layer may also be a surface. The core layer and cladding layer(s) typically have different chemical compositions. In some cases, a clad aluminum alloy product may have two different cladding layers with different compositions and properties.

[0030] 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. A clad aluminum alloy product may include other layers (e.g., to form a multi-layer aluminum material), some of which may be referred to as "intermediate layers," "outer layers," "liners," and other related terms. For example, a clad aluminum alloy product may have two, three, four, five, six, or more separate layers, each with a specific function. More generally, a clad aluminum alloy product may have as many layers as can be stacked and bonded together in one or more steps. In a commercial context, one possible limiting factor is production costs and / or scrap generated during the manufacture of a clad aluminum alloy product, which may become too high to be commercially viable as the number of layers in the clad aluminum alloy product increases. In the context of a clad aluminum alloy product suitable for brazing applications, one or more of the cladding layers may be the portion of the product that melts during the brazing cycle. The liner may be a layer that is not expected to melt during the brazing cycle and may impart some other benefit 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 intermediate layers on one or both sides of the main core layer.

[0031] In some embodiments, the clad aluminum alloy product includes a core layer and at least one cladding layer. In some cases, the clad aluminum alloy product includes a core layer, a first cladding layer, and a second cladding layer. In these cases, the first cladding layer may be adjacent to and in contact with a first side of the core layer, forming a first interface (i.e., there is no intervening layer between the first cladding layer and the first side of the core layer). The second cladding layer may be adjacent to and in contact with a second side of the core layer, forming a second interface (i.e., there is no intervening layer between the second cladding layer and the second side of the core layer). The first cladding layer and the second cladding layer may each include an alloy composition described herein. In some embodiments, the core layer is clad on only one side. In other embodiments, the core layer is clad on both sides. In other embodiments, the core layer is clad on one side of the core layer and a waterside liner or other layer is placed on the other side of the core layer, hi other embodiments, the core layer is unclad and is intended for use with other clad aluminum alloy products.

[0032] The aluminum alloy compositions described herein can be used as the core layer of clad aluminum alloy products. The aluminum alloys can tolerate a higher amount of Si than some standard 3xxx-series aluminum alloys (e.g., AA3003 aluminum alloy). Therefore, the aluminum alloy for the core layer can be produced from a relatively high-Si recycled aluminum alloy. For example, a clad aluminum alloy product can include a core layer containing a 3xxx-series aluminum alloy and one or more cladding layers containing a 4xxx-series aluminum alloy. The 4xxx-series aluminum alloy contains Si as a major alloying element. The high concentration of Si in clad aluminum alloy products limits their use as recycled aluminum for producing core alloys for brazing sheets. The aluminum alloys described herein can tolerate a higher amount of Si, thus allowing clad aluminum alloy products to be utilized as recycled materials. 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).

[0033] FIG. 1 provides a graph showing the effect of alloying elements on the solidus temperature of an aluminum alloy. Both Si and Cu concentrations lower the solidus temperature of an aluminum alloy, while Mn raises the solidus temperature of the aluminum alloy. Recycled aluminum alloy materials (e.g., clad aluminum alloy products) containing higher amounts of Si can lower the solidus temperature of the aluminum alloy. Specifically, core alloys with solidus temperatures below 600°C may be prone to localized melting during brazing. The aluminum alloy compositions for the core alloys described herein contain a balance of Si, Cu, and Mn that provides a solidus temperature of 600°C or higher. The Mn in the aluminum alloy composition offsets the Si and Cu to produce an aluminum alloy with a solidus temperature desirable for brazing applications.

[0034] Additionally, the aluminum alloy described herein contains up to 0.2 wt. % Mg. The amount of Mg in the aluminum alloy for the core layer is carefully balanced to provide good properties for brazing (e.g., by the CAB process). Aluminum alloys containing more than 0.2 wt. % Mg require a large amount of flux during the CAB process. However, using a larger amount of flux can increase flux residue after brazing. During heat exchanger operation, flux residue can cause gel formation in certain coolants, which can reduce the efficiency of the heat exchanger. Therefore, in the case of the CAB process, intensive flushing and cleaning may be required to remove excessive flux residue. For this reason, vacuum brazing is also an alternative processing option. The aluminum alloy described herein contains up to 0.2 wt. % Mg, which allows the use of a smaller amount of flux during brazing. A smaller amount of flux limits the amount of flux residue, avoiding the need for flushing and cleaning of the brazed heat exchanger.

[0035] The clad aluminum alloy products and methods described herein can be used in industrial applications including sacrificial components, fillers, heat sinks, 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 with dissimilar metals and as / with extruded components. Specifically, the clad aluminum alloy products described herein can form brazed products. Suitable cladding and core layers for use in such clad aluminum alloy products are described below.

[0036] Core layer Described below are novel aluminum alloy compositions that can be produced using relatively high contents of recycled aluminum alloy materials. In some embodiments, the aluminum alloys described herein can be used as core layers in combination with cladding layers to produce clad aluminum alloy products described herein, or can be used without a clad layer to produce bare, unclad core alloys. The resulting clad aluminum alloy products are suitable for use in a variety of applications, including, for example, as corrosion-resistant brazing sheet packages in producing cold plates (e.g., cooling plates or battery cooling plates) for electric vehicle batteries.

[0037] In some embodiments, the aluminum alloy is a modified 3xxx series aluminum alloy. For example, the aluminum alloy may be a modified AA3003 aluminum alloy. The aluminum alloys described herein exhibit good brazeability and corrosion resistance compared to unmodified 3xxx series aluminum alloys, despite being made from a relatively large amount of recycled aluminum alloys (e.g., Si-containing aluminum materials). The alloy's properties are achieved, in part, by the alloy's elemental composition.

