WO2024155383A1

WO2024155383A1 - Brazing sheets, articles formed from brazing sheets, and methods of forming articles

Info

Publication number: WO2024155383A1
Application number: PCT/US2023/083639
Authority: WO
Inventors: Farzin FATOLLAHI-FARD
Original assignee: Arconic Technologies Llc
Priority date: 2023-01-19
Filing date: 2023-12-12
Publication date: 2024-07-25
Also published as: MX2025004925A; CN120187555A

Abstract

Brazing sheets, articles formed from or including all or a portion of a brazing sheet, and methods of forming articles of manufacture are provided. The brazing sheet comprises a brazing layer and a core layer. The brazing layer comprises a 4XXX series aluminum alloy. The core layer comprises a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy: 0.2 to 0.6 silicon; 1.5 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 2.5 copper; 0 to 0.5 iron; 0 to 0.5 magnesium; 0 to 0.5 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum. The first aluminum alloy satisfies the equation Formula (I) and [Mg], [Fe], [Cr], and [Si] are, respectively, weight percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy.

Description

TITLE

BRAZING SHEETS, ARTICLES FORMED FROM BRAZING SHEETS, AND METHODS OF FORMING ARTICLES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/480,625, which was filed on January 19, 2023, the contents of which is hereby incorporated by reference into this specification.

FIELD OF USE

[0002] The present disclosure relates to brazing sheets, articles formed from or including brazing sheets, and methods of forming articles.

BACKGROUND

[0003] Various apparatus, such as, for example, heat exchangers, may be formed from stacked specially designed metal plates, such as, for example brazing sheets. Plate-type heat exchangers function by circulating two fluids (e.g., liquid, refrigerant, or combinations thereof) on opposite sides of a plate, allowing heat exchange between the fluids. There are challenges with designing acceptable brazing sheets and sourcing feedstock materials for producing the brazing sheets.

SUMMARY

[0004] One non-limiting aspect according to the present disclosure is directed to a brazing sheet comprising a brazing layer and a core layer. The brazing layer comprises a 4XXX series aluminum alloy. The core layer comprises a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy: 0.2 to 0.6 silicon; 1.5 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 2.5 copper; 0 to 0.5 iron; 0 to 0.5 magnesium; 0 to 0.5 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum. The first aluminum alloy satisfies the equation 3.1 < [Mg], [Fe], [Cr], and [Si] are, respectively, weight percentage

concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy. [0005] An additional non-limiting aspect according to the present disclosure is directed to an article including, or formed from parts including, a structural element comprising all or a portion of a brazing sheet. The brazing sheet comprises a brazing layer and a core layer. The brazing layer comprises a 4XXX series aluminum alloy. The core layer comprises a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy: 0.2 to 0.6 silicon; 1.5 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 2.5 copper; 0 to 0.5 iron; 0 to 0.5 magnesium; 0 to 0.5 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum. The first aluminum alloy satisfies the equation 3.1 <

_an(j [Mg], [F_e], [ ], _an(j [Si] are,

respectively, weight percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy.

[0006] Yet a further non-limiting aspect according to the present disclosure is directed to a method for forming an article of manufacture. The method comprises contacting a first part comprising a first material with a second part comprising all or a portion of a brazing sheet comprising a brazing layer and a core layer. The brazing layer comprises a 4XXX series aluminum alloy. The core layer comprises a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy: 0.2 to 0.6 silicon; 1.5 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 2.5 copper; 0 to 0.5 iron; 0 to 0.5 magnesium; 0 to 0.5 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and

[Mg] + [ e] + rCrl aluminum. The first aluminum alloy satisfies the equation 3.1 < - — - and [Mg],

[Fe], [Cr], and [Si] are, respectively, weight percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy. The method comprises brazing the first part to the second part by a process comprising at least one of controlled atmospheric brazing and vacuum brazing.

[0007] It is understood that the inventions disclosed and described in this specification are not limited to the aspects summarized in this Summary. The reader will appreciate the foregoing details, as well as others, upon considering the following detailed description of various non-limiting and non-exhaustive aspects according to this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The features and advantages of the examples, and the manner of attaining them, will become more apparent, and the examples will be better understood, by reference to the following description taken in conjunction with the accompanying drawing, wherein:

[0009] FIG. l is a schematic side elevational view of a first non-limiting embodiment of a brazing sheet according to the present disclosure;

[0010] FIG. 2 is a schematic side elevational view of a second non-limiting embodiment of a brazing sheet according to the present disclosure;

[0011] FIG. 3 is a schematic side elevational view of a third non-limiting embodiment of a brazing sheet according to the present disclosure;

[0012] FIG. 4 is a schematic side elevational view of a fourth non-limiting embodiment of a brazing sheet according to the present disclosure;

[0013] FIG. 5 is a schematic side elevational view of a fifth non-limiting embodiment of a brazing sheet according to the present disclosure; and

[0014] FIG. 6 is a flow chart illustrating a non-limiting embodiment of a method for forming an article according to the present disclosure.

[0015] The exemplifications set out herein illustrate certain embodiments, in one or more forms, and such exemplifications are not to be construed as limiting the scope of the appended claims in any manner.

