Method for producing aluminum alloy material and method for producing clad material

Abstract

To provide a method for producing an aluminum alloy material by which the aluminum alloy material having excellent brazability can easily be produced.SOLUTION: The method for producing an aluminum alloy material includes a selection step of selecting only an aluminum alloy scrap material having a Mg content of 0.10% by mass or less as a casting raw material A, a casting step of casting an ingot using the casting raw material A and the casting raw material B for addition, and a molding step of molding the ingot to mold an aluminum alloy material having a predetermined composition and a solidus temperature of 600 °C or higher. When a recycle ratio representing a mass ratio of the casting raw material A to the total mass of the ingot is represented by R (%) and a Si content in the casting raw material A is represented by [Si] A in mass%, the recycle ratio R is determined between the selection step and the casting step so that a value calculated by Formula (1): [Si] A * R / 100 is 0.50 or more and 1.10 or less. The casting raw material A contains predetermined amounts of Si and Zn.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing an aluminum alloy material and a method for producing a clad material using the aluminum alloy material. [Background technology]

[0002] In recent years, achieving carbon neutrality has become a challenge for society as a whole, and various methods for solving this problem are being considered. For example, in light of resource depletion, recycling of various materials has progressed, and recycling of metals, which are consumed in large quantities, has been carried out for some time. Furthermore, there is a demand for resource reuse in the field of aluminum alloy materials used in automotive heat exchangers. In particular, aluminum consumes a large amount of electricity and emits CO2 during the production of virgin metal. Therefore, reducing the amount of virgin metal used through recycling can significantly reduce CO2 emissions during the production of aluminum alloy materials.

[0003] However, because automotive heat exchangers are made of clad materials, which are made of aluminum alloy cores and laminated with sacrificial anode materials that impart corrosion resistance to the surface and brazing filler metals that impart brazing properties to the surface, recycling clad materials to produce core materials can sometimes result in a deterioration of the core material's properties. For this reason, recycling clad materials used in heat exchangers is more difficult than recycling single-layer aluminum alloy materials.

[0004] Patent Document 1 discloses a method for producing an aluminum alloy material using a casting raw material containing a predetermined content of scrap from automotive heat exchangers using clad materials and / or scrap from aluminum alloy clad materials used in automotive heat exchangers. The production method described in Patent Document 1 includes a casting step of casting an aluminum alloy ingot A having a predetermined composition using the casting raw material, and the natural electrode potential of the resulting aluminum alloy part A is specified. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7275336 Summary of the Invention [Problem to be solved by the invention]

[0006] However, even when the manufacturing method of the aluminum alloy material described in Patent Document 1 is used, it cannot be said that the brazeability is sufficiently excellent. Furthermore, Patent Document 1 describes using a casting raw material containing scrap made of an aluminum alloy containing one or more elements selected from the group consisting of Si, Fe, Cu, Mn, Mg, and Zn in predetermined amounts. However, Patent Document 1 does not specify the essential elements in the scrap, and the composition of the casting raw material is not described in the examples, so the effect cannot be fully confirmed.

[0007] The present invention has been made in consideration of these problems, and aims to provide a method for manufacturing an aluminum alloy material and a method for manufacturing a clad material that can easily manufacture an aluminum alloy material for a clad material having excellent brazability by using scrap generated during the manufacturing process of the clad material and discarded aluminum heat exchangers as raw materials for a new heat exchanger material, and can also easily manufacture a clad material having excellent brazability, thereby reducing the amount of new metal used and significantly reducing CO2 emissions. [Means for solving the problem]

[0008] The above object can be achieved by the following method (1) for producing an aluminum alloy material according to the present invention.

[0009] (1) A method for producing an aluminum alloy material, comprising the steps of: producing an aluminum alloy material using a casting raw material A and a casting raw material B; a selection step of selecting only aluminum alloy scrap material having a Mg content of 0.10% by mass or less from at least one of scrap of automotive heat exchangers using clad materials and scrap of aluminum alloy clad materials used for automotive heat exchangers, as the casting raw material A; A casting step of casting an ingot using the casting raw material A and the casting raw material B for addition; a molding step of molding the ingot into an aluminum alloy material having a solidus temperature of 600°C or higher, The recycling rate, which represents the mass ratio of the casting raw material A to the total mass of the ingot, is R (%), and the Si content in the casting raw material A is [Si] in mass%. A , when expressed as Between the selection step and the casting step, Formula (1): [Si] A ×R / 100 The value calculated by is 0.50 or more and 1.10 or less, a recycle rate determination step of determining a recycle rate R so that the casting step is a step of casting the ingot using the casting raw material A in an amount of R (%) relative to the total mass of the ingot and the casting raw material B in an amount of (100-R) (%) relative to the total mass of the ingot, The casting raw material A contains, with respect to the total mass of the casting raw material A, Si: 0.50% by mass or more, and Zn: 0.10% by mass or more, Contains at least one element selected from Fe: 0.10% by mass or more, Cu: 0.08% by mass or more, and Mn: 0.50% by mass or more, The aluminum alloy material is Si: 0.50 mass% or more and 1.10 mass% or less, Fe: 0.10% by mass or more and 1.00% by mass or less, Cu: 0.08% by mass or more and 0.80% by mass or less, Mn: 0.90% by mass or more and 1.80% by mass or less, and Zn: 0.10% by mass or more and 1.00% by mass or less, Mg: 0.10% by mass or less, Ti: 0.30% by mass or less, Cr: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, A method for producing an aluminum alloy material, characterized in that Mo: 0.30 mass % or less, with the balance consisting of Al and unavoidable impurities.

[0010] The method for producing the aluminum alloy material of the present invention is preferably the following (2) to (5).

[0011] (2) The method for producing an aluminum alloy material according to (1), wherein the recycling rate R is 20% or more and 50% or less.

[0012] (3) The method for producing an aluminum alloy material according to (1) or (2), wherein the casting raw material B does not contain Si.

[0013] (4) The method for producing an aluminum alloy material according to any one of (1) to (3), wherein the casting raw material B does not contain Zn.

[0014] (5) The method for producing an aluminum alloy material according to any one of (1) to (4), wherein the casting raw material A contains Zn: 1.00 mass % or less.

[0015] The above object can also be achieved by the following method (6) for producing a clad material according to the present invention.

[0016] (6) A method for producing a clad material including an aluminum alloy material produced by the production method according to any one of (1) to (5), The aluminum alloy material is used as a core aluminum alloy material, A method for producing a clad material, characterized in that the core aluminum alloy material and at least one functional aluminum alloy material are laminated to produce a clad material.

[0017] The method for producing the clad material of the present invention is preferably the following (7) to (11).

[0018] (7) The method for producing a clad material according to (6), wherein the functional aluminum alloy material includes at least one of an aluminum alloy material for brazing filler metal and an aluminum alloy material for sacrificial anode material.

[0019] (8) The aluminum alloy material for brazing filler metal is Si: 2.50% by mass or more and 13.00% by mass or less, and Fe: 0.05% by mass or more and 1.00% by mass or less; Zn: 5.50% by mass or less, Mn: 1.00% by mass or less, Cu: 1.00% by mass or less, Cr: 0.30% by mass or less, Ti: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, Mo: 0.30% by mass or less, Sb: 0.30% by mass or less, Sr: 0.10% by mass or less, The method for producing a clad material according to (7), characterized in that Na is 0.10 mass % or less, with the balance being Al and unavoidable impurities.

[0020] (9) The aluminum alloy material for the sacrificial anode material is Zn: 0.50 mass% or more and 6.00 mass% or less, Si: 0.05% by mass or more and 1.50% by mass or less, and Fe: 0.05% by mass or more and 2.00% by mass or less; Mg: 3.00% by mass or less, Mn: 1.80% by mass or less, Cu: 0.50% by mass or less, Cr: 0.30% by mass or less, Ti: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, The method for producing a clad material according to (7) or (8), characterized in that Mo is 0.30 mass % or less, with the balance consisting of Al and unavoidable impurities.

[0021] (10) The method for producing a clad material according to any one of (7) to (9), characterized in that the clad material has a structure in which the aluminum alloy material for brazing filler metal / the aluminum alloy material for core material / the aluminum alloy material for brazing filler metal or the aluminum alloy material for sacrificial anode material are laminated in this order.

[0022] (11) The clad material includes an intermediate layer between the core aluminum alloy material and the functional aluminum alloy material, The intermediate layer is Si: 0.05% by mass or more and 1.50% by mass or less, and Fe: 0.05% by mass or more and 2.00% by mass or less; Zn: 6.00% by mass or less, Mn: 1.80% by mass or less, Cu: 1.00% by mass or less, Cr: 0.30% by mass or less, Ti: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, The method for producing a clad material according to any one of (6) to (10), characterized in that Mo is 0.30 mass % or less, with the balance consisting of Al and unavoidable impurities. [Effects of the Invention]

[0023] According to the method for producing an aluminum alloy material of the present invention, scraps of automotive heat exchangers and scraps of aluminum alloy clad materials for automotive heat exchangers can be reused to produce an aluminum alloy material for clad materials having excellent brazability, thereby reducing the amount of virgin metal used and significantly reducing CO2 emissions.

[0024] Furthermore, according to the method for manufacturing a clad material of the present invention, an aluminum alloy material having the above-described excellent properties is used as an aluminum alloy material for the core material, so that a clad material with excellent brazing properties can be manufactured. DETAILED DESCRIPTION OF THE INVENTION

[0025] As a result of intensive studies, the present inventors have found that controlling the solidus temperature of an aluminum alloy material produced using scrap is important for obtaining excellent brazability. Furthermore, they have found that, in order to avoid a decrease in brazability due to a decrease in flux activity during brazing, it is effective to select only scrap material having a Mg content of 0.1 mass% or less as a casting raw material A, determine a recycling rate based on the Si content in the casting raw material A, and produce an aluminum alloy material of a desired composition. Hereinafter, a method for manufacturing an aluminum alloy material according to an embodiment of the present invention will be described in detail.