[0038] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 1: [Table 1]

[0039] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 2: [Table 2]

[0040] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 3: [Table 3]

[0041] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 4: [Table 4]

[0042] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 5: [Table 5]

[0043] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 6: [Table 6]

[0044] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 7: [Table 7]

[0045] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 8: [Table 8]

[0046] In some examples, the aluminum alloy for optional use as the core layer may have the following elemental composition shown in Table 9: [Table 9]

[0047] Silicon (Si) In some examples, the aluminum alloy comprises silicon (Si) in an amount between 0.70% and 1.35% (e.g., between 0.70% and 1.3%, between 0.8% and 1.3%, between 0.85% and 1.3%, between 0.85% and 1.25%, between 0.85% and 1.2%, between 0.85% and 1.15%, or between 0.9% and 1.1%) based on the total weight of the alloy. For example, aluminum alloys have the following percentages: 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%, 1.30%, 1.31%, 1.32%, 1.33%, or 1.35% Si. All percentages are expressed by weight. As noted above, Si can lower the solidus temperature of the aluminum alloy. The amount of Si is carefully balanced with Mn to provide the aluminum alloy with an appropriate solidus temperature for the brazing process. Additionally, aluminum alloys with Si contents between 0.7% and 1.3% may utilize recycled aluminum alloy scrap containing higher amounts of Si. For example, the aluminum alloys described herein may be produced from high-Si-content aluminum alloy process scrap, such as post-consumer clad aluminum alloy products containing a mixture of 3xxx and 4xxx series aluminum alloys. However, higher levels of Si (e.g., greater than 1.3 wt.%) increase the risk of corrosion during brazing.

[0048] Iron (Fe) In some examples, the alloy also 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, alloys may contain 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%, 0.30%, 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%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, The alloy may contain 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% Fe. In some cases, Fe is absent (i.e., 0%) in the alloy. All percentages are expressed by weight.

[0049] Copper (Cu) In some examples, the disclosed aluminum alloys include copper (Cu) in an amount between 0.1% and 0.6% (e.g., between 0.1% and 0.55%, between 0.1% and 0.5%, between 0.1% and 0.4%, between 0.15% and 0.45%, between 0.2% and 0.45%, between 0.2% and 0.4%, or between 0.23% and 0.43%) based on the total weight of the alloy. For example, alloys 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% The aluminum alloy may contain 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 by weight. The addition of Cu may increase the electrochemical potential of the aluminum alloy (e.g., core aluminum alloy) and therefore improve corrosion resistance.

[0050] Manganese (Mn) In some examples, the alloy may include manganese (Mn) in an amount between 0.9% and 2% (e.g., between 1% and 2%, between 1% and 1.9%, between 1.2% and 1.8%, or between 1.4% and 1.6%) based on the total weight of the alloy. For example, the alloy may 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%, 2.30%, 2.31%, 2.32%, 2.33%, 2.34%, 2.35%, 2.36%, 2.37%, 2.38%, 2.39%, 2.40%, 2.41%, 2.42%, 2.43%, 2.44%, 2.45%, 2.46%, 2.47%, 2.48%, 2.49%, 2.50%, 2.51%, 2.52%, 2.53%, 2.54%, 2.55%, 2.56%, 2.57%, 2.58%, 2.5 .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 The aluminum alloy may contain 0.74%, 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 by weight. As noted above, Mn can increase the solidus temperature of the aluminum alloy. Mn is added to the aluminum alloy composition to offset the higher amounts of Si and Cu in the aluminum alloy composition. Furthermore, Mn remains largely in solid solution, but small amounts precipitate as fine dispersoids during hot rolling and intermediate annealing.The effect of this microstructure is that when the material is heated to 600°C, as in brazing operations, the material retains its strength due to the solid solution strengthening effect of Mn. In this way, the Mn addition can be optimized to provide a useful balance of properties. Another positive effect of Mn is the formation of fine dispersoids to control the grain structure of the brazed heat exchanger or brazing sheet itself.

[0051] Magnesium (Mg) In some examples, the aluminum alloy may include magnesium (Mg) in an amount of up to 0.2% (e.g., 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 (i.e., 0%) in the alloy. All percentages are expressed by weight. The Mg content of an aluminum alloy can affect the amount of flux required during the CAB process. Aluminum alloys containing high amounts of Mg (e.g., greater than 0.2 wt.%) require larger amounts of flux. However, the higher the flux content, the greater the amount of flux residue after brazing. The flux residue can also cause uneven paint application and / or poor adhesion when applying lacquer. Beneficially, aluminum alloys containing 0.2 wt.% or less Mg allow for brazing with less flux, minimizing or reducing the amount of flux residue.

[0052] Chromium (Cr) In some examples, the alloy contains chromium (Cr) in an amount of up to 0.3% (e.g., 0.001%-0.3%, 0.01%-0.25%, 0.05%-0.2%, 0.001%-0.04%, 0%-0.05%, 0.001%-0.04%, or 0.01%-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%, The alloy may contain 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 (i.e., 0%) in the alloy. All percentages are expressed by weight.

[0053] Zinc (Zn) In some examples, the alloy includes zinc (Zn) in an amount of up to 0.5% (e.g., 0.001%-0.5%, 0.001%-0.4%, 0.001%-0.3%, 0.01%-0.2%, 0%-0.15%, 0%-0.1%, or 0%-0.03%) based on the total weight of the alloy. For example, alloys 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%, 0.20%, The alloy may contain 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%, or 0.50% Zn. In some cases, Zn is absent (i.e., 0%) in the alloy.

[0054] Titanium (Ti) In some examples, the alloy includes titanium (Ti) in an amount of up to 0.2% (e.g., 0%-0.15%, 0.001%-0.1%, 0%-0.05%, 0.001%-0.04%, or 0.01%-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 (i.e., 0%) in the alloy. All percentages are expressed by weight.

[0055] Zirconium (Zr) In some examples, the alloy includes zirconium (Zr) in an amount of up to 0.3% (e.g., 0%-0.25%, 0.001%-0.2%, 0.01%-0.15%, 0.01%-0.1%, 0%-0.05%, 0.001%-0.04%, or 0.01%-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%, 0.09%, 0.10%, The alloy may contain 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% Zr. In some cases, Zr is absent (i.e., 0%) in the alloy. All percentages are expressed by weight.

