Aluminum alloys and aluminum alloy clad materials

Abstract

The present invention aims to provide aluminum alloys and aluminum alloy clad materials. [Solution] The aluminum alloy according to the present invention has a composition in mass% of Fe: 0.05~1.0%, Si: 0.5~13.0%, Mn: 0.1~2.0%, Cu: 0.1~2.0%, and Mg: 0.01~2.0%, satisfying the relationship Mn≦2-0.08×Fe when Si<1.4, and Mn≦-0.68ln(Si)+2.2+0.03×Fe when Si≧1.4, with the remainder being Al and unavoidable impurities, and further comprising 10,000 μm of second-phase particles having a diameter of 10 μm or more in terms of equivalent circular diameter. 2 It is characterized by having fewer than 5 per unit.

Description

Technical Field

[0001] The present invention relates to an aluminum alloy and an aluminum alloy clad material.

Background Art

[0002] In recent years, the realization of a carbon-neutral society has become an issue. However, since aluminum consumes a large amount of electric power in refining, it is required to reduce the new ingot usage rate in product manufacturing by applying recycled materials. As recycled materials, so-called in-plant scrap materials discharged during manufacturing in the factory have been conventionally used, but this cannot sufficiently reduce the new ingot usage rate. In order to greatly reduce the new ingot usage rate, it can be solved by using not only in-plant scrap but also urban scrap. On the other hand, when a large amount of urban scrap is used, it is necessary to control the properties of alloys having a composition range that has never existed before.

[0003] For example, as an aluminum alloy plate for automotive applications as described in Patent Document 1 below, after specifying the contents of Si, Mn, Mg, Fe, Cu, Cr, Zn, Ti, etc. individually, the ratio of Si and Mn is specified to obtain excellent elongation. An aluminum alloy plate has been known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, materials with excellent recyclability have been desired, and it is desired to be excellent in strength and corrosion resistance while satisfying the necessary properties in aluminum alloys.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide aluminum alloys and aluminum alloy clad materials that improve recyclability, strength, and corrosion resistance by optimizing the content of Si, Fe, Mn, Cu, Mg, etc., and optimizing the precipitation state of the second phase particles. [Means for solving the problem]

[0007] "1" This form of aluminum alloy has a composition in mass% of Fe: 0.05~1.0%, Si: 0.5~13.0%, Mn: 0.1~2.0%, Cu: 0.1~2.0%, and Mg: 0.01~2.0%, satisfying the relationship Mn≦2-0.08×Fe when Si<1.4, and Mn≦-0.68ln(Si)+2.2+0.03×Fe when Si≧1.4, with the remainder being Al and unavoidable impurities, and furthermore, having 10,000 μm of second-phase particles with a diameter of 10 μm or more in terms of equivalent circle diameter. 2 It is characterized by having fewer than 5 per unit.

[0008] "2" The aluminum alloy described in "1" of this embodiment, which preferably contains one or more of Zr, Ti, Cr, Ni, Sn, Pb, and Sr in addition to the above composition, and the content of each individual element is 0.5% or less. "3" The aluminum alloy described in "1" of this embodiment preferably contains, in addition to the above composition, Zn: 0.01 to 5.0% by mass. "4" The aluminum alloy described in "2" of this embodiment preferably contains, in addition to the above composition, Zn: 0.01 to 5.0% by mass.

[0009] "5" The aluminum alloy clad material of this form is characterized in that it has an aluminum alloy as described in any of "1" to "4" as the core material, and has a sacrificial material bonded to one or both sides of the core material. "6" An aluminum alloy clad material as described in "5" of this embodiment, characterized in that the sacrificial material contains Zn: 0.1 to 6.0% by mass, with the remainder being Al and unavoidable impurities.