DESCRIPTION OF NON-LIMITING EMBODIMENTS

[0016] Various embodiments are described and illustrated herein to provide an overall understanding of the structure, function, and use of the disclosed articles and methods. The various embodiments described and illustrated herein are non-limiting and non-exhaustive. Thus, an invention is not limited by the description of the various non-limiting and non- exhaustive embodiments disclosed herein. Rather, the invention is defined solely by the claims. The features and characteristics illustrated and/or described in connection with various embodiments may be combined with the features and characteristics of other embodiments. Such modifications and variations are intended to be included within the scope of this specification. As such, the claims may be amended to recite any features or characteristics expressly or inherently described in, or otherwise expressly or inherently supported by, this specification. Further, the applicant reserves the right to amend the claims to affirmatively disclaim features or characteristics that may be present in the prior art. The various embodiments disclosed and described in this specification can comprise, consist of, or consist essentially of the features and characteristics as variously described herein.

[0017] Any references herein to “various embodiments”, “some embodiments”, “one embodiment”, “an embodiment”, “a non-limiting embodiment”, or like phrases mean that a particular feature, structure, step, or characteristic described in connection with the example is included in at least one embodiment. Thus, appearances of the phrases “various embodiments”, “some embodiments”, “one embodiment”, “an embodiment”, “a non-limiting embodiment”, or like phrases in the specification do not necessarily refer to the same embodiment. Furthermore, the particular described features, structures, steps, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, steps, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features, structures, steps, or characteristics of one or more other embodiments, without limitation.

Such modifications and variations are intended to be included within the scope of the present embodiments.

[0018] Various non-limiting embodiments of alloys discussed in connection with the present disclosure optionally include intentional additions of incidental elements that may, for example, aid in production of the alloy and/or improve one or more properties or characteristics of the alloy. For example, certain non-limiting embodiments of alloys according to the present disclosure may include intentional incidental additions of one or more of grain refining elements and/or one or more deoxidizing elements. In various nonlimiting embodiments, the total concentration of incidental elements in alloys according to the present disclosure preferably does not exceed 1 weight percent based on the total weight of the alloy, and the concentration of any single incidental element preferably does not exceed 0.2 weight percent based on the total weight of the alloy.

[0019] Various non-limiting embodiments of alloys discussed in connection with the present disclosure may include impurities. As used herein, “impurities” are elements or other materials that may be present in relatively minor concentrations in alloys according to the present disclosure but that are not intentionally added to enhance production or affect properties or characteristics of the alloy. For example, impurities in the alloys according to the present disclosure may be present in minor concentrations due to, for example, unavoidable or unintentional presence of the impurities in feed materials, incorporation from the local atmosphere during melting, refining, or other processing, or contamination by contact with processing equipment. In various non-limiting embodiments, the total concentration of impurities in alloys discussed in the present disclosure preferably does not exceed 0.15 weight percent based on the total weight of the alloy, and the concentration of any single impurity preferably does not exceed 0.05 weight percent based on the total weight of the alloy.

[0020] Brazing sheets typically include alloying elements that would be of value if they can be separated from scrap brazing sheets or from used or scrapped articles of manufacture formed from or including the brazing sheets. Brazing sheets typically include multiple layers, each having its own compositional specifications. It can be challenging to separate layers of a brazing sheet, remove an individual alloying element from a brazing sheet, or separate a layer from an article including or formed from a brazing sheet. As a result, the brazing sheets or articles may have to be recycled as a whole, without separation of layers or regions in which desired elements are present. Certain of the alloying elements in the scrap brazing sheets or scrap articles may be present at concentrations undesirable for use as recycled feed materials in the production of certain aluminum alloy sheets to be incorporated into brazing sheets. For example, some alloying elements may be present in the brazing sheets or scrap articles in concentrations that will adversely affect characteristics of a brazing sheet core layer such as, for example, corrosion resistance, grain size, and/or other microstructural characteristics of the core layer.

[0021] The present inventor has determined that a balance of chemistry modifications from elements present in scrap material with additional purposeful elemental additions can provide desired properties in aluminum alloy sheets for use in a brazing sheet. The present disclosure provides a brazing sheet that can exhibit advantageous recyclability, along with acceptable or superior formability, corrosion resistance, brazeability, strength, and diffusion resistance. Embodiments of a brazing sheet according to the present disclosure can comprise a brazing layer and a core layer. The brazing layer comprises a 4XXX series aluminum alloy. The core layer comprises a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy: 0.2 to 0.6 silicon; 1.5 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 2.5 copper; 0 to 0.5 iron; 0 to 0.5 magnesium; 0 to 0.5 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum. The first aluminum alloy satisfies the equation 3.1 < [Mg], [Fe], [Cr], and

[Si] are, respectively, weight percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy.

[0022] As used herein, the term “core layer” refers to a substrate layer of the brazing sheet. In various non-limiting embodiments, a “core layer” can be disposed substantially in the center of a brazing sheet. However, the position of the core layer in a brazing sheet according to the present disclosure is not limited to the center of a brazing sheet. The core layer may or may not be covered on both of its faces with another layer of the brazing sheet and, for example, the core layer can be disposed and partially or fully exposed on one side of the brazing sheet. Accordingly, in various non-limiting embodiments, the core layer of embodiments of a brazing sheet according to the present disclosure can be fully covered on both sides by other layers of the brazing sheet, have at least one side at least partially exposed, or have at least one side fully exposed.