[0056] Optionally, the alloy composition may further include other trace elements, sometimes referred to as impurities, in amounts of 0.05% or less, 0.04% or less, 0.03% or less, 0.02% or less, or 0.01% or less, respectively. These impurities may include, but are not limited to, Na, Ga, V, Ni, Sc, Ag, B, Bi, Li, Pb, Sn, Ca, Hf, Sr, or combinations thereof. Thus, Na, Ga, V, Ni, Sc, Ag, B, Bi, Li, Pb, Sn, Ca, Hf, or Sr may be present in the alloy in amounts of 0.05% or less, 0.04% or less, 0.03% or less, 0.02% or less, or 0.01% or less. In certain embodiments, the sum of all impurities does not exceed 0.15% by weight (e.g., 0.1% by weight). All percentages are expressed in weight percent. In certain embodiments, the remaining percentage of the alloy is aluminum.

[0057] In some embodiments, an exemplary alloy includes 0.85%-1.15% Si, max 0.38% Fe, 0.23%-0.43% Cu, 1.40%-1.60% Mn, max 0.1% Mg, max 0.03% Cr, max 0.04% Zn, max 0.1% Ti, max 0.01% Zr, and max 0.15% total impurities, with the balance being Al. All percentages are expressed by weight.

[0058] 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 balance Al.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] Cladding Layer In some embodiments, the cladding layer is a 1xxx, 3xxx, 4xxx, or 7xxx series aluminum alloy.

[0065] In some embodiments, the cladding layer is a 4xxx series aluminum alloy, which may include 1% to 15% by weight of 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 modifications thereof.

[0066] Recycled aluminum alloy materials for core alloys The aluminum alloys described herein can tolerate large amounts of recycled aluminum alloy material, substantially reducing Scope 3 emissions, as further defined below. The impact of impurities and / or alloying elements (from recycled aluminum alloy material) on the mechanical properties of the aluminum alloy is reduced by providing an aluminum alloy composition that is tailored to offset the impurities. This allows for the production of aluminum alloys that can exhibit desirable properties despite the use of large amounts of recycled aluminum alloy material with high impurities (e.g., post-consumer clad aluminum alloy products including 3xxx / 4xxx series aluminum alloys).

[0067] A business's net greenhouse gas emissions are often measured in CO2 equivalents and are referred to as the business's "carbon footprint." A business's carbon footprint is considered a representative measure of that business's environmental impact on atmospheric GHG concentrations. Businesses that take initiatives to reduce their carbon footprint are often considered socially responsible and, therefore, are often labeled as "green" or environmentally friendly. As used herein, the term CO2 is meant to mean and include all types of GHG emissions.

[0068] There are several basic elements to consider when determining, or attempting to measure, a company's carbon footprint. The primary concern is the impact of the business, taking into account emissions resulting from activities carried out by the company itself (and other emitting businesses over which it has ownership or control). There are also upstream and downstream impacts that may be taken into account when determining the company's net emissions. For accurate "carbon accounting" purposes, a company's operations may be further broken down into direct and indirect GHG emissions.

[0069] Direct operational emissions are defined as those that originate from sources owned or controlled by the business, including, for example, emissions from combustion in owned boilers or vehicles. For purposes of preparing emissions data reports for carbon audits and regulatory submissions, a business's direct emissions are often collectively referred to by those skilled in the art as Scope 1 emissions. These emissions can be accurately measured using a formula, which may require, for example, knowledge of the mass / volume of fuel burned per unit time and knowledge of how the fuel was burned.

[0070] A company's Scope 1 emissions can be affected by many factors, including the way its factories operate or the way goods are transported within and by the company. For example, a company that uses hybrid vehicles to transport goods rather than traditional internal combustion vehicles can be considered to have reduced its carbon footprint to some extent. Similarly, a company that has attempted to reduce emissions in its factories, for example by using on-site renewable heat sources such as solar thermal panels, will have a smaller carbon footprint than a company that has not made such efforts.

[0071] Indirect business emissions are defined as those resulting from the generation of electricity consumed by a business. These emissions physically occur at the facilities where electricity is generated by the business's suppliers and are often collectively referred to by those skilled in the art as Scope 2 emissions. These emissions can also be calculated with precision using knowledge of the amount of electricity (e.g., megawatt-hours) used over a specific period of time, and then using "emissions factors" associated with a specific electricity supplier and specific tariff.

[0072] If a company chooses an electricity supply tariff that includes a renewable energy component, these Scope 2 emissions will be reduced proportionately. Similarly, emissions can be lowered if a company can reduce the need to bring in electricity from external suppliers through methods such as improving energy efficiency or developing on-site renewable power such as solar panels.

[0073] When calculating a net carbon footprint, a range of other emissions associated with a business's activities may also be considered. These vary by industry sector and subsector and are often referred to as Scope 3 emissions. These may include emissions resulting from activities such as employee travel and downstream consumer travel to a business's facilities. When estimating Scope 3 emissions, both upstream and downstream suppliers in a business's value chain may be considered. This may be important, for example, because "carbon-intensive" parts of the value chain may result from a business's operations even if they are not carried out by the business itself but by a third party. An example of the latter is an online mail-order company that may have small warehouses and offices and therefore low direct and indirect emissions, but outsources them to a delivery company with a large number of trucks and high emissions. Downstream impact factors may also be influenced by numerous other factors, which may vary by industry.

[0074] The aluminum alloys described herein contain less primary aluminum than conventional 3xxx series aluminum alloys, thereby lowering Scope 3 emissions during aluminum alloy production and reducing the overall carbon footprint. To reduce the amount of primary aluminum and incorporate a large amount of recycled aluminum alloy material, the aluminum alloy composition is carefully tailored to achieve a balance of mechanical properties. For example, Figure 1 provides an example phase diagram of the solidus temperature of an aluminum alloy as a function of Si concentration in the aluminum alloy. Si is a common alloying element found in some recycled aluminum alloy materials and can affect mechanical properties when used to produce new aluminum alloys. As shown in Figure 1, when aluminum alloys are produced from recycled aluminum materials containing high concentrations of Si, the solidus temperature of the aluminum alloy produced from these recycled materials can be significantly lower than 600°C. Aluminum alloys with solidus temperatures below 600°C may be prone to localized melting and cannot be used to produce core aluminum alloys. Therefore, the type and amount of recycled aluminum alloy material that can be used to produce core aluminum alloys is limited based on the amount of Si.