[0010] "7" The aluminum alloy clad material described in "6" of this embodiment is preferably such that the sacrificial material contains one or more of the following by mass%, in the form of Cr: 0.05-0.5%, Ti: 0.05-0.5%, and Mg: 0.01-2.0%, with the remainder being Al and unavoidable impurities. "8" The aluminum alloy clad material described in "6" of this embodiment is preferably such that the sacrificial material is restricted to 0.05% or less by mass of Cu, with the remainder consisting of Al and unavoidable impurities. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide aluminum alloys and aluminum alloy clad materials that are excellent in terms of recyclability, strength, and corrosion resistance. [Brief explanation of the drawing]

[0012] [Figure 1] This is a cross-sectional view showing a first embodiment of the aluminum alloy clad material according to the present invention. [Modes for carrying out the invention]

[0013] An example of an embodiment of the present invention will be described in detail below based on the attached drawings. Note that, for convenience, the drawings used in the following description may show enlarged versions of key features to make them easier to understand.

[0014] In this embodiment, the aluminum alloy clad material A, as an example, consists of a clad material in which a sacrificial material 2 is bonded to one side of a core material 1 made of aluminum alloy, as shown in Figure 1. Although Figure 1 shows an example in which the sacrificial material 2 is bonded to one side of the core material 1, the sacrificial material 2 may be bonded to both sides of the core material 1. Incidentally, the aluminum alloy clad material A can have a multilayer structure for the core material 1 and the sacrificial material 2, respectively, and may have a structure such as providing another layer between the core material 1 and the sacrificial material 2, and may have a four-layer structure or a five-layer structure of two or more layers.

[0015] "Core material 1" In this embodiment, the core material 1 contains, in mass%, Fe: 0.05 to 1.0%, Si: 0.5 to 13.0%, Mn: 0.1 to 2.0%, Cu: 0.1 to 2.0%, Mg: 0.01 to 2.0%, and the balance is composed of Al and unavoidable impurities. Moreover, it is preferable that the contents of Mn, Si, and Fe satisfy the relationship of Mn ≦ 2 - 0.08 × Fe in the range where Si < 1.4. Moreover, it is preferable that the contents of Mn, Si, and Fe satisfy the relationship of Mn ≦ -0.68ln(Si) + 2.2 + 0.03 × Fe in the range where Si ≧ 1.4. In addition, when expressing the range of mass% described in this specification using "~", unless otherwise specified, it means notation including the lower limit and the upper limit. Therefore, as an example, 0.05 to 1.0% means a content of 0.05% or more and 1.0% or less.

[0016] In addition to the above-mentioned elements, the aluminum alloy constituting the core material 1 contains, in mass%, one or more of Zr, Ti, Cr, Ni, Sn, Pb, Sr, and it is preferable that the content of each element is 0.5% or less. That is, it is preferable to satisfy any one or more or all of Zr ≦ 0.5 mass%, Ti ≦ 0.5 mass%, Cr ≦ 0.5 mass%, Ni ≦ 0.5 mass%, Sn ≦ 0.5 mass%, Pb ≦ 0.5 mass%, Sr ≦ 0.5 mass%. In addition to the above-mentioned elements, the aluminum alloy constituting the core material 1 may contain, in mass%, Zn: 0.01 to 5.0 mass%. Hereinafter, the content of the elements contained in the core material 1 will be described.

[0017] Fe: 0.05 to 1.0% Fe is added to precipitate as intermetallic compounds such as Al-Mn-Fe and Al-Mn-Si-Fe to improve the material strength. If the Fe content is below the lower limit, the cost will increase. If it exceeds the upper limit, huge intermetallic compounds (crystallized products) will be generated during casting, resulting in a decrease in rolling property. Si: 0.5~13.0% Si is added not only to improve the material strength by solid solution but also to precipitate as Al-Mn-Si and Al-Mn-Si-Fe compounds to improve the material strength. If the Si content is below the lower limit, sufficient effects cannot be obtained. If it exceeds the upper limit, huge intermetallic compounds (crystallized products) will be generated during casting, resulting in a decrease in rolling property.