[0023] Referring to FIG. 1, a brazing sheet 100 is provided. The brazing sheet 100 comprises a core layer 102 and a brazing layer 104. In various non-limiting embodiments, the core layer 102 and the brazing layer 104 are bonded (e.g., roll bonded) together to form the brazing sheet 100. The brazing sheet 100 illustrated in FIG. 1 includes two layers. However, the brazing sheet 100 can comprise one or more additional layers, as described herein, such as, for example, three layers as illustrated in FIGs. 2 and 5, four layers as illustrated in FIG. 4, or five layers as illustrated in FIG. 3.

[0024] Referring again to FIG. 1, the brazing sheet 100 can be subjected to brazing as a step in a production process to form an article of manufacture. For example, in a brazing step an assembly comprising a part and the brazing sheet 100 are heated to a temperature that is at least as high as the melting temperature of the brazing layer 104 such that the brazing layer 104 melts and flows to wet a surface of the part and subsequently solidifies to form a suitable braze joint between the brazing sheet 100 and the part. In various embodiments, the temperature to which the assembly is heated in the brazing step can be sufficiently high to dissolve soluble phases in the brazing sheet 100. Typically, during brazing the assembly is heated to a temperature in a range of 590°C to 610°C. In various embodiments, the heated assembly is cooled quickly, which can minimize the precipitation of undesirable soluble phases.

[0025] During brazing, it can be desirable that the core layer 102 does not melt such that the core layer 102 retains a desired strength, structural integrity, and corrosion performance. For example, in various embodiments the core layer 102 can comprise a core layer solidus temperature greater than the brazing temperature to which the brazing sheet 100 is subjected. For example, the core layer 102 can comprise a core layer solidus temperature of at least 600°C, such as, for example, at least 605°C, at least 610°C, or at least 615°C.

[0026] In various embodiments, the core layer 102 can be unhomogenized and H-temper. As used herein, H-temper has the meaning provided in ANSI H35.1/H35. l(M)-2017. The core layer 102 can develop a brown band, which can be resistant to corrosion. The brown band can form in the core layer 102 when silicon diffuses from the brazing layer 104 to the core layer 102 and forms precipitates with manganese and iron in solid solution during a brazing process. The brown band in the core layer 102 can comprise small-scale Al_xMn_ySiz or Alx(Mn,Fe,Cr)_ySiz dispersoids that form a band near the interface between the brazing layer 104 and the core layer 102. The formation of dispersoids at this interface pulls manganese out of solid solution and creates a more electrochemically negative region in the brazing sheet 100 that is anodic to the center of the brazing sheet 100, thereby increasing the overall corrosion resistance of the core layer 102. As the presence of silicon in the core layer 102 can affect the formation of a brown band and the core solidus temperature, highly corrosion resistant core layers that contain high levels of silicon typically do not rely on brown band formation for corrosion resistance. The present inventor has determined that silicon, and other alloying elements, can be present in the core layer 102 while achieving desirable brown band formation for enhanced corrosion resistance by adjusting the chemistry of the core layer 102 to compensate for a high level of silicon that may result from using brazing sheet scrap in producing the brazing sheet 100.

[0027] The core layer 102 of the brazing sheet 100 comprises a first aluminum alloy, such as, for example, a 3XXX series aluminum alloy. The first aluminum alloy can comprise, in weight percentages based on the total weight of the first aluminum alloy, 0.2 to 0.6 silicon, such as, for example, 0.2 to 0.55 silicon, 0.25 to 0.55 silicon, 0.25 to 0.5 silicon, 0.3 to 0.55 silicon, 0.3 to 0.5 silicon, 0.3 to 0.45 silicon, or 0.3 to 0.4 silicon. The silicon content may be derived from the scrap material used in producing the core layer 102.

[0028] It was discovered that maintaining a suitable balance of certain elements in the core layer 102 can allow the core layer 102 to include a substantial amount of scrap material and still exhibit desirable properties. For example, the first aluminum alloy can satisfy the equation X < [Mg], [Fe], [Cr], and [Si] are, respectively, weight

percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy. X can be at least 3.1, such as, for example, at least 3.2, at least 3.3, at least 3.4, at least 3.5, at least 3.6, at least 3.7, at least 3.8, at least 3.9, or at least 4. X can be no greater than 10. For example, X can be in a range of 3.1 to 10.

[0029] In various non-limiting embodiments, maintaining a suitably high manganese-to- silicon weight ratio in the core layer 102 can allow the core layer 102 to include a substantial amount of scrap material and still exhibit desirable properties. For example, the weight ratio of manganese to silicon in the first aluminum alloy can be at least 3.1, such as, for example, at least 3.2, at least 3.3, at least 3.4, at least 3.5, at least 3.6, at least 3.7, at least 3.8, at least 3.9, or at least 4. The weight ratio of manganese to silicon can be no greater than 10. For example, the weight ratio of manganese to silicon in the first aluminum alloy can be in a range of 3.1 to 10.

[0030] The first aluminum alloy can comprise, in weight percentages based on the total weight of the first aluminum alloy, 1.5 to 2 manganese, such as, for example, 1.55 to 2 manganese, 1.6 to 2 manganese, 1.65 to 2 manganese, 1.7 to 2 manganese, 1.6 to 1.95 manganese, 1.6 to 1.9 manganese, 1.65 to 1.9 manganese, or 1.65 to 1.85 manganese.