[0075] The aluminum alloy compositions described herein may contain a greater amount of recycled aluminum alloy material compared to conventional 3xxx series aluminum alloys, reducing the overall carbon footprint of the aluminum alloy. Aluminum alloys produced from recycled aluminum alloys with little or no primary aluminum minimize potential environmental impacts. While primary aluminum constitutes only a small portion of the raw material inputs into many aluminum alloys, it nonetheless contributes significantly to the environmental impact of many aluminum alloy products. Given the significant impact of primary aluminum on the carbon footprint, one way to reduce Scope 3 emissions (as defined above) during aluminum alloy production is to reduce the use of primary aluminum and increase the use of recycled aluminum alloy material. For example, Figure 2 shows that a 1% increase in primary aluminum increases the carbon footprint of an aluminum alloy by 117 kg CO₂e per 1,000 kg of product produced. Therefore, a 1% increase in recycled aluminum alloy material used to produce an aluminum alloy reduces the carbon footprint by the same amount. Although there are commercially available aluminum alloys that can incorporate higher amounts of recycled aluminum alloy material, allowing for higher amounts of certain critical elements (e.g., Mg, Si, Cu, and Mn), these aluminum alloys cannot be considered for critical components in heat exchangers (e.g., components where corrosion is critical), which may require tighter chemical tolerances to achieve the desired properties.

[0076] In some embodiments, the aluminum alloys described herein provide compositions suitable for utilizing post-consumer clad aluminum alloy products as recycled materials. Specifically, the aluminum alloys described herein can be produced from a substantial proportion of post-consumer clad aluminum alloy products, including mixtures of 3xxx and 4xxx series aluminum alloys. The aluminum alloy compositions for the core alloys described herein include a balance of Si, Cu, and Mn that provides a solidus temperature above 600°C. The Mn in the aluminum alloy composition offsets the Si and Cu to produce an aluminum alloy with a solidus temperature desirable for brazing applications.

[0077] In some embodiments, post-consumer clad aluminum alloy products comprising mixtures of 3xxx and 4xxx series aluminum alloys can be used as recycled materials. As discussed herein, aluminum alloy compositions can utilize recycled aluminum alloy materials (e.g., post-consumer clad aluminum alloy products) to produce aluminum alloys with the aluminum alloy composition. The aluminum alloys can be produced using a higher amount of recycled aluminum alloy material and a reduced amount of primary aluminum. In some embodiments, the aluminum alloy compositions described herein can be produced from mixtures of 3xxx and 4xxx series aluminum alloys. In some aspects, the aluminum alloys described herein include recycled aluminum alloy materials in an amount of 50% or more, e.g., 52% or more, 54% or more, 56% or more, 58% or more, 60% or more, 62% or more, 64% or more, or 65% or more. As noted above, in some aspects, the aluminum alloys described herein are particularly suitable for utilizing mixtures of 3xxx series aluminum alloy scrap and 4xxx series aluminum alloy scrap.

[0078] In some embodiments, the aluminum alloy contains 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% primary aluminum, all expressed in weight percent.

[0079] Alloy properties of the core alloy In some embodiments, the solidus temperature of an aluminum alloy for use as a 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., begins to melt). The core layers described herein have solidus temperatures that avoid localized melting during brazing. If the solidus temperature of the core layer is low (e.g., less than 600°C), the core alloy may be prone to localized 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).

[0080] In certain embodiments, the aluminum alloys described herein may have a yield strength 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 the O temper. In certain embodiments, the aluminum alloys described herein may have a yield strength 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 in the O temper.

[0081] In certain embodiments, the aluminum alloys described herein may have an ultimate tensile strength 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 the O temper. In some embodiments, the aluminum alloys described herein may have a yield strength 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 in between, in the O temper.

[0082] In certain embodiments, the aluminum alloys described herein may have sufficient formability to meet an elongation of at least 15% (e.g., at least 16%, at least 17%, at least 18%, at least 19%, or at least 20%) in the O temper.

[0083] Preparation and Processing Methods In certain embodiments, the disclosed alloy compositions are the product of the disclosed methods. Without intending to limit the disclosure, the properties of aluminum alloys are determined in part by the formation of the microstructure during the preparation of the alloy. In certain embodiments, the method of preparation of the alloy composition can influence or even determine whether the alloy has the appropriate properties for a desired application. casting

[0084] 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 conducted according to standards widely used in the aluminum industry, as known to those skilled in the art. The DC process can result in an ingot. Optionally, the casting process can be a continuous casting (CC) process or an electromagnetic casting (EMC) process. In some embodiments, the ingot can be scalped after casting and before downstream processing. In some embodiments, the casting process can include an electromagnetic casting (EMC) process.

[0085] The cast aluminum alloy may then be subjected to further processing steps. For example, the processing methods described herein may include optional homogenizing, preheating, hot rolling, cold rolling, slitting, and / or annealing steps.

[0086] Homogenization 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 be used in combination with the preheating step. For example, a cast aluminum alloy may be homogenized and then subjected to preheating.

[0087] The homogenization step may include heating the cast aluminum alloy described herein to achieve 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 temperature in between). 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 heating rate 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 heating rate to the homogenization temperature can 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).

[0088] The cast aluminum alloy is then soaked (i.e., held at the specified temperature) for a period of time within the homogenization temperature range. By way of non-limiting example, the cast aluminum alloy may be soaked for up to 30 hours (e.g., 10 minutes to 30 hours, inclusive). For example, the cast aluminum alloy may be soaked at a temperature of 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 time in between.

[0089] preheat The preheating step may include heating the cast aluminum alloy described herein to achieve 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 temperature in between). 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 heating rate 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 heating rate to the preheat temperature can 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).

[0090] The cast aluminum alloy is then soaked (i.e., held at the specified temperature) for a period of time within the preheat temperature range. According to one non-limiting example, the cast aluminum alloy may be soaked for up to 30 hours (e.g., 10 minutes to 30 hours, inclusive). For example, the cast aluminum alloy may be soaked at a temperature of 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 time in between. In some embodiments, the cast aluminum alloy is soaked at a preheat temperature of 480°C to 560°C for 5 hours to 7 hours.