[0026] [Method of manufacturing aluminum alloy materials] The method for producing an aluminum alloy material according to this embodiment is a method for producing an aluminum alloy material using a casting raw material A and a casting raw material B.

[0027] <Selection process> From at least one of scrap of automotive heat exchangers using clad materials and scrap of aluminum alloy clad materials used in automotive heat exchangers, only aluminum alloy scrap materials having a Mg content of 0.1% by mass or less are selected to form casting raw material A. Since Mg is an element that reacts with flux during brazing and reduces the activity of the flux, by selecting only aluminum alloy scrap materials having a Mg content of 0.1% by mass or less to form casting raw material A, it is possible to easily produce an aluminum alloy material with excellent brazability even when the scrap materials are reused.

[0028] In this specification, "scrap from automotive heat exchangers using clad material" refers to scrap generated when automotive heat exchangers using clad material are discarded. Also, "scrap from aluminum alloy clad material used in automotive heat exchangers" refers to both scrap generated when manufacturing aluminum alloy clad material and scrap from clad material generated when manufacturing automotive heat exchangers. In this specification, these are sometimes simply referred to as "scrap."

[0029] If an attempt is made to produce an aluminum alloy material by selecting only aluminum alloy scrap having a Mg content exceeding 0.1% by mass, the amount of casting raw material B used must be increased to obtain an aluminum alloy material with the desired Mg content. As a result, it is not possible to reduce the amount of virgin metal used, and CO2 emissions increase. Therefore, in the selection process, only aluminum alloy scrap having a Mg content of 0.1% by mass or less relative to the total mass of the aluminum alloy scrap (casting raw material A) is selected. Furthermore, it is preferable to select only aluminum alloy scrap having a Mg content of 0.05% by mass or less, more preferably to select only aluminum alloy scrap having a Mg content of less than 0.05% by mass, and even more preferably to select only aluminum alloy scrap that is substantially free of Mg. Note that "substantially free of Mg" includes the inclusion of Mg at the level of an unavoidable impurity contained in the raw material of an aluminum alloy clad material generally used for automotive heat exchangers.

[0030] <Recycling rate determination process> In this embodiment, in the casting step described below, an ingot is cast using the casting raw material A and the additional casting raw material B based on the recycling rate. Therefore, in this step, the recycling rate is determined based on the Si content in the casting raw material A. Specifically, the recycling rate representing the mass ratio of the casting raw material A to the total mass of the ingot obtained by the casting step is defined as R (%), and the Si content in the casting raw material A is defined as [Si] in mass%. A , the recycle rate R is determined so that the value calculated by the following formula (1) is 0.50 or more and 1.10 or less. The value calculated by the following formula (1) is the Si content in the aluminum alloy material when Si is not contained in the additive casting raw material B used in the subsequent casting process.

[0031] Formula (1): [Si] A ×R

[0032] By determining the recycling rate based on the Si content in the casting raw material A so as to achieve a target Si content, the Si content in the aluminum alloy material can be adjusted to a desired range even if the casting raw material B which does not contain Si is used in the casting step.

[0033] <Casting process> After the recycle rate determination step, an ingot is cast using the casting raw material A and the additional casting raw material B. Specifically, the ingot is cast using the casting raw material A in an amount of R (%) relative to the total mass of the ingot to be obtained and the casting raw material B in an amount of (100-R) (%) relative to the total mass of the ingot.

[0034] <Molding process> The ingot cast in the above casting step is molded to form an aluminum alloy material having a solidus temperature of 600°C or higher. If the solidus temperature of the molded aluminum alloy material is lower than 600°C, the aluminum alloy material will melt when brazing the final product, resulting in a decrease in brazability. Therefore, in this embodiment, the composition of the aluminum alloy material is controlled so that the solidus temperature of the obtained aluminum alloy material falls within the following range.

[0035] (Solidus temperature: 600℃ or higher) If the solidus temperature of the aluminum alloy material produced by the production method according to the present embodiment is lower than 600°C, the aluminum alloy material will melt during brazing, resulting in reduced brazing properties. Furthermore, if the solidus temperature is high, the furnace temperature can be set high, allowing the Si content in the brazing material to be reduced. Therefore, the solidus temperature of the aluminum alloy material is set to 600°C or higher, preferably 605°C or higher, and more preferably 610°C or higher. From the viewpoint of recyclability, it is preferable to set the target value of the solidus temperature low, as this facilitates control of each component.

[0036] The chemical components of the casting raw material A used and the aluminum alloy material to be produced, as well as the reasons for limiting the contents thereof, will be described in detail below. First, the chemical components in the casting raw material A will be described.

[0037] <Casting raw material A> (Si:0.50 mass% or more) Si is an element that improves the strength of an aluminum alloy material by dissolving in the matrix or by forming an Al-Mn-Si intermetallic compound together with Mn. As described above, in this embodiment, the recycle rate is determined based on the Si content of scrap (casting raw material A). This is because scrap generally contains a large amount of Si, which is a component of brazing filler metal. If the Si content of the casting raw material A is less than 0.50 mass%, the Si content in the aluminum alloy material decreases regardless of the recycle rate, and the effect of improving the strength of the aluminum alloy material cannot be sufficiently obtained. Therefore, the Si content in the casting raw material A is set to 0.50 mass% or more, preferably 0.60 mass% or more, and more preferably 0.70 mass% or more, relative to the total mass of the casting raw material A.

[0038] (Zn: 0.10% by mass or more) Scrap generally contains Zn, a component derived from sacrificial anode materials, and the average Zn content in scrap is approximately 0.25 to 0.80 mass%. Therefore, the lower limit of the Zn content in the casting raw material A is determined based on the lower limit of the Zn contained in the casting raw material A as a component of the sacrificial anode material. If the Zn content in the casting raw material A is 0.10 mass% or more, a general clad material for automotive heat exchangers can be used regardless of the recycling rate. Therefore, the Zn content in the casting raw material A is 0.10 mass% or more, preferably 0.12 mass% or more, and more preferably 0.15 mass% or more, relative to the total mass of the casting raw material A.

[0039] On the other hand, if the Zn content in the casting raw material A is too high, the Zn content in the aluminum alloy material also increases, which may affect the solidus temperature depending on the recycling rate. Specifically, if the Zn content in the casting raw material A is 1.00 mass% or less, a decrease in the solidus temperature can be suppressed regardless of the recycling rate. Therefore, the Zn content in the casting raw material A is preferably 1.00 mass% or less, more preferably 0.70 mass% or less, even more preferably 0.50 mass% or less, and particularly preferably 0.30 mass% or less, based on the total mass of the casting raw material A.

[0040] The casting raw material A used in this embodiment contains, in addition to the above-mentioned Si and Zn, at least one element selected from Fe, Cu, and Mn in the ranges shown below.

[0041] (Fe: 0.10% by mass or more) Fe is an element that easily forms intermetallic compounds of a size that can become recrystallization nuclei. Since commonly used aluminum alloy materials contain Fe, regardless of whether scrap is used or not, the lower limit of the Fe content in the scrap is not particularly limited. However, if the Fe content in the casting raw material A is 0.10 mass% or more, it is not necessary to use a casting raw material B with an extremely low Fe content, and an aluminum alloy material with a desired Fe content can be obtained. Therefore, when using a casting raw material A containing Fe, it is preferable to use scrap (casting raw material A) whose Fe content relative to the total mass of the casting raw material A is 0.10 mass% or more.

[0042] (Cu:0.08% by mass or more) Scrap generally contains Cu, and the average Cu content in the scrap is about 0.10 to 0.60 mass%. Therefore, although there is no particular limitation on the lower limit of the Cu content in the scrap, when using a casting raw material A containing Cu, it is preferable to use scrap (casting raw material A) in which the Cu content relative to the total mass of the casting raw material A is 0.08 mass% or more. It is more preferable to use scrap in which the Cu content in the casting raw material A is 0.10 mass% or more, even more preferable to use scrap in which the Cu content is 0.20 mass% or more, and particularly preferable to use scrap in which the Cu content is 0.30 mass% or more.

[0043] (Mn: 0.50% by mass or more) Mn is an element that improves the strength of an aluminum alloy material by dispersion strengthening through the formation of an Al-Mn-Si intermetallic compound together with Si, and by solid-solution strengthening through dissolving in the aluminum matrix. In this embodiment, Mn may be contained in the casting raw material B for the purpose of improving the strength of the aluminum alloy material. Therefore, although the lower limit of the Mn content in the scrap is not particularly limited, when using a casting raw material A containing Mn, it is preferable to use scrap (casting raw material A) in which the Mn content relative to the total mass of the casting raw material A is 0.50 mass% or more. Furthermore, it is more preferable to use scrap in which the Mn content in the casting raw material A is 0.90 mass% or more, and even more preferable to use scrap in which the Mn content is 1.00 mass% or more.

[0044] Next, the chemical components of the aluminum alloy material produced by the production method according to the embodiment of the present invention, the reasons for limiting the contents thereof, and a preferable recycling rate will be described.

[0045] <Aluminum alloy material> (Si: 0.50 mass% or more and 1.10 mass% or less) As described above, Si is an element that improves the strength of an aluminum alloy material by dissolving in the matrix and by forming an Al-Mn-Si intermetallic compound together with Mn. In this embodiment, the recycle rate is determined based on the Si content in the casting raw material A so that the Si content in the aluminum alloy material falls within a predetermined range. Therefore, an aluminum alloy material having a desired Si content can be obtained without adjusting the Si content by using the casting raw material B.

[0046] If the Si content in the aluminum alloy material is less than 0.50 mass%, the effect of improving the strength of the aluminum alloy material cannot be sufficiently obtained. Therefore, the Si content in the aluminum alloy material is set to 0.50 mass% or more, preferably 0.60 mass% or more, and more preferably 0.65 mass% or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Si content in the aluminum alloy material exceeds 1.10 mass%, the solidus temperature of the aluminum alloy material decreases, and melting occurs during brazing. Therefore, the Si content in the aluminum alloy material is set to 1.10 mass% or less, preferably 1.05 mass% or less, and more preferably 1.00 mass% or less, relative to the total mass of the aluminum alloy material.