[0031] The first aluminum alloy can comprise, in weight percentages based on the total weight of the first aluminum alloy, 0.01 to 0.2 titanium, such as, for example, 0.03 to 0.2 titanium, 0.05 to 0.2 titanium, or 0.1 to 0.2 titanium.

[0032] The first aluminum alloy of the core layer 102 can comprise, in weight percentages based on the total weight of the first aluminum alloy: 0.2 to 0.6 silicon; 1.5 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 2.5 copper; 0 to 0.5 iron; 0 to 0.5 magnesium; 0 to 0.5 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum. In various non-limiting embodiments, the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy: 0.2 to 0.5 silicon; 1.6 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 1 copper; 0.1 to 0.4 iron; 0 to 0.1 magnesium; 0 to 0.25 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum. In certain non-limiting embodiments, the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy: 0.3 to 0.4 silicon; 1.6 to 2 manganese; 0.01 to 0.2 titanium; 0.5 to 1 copper; 0.1 to 0.4 iron; 0 to 0.1 magnesium; 0 to 0.25 zinc; 0 to 0.3 chromium; 0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum.

[0033] The chemistry of the core layer 102 can be modified to include another corrosion protection mechanism in addition to or alternatively to a brown band. For example, the core layer 102 can be modified to include a concentration of copper that imparts galvanic protection to the core layer 102. A copper concentration that is too high could undesirably affect properties of the core layer 102. In various examples, the core layer 102 can comprise a weight ratio of copper to manganese in the first aluminum alloy of no greater than 1, such as, for example, no greater than 0.9, or no greater than 0.8.

[0034] The core layer 102 can be formed from an ingot comprising, for example, at least 10% scrap material, such as, for example, at least 20% scrap material, at least 30% scrap material, at least 40% scrap material, or at least 50% scrap material. The remainder of the material in the ingot can be feed materials, such as, for example, primary aluminum (e.g., grade P1020) and optionally hardeners. The amount of scrap material included may be balanced based on the amount of silicon or other alloying elements contained in the scrap material. For example, the amount of scrap material and the amount of the feed materials included in a melt to form the ingot for the core layer 102 may be selected such that the resulting core layer 102 includes no greater than 0.6 wt% silicon by weight based on the total weight of the core layer 102. The scrap material can be, for example, pre-consumer waste produced for manufacturing brazing sheets or components thereof (e.g., revert) and/or postconsumer waste obtained from a third party source. The scrap material can comprise, for example, scrap brazing sheets, used or scrapped articles of manufacture formed from or including brazing sheets, and/or scrap material from another source.

[0035] The brazing layer 104 of the brazing sheet 100 comprises a second aluminum alloy, such as, for example, a 4XXX series aluminum alloy. In various non-limiting embodiments, the second aluminum alloy comprises, in weight percentages based on total weight of the aluminum alloy: 5 to 15 silicon; 0 to 2 magnesium; 0 to 1 iron; 0 to 3 zinc; 0 to 2 copper; 0 to 1 manganese; 0 to 0.3 bismuth; optionally incidental elements; impurities; and aluminum. The brazing layer 104 exhibits a brazing layer solidus temperature that is lower than the core layer solidus temperature, such as, for example, at least 5°C lower, at least 10°C lower, at least 15°C lower, at least 20°C lower, at least 25°C lower, or at least 30°C lower than the core layer solidus temperature. Ensuring that the brazing layer solidus temperature is sufficiently lower than the core layer solidus temperature can enable a brazing process wherein heating the brazing sheet 100 to a suitable temperature melts the brazing layer 104, while the core layer 102 remains substantially solid.

[0036] The thickness of each layer in the brazing sheet 100 can be configured based on the desired structural properties of the article (e.g., a heat exchanger) that is to be produced from or that is to incorporate the brazing sheet 100. For example, in various non-limiting embodiments, the core layer 102 can comprise a first thickness, ti, that can be in a range of 60% to 97% of a total thickness (z.e., ttotai) of the brazing sheet 100. In various non-limiting embodiments, the brazing layer 104 can comprise a second thickness, t2, that is in a range of 3% to 20% of the total thickness (ttotai) of the brazing sheet 100. In various non-limiting embodiments, the first thickness, ti, is greater than the second thickness, t2. In certain nonlimiting embodiments, the total thickness (ttotai) of the brazing sheet 100 is in a range of 100 pm to 5 mm, such as, for example, in a range of 200 pm to 1 mm.

[0037] In various non-limiting embodiments, a brazing sheet according to the present disclosure may comprise one or more layers in addition to a core layer and a brazing layer. For example, referring to the non-limiting embodiment shown schematically in FIG. 2, a brazing sheet 200 comprises the core layer 102, the brazing layer 104, and a layer 206 disposed on a second side 102b of the core layer 102 opposite a first side 102a of the core layer 102 on which the brazing layer 104 is deposited. In various embodiments, the layer 206 may be a second brazing layer configured according to brazing layer 104 described above, or the layer 206 can be a waterside liner. In various non-limiting embodiments, the core layer 102, the brazing layer 104, and the layer 206 are bonded (e.g., roll bonded) together to form the brazing sheet 200.