[0091] hot rolling Following the homogenization and / or preheating steps, 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 may be too high, making the alloy more susceptible to cracking. If the hot rolling temperature is too high (e.g., above 560°C), the aluminum alloy may become too soft and break in the hot rolling mill. In some embodiments, the cast aluminum alloy may be hot rolled at a temperature of 350°C to about 500°C.

[0092] In certain cases, the cast aluminum alloy may be hot rolled to a thickness gauge of 2 mm to 15 mm (e.g., 2.5 mm to 12 mm). For example, the cast aluminum alloy may be hot rolled to a thickness gauge 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 certain cases, the cast aluminum alloy may be hot rolled to a gauge greater than 15 mm (i.e., plate). In other cases, the cast aluminum alloy may be hot rolled to a gauge less than 4 mm (i.e., sheet).

[0093] cold rolling The hot rolling step may be followed by an optional cold rolling step. The cold rolling step may include one or more cold rolling passes. In certain embodiments, the hot rolled product from the hot rolling step may be cold rolled to produce, for example, a thin gauge sheet or sheet. In some embodiments, the thin gauge sheet or sheet is cold rolled to have a final gauge thickness (i.e., a first thickness) of 0.02 mm to 10.0 mm (e.g., 0.2 mm to 3 mm). In some embodiments, the cold rolling step may further include two cold rolling steps. Two or more cold rolling steps may successively reduce the thickness to the final gauge thickness.

[0094] Slitting and / or annealing Optionally, the method may further include intermittent and / or final annealing steps during or after the cold rolling step. In some embodiments, the thin gauge sheet or sheet may be subjected to a final anneal. In some embodiments, the final annealing step is a continuous annealing and solution treatment step. The thin gauge sheet or sheet is heated to a maximum 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., held at the indicated temperature) above the predetermined temperature for a period of time. In some examples, the thin gauge sheet or sheet may be soaked for up to about 10 minutes (e.g., 1 second to 10 minutes, inclusive). For example, the sheet can be immersed 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.

[0095] In some embodiments, the method may optionally include a slitting step. The thin gauge sheet or sheet may be subjected to slitting after cold rolling or a final anneal. In some embodiments, the thin gauge sheet or sheet may be slit to a final thickness or into multiple narrower widths / rings / coils before or after the final anneal.

[0096] Brazing Method The clad aluminum alloy products described herein are suitable for brazing applications. Accordingly, various brazing processes and technology steps may be suitable for use with embodiments of the present disclosure. The clad aluminum alloy products may be brazed in an inert gas atmosphere. Any suitable inert gas may be used, including, for example, argon, helium, nitrogen, etc. The clad aluminum alloy products described herein are suitable for CAB. In the brazing cycle, the clad aluminum alloy products may be heated in a CAB furnace. In some embodiments, the aluminum alloys may be used for other joining processes such as vacuum brazing, flame brazing, flux brazing rings / shims, induction heating, laser brazing, welding, adhesive bonding, among others.

[0097] In some embodiments, the surface of the metal component to be joined to the clad aluminum alloy product is prepared (e.g., pretreated) prior to brazing. In some embodiments, the metal component to be joined is subjected to one or more pretreatments that can be used to promote adhesion between the clad aluminum alloy product and the metal component. Adhesion of the clad aluminum alloy product to the metal component, e.g., the cladding layer of the clad aluminum alloy product, can be improved to obtain a good brazed joint by pretreating the outer surface of the metal component on which the clad aluminum alloy product is deposited. In some embodiments, the pretreatment includes a pre-cleaning step during which the surface of the metal component is treated to remove grease, oil, buffing compounds, rolling lubricants, or slit oils. This can be accomplished by a number of methods, such as thermal degreasing, solvent cleaning, solvent emulsion cleaning, mechanical polishing, or mild etching.

[0098] In some embodiments, the surfaces of the metal parts to be joined are etched to remove traces of oil and grease remaining from the rolling process and to create a thinner oxide layer. For example, a preparation process may involve etching the surfaces of the metal parts using a caustic cleaner (e.g., 10% NaOH) to remove any traces of oil or grease. In some embodiments, etching the surfaces may provide surface properties that are important for forming a good brazed joint.

[0099] In some embodiments, the brazing process is carried out in a dry atmosphere with little or no atmospheric oxygen. In some embodiments, the brazing process is carried out in an inert atmosphere of nitrogen, argon, or helium. The brazing process may include heating the clad aluminum alloy product described herein to achieve 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 anywhere in between). 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 heating rate to the brazing temperature can be 200°C / hr or less, 180°C / hr or less, 160°C / hr or less, 140°C / hr or less, 120°C / hr or less, 100°C / hr or less, 75°C / hr or less, 50°C / hr or less, 40°C / hr or less, 30°C / hr or less, 25°C / hr or less, 20°C / hr or less, 15°C / hr or less, or 10°C / hr or less. In other cases, the heating rate to the brazing temperature can be 10°C / min to 200°C / min (e.g., 10°C / min to 175°C / min, 10°C / min to 150°C / min, 0°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 heating rate to maximum temperature in the CAB furnace is less than 3 minutes.

[0100] In some embodiments, the clad aluminum alloy article 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 article may then be heated at a rate of 25°C / minute until a temperature of 605°C is reached, followed by a heat soak at 605°C for 3 minutes. The clad aluminum alloy article may then be cooled to 570°C, removed from the furnace, and cooled at room temperature. In some embodiments, the clad aluminum alloy article is heated in a CAB furnace to 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).

[0101] In some embodiments, methods are provided for manufacturing articles, such as heat exchangers, joined by brazing or an assembly of brazed components. The methods may include providing components, at least one of which is made from the clad aluminum alloy product described herein. The methods may include assembling components, such as corrugated finstock, with other components, such as tubing, to form an assembly. The methods may further include brazing the assembly without applying a brazing flux to the assembly of components. The entire assembly is brazed in a controlled inert gas atmosphere at a brazing temperature, typically in the range of 560°C to 620°C, for a time sufficient to melt and spread the filler joining the various components, e.g., a dwell time of 1 to 5 minutes. The oxygen content in the brazing atmosphere should be as low as reasonably possible, preferably less than 100 ppm, more preferably less than 50 ppm, e.g., 25 ppm or less. The methods may further include cooling the brazed assembly, typically to below 100°C, e.g., to room temperature, e.g., using blown air or any other suitable cooling medium.