[0047] (Fe: 0.10 mass% or more and 1.00 mass% or less) Fe is an element that easily forms intermetallic compounds of a size that can become recrystallization nuclei. Since Fe is generally contained in the casting raw material A, in order to make the Fe content in the aluminum alloy material less than 0.10 mass%, it is necessary to use high-purity aluminum ingot (casting raw material B), which increases production costs. Therefore, the Fe content in the aluminum alloy material is set to 0.10 mass% or more, preferably 0.12 mass% or more, and more preferably 0.15 mass% or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Fe content in the aluminum alloy material exceeds 1.00 mass%, the crystal grain size after brazing becomes fine, and brazing material diffusion occurs, resulting in a decrease in erosion resistance. Therefore, the Fe content in the aluminum alloy material is set to 1.00 mass% or less, preferably 0.80 mass% or less, and more preferably 0.60 mass% or less, relative to the total mass of the aluminum alloy material.

[0048] (Cu: 0.08 mass% or more and 0.80 mass% or less) Scrap generally contains Cu. Therefore, in order to make the Cu content in the aluminum alloy material less than 0.08% by mass, it is necessary to use high-purity aluminum ingot (casting raw material B), which increases production costs. Furthermore, if the Cu content in the aluminum alloy material is less than 0.08% by mass, the corrosion resistance of the aluminum alloy material decreases. Therefore, the Cu content in the aluminum alloy material is set to 0.08% by mass or more, preferably 0.10% by mass or more, more preferably 0.20% by mass or more, and even more preferably 0.30% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Cu content in the aluminum alloy material exceeds 0.80% by mass, the solidus temperature decreases and melting occurs during brazing. Therefore, the Cu content in the aluminum alloy material is set to 0.80% by mass or less, preferably 0.70% by mass or less, and more preferably 0.65% by mass or less, relative to the total mass of the aluminum alloy material.

[0049] (Mn: 0.90 mass% or more and 1.80 mass% or less) Mn is an element that has the effect of improving the strength of an aluminum alloy material. If the Mn content in the aluminum alloy material is less than 0.90 mass%, the effect of improving strength cannot be sufficiently obtained. Furthermore, if the Mn content in the aluminum alloy material is less than 0.90 mass%, the solidus temperature also rises and brazability deteriorates. Therefore, the Mn content in the aluminum alloy material is set to 0.90 mass% or more, preferably 1.00 mass% or more, and more preferably 1.05 mass% or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Mn content in the aluminum alloy material exceeds 1.80 mass%, giant intermetallic compounds are likely to be formed during casting, which reduces plastic workability. Therefore, the Mn content in the aluminum alloy material is set to 1.80 mass% or less, preferably 1.70 mass% or less, and more preferably 1.65 mass% or less, relative to the total mass of the aluminum alloy material.

[0050] (Zn: 0.10 mass% or more and 1.00 mass% or less) Scrap generally contains Zn, a component derived from sacrificial anode materials. Therefore, in order to make the Zn content in the aluminum alloy material less than 0.10 mass%, it is necessary to use high-purity aluminum ingot (casting raw material B), which increases production costs. Therefore, the Zn content in the aluminum alloy material is set to 0.10 mass% or more, preferably 0.12 mass% or more, and more preferably 0.15 mass% or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Zn content in the aluminum alloy material exceeds 1.00 mass%, the solidus temperature decreases. Therefore, the Zn content in the aluminum alloy material is set to 1.00 mass% or less, preferably 0.50 mass% or less, and more preferably 0.30 mass% or less, relative to the total mass of the aluminum alloy material.

[0051] (Mg: 0.10% by mass or less) Since Mg is an element that reacts with flux during brazing and reduces brazability, a small Mg content in the aluminum alloy material is preferable. In this embodiment, as described above, only aluminum alloy scrap material having a Mg content of 0.1 mass% or less is selected as the casting raw material A, and therefore, it is preferable that the casting raw material B also does not contain Mg. If the Mg content in the aluminum alloy material exceeds 0.10 mass%, the brazability decreases. Therefore, the Mg content in the aluminum alloy material is set to 0.10 mass% or less, preferably 0.05 mass% or less, and more preferably 0 mass%, relative to the total mass of the aluminum alloy material.

[0052] (Cr: 0.30 mass% or less) Cr is an element that improves the strength of an aluminum alloy material through solid solution strengthening and also precipitates Al-Cr intermetallic compounds, which act to coarsen crystal grains after brazing. Therefore, the aluminum alloy material may contain Cr as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Cr content in the aluminum alloy material is not particularly limited, but a Cr content of 0.05% by mass or more in the aluminum alloy material can achieve the effect of improving the strength of the aluminum alloy material. Therefore, the Cr content in the aluminum alloy material is preferably 0.05% by mass or more, and more preferably 0.10% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Cr content in the aluminum alloy material exceeds 0.30% by mass, giant intermetallic compounds are likely to be formed, which may result in a decrease in plastic workability. Therefore, the Cr content in the aluminum alloy material is 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the aluminum alloy material.

[0053] (Ti: 0.30% by mass or less) Ti is an element that has the effect of improving the strength of an aluminum alloy material through solid-solution strengthening. Therefore, the aluminum alloy material may contain Ti as necessary, but it may also contain 0% by mass. In this embodiment, the lower limit of the Ti content in the aluminum alloy material is not particularly limited, but when the Ti content in the aluminum alloy material is 0.05% by mass or more, the effect of improving the strength of the aluminum alloy material can be obtained. Therefore, the Ti content in the aluminum alloy material is preferably 0.05% by mass or more, and more preferably 0.10% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, when the Ti content in the aluminum alloy material exceeds 0.30% by mass, giant intermetallic compounds are likely to be formed, which may result in a decrease in plastic workability. Therefore, the Ti content in the aluminum alloy material is 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the aluminum alloy material.

[0054] (Zr: 0.30% by mass or less) Zr is an element that improves the strength of an aluminum alloy material through solid solution strengthening and also precipitates Al-Zr-based intermetallic compounds, which act to coarsen crystal grains after brazing. Therefore, the aluminum alloy material may contain Zr as needed, but it may contain 0 mass% Zr. In this embodiment, the lower limit of the Zr content in the aluminum alloy material is not particularly limited, but when the Zr content in the aluminum alloy material is 0.05 mass% or more, the effect of improving the strength of the aluminum alloy material can be obtained. Therefore, the Zr content in the aluminum alloy material is preferably 0.05 mass% or more, and more preferably 0.10 mass% or more, relative to the total mass of the aluminum alloy material. On the other hand, when the Zr content in the aluminum alloy material exceeds 0.30 mass%, giant intermetallic compounds are likely to be formed, which may deteriorate the plastic workability. Therefore, the Zr content in the aluminum alloy material is 0.30 mass% or less, preferably 0.25 mass% or less, and more preferably 0.20 mass% or less, relative to the total mass of the aluminum alloy material.

[0055] (V: 0.30% by mass or less) V is an element that has the effect of improving the strength of an aluminum alloy material through solid solution strengthening. Therefore, the aluminum alloy material may contain V as necessary, but it may also contain 0 mass% V. In this embodiment, the lower limit of the V content in the aluminum alloy material is not particularly limited, but when the V content in the aluminum alloy material is 0.05 mass% or more, the effect of improving the strength of the aluminum alloy material can be obtained. Therefore, the V content in the aluminum alloy material is preferably 0.05 mass% or more, and more preferably 0.10 mass% or more, relative to the total mass of the aluminum alloy material. On the other hand, when the V content in the aluminum alloy material exceeds 0.30 mass%, giant intermetallic compounds are likely to be formed, which may result in a decrease in plastic workability. Therefore, the V content in the aluminum alloy material is 0.30 mass% or less, preferably 0.25 mass% or less, and more preferably 0.20 mass% or less, relative to the total mass of the aluminum alloy material.

[0056] (Ca: 0.30% by mass or less) Ca increases the pH upon dissolution and inhibits the corrosion reaction by suppressing the pH decrease due to the hydrolysis reaction at the local anode where Al dissolution occurs. Therefore, Ca is an effective element for improving corrosion resistance. Therefore, the aluminum alloy material may contain Ca as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Ca content in the aluminum alloy material is not particularly limited. However, when the Ca content in the aluminum alloy material is 0.01% by mass or more, the effect of improving the corrosion resistance of the aluminum alloy material can be obtained. Therefore, the Ca content in the aluminum alloy material is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, when the Ca content in the aluminum alloy material exceeds 0.30% by mass, brazing performance may be reduced in brazing using a fluoride-based flux. Therefore, the Ca content in the aluminum alloy material is 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the aluminum alloy material.

[0057] (Sc: 0.20% by mass or less) Sc is an element that has the effect of improving the strength of an aluminum alloy material through solid solution strengthening. Therefore, the aluminum alloy material may contain Sc as necessary, but it may also contain 0 mass%. In this embodiment, the lower limit of the Sc content in the aluminum alloy material is not particularly limited, but when the Sc content in the aluminum alloy material is 0.01 mass% or more, the effect of improving the strength of the aluminum alloy material can be obtained. Therefore, the Sc content in the aluminum alloy material is preferably 0.01 mass% or more, and more preferably 0.05 mass% or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Sc content in the aluminum alloy material exceeds 0.20 mass%, cracks may easily occur during cold rolling. Therefore, the Sc content in the aluminum alloy material is 0.20 mass% or less, preferably 0.15 mass% or less, and more preferably 0.10 mass% or less, relative to the total mass of the aluminum alloy material.