[0018] Mn: 0.1~2.0% Mn is contained to precipitate as intermetallic compounds such as Al-Mn, Al-Mn-Si, and Al-Mn-Si-Fe to improve the material strength. If the Mn content is below the lower limit, the effect is insufficient. If it exceeds the upper limit, huge intermetallic compounds (crystallized products) will be generated during casting, resulting in a decrease in rolling property. Cu: 0.1~2.0% Cu is added to dissolve in the solid solution to improve the material strength. If the Cu content is below the lower limit, the effect is insufficient. If it exceeds the upper limit, the material strength will be too high, making it difficult to manufacture the material.

[0019] Mg: 0.01~2.0% Mg is contained to precipitate as a solid solution or as intermetallic compounds such as Mg2Si to improve the material strength. If the Mg content is below the lower limit, the effect is insufficient. If it exceeds the upper limit, the material strength will be too high, making it difficult to manufacture the material.

[0020] Contents of Mn, Si, and Fe When the contents of Mn, Si, and Fe satisfy the relationship of Mn ≦ 2 - 0.08×Fe in the range of Si < 1.4 and the relationship of Mn ≦ -0.68ln(Si) + 2.2 + 0.03×Fe in the range of Si ≧ 1.4 If the predetermined relationship shown by the above relational expression cannot be satisfied, huge intermetallic compounds (crystallized products) will be generated during casting, resulting in a decrease in rolling property.

[0021] Observation in the RD-TD direction revealed that second-phase particles with a diameter of 10 μm or more in terms of equivalent circular diameter were found to be 10,000 μm in size. 2 Less than 5 per area If a large number of coarse second-phase particles are distributed, side cracks will occur during cold rolling, reducing productivity. Therefore, second-phase particles with a diameter of 10 μm or more in terms of equivalent circular diameter should be distributed over 10,000 μm. 2 The number must be less than 5 per unit.

[0022] It contains one or more of the following elements: Zr, Ti, Cr, Ni, Sn, Pb, and Sr, with each element's content being 0.5% by mass or less. These elements precipitate as intermetallic compounds and are included to improve material strength. If the content exceeds the upper limit, large intermetallic compounds (crystallized deposits) are formed during casting, reducing rollability.

[0023] Zn: 0.01~5.0% Zinc is added to control the potential difference with sacrificial corrosion inhibitors by forming a solid solution and lowering the natural potential, thereby reducing the corrosion rate of the sacrificial corrosion inhibitors. Alternatively, it is added to sacrificially protect other components by becoming less corrosive itself. If the Zn content is below the lower limit, the effect is insufficient, and if it exceeds the upper limit, the potential becomes excessively lower, reducing self-corrosion resistance.

[0024] "Sacrificial material" In applications requiring corrosion resistance, a single alloy is insufficient to ensure adequate corrosion resistance; therefore, corrosion protection measures using a sacrificial material are applied. For this reason, the sacrificial material preferably contains 0.1 to 6.0% Zn. Zn: 0.1~6.0% Zn, through solid solution, lowers the potential of sacrificial material 2 compared to core material 1, thereby protecting core material 1 from corrosion. In the sacrificial material, if the Zn content is below the lower limit, sufficient effect cannot be obtained, and if it exceeds the upper limit, the potential becomes excessively lower, increasing the rate of self-corrosion.

[0025] Cr, Ti, Mg content The sacrificial material preferably contains Zn, along with one or more of the following by mass%, in the following amounts: Cr: 0.05-0.5%, Ti: 0.05-0.5%, and Mg: 0.01-2.0%, with the remainder being Al and unavoidable impurities. Cr: 0.05~0.5% Cr is formed by solid solution in the matrix or by densely distributing Cr-containing compounds. Cr separated from the matrix due to minor corrosion, or Cr generated by the decomposition of compounds, concentrates on the alloy surface, forming a corrosion-resistant oxide film containing Cr in the corroded areas. This oxide film formation improves the corrosion resistance of the alloy. Below the lower limit of Cr content, sufficient effect is not obtained; above the upper limit, large intermetallic compounds (crystallized deposits) are formed during casting, reducing rollability.