[0038] In embodiments in which the layer 206 is a second brazing layer, the layer 106 and the brazing layer 104 may have the same composition or may have different compositions. [0039] In embodiments in which the layer 206 is a waterside liner, the waterside liner can provide corrosion protection to the brazing sheet 200 and can be in contact with coolant during operation of an article comprising all or a portion of the brazing sheet 200. The waterside liner can comprise a third aluminum alloy comprising, in weight percentages based on total weight of the third aluminum alloy: 0.5 to 12 zinc; 0.1 to 1.2 silicon; 0 to 1 iron; 0 to 0.3 copper; 0 to 1.5 manganese; 0 to 0.6 magnesium; 0 to 0.2 titanium; 0 to 0.2 zirconium; optionally incidental elements; impurities; and aluminum.

[0040] In various non-limiting embodiments, a brazing sheet according to the present disclosure may comprise one or two interliner layers. Referring to the non-limiting embodiment shown schematically in FIG. 3, a brazing sheet 300 comprises the core layer 102, the brazing layer 104, a layer 206, an interliner layer 308, and an interliner layer 310. The interliner layer 308 is intermediate the brazing layer 104 and the core layer 102, and the interliner layer 310 is intermediate the layer 206 and the core layer 102. In various nonlimiting embodiments, the core layer 102, the brazing layer 104, the layer 206, the interliner layer 308, and the interliner layer 310 are bonded (e.g., roll bonded) together to form the brazing sheet 300.

[0041] Each of the interliner layers 308 and 310 of the brazing sheet 100 individually comprises a third aluminum alloy. The third aluminum alloy can comprise, in weight percentages based on total weight of the third aluminum alloy: 0.05 to 1.5 silicon; 0 to 2 manganese; 0 to 2 magnesium; 0 to 2 copper; 0 to 0.8 iron; 0 to 3 zinc; 0 to 0.5 zirconium; 0 to 1.0 chromium; 0 to 0.5 bismuth; 0 to 0.3 titanium; optionally incidental elements; impurities; and aluminum. The compositions of the interliner layers 308 and 310 may be the same or different.

[0042] In various non-limiting embodiments, a brazing sheet according to the present disclosure may not comprise the interliner layer 310, and the layer 206 may be in direct contact with the core layer 102. For example, referring to the non-limiting embodiment shown schematically in FIG. 4, a brazing sheet 400 comprises the core layer 102, the brazing layer 104, a layer 206, and an interliner layer 308. In various non-limiting embodiments, the core layer 102, the brazing layer 104, the layer 206, and the interliner layer 308 are bonded (e.g., roll bonded) together to form the brazing sheet 400. [0043] In various non-limiting embodiments, a brazing sheet according to the present disclosure may not comprise the interliner layer 310 or the layer 206, and the core layer 102 may be exposed on one side. Referring to the non-limiting embodiment shown schematically in FIG. 5, a brazing sheet 500 comprises the core layer 102, the brazing layer 104, and an interliner layer 308. In various non-limiting embodiments, the core layer 102, the brazing layer 104, and the interliner layer 308 are bonded (e.g., roll bonded) together to form the brazing sheet 500.

[0044] The thickness of each layer in the brazing sheet 200, brazing sheet 300, brazing sheet 400, and brazing sheet 500 can be configured based on the desired structural properties of the article e.g., a heat exchanger) that is to be produced from or that is to incorporate the brazing sheet 100. For example, in various non-limiting embodiments, the core layer 102 can comprise a first thickness, ti, that can be in a range of 60% to 93% of a total thickness (i.e., ttotai) of the respective brazing sheet 200, 300, 400, or 500. In various non-limiting embodiments, if present, the interliner layers 308 and 310 can comprise a third thicknesses, t3 and t3', and a sum of the two thickness can be in a range of 3% to 30% of a total thickness (ttotai) of the respective brazing sheet 200, 300, 400, or 500. In various non-limiting embodiments, the brazing layers 104 and layer 206 can comprise second thicknesses, t2 and t2', and a sum of the two thickness can be in a range of 3% to 20% of the total thickness (ttotai) of the respective brazing sheet 200, 300, 400, or 500. In various non-limiting embodiments, the first thickness, ti, is greater than each second thickness, t2 and t2^r, and also is greater than each third thickness, t3 and t3'. In certain non-limiting embodiments, the total thickness (ttotai) of the brazing sheet 200, 300, 400, or 500 is in a range of 100 pm to 5 mm, such as, for example, in a range of 200 pm to 1 mm.

[0045] The brazing sheet 200 can be suitable for at least one of controlled atmospheric brazing and vacuum brazing. For example, the brazing sheet 200 can comprise layers having compositions so that the brazing sheet 200 is suitable for controlled atmospheric brazing and/or vacuum brazing. In various non-limiting embodiments in which the brazing sheet 100, 200, 300, 400, and 500 may be subjected to a brazing process utilizing a flux, magnesium diffusion from the brazing sheet according to the present disclosure may be undesirable as it may interfere with the flux. In various non-limiting embodiments, the brazing sheet according to the present disclosure is configured to inhibit diffusion from the brazing sheet (e.g., inhibit diffusion of magnesium) such that flux can be used in the brazing process. In certain non-limiting embodiments, the brazing sheet 100, 200, 300, 400, and 500 according to the present disclosure may have a composition suitable for vacuum brazing (e.g., fluxless vacuum brazing). In various non-limiting embodiments in which the brazing sheet 100, 200, 300, 400, and 500 is subjected to flux-free brazing (e.g., brazing in an inert atmosphere with residual O2 in a CAB furnace, without the use of any flux), magnesium diffusion from the brazing sheet can be advantageous, for example, to dissolve an oxide layer formed on the brazing layer 104 and/or facilitate wettability of the surface to be brazed.