[0058] (Ni: 0.30% by mass or less) Ni is an element that crystallizes or precipitates as an intermetallic compound in the alloy structure, thereby improving strength. Therefore, the aluminum alloy material may contain Ni as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Ni content in the aluminum alloy material is not particularly limited. However, when the Ni content in the aluminum alloy material is 0.01% by mass or more, the effect of improving the strength of the aluminum alloy material can be obtained. Therefore, the Ni content in the aluminum alloy material is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, when the Ni content in the aluminum alloy material exceeds 0.30% by mass, the solidus temperature of the aluminum alloy material decreases, and melting occurs during brazing. Therefore, the Ni content in the aluminum alloy material is set to 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the aluminum alloy material.

[0059] (Mo: 0.30% by mass or less) Mo is an element that has the effect of improving corrosion resistance by dissolving in water to form molybdate, which acts as an oxygen diffusion barrier and suppresses the reduction reaction of dissolved oxygen in water, thereby suppressing general corrosion. Therefore, the aluminum alloy material may contain Mo as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Mo content in the aluminum alloy material is not particularly limited, but if the Mo content in the aluminum alloy material is 0.01% by mass or more, the effect of improving the corrosion resistance of the aluminum alloy material can be obtained. Therefore, the Mo content in the aluminum alloy material is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, if the Mo content in the aluminum alloy material exceeds 0.30% by mass, the aluminum alloy may become embrittled and the workability may deteriorate. Therefore, the Mo content in the aluminum alloy material is 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the aluminum alloy material.

[0060] (Remainder: Al and inevitable impurities) The balance of the aluminum alloy material produced in this embodiment is Al and unavoidable impurities. Examples of the unavoidable impurities include Na and Sr. The total amount of the unavoidable impurities in the aluminum alloy material is preferably 0.05 mass% or less with respect to the total mass of the aluminum alloy material.

[0061] (Recycling rate R: 20% to 50%) As described above, in this embodiment, the recycle rate is determined based on the Si content in the casting raw material A so as to achieve a target Si content. The recycle rate R is a value expressed as a percentage of the mass of the casting raw material A relative to the total mass of the aluminum alloy material to be produced. By setting the recycle rate R to 20% or more, it is possible to sufficiently obtain the effect of reducing CO2 emissions resulting from the use of virgin metal. Therefore, the recycle rate R is preferably set to 20% or more, more preferably set to 25% or more, and even more preferably set to 30% or more. Furthermore, by setting the recycle rate R to 50% or less, it is possible to control the Si content in the aluminum alloy material within an appropriate range. Therefore, the recycle rate R is preferably set to 50% or less, more preferably set to 45% or less, and even more preferably set to 40% or less.

[0062] Next, the casting raw material B will be briefly described. The casting raw material B is a raw material added to bring each element in the aluminum alloy material to a target content, and therefore the elements contained in the casting raw material B and their contents are not particularly limited. However, in this embodiment, the recycling rate is determined based on the Si content in the casting raw material A so that the Si content in the aluminum alloy material falls within a predetermined range. Therefore, it is preferable that the casting raw material B does not contain Si. Furthermore, Zn is an element that lowers the solidus temperature, which is an object of the present invention. For this reason, it is preferable that Zn is also supplied only from the casting raw material A, that is, it is preferable that the casting raw material B does not contain Zn.

[0063] Next, a method for manufacturing a clad material according to an embodiment of the present invention will be described in detail.

[0064] [Method of manufacturing clad materials] The method for producing a clad material according to this embodiment is a method for producing a clad material including an aluminum alloy material produced by the method for producing an aluminum alloy material according to the embodiment. Specifically, the aluminum alloy material is used as a core aluminum alloy material, and the core aluminum alloy material and at least one or more functional aluminum alloy materials are laminated together to produce a clad material.

[0065] The functional aluminum alloy material includes at least one of an aluminum alloy material for brazing filler metal and an aluminum alloy material for sacrificial anode material. The clad material preferably has a structure in which the aluminum alloy material for brazing filler metal / aluminum alloy material for core material / aluminum alloy material for brazing filler metal or aluminum alloy material for sacrificial anode material are laminated in this order. Furthermore, the clad material may include an intermediate layer between the aluminum alloy material for core material and the functional aluminum alloy material.

[0066] The contents of the chemical components in the aluminum alloy material for brazing filler metal, the aluminum alloy material for sacrificial anode material, and the intermediate layer, as well as the reasons for limiting the numerical values ​​thereof, will be explained below.

[0067] <Aluminum alloy for brazing filler metal> (Si: 2.50 mass% or more and 13.00 mass% or less) Si in the aluminum alloy material for brazing filler metal improves the liquid phase ratio at the brazing heating temperature, thereby ensuring the amount of molten brazing filler metal. If the Si content in the aluminum alloy material for brazing filler metal is 2.50% by mass or more, a sufficient amount of molten brazing filler metal can be ensured, and the fluidity of the molten brazing filler metal can be maintained appropriately, resulting in excellent brazing properties. Therefore, the Si content in the aluminum alloy material for brazing filler metal is preferably 2.50% by mass or more, more preferably 3.00% by mass or more, and even more preferably 3.50% by mass or more, based on the total mass of the aluminum alloy material for brazing filler metal. Furthermore, if the Si content in the aluminum alloy material for brazing filler metal is 13.00% by mass or less, the fluidity of the molten brazing filler metal can be prevented from becoming too high, and the occurrence of erosion due to the molten brazing filler metal can be suppressed. Therefore, the Si content in the aluminum alloy material for brazing filler metal is preferably 13.00% by mass or less, more preferably 12.50% by mass or less, and even more preferably 12.00% by mass or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0068] (Fe: 0.05 mass% or more and 1.00 mass% or less) Fe in aluminum alloy brazing filler metals tends to form Al-Fe and Al-Fe-Si compounds, which reduces the effective Si content of the brazing filler metal. Furthermore, the formation of Al-Fe and Al-Fe-Si compounds may reduce the fluidity of the brazing filler metal during brazing, potentially impairing brazing performance. Since commonly used aluminum alloy brazing filler metals contain Fe, if the Fe content in the aluminum alloy brazing filler metal is 0.05% by mass or more, it is not necessary to use high-purity metal as a raw material for producing the aluminum alloy brazing filler metal. Therefore, the Fe content in the aluminum alloy brazing filler metal is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.12% by mass or more, based on the total mass of the aluminum alloy brazing filler metal. On the other hand, if the Fe content in the aluminum alloy brazing filler metal is 1.00% by mass or less, good brazing performance can be achieved. Therefore, the Fe content in the aluminum alloy material for brazing filler metal is preferably 1.00 mass% or less, more preferably 0.80 mass% or less, and even more preferably 0.60 mass% or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0069] (Zn: 5.50% by mass or less) Zn is an alloying element that makes the potential of an aluminum alloy less noble. Therefore, when the aluminum alloy material for brazing filler metal contains Zn, it acts as a sacrificial anode material and provides the effect of sacrificial corrosion protection. However, in this embodiment, the Zn content in the aluminum alloy material for brazing filler metal may be 0% by mass. Furthermore, when the Zn content in the aluminum alloy material for brazing filler metal is 5.50% by mass or less, it is possible to prevent a decrease in workability and suppress the occurrence of cracks during cold rolling. Therefore, the Zn content in the aluminum alloy material for brazing filler metal is preferably 5.50% by mass or less, more preferably 5.00% by mass or less, and even more preferably 4.50% by mass or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0070] (Mn: 1.00% by mass or less) Mn in the aluminum alloy material for brazing filler metal improves the viscosity of the molten brazing filler metal and suppresses the flow of the molten brazing filler metal, but in this embodiment, the Mn content in the aluminum alloy material for brazing filler metal may be 0% by mass. Furthermore, if the Mn content in the aluminum alloy material for brazing filler metal is 1.00% by mass or less, the generation of Al-Mn(-Fe-Si)-based compounds with a high specific gravity in the molten brazing filler metal can be suppressed, and the amount of molten brazing filler metal can be kept appropriate. Therefore, the Mn content in the aluminum alloy material for brazing filler metal is preferably 1.00% by mass or less, more preferably 0.95% by mass or less, and even more preferably 0.90% by mass or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0071] (Cu: 1.00% by mass or less) Cu in the aluminum alloy material for brazing filler metal has the effect of improving the corrosion resistance of the region formed when brazing heat is applied, but in this embodiment, the Cu content in the aluminum alloy material for brazing filler metal may be 0 mass%. Furthermore, when the Cu content in the aluminum alloy material for brazing filler metal is 1.00 mass% or less, diffusion into the intermediate material during brazing heat is suppressed, and a decrease in corrosion resistance when brazing heat is applied can be prevented. Therefore, the Cu content in the aluminum alloy material for brazing filler metal is preferably 1.00 mass% or less, more preferably 0.95 mass% or less, and even more preferably 0.90 mass% or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0072] (Cr: 0.30 mass% or less) Cr in the aluminum alloy for brazing filler metal improves strength through solid solution strengthening and also precipitates Al-Cr intermetallic compounds, which act to coarsen crystal grains after brazing. In this embodiment, the Cr content in the aluminum alloy for brazing filler metal may be 0% by mass. Furthermore, if the Cr content in the aluminum alloy for brazing filler metal is 0.30% by mass or less, the formation of large intermetallic compounds can be suppressed, and good plastic workability can be obtained. Therefore, the Cr content in the aluminum alloy for brazing filler metal is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the aluminum alloy for brazing filler metal.

[0073] (Ti: 0.30% by mass or less) Although Ti in the aluminum alloy material for brazing filler metal improves the viscosity of the molten brazing filler metal and suppresses the flow of the molten brazing filler metal, in this embodiment, the Ti content in the aluminum alloy material for brazing filler metal may be 0% by mass. Furthermore, if the Ti content in the aluminum alloy material for brazing filler metal is 0.30% by mass or less, the generation of Al-Ti compounds with a high specific gravity in the molten brazing filler metal can be suppressed, and an excessive amount of molten brazing filler metal flowing downward in the vertical direction can be prevented. Therefore, the Ti content in the aluminum alloy material for brazing filler metal is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0074] (Zr: 0.30% by mass or less) Zr in the aluminum alloy for brazing filler metal improves strength through solid solution strengthening and also precipitates Al-Zr-based intermetallic compounds, which act to coarsen crystal grains after brazing. In this embodiment, the Zr content in the aluminum alloy for brazing filler metal may be 0% by mass. Furthermore, if the Zr content in the aluminum alloy for brazing filler metal is 0.30% by mass or less, the formation of large intermetallic compounds can be suppressed, and a decrease in plastic workability can be prevented. Therefore, the Zr content in the aluminum alloy for brazing filler metal is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the aluminum alloy for brazing filler metal.