[0026] Ti: 0.05~0.5% By forming layers with different Ti concentrations through peritectic reactions during casting and subsequent appropriate rolling processes, the corrosion morphology can be controlled planarly, thereby reducing the corrosion rate. Below the lower limit of Ti content, sufficient effect cannot be obtained, and above the upper limit, coarse intermetallic compounds are formed during casting, reducing rollability. Mg: 0.01~2.0% Magnesium (Mg) can improve corrosion resistance by forming an MgO film. If the Mg content is below the lower limit, sufficient effect cannot be obtained, and if it exceeds the upper limit, the material strength becomes too high, making material manufacturing difficult.

[0027] Restriction on Cu to 0.05% or less When copper (Cu) is included in the sacrificial material, it can be distributed as an Al-Cu compound, or Cu ions leached from the matrix due to corrosion can adhere to the material as metallic Cu, acting as a strong cathode and degrading the material's corrosion resistance. Therefore, it is preferable to limit the Cu content in the sacrificial material to 0.05% or less.

[0028] "Manufacturing method" For example, aluminum alloy sheets for constructing the bare material can be obtained by first obtaining a cast material from molten aluminum alloy that satisfies the composition of the bare material, and then by homogenizing the cast material, surface machining, soaking treatment, hot rolling, and cold rolling. When a core material is combined with a sacrificial material to form a clad material, one example is to obtain a cast material from molten aluminum alloy that satisfies the core material composition, and then surface-machine the cast material to obtain the material for the clad material. Alternatively, after obtaining a cast material from molten aluminum alloy that satisfies the sacrificial material composition, the material for the clad material may be obtained through homogenization treatment, surface machining, soaking treatment, and cutting. The desired aluminum alloy clad material can be obtained by assembling the core material and the sacrificial material, and then undergoing clad rolling and cold rolling. Intermediate annealing, final annealing, and aging treatments may be performed as needed.

[0029] "Casting and cooling rates of bare and clad materials in each process" A cooling rate of 0.1°C / s or higher is desirable during casting. If the cooling rate during casting is less than the specified rate, the time spent in the crystallization temperature range during casting will be prolonged, resulting in the formation of coarse intermetallic compounds that cannot be sufficiently crushed during the rolling process. For the same reason, a cooling rate of 1°C / s or higher is desirable during casting.

[0030] "Equivalent strain in hot rolling of bare and clad materials" Equivalent strain ε > 5.0 in hot rolling. By controlling the equivalent strain ε shown in equation (1) below, coarse intermetallic compounds generated during casting can be crushed. ε=(2 / √3)ln(t0 / t)...Equation (1) t0: Hot rolling start thickness (slab thickness) t: Hot-rolled finish thickness

[0031] Other manufacturing conditions are not specifically defined, but the following conditions may be selected as examples. "Homogenization process" It can be performed at a temperature of 400-620°C for 1-12 hours. "Soaking treatment" The temperature can be selected from 430 to 550°C for 1 to 12 hours. "Intermediate annealing, final annealing" It can be performed at a temperature of 150-450°C for 1-12 hours. Solution treatment Perform the procedure at 300-580°C for 1-180 minutes, then cool with water. "Statute of limitations processing" It can be performed at a temperature of 150-450°C for a period of 1-1000 minutes.

[0032] As a result of the manufacturing method described above, the material contains Fe: 0.05~1.0%, Si: 0.5~13.0%, Mn: 0.1~2.0%, Cu: 0.1~2.0%, and Mg: 0.01~2.0%. The content of Mn, Si, and Fe satisfies the relationship Mn ≤ 2 - 0.08 × Fe when Si < 1.4, and Mn ≤ -0.68ln(Si) + 2.2 + 0.03 × Fe when Si ≥ 1.4, with the remainder being Al and unavoidable impurities. Furthermore, the second phase particles have a diameter of 10 μm or more in terms of equivalent circular diameter and are 10,000 μm in size. 2 An aluminum alloy sheet material can be obtained as a bare material, characterized by having fewer than 5 particles per unit area. Furthermore, it is possible to obtain an aluminum alloy clad material having a sacrificial material on one or both sides of the core material.