[0046] In various non-limiting embodiments, an article such as, for example, a heat exchanger, can comprise a structural element comprising all or a portion of brazing sheet 100, 200, 300, 400, and/or 500. The heat exchanger can have a galvanic corrosion resistance evaluated under ASTM G85 Annex A3 (2019) of at least 20 days, such as, for example, at least 25 days, or at least 30 days. The heat exchanger can be, for example, an oil cooler, a radiator, a cooling system (e.g., battery cooling system), or a liquid cooled condenser. In various non-limiting embodiments, the article can comprise a tube shape.

[0047] FIG. 6 provides a block diagram of a non-limiting embodiment of a method according to the present disclosure for forming an article of manufacture such as, for example, a heat exchanger. The method embodiment comprises contacting a first part comprising a first material with a second part comprising all or a portion of a non-limiting embodiment of a brazing sheet according to the present disclosure. For example, a non-limiting embodiment of a method according to the present disclosure may comprise contacting a first part comprising a first material with a second part comprising all or a portion of brazing sheet 100, 200, 300, 400, 500, and/or a different embodiment of a brazing sheet according to the present disclosure (FIG. 4, step 602). In various non-limiting embodiments, the first part can be brazed to the second part by a process comprising at least one of controlled atmospheric brazing and vacuum brazing (FIG. 6, step 604). In various non-limiting embodiments, the first material comprises aluminum or an aluminum alloy.

[0048] The following numbered clauses are directed to various non-limiting embodiments and aspects according to the present disclosure.

[0049] Clause 1. A brazing sheet comprising: a brazing layer comprising a 4XXX series aluminum alloy; and a core layer comprising a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy,

0.2 to 0.6 silicon,

1.5 to 2 manganese,

0.01 to 0.2 titanium,

0.5 to 2.5 copper,

0 to 0.5 iron,

0 to 0.5 magnesium,

0 to 0.5 zinc,

0 to 0.3 chromium,

0 to 0.25 zirconium, optionally incidental elements, impurities, and aluminum, wherein 3.1 <

_an(j [Mg], [Fe], [Cr], and [Si] are, respectively,

[5lJ weight percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy.

[0050] Clause 2. The brazing sheet of clause 1, wherein 3.2 < [Mg],

[Fe], [Cr], and [Si] are, respectively, weight percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy.

[0051] Clause 3. The brazing sheet of any of clauses 1-2, wherein the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy:

0.2 to 0.5 silicon;

1.6 to 2 manganese;

0.1 to 0.2 titanium;

0.5 to 1 copper;

0.1 to 0.4 iron;

0 to 0.1 magnesium;

0 to 0.25 zinc;

0 to 0.3 chromium;

0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum.

[0052] Clause 4. The brazing sheet of any of clauses 1-3, wherein the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy:

0.3 to 0.4 silicon;

1.6 to 2 manganese;

0.1 to 0.2 titanium;

0.5 to 1 copper;

0.1 to 0.4 iron;

0 to 0.1 magnesium;

0 to 0.25 zinc;

0 to 0.3 chromium;

0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum.

[0053] Clause 5. The brazing sheet of any of clauses 1-4, wherein a weight ratio of copper to manganese in the first aluminum alloy is no greater than 1.

[0054] Clause 6. The brazing sheet of any of clauses 1-5, wherein the core layer is unhomogenized.

[0055] Clause 7. The brazing sheet of any of clauses 1-6, wherein the 4XXX series aluminum alloy of the brazing layer comprises, in weight percentages based on total weight of the 4XXX series aluminum alloy:

5 to 15 silicon;

0 to 2 magnesium;

0 to 1 iron;

0 to 3 zinc;

0 to 2 copper;

0 to 1 manganese;

0 to 0.3 bismuth; optionally incidental elements; impurities; and aluminum.

[0056] Clause 8. The brazing sheet of any of clauses 1-7, wherein the core layer and the brazing layer are bonded together.

[0057] Clause 9. The brazing sheet of any of clauses 1-8, further comprising a waterside liner layer, wherein the core layer is intermediate the waterside liner layer and the brazing layer.

[0058] Clause 10. The brazing sheet of clause 9, wherein the core layer, the waterside liner layer, and the brazing layer are bonded together.

[0059] Clause 11. The brazing sheet of any of clauses 9-10, wherein the waterside liner layer comprises a third aluminum alloy comprising, in weight percentages based on total weight of the third aluminum alloy:

0.5 to 12 zinc;

0.1 to 1.2 silicon;

0 to 1 iron;

0 to 0.3 copper;

0 to 1.5 manganese;

0 to 0.6 magnesium;

0 to 0.2 titanium;

0 to 0.2 zirconium; optionally incidental elements; impurities; and aluminum.

[0060] Clause 12. The brazing sheet of any of clauses 1-8, wherein: the brazing layer is a first brazing layer disposed on a first side of the core layer; and the brazing sheet further comprises a second brazing layer disposed on a second side of the core layer, opposite the first side of the core layer, wherein the second brazing layer comprises a 4XXX series aluminum alloy. [0061] Clause 13. The brazing sheet of clause 12, wherein the core layer, the first brazing layer, and the second brazing layer are bonded together.