[0075] (V: 0.30% by mass or less) V in the aluminum alloy for brazing filler metal is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the V content in the aluminum alloy for brazing filler metal may be 0 mass%. Furthermore, if the V content in the aluminum alloy for brazing filler metal is 0.30 mass% or less, the formation of large intermetallic compounds can be suppressed, and a decrease in plastic workability can be prevented. Therefore, the V content in the aluminum alloy for brazing filler metal is preferably 0.30 mass% or less, more preferably 0.20 mass% or less, and even more preferably 0.10 mass% or less, based on the total mass of the aluminum alloy for brazing filler metal.

[0076] (Ca: 0.30% by mass or less) Ca increases the pH upon dissolution and inhibits the corrosion reaction by suppressing the pH decrease due to the hydrolysis reaction at the local anode where Al dissolution occurs. Therefore, Ca is an effective element for improving corrosion resistance. Therefore, the aluminum alloy material for brazing filler metal may contain Ca as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Ca content in the aluminum alloy material for brazing filler metal is not particularly limited. However, if the Ca content in the aluminum alloy material for brazing filler metal is 0.01% by mass or more, the effect of improving the corrosion resistance of the aluminum alloy material for brazing filler metal can be obtained. Therefore, the Ca content in the aluminum alloy material for brazing filler metal is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the aluminum alloy material for brazing filler metal. On the other hand, if the Ca content in the aluminum alloy material for brazing filler metal exceeds 0.30% by mass, brazing performance may be reduced when brazing using a fluoride-based flux. Therefore, the Ca content in the aluminum alloy material for brazing filler metal is set to 0.30 mass % or less, preferably 0.25 mass % or less, and more preferably 0.20 mass % or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0077] (Sc: 0.20% by mass or less) Sc is an element that has the effect of improving the strength of an aluminum alloy material for brazing filler metal by solid solution strengthening. Therefore, the aluminum alloy material for brazing filler metal may contain Sc as necessary, but it may also contain 0 mass%. In this embodiment, the lower limit of the Sc content in the aluminum alloy material for brazing filler metal is not particularly limited. However, when the Sc content in the aluminum alloy material for brazing filler metal is 0.01 mass% or more, the effect of improving the strength of the aluminum alloy material for brazing filler metal can be obtained. Therefore, the Sc content in the aluminum alloy material for brazing filler metal is preferably 0.01 mass% or more, and more preferably 0.05 mass% or more, relative to the total mass of the aluminum alloy material for brazing filler metal. On the other hand, when the Sc content in the aluminum alloy material for brazing filler metal exceeds 0.20 mass%, cracks may easily occur during cold rolling. Therefore, the Sc content in the aluminum alloy material for brazing filler metal is 0.20 mass% or less, preferably 0.15 mass% or less, and more preferably 0.10 mass% or less, relative to the total mass of the aluminum alloy material for brazing filler metal.

[0078] (Ni: 0.30% by mass or less) Ni is an element that crystallizes or precipitates as an intermetallic compound in the alloy structure, thereby improving strength. Therefore, the aluminum alloy material for brazing filler metal may contain Ni, if necessary, but it may contain 0% by mass. In this embodiment, the lower limit of the Ni content in the aluminum alloy material for brazing filler metal is not particularly limited. However, when the Ni content in the aluminum alloy material for brazing filler metal is 0.01% by mass or more, the effect of improving the strength of the aluminum alloy material for brazing filler metal can be obtained. Therefore, the Ni content in the aluminum alloy material for brazing filler metal is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, when the Ni content in the aluminum alloy material for brazing filler metal exceeds 0.30% by mass, the solidus temperature of the aluminum alloy material for brazing filler metal decreases. Therefore, the Ni content in the aluminum alloy material for brazing filler metal is 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the aluminum alloy material for brazing filler metal.

[0079] (Mo: 0.30% by mass or less) Mo is an element that improves corrosion resistance by dissolving in water to form molybdate, which acts as an oxygen diffusion barrier and inhibits the reduction reaction of dissolved oxygen in water, thereby suppressing general corrosion. Therefore, the aluminum alloy material for brazing filler metal may contain Mo as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Mo content in the aluminum alloy material for brazing filler metal is not particularly limited. However, if the Mo content in the aluminum alloy material for brazing filler metal is 0.01% by mass or more, the effect of improving the corrosion resistance of the aluminum alloy material for brazing filler metal can be obtained. Therefore, the Mo content in the aluminum alloy material for brazing filler metal is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the aluminum alloy material for brazing filler metal. On the other hand, if the Mo content in the aluminum alloy material for brazing filler metal exceeds 0.30% by mass, the aluminum alloy material for brazing filler metal may become embrittled, resulting in deterioration of workability. Therefore, the Mo content in the aluminum alloy material for brazing filler metal is set to 0.30 mass % or less, preferably 0.25 mass % or less, and more preferably 0.20 mass % or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0080] (Sb: 0.30% by mass or less) Sb in the aluminum alloy material for brazing filler metal is an element that has the effect of refining Si particles and improving brazing properties, but in this embodiment, the Sb content in the aluminum alloy material for brazing filler metal may be 0 mass%. Furthermore, if the Sb content in the aluminum alloy material for brazing filler metal is 0.30 mass% or less, a decrease in the fluidity of the brazing filler metal can be prevented. Therefore, the Sb content in the aluminum alloy material for brazing filler metal is preferably 0.30 mass% or less, more preferably 0.20 mass% or less, and even more preferably 0.10 mass% or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0081] (Sr: 0.10% by mass or less) Sr in the aluminum alloy material for brazing filler metal is an element that has the effect of refining Si particles and improving brazing properties, but in this embodiment, the Sr content in the aluminum alloy material for brazing filler metal may be 0% by mass. Furthermore, if the Sr content in the aluminum alloy material for brazing filler metal is 0.10% by mass or less, oxidation of Sr during casting can be prevented. Therefore, the Sr content in the aluminum alloy material for brazing filler metal is preferably 0.10% by mass or less, more preferably 0.05% by mass or less, and even more preferably 0.02% by mass or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0082] (Na: 0.10% by mass or less) Na in the aluminum alloy material for brazing filler metal is an element that has the effect of refining Si particles and improving brazing properties, but in this embodiment, the Na content in the aluminum alloy material for brazing filler metal may be 0 mass%. Furthermore, if the Na content in the aluminum alloy material for brazing filler metal is 0.10 mass% or less, oxidation of Na during casting can be prevented. Therefore, the Na content in the aluminum alloy material for brazing filler metal is preferably 0.10 mass% or less, more preferably 0.05 mass% or less, and even more preferably 0.02 mass% or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0083] (Remainder: Al and inevitable impurities) The remainder of the aluminum alloy material for brazing filler metal in the clad material is Al and unavoidable impurities. Examples of the unavoidable impurities include rare earth elements other than Be and Sc, and Li. Specifically, Be may be contained in an amount of 0.01% by mass or less, and other elements may be contained in an amount of less than 0.01% by mass. The total amount of unavoidable impurities in the aluminum alloy material for brazing filler metal is preferably 0.05% by mass or less, based on the total mass of the aluminum alloy material for brazing filler metal.

[0084] <Aluminum alloy for sacrificial anodes> (Zn: 0.50 mass% or more and 6.00 mass% or less) Zn in the aluminum alloy material for sacrificial anode material is an element that has the effect of preventing pitting corrosion and crevice corrosion by making the potential of the base material less noble and enhancing the sacrificial corrosion protection effect for the aluminum alloy material for the core material and the intermediate layer. If the Zn content in the aluminum alloy material for sacrificial anode material is 0.50% by mass or more, sufficient sacrificial corrosion protection effect can be obtained. Therefore, the Zn content in the aluminum alloy material for sacrificial anode material is preferably 0.50% by mass or more, more preferably 0.60% by mass or more, and even more preferably 0.70% by mass or more, based on the total mass of the aluminum alloy material for sacrificial anode material. Furthermore, if the Zn content in the aluminum alloy material for sacrificial anode material is 6.00% by mass or less, excessive increase in the self-corrosion of the sacrificial anode material can be prevented, and a decrease in the corrosion resistance of the clad material can be suppressed. Therefore, the Zn content in the aluminum alloy material for sacrificial anode material is preferably 6.00 mass% or less, more preferably 5.70 mass% or less, and even more preferably 5.50 mass% or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0085] (Si: 0.05 mass% or more and 1.50 mass% or less) Si in the aluminum alloy material for sacrificial anodes is an element that has the effect of improving the strength of the aluminum alloy material for sacrificial anodes. If the Si content in the aluminum alloy material for sacrificial anodes is 0.05% by mass or more, the effect of improving the strength can be obtained. Therefore, the Si content in the aluminum alloy material for sacrificial anodes is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.15% by mass or more, based on the total mass of the aluminum alloy material for sacrificial anodes. Furthermore, if the Si content in the aluminum alloy material for sacrificial anodes is 1.50% by mass or less, a decrease in the solidus temperature can be suppressed, and melting during brazing can be prevented. Therefore, the Si content in the aluminum alloy material for sacrificial anodes is preferably 1.50% by mass or less, more preferably 1.45% by mass or less, and even more preferably 1.40% by mass or less, based on the total mass of the aluminum alloy material for sacrificial anodes.