[0102] Although metal parts such as aluminum alloy articles are described throughout the document, the methods and articles apply to any metal, hi 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 material, a sheet used in a composite material, or any other suitable metal or combination of materials.

[0103] How to use The aluminum alloys and methods described herein can be used in industrial applications, including sacrificial components, heat dissipation, heating, ventilation, air conditioning and refrigeration, packaging, and building materials. The aluminum alloys described herein can be used in a variety of applications, such as for the manufacture of fins for heat exchangers. In one example, the improved aluminum alloys described herein are useful for high-performance, lightweight automotive heat exchangers. More generally, the aluminum alloys described herein can be used in automotive heat exchangers such as radiators, condensers, heaters, intercoolers, charge air coolers, oil coolers, exhaust coolers, fuel coolers, cold plates (e.g., also called chiller plates or battery cold plates), and evaporators. Cold plates are typically produced by brazing a bare aluminum flat sheet to a formed sheet with a clad liner on one side and, optionally, a 1xxx or 7xxx sacrificial liner on the other side (e.g., the coolant channel side). The described aluminum alloys can be used in the bare flat sheet and / or as the core alloy of the formed sheet. As noted above, the compositions and processes for producing the improved aluminum alloys described herein result in materials having a combination of useful features and properties that make them suitable for 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 envisioned. The improved aluminum alloys described herein can be used to make a variety of devices that use heat exchangers and are manufactured by brazing, such as devices used in heating, ventilation, and air conditioning (HVAC).

[0104] The aluminum alloys disclosed herein are suitable replacements for metals traditionally used in indoor and outdoor HVAC units. As used herein, "indoor" refers to an arrangement contained within any human-made structure with controlled environmental conditions. As used herein, "outdoor" refers to an arrangement not entirely contained within any human-made structure, but exposed to geological and meteorological environmental conditions, including: air, solar radiation, wind, rain, sleet, snow, icy rain, ice, hail, dust storms, humidity, dryness, smoke (e.g., cigarette smoke, house fire smoke, industrial incinerator smoke, and wildfire smoke), smog, fossil fuel exhaust, biofuel exhaust, salts (e.g., highly saline air in areas near salt water bodies), radiation, electromagnetic waves, corrosive gases, corrosive liquids, galvanic metals, galvanic alloys, corrosive solids, plasma, fire, electrostatic discharge (e.g., lightning), biological material (e.g., animal waste, saliva, excreted oils, vegetation), windblown particulates, changes in air pressure, and diurnal temperature changes. The aluminum alloys described herein offer better corrosion performance and higher strength than currently used alloys.

[0105] The following examples serve to further illustrate the present invention, but do not, however, constitute any limitation thereof. To the contrary, it should be clearly understood that various embodiments, modifications thereof, and equivalents thereof, which may suggest themselves to those skilled in the art after reading the description herein, can be used without departing from the spirit of the present invention. In the studies described in the following examples, conventional procedures were followed unless otherwise noted. Some procedures are described below for illustrative purposes.

[0106] Examples Example 1: An aluminum alloy comprising 0.8-1.3 wt% Si, max 0.6 wt% Fe, 0.1-0.6 wt% Cu, 0.9-2 wt% Mn, max 0.2 wt% Mg, max 0.3 wt% Cr, max 0.5 wt% Zn, max 0.2 wt% Ti, max 0.3 wt% Zr, max 0.15 wt% impurities, and the balance Al.

[0107] Example 2: Any of the preceding or subsequent examples, comprising 0.8-1.3 wt.% Si, maximum 0.6 wt.% Fe, 0.1-0.6 wt.% Cu, 0.9-2 wt.% Mn, maximum 0.2 wt.% Mg, maximum 0.25 wt.% Cr, maximum 0.4 wt.% Zn, maximum 0.2 wt.% Ti, maximum 0.25 wt.% Zr, maximum 0.15 wt.% impurities, and balance Al.

[0108] Example 3: Any of the preceding or subsequent examples, comprising 0.8-1.3 wt.% Si, maximum 0.4 wt.% Fe, 0.1-0.5 wt.% Cu, 0.9-2 wt.% Mn, maximum 0.1 wt.% Mg, maximum 0.2 wt.% Cr, maximum 0.3 wt.% Zn, maximum 0.2 wt.% Ti, maximum 0.2 wt.% Zr, maximum 0.15 wt.% impurities, and balance Al.

[0109] Example 4: Any example described in any preceding or following example, 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 balance Al.

[0110] Example 5: Any example described in any preceding or subsequent example, comprising 0.85-1.25 wt.% Si, max. 0.5 wt.% Fe, 0.2-0.5 wt.% Cu, 1.2-1.8 wt.% Mn, max. 0.15 wt.% Mg, max. 0.10 wt.% Cr, max. 0.10 wt.% Zn, max. 0.1 wt.% Ti, max. 0.1 wt.% Zr, max. 0.15 wt.% impurities, and balance Al.

[0111] Example 6: Any example described in any preceding or subsequent example, comprising 0.85-1.15 wt.% Si, maximum 0.38 wt.% Fe, 0.23-0.43 wt.% Cu, 1.4-1.6 wt.% Mn, maximum 0.1 wt.% Mg, maximum 0.05 wt.% Cr, maximum 0.05 wt.% Zn, maximum 0.1 wt.% Ti, maximum 0.05 wt.% Zr, maximum 0.15 wt.% impurities, and balance Al.

[0112] Example 7: Any example described in any preceding or subsequent example, comprising 0.9-1.1 wt.% Si, maximum 0.35 wt.% Fe, 0.23-0.43 wt.% Cu, 1.4-1.6 wt.% Mn, maximum 0.05 wt.% Mg, maximum 0.03 wt.% Cr, maximum 0.04 wt.% Zn, maximum 0.1 wt.% Ti, maximum 0.01 wt.% Zr, maximum 0.15 wt.% impurities, and balance Al.