[0062] Clause 14. The brazing sheet of claim 12, further comprising a first interliner layer, wherein the first interliner layer is intermediate the core layer and the first brazing layer.

[0063] Clause 15. The brazing sheet of clause 14, further comprising a second interliner layer, wherein the second interliner layer is intermediate the core layer and the second brazing layer.

[0064] Clause 16. The brazing sheet of any of clauses 1-11, further comprising an interliner layer, wherein the interliner layer is intermediate the core layer and the brazing layer.

[0065] Clause 17. The brazing sheet of any of clauses 1-16, wherein the brazing sheet has a composition suitable for at least one of controlled atmospheric brazing and vacuum brazing.

[0066] Clause 18. The brazing sheet of claim 1, wherein: the core layer comprises a first thickness in a range of 60% to 97% of a total thickness of the brazing sheet; and the brazing layer comprises a second thickness in a range of 3% to 20% of the total thickness of the brazing sheet.

[0067] Clause 19. The brazing sheet of any of clauses 1-18, wherein the brazing sheet comprises at least 30% scrap material.

[0068] Clause 20. An article of manufacture including, or formed from parts including, a structural element comprising all or a portion of the brazing sheet of any of clauses 1-19.

[0069] Clause 21. The article of clause 20, wherein the article is a tube-shaped article.

[0070] Clause 22. The article of any of clauses 20-21, wherein the article comprises a heat exchanger.

[0071] Clause 23. The article of clause 22, wherein the article has a galvanic corrosion resistance evaluated under ASTM G85 Annex A3 (2019) of at least 20 days.

[0072] Clause 24. A method for forming an article of manufacture, the method comprising: contacting a first part comprising a first material with a second part comprising all or a portion of the brazing sheet of any of clauses 1-19; and brazing the first part to the second part by a process comprising at least one of controlled atmospheric brazing and vacuum brazing.

[0073] Clause 25. The method of clause 24, wherein the first material comprises aluminum or an aluminum alloy.

[0074] Clause 26. The method of claim 23, wherein the article of manufacture is a heat exchanger.

[0075] Clause 27. The brazing sheet of any of clauses 1-19, wherein the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy:

0.2 to 0.5 silicon;

1.6 to 2 manganese;

0.01 to 0.2 titanium;

0.5 to 1 copper;

0.1 to 0.4 iron;

0 to 0.1 magnesium;

0 to 0.25 zinc;

0 to 0.3 chromium;

0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum.

[0076] Clause 28. The brazing sheet of any of clauses 1-19, wherein the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy:

0.3 to 0.4 silicon;

1.6 to 2 manganese;

0.01 to 0.2 titanium;

0.5 to 1 copper;

0.1 to 0.4 iron;

0 to 0.1 magnesium;

0 to 0.25 zinc; 0 to 0.3 chromium;

0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum.

[0077] Clause 29. A brazing sheet comprising: a brazing layer comprising a 4XXX series aluminum alloy; and a core layer comprising a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy,

0.2 to 0.6 silicon,

1.5 to 2 manganese, wherein a weight ratio of manganese to silicon in the first aluminum alloy is at least 3.1,

0.1 to 0.2 titanium,

0.5 to 2.5 copper,

0 to 0.5 iron,

0 to 0.5 magnesium,

0 to 0.5 zinc,

0 to 0.3 chromium,

0 to 0.25 zirconium, optionally incidental elements, impurities, and aluminum.

[0078] Clause 30. A brazing sheet comprising: a brazing layer comprising a 4XXX series aluminum alloy; and a core layer comprising a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy,

0.2 to 0.6 silicon,

0.01 to 0.2 titanium,

0.5 to 2.5 copper,

0 to 0.5 iron, 0 to 0.5 magnesium, 0 to 0.5 zinc, 0 to 0.3 chromium, 0 to 0.25 zirconium, optionally incidental elements, impurities, and aluminum.

[0079] In this specification, unless otherwise indicated, all numerical parameters are to be understood as being prefaced and modified in all instances by the term “about,” in which the numerical parameters possess the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter described herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0080] Also, any numerical range recited herein includes all sub-ranges subsumed within the recited range. For example, a range of “1 to 10” includes all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10. Also, all ranges recited herein are inclusive of the end points of the recited ranges. For example, a range of “1 to 10” includes the end points 1 and 10. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited. All such ranges are inherently described in this specification.

[0081] The grammatical articles “a,” “an,” and “the,” as used herein, are intended to include “at least one” or “one or more,” unless otherwise indicated, even if “at least one” or “one or more” is expressly used in certain instances. Thus, the foregoing grammatical articles are used herein to refer to one or more than one (i.e., to “at least one”) of the particular identified elements. Further, the use of a singular noun includes the plural and the use of a plural noun includes the singular, unless the context of the usage requires otherwise. [0082] One skilled in the art will recognize that the herein described articles and methods, and the discussion accompanying them, are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific examples/embodiments set forth and the accompanying discussions are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components, devices, operations/actions, and objects should not be taken to be limiting.

While the present disclosure provides descriptions of various specific aspects for the purpose of illustrating various aspects of the present disclosure and/or its potential applications, it is understood that variations and modifications will occur to those skilled in the art.