[0086] (Fe: 0.05 mass% or more and 2.00 mass% or less), Fe in the aluminum alloy for sacrificial anodes is an element that forms an Al-Fe-Mn-Si compound with Si and Mn, and has the effect of improving strength through dispersion strengthening. When the Fe content in the aluminum alloy for sacrificial anodes is 0.05% by mass or more, the effect of improving strength can be obtained. Therefore, the Fe content in the aluminum alloy for sacrificial anodes is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.12% by mass or more, based on the total mass of the aluminum alloy for sacrificial anodes. Furthermore, when the Fe content in the aluminum alloy for sacrificial anodes is 2.00% by mass or less, the formation of large intermetallic compounds during casting can be prevented, and a decrease in plastic workability can be suppressed. Therefore, the Fe content in the aluminum alloy for sacrificial anodes is preferably 2.00% by mass or less, more preferably 1.80% by mass or less, and even more preferably 1.60% by mass or less, based on the total mass of the aluminum alloy for sacrificial anodes.

[0087] (Mg: 3.00% by mass or less) Mg in the aluminum alloy material for sacrificial anode material is an element that not only improves the strength of the aluminum alloy material for sacrificial anode material itself by precipitating Mg2Si, but also has the effect of diffusing Mg into the core material by brazing heat, thereby improving the strength of the core material. However, in this embodiment, the Mg content in the aluminum alloy material for sacrificial anode material may be 0% by mass. Furthermore, if the Mg content in the aluminum alloy material for sacrificial anode material is 3.00% by mass or less, it can be easily pressure-bonded during hot clad rolling. Therefore, the Mg content in the aluminum alloy material for sacrificial anode material is preferably 3.00% by mass or less, more preferably 2.80% by mass or less, and even more preferably 2.60% by mass or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0088] (Mn: 1.80% by mass or less) Mn in the aluminum alloy material for sacrificial anode material is an element that has the effect of improving strength after brazing by dissolving in the base metal and forming an Al-Mn-Si intermetallic compound with Si. However, in this embodiment, the Mn content in the aluminum alloy material for sacrificial anode material may be 0% by mass. Furthermore, if the Mn content in the aluminum alloy material for sacrificial anode material is 1.80% by mass or less, the fluidity of the molten brazing filler metal on the surface of the aluminum alloy material for sacrificial anode material side during brazing is increased, thereby improving brazing properties. Therefore, the Mn content in the aluminum alloy material for sacrificial anode material is preferably 1.80% by mass or less, more preferably 1.60% by mass or less, and even more preferably 1.40% by mass or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0089] (Cu: 0.50% by mass or less) When the Cu content in the aluminum alloy material for sacrificial anode material is 0.50 mass% or less, the pitting corrosion potential of the sacrificial anode material is prevented from becoming nobler, and the effect of sacrificial corrosion protection can be sufficiently obtained. Therefore, the Cu content in the aluminum alloy material for sacrificial anode material is preferably 0.50 mass% or less, more preferably 0.40 mass% or less, and even more preferably 0.30 mass% or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0090] (Cr: 0.30 mass% or less) Cr in the aluminum alloy for sacrificial anode material is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the Cr content in the aluminum alloy for sacrificial anode material may be 0% by mass. Furthermore, if the Cr content in the aluminum alloy for sacrificial anode material is 0.30% by mass or less, it is possible to prevent the formation of large intermetallic compounds during casting and suppress a decrease in plastic workability. Therefore, the Cr content in the aluminum alloy for sacrificial anode material is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the aluminum alloy for sacrificial anode material.

[0091] (Ti: 0.30% by mass or less) Ti in the aluminum alloy for sacrificial anode material is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the Ti content in the aluminum alloy for sacrificial anode material may be 0% by mass. Furthermore, if the Ti content in the aluminum alloy for sacrificial anode material is 0.30% by mass or less, it is possible to prevent the formation of large intermetallic compounds during casting and suppress a decrease in plastic workability. Therefore, the Ti content in the aluminum alloy for sacrificial anode material is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the aluminum alloy for sacrificial anode material.

[0092] (Zr: 0.30% by mass or less) Zr in the aluminum alloy for sacrificial anode material is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the Zr content in the aluminum alloy for sacrificial anode material may be 0% by mass. Furthermore, if the Zr content in the aluminum alloy for sacrificial anode material is 0.30% by mass or less, it is possible to prevent the formation of giant intermetallic compounds during casting and suppress a decrease in plastic workability. Therefore, the Zr content in the aluminum alloy for sacrificial anode material is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the aluminum alloy for sacrificial anode material.

[0093] (V: 0.30% by mass or less) V in the aluminum alloy for sacrificial anode material is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the V content in the aluminum alloy for sacrificial anode material may be 0% by mass. Furthermore, if the V content in the aluminum alloy for sacrificial anode material is 0.30% by mass or less, it is possible to prevent the formation of large intermetallic compounds during casting and suppress a decrease in plastic workability. Therefore, the V content in the aluminum alloy for sacrificial anode material is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the aluminum alloy for sacrificial anode material.

[0094] (Ca: 0.30% by mass or less) Ca increases the pH upon dissolution and inhibits the pH drop due to the hydrolysis reaction at the local anode where Al dissolution occurs, thereby inhibiting the corrosion reaction. Therefore, the aluminum alloy material for sacrificial anodes may contain Ca as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Ca content in the aluminum alloy material for sacrificial anodes is not particularly limited. However, if the Ca content in the aluminum alloy material for sacrificial anodes is 0.01% by mass or more, the corrosion resistance of the aluminum alloy material for sacrificial anodes can be improved. Therefore, the Ca content in the aluminum alloy material for sacrificial anodes is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the aluminum alloy material for sacrificial anodes. On the other hand, if the Ca content in the aluminum alloy material for sacrificial anodes exceeds 0.30% by mass, brazing performance may be reduced when brazing using a fluoride-based flux. Therefore, the Ca content in the aluminum alloy material for sacrificial anode material is set to 0.30 mass% or less, preferably 0.25 mass% or less, and more preferably 0.20 mass% or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0095] (Sc: 0.20% by mass or less) Sc is an element that has the effect of improving the strength of an aluminum alloy material for a sacrificial anode material by solid solution strengthening. Therefore, the aluminum alloy material for a sacrificial anode material may contain Sc as necessary, but it may also contain 0% by mass. In this embodiment, the lower limit of the Sc content in the aluminum alloy material for a sacrificial anode material is not particularly limited, but when the Sc content in the aluminum alloy material for a sacrificial anode material is 0.01% by mass or more, the effect of improving the strength of the aluminum alloy material for a sacrificial anode material can be obtained. Therefore, the Sc content in the aluminum alloy material for a sacrificial anode material is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the aluminum alloy material for a sacrificial anode material. On the other hand, when the Sc content in the aluminum alloy material for a sacrificial anode material exceeds 0.20% by mass, cracks may be more likely to occur during cold rolling. Therefore, the Sc content in the aluminum alloy material for sacrificial anode material is set to 0.20 mass% or less, preferably 0.15 mass% or less, and more preferably 0.10 mass% or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0096] (Ni: 0.30% by mass or less) Ni is an element that crystallizes or precipitates as an intermetallic compound in the alloy structure, thereby improving strength. Therefore, the aluminum alloy material for sacrificial anode material may contain Ni as needed, but it may contain 0% by mass. In this embodiment, the lower limit of the Ni content in the aluminum alloy material for sacrificial anode material is not particularly limited. However, when the Ni content in the aluminum alloy material for sacrificial anode material is 0.01% by mass or more, the effect of improving the strength of the aluminum alloy material for sacrificial anode material can be obtained. Therefore, the Ni content in the aluminum alloy material for sacrificial anode material is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the aluminum alloy material. On the other hand, when the Ni content in the aluminum alloy material for sacrificial anode material exceeds 0.30% by mass, the solidus temperature of the aluminum alloy material for sacrificial anode material decreases. Therefore, the Ni content in the aluminum alloy material for sacrificial anode material is set to 0.30 mass % or less, preferably 0.25 mass % or less, and more preferably 0.20 mass % or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0097] (Mo: 0.30% by mass or less) Mo is an element that has the effect of improving corrosion resistance by dissolving in water to form molybdate, which acts as an oxygen diffusion barrier and suppresses the reduction reaction of dissolved oxygen in water, thereby suppressing general corrosion. Therefore, the aluminum alloy material for sacrificial anode material may contain Mo as needed, but it may also contain 0% by mass. In this embodiment, the lower limit of the Mo content in the aluminum alloy material for sacrificial anode material is not particularly limited, but if the Mo content in the aluminum alloy material for sacrificial anode material is 0.01% by mass or more, the effect of improving the corrosion resistance of the aluminum alloy material for sacrificial anode material can be obtained. Therefore, the Mo content in the aluminum alloy material for sacrificial anode material is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total mass of the aluminum alloy material for sacrificial anode material. On the other hand, if the Mo content in the aluminum alloy material for sacrificial anode material exceeds 0.30% by mass, the aluminum alloy for sacrificial anode material may become embrittled, resulting in deterioration of workability. Therefore, the Mo content in the aluminum alloy material for sacrificial anode material is set to 0.30 mass % or less, preferably 0.25 mass % or less, and more preferably 0.20 mass % or less, based on the total mass of the aluminum alloy material for sacrificial anode material.

[0098] (Remainder: Al and inevitable impurities) The remainder of the aluminum alloy material for sacrificial anode materials in the clad material is Al and unavoidable impurities. Examples of unavoidable impurities include rare earth elements other than Be, Sb, and Sc, and Li. Specifically, Be may be contained in an amount of 0.01% by mass or less, and other elements may be contained in an amount of less than 0.01% by mass. The total amount of unavoidable impurities in the aluminum alloy material for sacrificial anode materials is preferably 0.05% by mass or less, based on the total mass of the aluminum alloy material for sacrificial anode materials.