[0113] Example 8: Any preceding or subsequent example, wherein the aluminum alloy comprises more than 50% recycled aluminum alloy material.

[0114] Example 9: Any of the preceding or subsequent examples, wherein the recycled aluminum alloy material comprises a post-consumer clad aluminum alloy product comprising a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys.

[0115] Example 10: Any preceding or subsequent example, wherein the aluminum alloy has a solidus temperature of 600°C or greater.

[0116] Example 11: Any preceding or subsequent example, wherein the aluminum alloy has an ultimate tensile strength of 125 MPa to 200 MPa.

[0117] Example 12: Any preceding or subsequent example, wherein the aluminum alloy has a yield strength of 35 MPa to 80 MPa.

[0118] Example 13: Any of the preceding or subsequent examples, wherein the aluminum alloy comprises 0.85-1.25 wt.% Si, max. 0.50 wt.% Fe, 0.2-0.55 wt.% Cu, 1.2-1.8 wt.% Mn, max. 0.15 wt.% Mg, max. 0.1 wt.% Cr, max. 0.1 wt.% Zn, max. 0.1 wt.% Ti, max. 0.05 wt.% Zr, max. 0.15 wt.% impurities, and balance Al; comprises more than 50% recycled aluminum alloy material, including post-consumer clad aluminum alloy products comprising a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys; and has a solidus temperature of 600°C or greater.

[0119] Example 14: An unclad aluminum alloy product comprising the aluminum alloy of any preceding or following example.

[0120] Example 15: An unclad aluminum alloy product comprising a core layer comprising the aluminum alloy of any preceding or subsequent example.

[0121] Example 16: A clad aluminum alloy product comprising: a core layer having a first side and a second side; and at least one cladding layer on the first side or the second side, wherein the core layer and / or the cladding layer comprises 0.8-1.3 wt.% Si, maximum 0.6 wt.% Fe, 0.1-0.6 wt.% Cu, 0.9-2 wt.% Mn, maximum 0.2 wt.% Mg, maximum 0.3 wt.% Cr, maximum 0.5 wt.% Zn, maximum 0.2 wt.% Ti, maximum 0.3 wt.% Zr, maximum 0.15 wt.% impurities, and the balance Al.

[0122] Example 17: Any of the preceding or subsequent examples, wherein the at least one cladding layer comprises a 1xxx, 3xxx, 4xxx, or 7xxx series aluminum alloy.

[0123] Example 18: A heat exchanger comprising the clad aluminum alloy product of any preceding or following example.

[0124] Example 19: A method of forming a brazed product, the method comprising the steps of providing one or more metal components; and disposing a clad aluminum alloy product on or between the one or more metal components to form an assembly, the clad aluminum alloy product comprising 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 an amount of flux prior to brazing; and cooling the brazed assembly, wherein the core layer comprises 0.8-1.3 wt.% Si, max. 0.6 wt.% Fe, 0.1-0.6 wt.% Cu, 0.9-2 wt.% Mn, max. 0.2 wt.% Mg, max. 0.3 wt.% Cr, max. 0.5 wt.% Zn, max. 0.2 wt.% Ti, max. 0.3 wt.% Zr, max. 0.15 wt.% impurities, and balance Al.

[0125] Example 20: Any of the preceding or subsequent examples, wherein the brazing comprises controlled atmosphere brazing.

[0126] Example 21: Any of the preceding or subsequent examples, wherein the assembly is brazed at a brazing temperature of 560°C to 620°C.

[0127] Example 22: Any of the preceding or subsequent examples, wherein 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 balance Al.

[0128] Example 22: Any of the preceding or subsequent examples, wherein 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 0.25 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.

[0129] Example 23: Any of the preceding or subsequent examples, wherein the aluminum alloy comprises 0.7-1.3 wt.% Si, maximum 0.4 wt.% Fe, 0.1-0.5 wt.% Cu, 0.9-2 wt.% Mn, maximum 0.1 wt.% Mg, maximum 0.2 wt.% Cr, maximum 0.3 wt.% Zn, maximum 0.2 wt.% Ti, maximum 0.2 wt.% Zr, maximum 0.15 wt.% impurities, and the balance Al.

[0130] Example 24: Any example of any preceding or subsequent example, wherein 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 balance Al.

[0131] Example 25: Any of the preceding or subsequent examples, wherein the aluminum alloy comprises 0.7-1.25 wt.% Si, maximum 0.5 wt.% Fe, 0.2-0.5 wt.% Cu, 1.2-1.8 wt.% Mn, maximum 0.15 wt.% Mg, maximum 0.10 wt.% Cr, maximum 0.10 wt.% Zn, maximum 0.1 wt.% Ti, maximum 0.1 wt.% Zr, maximum 0.15 wt.% impurities, and the balance Al.

[0132] Example 26: Any of the preceding or subsequent examples, wherein the aluminum alloy comprises 0.7-1.15 wt.% Si, maximum 0.38 wt.% Fe, 0.23-0.43 wt.% Cu, 1.4-1.6 wt.% Mn, maximum 0.1 wt.% Mg, maximum 0.05 wt.% Cr, maximum 0.05 wt.% Zn, maximum 0.1 wt.% Ti, maximum 0.05 wt.% Zr, maximum 0.15 wt.% impurities, and balance Al.

[0133] All patents, publications, and abstracts cited above are incorporated herein by reference in their entirety. Various embodiments of the present invention have been described in fulfillment of various objectives of the present invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous changes and modifications thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention, as defined in the following claims. [Example]

[0134] Sample Alloy 1 and Sample Alloy 2 described herein are modified 3xxx series aluminum alloys formulated to have good brazing properties and good corrosion resistance properties despite being made from a large amount of recycled aluminum alloy material. Sample Alloys 1 and 2 have a high Mn content (e.g., 0.9 wt.% to 2 wt.%), which increases the solidus temperature of the aluminum alloy and offsets the large amounts of Si and Cu that result from the incorporation of recycled aluminum alloy material. Additionally, Sample Alloys 1-2 contain less than 0.2 wt.% Mg, which facilitates controlled atmosphere brazing (CAB), for example, by allowing for a relatively small amount of flux. Thus, the modified aluminum alloys provide a recyclable alternative to conventional 3xxx series aluminum alloys (e.g., AA3003 aluminum alloy) used as core alloys in heat exchanger products. The compositions of Sample Alloys 1-2 are shown in Table 10 below. [Table 10]

[0135] Separate clad aluminum alloy samples were prepared using Sample Alloys 1 and 2 as core layers. Sample Alloy 1 had a thickness of 0.6 mm. One side of Sample Alloy 1 was clad with AA4343 aluminum alloy to produce a first clad aluminum alloy product. The ratio of the cladding layer thickness 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 a second clad aluminum alloy product. The ratio of the cladding layer thickness to the entire sheet before brazing was 6.5%.