Accordingly, the invention or inventions described herein should be understood to be at least as broad as they are claimed and not as more narrowly defined by particular illustrative aspects provided herein.

Claims

CLAIMS What is claimed is:

1. A brazing sheet comprising: a brazing layer comprising a 4XXX series aluminum alloy; and a core layer comprising a first aluminum alloy comprising, in weight percentages based on total weight of the first aluminum alloy,

0.2 to 0.6 silicon,

1.5 to 2 manganese,

0.01 to 0.2 titanium,

0.5 to 2.5 copper,

0 to 0.5 iron,

0 to 0.5 magnesium,

0 to 0.5 zinc,

0 to 0.3 chromium,

_anc[ [Mg], [Fe], [Cr], and [Si] are, respectively, weight

[5lJ percentage concentrations of manganese, iron, chromium, and silicon in the first aluminum alloy.

2. The brazing sheet of claim 1, wherein 3.2 < [Mg], [Fe], [Cr], and

3. The brazing sheet of claim 1, wherein the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy:

0.2 to 0.5 silicon;

1.6 to 2 manganese;

0.1 to 0.2 titanium;

0.5 to 1 copper;

0.1 to 0.4 iron;

0 to 0.1 magnesium;

0 to 0.25 zinc;

0 to 0.3 chromium;

0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum.

4. The brazing sheet of claim 1, wherein the first aluminum alloy comprises, in weight percentages based on total weight of the first aluminum alloy:

0.3 to 0.4 silicon;

1.6 to 2 manganese;

0.1 to 0.2 titanium;

0.5 to 1 copper;

0.1 to 0.4 iron;

0 to 0.1 magnesium;

0 to 0.25 zinc;

0 to 0.3 chromium;

0 to 0.25 zirconium; optionally incidental elements; impurities; and aluminum.

5. The brazing sheet of claim 1, wherein a weight ratio of copper to manganese in the first aluminum alloy is no greater than 1.

6. The brazing sheet of claim 1, wherein the core layer is unhomogenized.

7. The brazing sheet of claim 1, wherein the 4XXX series aluminum alloy of the brazing layer comprises, in weight percentages based on total weight of the 4XXX series aluminum alloy:

5 to 15 silicon;

0 to 2 magnesium; 0 to 1 iron;

0 to 3 zinc;

0 to 2 copper;

0 to 1 manganese;

0 to 0.3 bismuth; optionally incidental elements; impurities; and aluminum.

8. The brazing sheet of claim 1, wherein the core layer and the brazing layer are bonded together.

9. The brazing sheet of claim 1, further comprising a waterside liner layer, wherein the core layer is intermediate the waterside liner layer and the brazing layer.

10. The brazing sheet of claim 9, wherein the core layer, the waterside liner layer, and the brazing layer are bonded together.

11. The brazing sheet of claim 9, wherein the waterside liner layer comprises a third aluminum alloy comprising, in weight percentages based on total weight of the third aluminum alloy:

0.5 to 12 zinc;

0.1 to 1.2 silicon;

0 to 1 iron;

0 to 0.3 copper;

0 to 1.5 manganese;

0 to 0.6 magnesium;

0 to 0.2 titanium;

0 to 0.2 zirconium; optionally incidental elements; impurities; and aluminum.

12. The brazing sheet of claim 1, wherein: the brazing layer is a first brazing layer disposed on a first side of the core layer; and the brazing sheet further comprises a second brazing layer disposed on a second side of the core layer, opposite the first side of the core layer, wherein the second brazing layer comprises a 4XXX series aluminum alloy.

13. The brazing sheet of claim 12, wherein the core layer, the first brazing layer, and the second brazing layer are bonded together.

14. The brazing sheet of claim 12, further comprising a first interliner layer, wherein the first interliner layer is intermediate the core layer and the first brazing layer.

15. The brazing sheet of claim 14, further comprising a second interliner layer, wherein the second interliner layer is intermediate the core layer and the second brazing layer.

16. The brazing sheet of claim 1, further comprising an interliner layer, wherein the interliner layer is intermediate the core layer and the brazing layer.

17. The brazing sheet of claim 1, wherein the brazing sheet has a composition suitable for at least one of controlled atmospheric brazing and vacuum brazing.

18. The brazing sheet of claim 1, wherein: the core layer comprises a first thickness in a range of 60% to 97% of a total thickness of the brazing sheet; and the brazing layer comprises a second thickness in a range of 3% to 20% of the total thickness of the brazing sheet.

19. The brazing sheet of claim 1, wherein the brazing sheet comprises at least 30% scrap material.

20. An article of manufacture including, or formed from parts including, a structural element comprising all or a portion of the brazing sheet of claim 1.

21. The article of claim 20, wherein the article is a tube-shaped article.

22. The article of claim 20, wherein the article comprises a heat exchanger.

23. The article of claim 22, wherein the article has a galvanic corrosion resistance evaluated under ASTM G85 Annex A3 (2019) of at least 20 days.

24. A method for forming an article of manufacture, the method comprising: contacting a first part comprising a first material with a second part comprising all or a portion of the brazing sheet of claim 1; and brazing the first part to the second part by a process comprising at least one of controlled atmospheric brazing and vacuum brazing.

25. The method of claim 24, wherein the first material comprises aluminum or an aluminum alloy.

26. The method of claim 24, wherein the article of manufacture is a heat exchanger.