[0099] <Middle class> (Si: 0.05 mass% or more and 1.50 mass% or less) Si in the intermediate layer is an element that improves strength after brazing by dissolving in the base material and forming an Al-Mn-Si intermetallic compound with Mn. When the Si content in the intermediate layer is 0.05% by mass or more, the strength improvement effect can be sufficiently obtained. Therefore, the Si content in the intermediate layer is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.15% by mass or more, based on the total mass of the intermediate layer. Furthermore, when the Si content in the intermediate layer is 1.50% by mass or less, a decrease in the solidus temperature can be suppressed, and melting during brazing can be prevented. Therefore, the Si content in the intermediate layer is preferably 1.50% by mass or less, more preferably 1.40% by mass or less, and even more preferably 1.30% by mass or less, based on the total mass of the intermediate layer.

[0100] (Fe: 0.05 mass% or more and 2.00 mass% or less) The Fe in the intermediate layer is an element that forms an Al-Fe-Mn-Si compound with Si and Mn, and has the effect of improving strength through dispersion strengthening. When the Fe content in the intermediate layer is 0.05% by mass or more, the effect of improving strength can be sufficiently obtained. Therefore, the Fe content in the intermediate layer is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.12% by mass or more, based on the total mass of the intermediate layer. Furthermore, when the Fe content in the intermediate layer is 2.00% by mass or less, the formation of large intermetallic compounds during casting can be prevented, and a decrease in plastic workability can be suppressed. Therefore, the Fe content in the intermediate layer is preferably 2.00% by mass or less, more preferably 1.80% by mass or less, and even more preferably 1.60% by mass or less, based on the total mass of the intermediate layer.

[0101] (Zn: 6.00% by mass or less) Zn in the intermediate layer is an element that has the effect of lowering the potential of the intermediate layer and improving corrosion resistance, but in this embodiment, the Zn content in the intermediate layer may be 0% by mass. Furthermore, if the Zn content in the intermediate layer is 6.00% by mass or less, a decrease in the solidus temperature of the intermediate layer can be suppressed, and melting of the intermediate layer during brazing can be prevented. Therefore, the Zn content in the intermediate layer is preferably 6.00% by mass or less, more preferably 5.80% by mass or less, and even more preferably 5.60% by mass or less, relative to the total mass of the intermediate layer.

[0102] (Mn: 1.80% by mass or less) Mn in the intermediate layer is an element that has the effect of improving strength after brazing by dissolving in the base material and forming an Al-Mn-Si intermetallic compound together with Si. However, in this embodiment, the Mn content in the intermediate layer may be 0% by mass. Furthermore, if the Mn content in the intermediate layer is 1.80% by mass or less, the precipitation of coarse intermetallic compounds can be prevented and a decrease in rollability can be suppressed. Therefore, the Mn content in the intermediate layer is preferably 1.80% by mass or less, more preferably 1.70% by mass or less, and even more preferably 1.60% by mass or less, relative to the total mass of the intermediate layer.

[0103] (Cu: 1.00% by mass or less) Cu in the intermediate layer is an element that dissolves in the base material after brazing and has the effect of improving the strength after brazing. However, in this embodiment, the Cu content in the intermediate layer may be 0% by mass. Furthermore, if the Cu content in the intermediate layer is 1.00% by mass or less, a decrease in the solidus temperature can be suppressed and melting of the intermediate layer during brazing can be prevented. Therefore, the Cu content in the intermediate layer is preferably 1.00% by mass or less, more preferably 0.90% by mass or less, and even more preferably 0.80% by mass or less, relative to the total mass of the intermediate layer.

[0104] (Cr: 0.30 mass% or less) Cr in the intermediate layer is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the Cr content in the intermediate layer may be 0% by mass. Furthermore, if the Cr content in the intermediate layer is 0.30% by mass or less, the formation of large intermetallic compounds during casting can be prevented, and a decrease in plastic workability can be suppressed. Therefore, the Cr content in the intermediate layer is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the intermediate layer.

[0105] (Ti: 0.30% by mass or less) Ti in the intermediate layer is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the Ti content in the intermediate layer may be 0% by mass. Furthermore, if the Ti content in the intermediate layer is 0.30% by mass or less, the formation of large intermetallic compounds during casting can be prevented, and a decrease in plastic workability can be suppressed. Therefore, the Ti content in the intermediate layer is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the intermediate layer.

[0106] (Zr: 0.30% by mass or less) Zr in the intermediate layer is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the Zr content in the intermediate layer may be 0% by mass. Furthermore, if the Zr content in the intermediate layer is 0.30% by mass or less, it is possible to prevent the formation of large intermetallic compounds during casting and suppress a decrease in plastic workability. Therefore, the Zr content in the intermediate layer is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the intermediate layer.

[0107] (V: 0.30% by mass or less) V in the intermediate layer is an element that has the effect of improving strength through solid solution strengthening, but in this embodiment, the V content in the intermediate layer may be 0% by mass. Furthermore, if the V content in the intermediate layer is 0.30% by mass or less, it is possible to prevent the formation of large intermetallic compounds during casting and suppress a decrease in plastic workability. Therefore, the V content in the intermediate layer is preferably 0.30% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.10% by mass or less, based on the total mass of the intermediate layer.

[0108] (Ca: 0.30% by mass or less) Ca increases the pH upon dissolution and inhibits the pH drop due to hydrolysis at the local anode where Al dissolution occurs, thereby inhibiting corrosion reactions. Therefore, Ca is an effective element for improving corrosion resistance. Therefore, the intermediate layer may contain Ca, if necessary, but it may contain 0% by mass. In this embodiment, the lower limit of the Ca content in the intermediate layer is not particularly limited. However, a Ca content of 0.01% by mass or more in the intermediate layer can improve the corrosion resistance of the intermediate layer. Therefore, the Ca content in the intermediate layer is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the intermediate layer. On the other hand, a Ca content exceeding 0.30% by mass in the intermediate layer may degrade brazing properties in brazing using a fluoride-based flux. Therefore, the Ca content in the intermediate layer is 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the intermediate layer.

[0109] (Sc: 0.20% by mass or less) Sc is an element that has the effect of improving the strength of the intermediate layer through solid solution strengthening. Therefore, the intermediate layer may contain Sc as needed, but it may also contain 0 mass%. In this embodiment, there is no particular limitation on the lower limit of the Sc content in the intermediate layer. However, when the Sc content in the intermediate layer is 0.01 mass% or more, the effect of improving the strength of the intermediate layer can be obtained. Therefore, the Sc content in the intermediate layer is preferably 0.01 mass% or more, and more preferably 0.05 mass% or more, relative to the total mass of the intermediate layer. On the other hand, if the Sc content in the intermediate layer exceeds 0.20 mass%, cracks may easily occur during cold rolling. Therefore, the Sc content in the intermediate layer is 0.20 mass% or less, preferably 0.15 mass% or less, and more preferably 0.10 mass% or less, relative to the total mass of the intermediate layer.

[0110] (Ni: 0.30% by mass or less) Ni is an element that crystallizes or precipitates as an intermetallic compound in the alloy structure, thereby improving strength. Therefore, the intermediate layer may contain Ni, if necessary, but it may contain 0% by mass. In this embodiment, the lower limit of the Ni content in the intermediate layer is not particularly limited. However, when the Ni content in the intermediate layer is 0.01% by mass or more, the effect of improving the strength of the intermediate layer can be obtained. Therefore, the Ni content in the intermediate layer is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the aluminum alloy material. On the other hand, when the Ni content in the intermediate layer exceeds 0.30% by mass, the solidus temperature of the intermediate layer decreases. Therefore, the Ni content in the intermediate layer is 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the intermediate layer.

[0111] (Mo: 0.30% by mass or less) Mo is an element that improves corrosion resistance by dissolving in water to form molybdate, which acts as an oxygen diffusion barrier and suppresses the reduction reaction of dissolved oxygen in water, thereby suppressing general corrosion. Therefore, the intermediate layer may contain Mo, if necessary, but it may contain 0% by mass. In this embodiment, the lower limit of the Mo content in the intermediate layer is not particularly limited. However, a Mo content of 0.01% by mass or more in the intermediate layer can improve the corrosion resistance of the intermediate layer. Therefore, the Mo content in the intermediate layer is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total mass of the intermediate layer. On the other hand, a Mo content of more than 0.30% by mass in the intermediate layer may embrittle the intermediate layer and deteriorate its workability. Therefore, the Mo content in the intermediate layer is set to 0.30% by mass or less, preferably 0.25% by mass or less, and more preferably 0.20% by mass or less, relative to the total mass of the intermediate layer.

[0112] (Remainder: Al and inevitable impurities) The remainder of the intermediate layer in the clad material is Al and unavoidable impurities. Examples of unavoidable impurities include rare earth elements other than Be, Sb, and Sc, and Li. Specifically, Be may be contained in an amount of 0.01% by mass or less, and other elements may be contained in an amount of less than 0.01% by mass. The total amount of unavoidable impurities in the intermediate layer is preferably 0.05% by mass or less of the total mass of the intermediate layer. [Example]

[0113] The present embodiment will be described in more detail below with reference to examples, but the present invention is not limited to these examples, and modifications can be made within the scope of the spirit of the present invention, and all such modifications are included in the technical scope of the present invention.

[0114] <Aluminum alloy manufacturing> Aluminum alloy materials having various chemical compositions were manufactured by assuming that scrap (casting raw material A) having various chemical compositions shown in Table 1 below and additive casting raw material B having various chemical compositions shown in Table 2 below were used. The content of each component in the aluminum alloy materials and the recycling rate are shown in Table 3.

[0115] <Clad material production> Ingots having various compositions were cast, then homogenized, each surface was chamfered, and further hot-rolled to a desired thickness to produce functional aluminum alloy materials (aluminum alloy materials for brazing filler metals and aluminum alloy materials for sacrificial anode materials) having the compositions shown in Table 4 below. Then, a portion of the aluminum alloy material shown in Table 3 was used as a core material, and functional aluminum alloy materials were laminated on only one surface or on both one surface and the other surface. The laminate was then hot-rolled, reheated, and hot-rolled. Then, in the case of the O and H24 tempers, cold rolling and final annealing were performed to produce test materials (Nos. T1 to T5 and T21) with the desired final thicknesses. In the case of the H14 temper, cold rolling, intermediate annealing, and cold rolling were performed to produce test materials (Nos. T6 to T7 and T9) with the desired final thicknesses. In the case of H34 temper, cold rolling, intermediate annealing, cold rolling, and stabilization treatment were performed to produce test material (No. T8) with a specified final plate thickness. The aluminum alloy material numbers used for evaluation, and for those that produced clad materials, the functional aluminum alloy material numbers used, clad ratios, temper types, and final plate thicknesses of the clad materials are shown in Table 5 below.