[0136] Both clad aluminum alloy samples were tested to determine their mechanical properties. The tensile properties of each of the clad aluminum alloy samples were determined using ISO 6892-1 B (sample type E12.5). The bending behavior was determined using DIN EN 1396:2015, and the grain size was determined using ASTM E112. Each of the clad aluminum alloy products was tested for its mechanical properties before and after brazing at 600°C for 3 minutes. The first clad aluminum alloy product had a yield strength of 52.8 MPa and a tensile strength of 149.8 MPa before brazing. Furthermore, the first clad aluminum alloy product exhibited a tensile elongation of 22.9% before brazing. After brazing under the above conditions, the first clad aluminum alloy product was retested for its yield strength and tensile strength. The first clad aluminum alloy sample exhibited a yield strength of 53.3 MPa and a tensile strength of 158.8 MPa after brazing. The yield strength of the first clad aluminum alloy sample was similar before and after brazing. Furthermore, the tensile strength of the first clad aluminum alloy sample increased after brazing.

[0137] In addition to determining the mechanical properties of the first clad aluminum alloy samples, the first clad aluminum alloy samples were tested to observe their bending behavior before brazing. In the longitudinal direction (e.g., parallel to the grain orientation of the core layer) and the long transverse direction (e.g., the largest dimension transverse to the longitudinal direction), the first clad aluminum alloy samples were crack-free at a bend angle of 180° and zero radius. Additionally, the grain size of the core alloy of the first clad aluminum alloy samples was characterized before and after brazing. The average grain size of the first clad aluminum alloy samples was ASTM No. 6 or greater before and after brazing, indicating little change in grain size after brazing.

[0138] The second clad aluminum alloy sample was tested for its mechanical properties before and after brazing at 600°C for 5 minutes. The second clad aluminum alloy sample had a 0.2% offset yield strength of 52 MPa and a tensile strength of 153 MPa before brazing. Furthermore, the second clad aluminum alloy sample exhibited a tensile elongation of 26.4% before brazing. After brazing, the second clad aluminum alloy sample was again tested for its yield strength and tensile strength. After brazing, the second clad aluminum alloy sample exhibited a yield strength of 52.8 MPa and a tensile strength of 163.5 MPa. Similar to the first clad aluminum alloy sample, the yield strengths of the second clad aluminum alloy sample were similar before and after brazing. Furthermore, the tensile strength of the second clad aluminum alloy sample was higher after brazing, indicating that sample alloy 2 exhibits favorable brazing properties despite being manufactured from a large amount of recycled aluminum alloy material.

[0139] The second clad aluminum alloy samples were also tested to determine their bending behavior before brazing. In both the longitudinal and transverse directions, the second clad aluminum alloy samples were crack-free at a 180° bend angle and zero radius. The grain size of the second clad aluminum alloy samples was equal to or greater than ASTM grain size No. 7 before and after brazing. Similar to the first clad aluminum alloy samples, the grain size of the second clad aluminum alloy samples remained substantially unchanged after brazing.

Claims

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

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

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

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

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

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

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

8. 10. The aluminum alloy of claim 1 comprising greater than 50% recycled aluminum alloy material.

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

10. 10. The aluminum alloy of claim 1 having a solidus temperature of 600°C or greater.

11. 2. The aluminum alloy of claim 1, wherein the aluminum alloy has an ultimate tensile strength of 125 MPa to 200 MPa.

12. 2. The aluminum alloy of claim 1, wherein the aluminum alloy has a yield strength of 35 MPa to 80 MPa.

13. 0.85-1.25 wt.% Si, max. 0.50 wt.% Fe, 0.2-0.55 wt.% Cu, 1.2-1.8 wt.% Mn, max. 0.15 wt.% Mg, max. 0.1 wt.% Cr, max. 0.1 wt.% Zn, max. 0.1 wt.% Ti, max. 0.05 wt.% Zr, max. 0.15 wt.% impurities, and balance Al; comprising more than 50% recycled aluminum alloy material, including post-consumer clad aluminum alloy products comprising a mixture of 3xxx series aluminum alloys and 4xxx series aluminum alloys; 10. The aluminum alloy of claim 1 having a solidus temperature of 600°C or greater.

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

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

16. A clad aluminum alloy product, comprising: a core layer having a first side and a second side; at least one cladding layer on the first side or the second side; % Si, max 0.6 wt % Fe, 0.1-0.6 wt % Cu, 0.9-2 wt % Mn, max 0.2 wt % Mg, max 0.3 wt % Cr, max 0.5 wt % Zn, max 0.2 wt % Ti, max 0.3 wt % Zr, max 0.15 wt % impurities, and the balance Al.

17. 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. 17. A heat exchanger comprising the clad aluminum alloy product of claim 16.

19. 1. A method of forming a brazed product, comprising: Providing one or more metal components; providing a clad aluminum alloy product on or between the one or more metal components to form an assembly, the clad aluminum alloy product including 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 quantity of flux prior to brazing; and cooling the brazed assembly, wherein the core layer comprises 0.7-1.3 wt.% Si, max. 0.6 wt.% Fe, 0.1-0.6 wt.% Cu, 0.9-2 wt.% Mn, max. 0.2 wt.% Mg, max. 0.3 wt.% Cr, max. 0.5 wt.% Zn, max. 0.2 wt.% Ti, max. 0.3 wt.% Zr, max. 0.15 wt.% impurities, and balance 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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