[0116] In Tables 1 to 4, in the column for the content of each component, "-" indicates that the element is not contained or that the content is less than 0.05 mass%. The balance of each component in the aluminum alloy materials and functional aluminum alloy materials shown in Tables 3 and 4 is Al and unavoidable impurities.

[0117] <Evaluation of test materials> (Calculation of solidus temperature) The solidus temperature of the obtained aluminum alloy material was calculated using integrated thermodynamic calculation software (Thermo-Calc). The temperature at which the liquid phase ratio exceeded 1% in the calculation was defined as the "solidus temperature of the aluminum alloy material."

[0118] (Measurement of tensile strength) The obtained clad material was subjected to a tensile test in accordance with JIS Z 2241 to measure the tensile strength.

[0119] (flow coefficient) The flow coefficients of test material No. T9, in which the Mg content of the aluminum alloy material was 0.01 mass%, and test material No. T21, in which the Mg content of the aluminum alloy material was 0.17 mass%, were calculated by an inverted T-shaped fluidity test. The fluidity test was carried out by applying aluminum brazing flux FL-7 (manufactured by Morita Chemical Industry Co., Ltd.) to the brazing material surface of the aluminum alloy material at a rate of 5±0.1 g / m 2 The test was carried out by applying the coating amount of 100% Cr to the aluminum alloy sheets, assembling them into an inverted T-shape, and then brazing. The brazing conditions for the test were 600°C for 3 minutes. Note that, since the Mg content affects the flow coefficient, the flow coefficients of test materials other than test material Nos. T9 and T21 were not measured because they contained no Mg and it was assumed that the flow coefficients were 0.57 or higher. The measurement results are also shown in Table 5 below.

[0120] In Table 5, in the column for clad material, "-" indicates that the clad material was not produced. In addition, in the measurement results, "-" indicates that the measurement was not performed. Furthermore, in the column for evaluation results in Table 5, those having a solidus temperature of 600°C or higher and a flow coefficient of 0.40 or higher were judged to have excellent brazability and were marked with "○". Those not meeting either of the above criteria were judged to have poor brazability and were marked with "×". As described above, since the magnesium content in the aluminum alloy material of test material Nos. T1 to T8, T10 to T20, and T22 to T25 is lower than that of test material No. T9, it can be determined that the flow coefficient is 0.57 or higher.

[0121] [Table 1]

[0122] [Table 2]

[0123] [Table 3]

[0124] [Table 4]

[0125] [Table 5]

[0126] As shown in Tables 1 to 5 above, in the test materials Nos. T1 to T20, which are examples of the invention, aluminum alloy scrap material having a Mg content of 0.10% by mass or less was used as the casting raw material A. Furthermore, the recycling rate was determined based on the Si content in the casting raw material A, and aluminum alloy materials were manufactured so as to have a predetermined solidus temperature, and some of them were made into clad materials. Therefore, the brazability evaluation results were good. Thus, when aluminum alloy materials are manufactured using the manufacturing method of the present invention, scrap from automotive heat exchangers in which clad materials are used, and aluminum alloy clad materials used in automotive heat exchangers, can be reused. Furthermore, even when the recycling rate is 20% or more, aluminum alloy materials with excellent brazability can be manufactured, which allows for a reduction in the amount of virgin metal used and a significant reduction in CO2 emissions.

[0127] On the other hand, in the comparative example, test material No. T21, the casting raw material A having a Mg content exceeding 0.10 mass % was used, and the Mg content in the aluminum alloy material exceeded the upper limit specified in the present invention, resulting in poor brazability. In the test material No. T22, the Mn content in the aluminum alloy material was less than the lower limit specified in the present invention, and therefore the brazeability was poor. For test materials No. T23 and T24, the Si content in casting raw material A was calculated as [Si] in mass%. A , when expressed as (1): [Si] A × R / 100 exceeded 1.10. Specifically, [Si] A was 2.20, and the recycle rates of test materials Nos. T23 and T24 were 55% and 54%, respectively, so the values ​​calculated by formula (1) were 1.20 and 1.19, respectively. Therefore, the Si content in the aluminum alloy material exceeded the upper limit specified in the present invention, and the brazeability was poor. In Test No. T25, the Zn content in the aluminum alloy material exceeded the upper limit specified in the present invention, and therefore the brazeability was poor. In Test No. T26, the Cu content in the aluminum alloy material exceeded the upper limit specified in the present invention, and therefore the brazeability was poor.

Claims

1. A method for producing an aluminum alloy material using a casting raw material A and a casting raw material B, comprising: a selection step of selecting only aluminum alloy scrap material having a Mg content of 0.10% by mass or less from at least one of scrap of automotive heat exchangers using clad materials and scrap of aluminum alloy clad materials used for automotive heat exchangers, as the casting raw material A; a casting step of casting an ingot using the casting raw material A and the casting raw material B for addition; a molding step of molding the ingot to mold an aluminum alloy material having a solidus temperature of 600°C or higher, The recycling rate, which represents the mass ratio of the casting raw material A to the total mass of the ingot, is R (%), and the Si content in the casting raw material A is [Si] in mass%. Ａ , when expressed as Between the selection step and the casting step, Expression (1): [Si] Ａ ×R / 100 The value calculated by is 0.50 or more and 1.10 or less, a recycle rate determination step of determining a recycle rate R so that the casting step is a step of casting the ingot using the casting raw material A in an amount of R (%) relative to the total mass of the ingot and the casting raw material B in an amount of (100-R) (%) relative to the total mass of the ingot, The casting raw material A contains, with respect to the total mass of the casting raw material A, Si: 0.50% by mass or more, and Zn: 0.10% by mass or more, Contains at least one element selected from Fe: 0.10% by mass or more, Cu: 0.08% by mass or more, and Mn: 0.50% by mass or more, The aluminum alloy material is Si: 0.50% by mass or more and 1.10% by mass or less, Fe: 0.10% by mass or more and 1.00% by mass or less, Cu: 0.08% by mass or more and 0.80% by mass or less, Mn: 0.90% by mass or more and 1.80% by mass or less, and Zn: 0.10% by mass or more and 1.00% by mass or less; Mg: 0.10% by mass or less, Ti: 0.30% by mass or less, Cr: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, 1. A method for producing an aluminum alloy material, comprising: Mo: 0.30 mass% or less; and the balance consisting of Al and unavoidable impurities.

2. The method for producing an aluminum alloy material according to claim 1, wherein the recycling rate R is 20% or more and 50% or less.

3. The method for producing an aluminum alloy material according to claim 1, wherein the casting raw material B does not contain Si.

4. The method for producing an aluminum alloy material according to claim 1, wherein the casting raw material B does not contain Zn.

5. 2. The method for producing an aluminum alloy material according to claim 1, wherein the casting raw material A contains Zn: 1.00 mass % or less.

6. A method for producing a clad material containing an aluminum alloy material produced by the production method according to any one of claims 1 to 5, The aluminum alloy material is used as a core aluminum alloy material, A method for producing a clad material, characterized in that the core aluminum alloy material and at least one functional aluminum alloy material are laminated to produce a clad material.

7. 7. The method for producing a clad material according to claim 6, wherein the functional aluminum alloy material includes at least one of an aluminum alloy material for brazing filler metal and an aluminum alloy material for sacrificial anode metal.

8. The aluminum alloy material for brazing filler metal is Si: 2.50% by mass or more and 13.00% by mass or less, and Fe: 0.05% by mass or more and 1.00% by mass or less; Zn: 5.50% by mass or less, Mn: 1.00% by mass or less, Cu: 1.00% by mass or less, Cr: 0.30% by mass or less, Ti: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, Mo: 0.30% by mass or less, Sb: 0.30% by mass or less, Sr: 0.10% by mass or less, The method for producing a clad material according to claim 7, characterized in that Na is 0.10 mass % or less, and the balance is Al and unavoidable impurities.

9. The aluminum alloy material for the sacrificial anode material is Zn: 0.50% by mass or more and 6.00% by mass or less, Si: 0.05% by mass or more and 1.50% by mass or less, and Fe: 0.05% by mass or more and 2.00% by mass or less; Mg: 3.00% by mass or less, Mn: 1.80% by mass or less, Cu: 0.50% by mass or less, Cr: 0.30% by mass or less, Ti: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, The method for producing a clad material according to claim 7, characterized in that Mo: 0.30 mass % or less, the balance consisting of Al and unavoidable impurities.

10. 8. The method for manufacturing a clad material according to claim 7, wherein the clad material has a structure in which the aluminum alloy material for brazing filler metal / the aluminum alloy material for core material / the aluminum alloy material for brazing filler metal or the aluminum alloy material for sacrificial anode material are laminated in this order.

11. The clad material includes an intermediate layer between the core aluminum alloy material and the functional aluminum alloy material, The intermediate layer is Si: 0.05% by mass or more and 1.50% by mass or less, and Fe: 0.05% by mass or more and 2.00% by mass or less; Zn: 6.00% by mass or less, Mn: 1.80% by mass or less, Cu: 1.00% by mass or less, Cr: 0.30% by mass or less, Ti: 0.30% by mass or less, Zr: 0.30% by mass or less, V: 0.30% by mass or less, Ca: 0.30% by mass or less, Sc: 0.20% by mass or less, Ni: 0.30% by mass or less, The method for producing a clad material according to claim 6, characterized in that Mo: 0.30 mass % or less, the balance consisting of Al and unavoidable impurities.

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