[0033] If the aforementioned aluminum alloy sheet material is used, it is possible to obtain an aluminum alloy sheet material with excellent material strength of 150 MPa or more. Furthermore, if this aluminum alloy sheet material is used, it can be manufactured without the occurrence of defects such as side cracks during the manufacturing process. This aluminum alloy sheet material has excellent corrosion resistance. The aforementioned aluminum alloy clad material possesses excellent material strength of 150 MPa or more, and can be manufactured without defects such as side cracks occurring during the manufacturing process. This aluminum alloy clad material also has excellent corrosion resistance. Note that the occurrence of side cracks is correlated with recyclability, as it occurs when manufacturing high-concentration alloys due to degradation caused by an excess of coarse intermetallic compounds. [Examples]

[0034] Aluminum alloys (No. 1 to 68) with the compositions shown in Tables 1 to 3 below were melted and then subjected to hot rolling and cold rolling to produce aluminum alloy sheets with a thickness of 0.3 mm. Final annealing was carried out at 360°C for 3 hours to obtain a core material (bare material) as tempered O material. Aluminum alloys (No. 1-25) with the compositions shown in Table 4 below were melted down, and sacrificial materials were prepared by homogenizing the cast material, surface machining, soaking treatment, hot rolling, and cold rolling. The aforementioned bare material was combined with a sacrificial material as the core material, and cladding was performed so that the cladding ratio of the sacrificial material to the core material was 10%. A final annealing was then performed at 360°C for 3 hours to obtain an aluminum alloy clad material with a temper of O. Table 5 shows the manufacturing conditions for producing the aforementioned core material, including the cooling rate during casting, the strain equivalent to hot rolling, and the reduction ratio per cold rolling pass. The number of second-phase particles was measured in the obtained core material (bare material).

[0035] (Measurement method for second-phase particles) The surface of the test material was polished with abrasive grains of approximately 0.1 μm, and fully automated particle analysis was performed from the surface direction using the EDS attached to FE-EPMA (JEOL JXA-8530F), with the surface direction measured at 10,000 μm. 2 Measurements were taken within a 100 μm square observation field. The acceleration voltage was 15 kV and the irradiation current was 5 nA.

[0036] (Measurement of material strength) Samples were cut parallel to the rolling direction to prepare JIS No. 13B test specimens, and tensile tests were performed. A: Good (200 MPa or more), B: Fairly good (150 MPa or more but less than 200 MPa), C: Poor (less than 150 MPa). (Side crack occurrence status) The depth of side cracks was investigated when the material was rolled down to 0.3 mm. The vertical distance from the edge of the sheet material to the point of maximum crack depth was measured. C was judged as follows: A: less than 0.5 mm (very good), B: 0.5 mm to less than 1.5 mm (good), C: 1.5 mm to less than 3.0 mm (somewhat good), and C: 3.0 mm or more (poor).

[0037] (Measurement of corrosion depth of bare material) Evaluated according to ASTM standards, test specimen size 80mm x 20mm, single-sided exposure. The maximum corrosion depth after 100 hours of SWAAT loading was evaluated. A corrosion depth of less than 150 μm was judged as good (A), 150 μm to less than 250 μm was judged as slightly good (B), and 250 μm or more was judged as poor (C). (Corrosion depth of clad material) Evaluated according to ASTM standards, specimen size 80mm x 20mm, sacrificial material surface exposed on one side. The maximum corrosion depth after 1000 hours of SWAAT loading was evaluated. Corrosion depth of less than 50 μm: A (good), 50 μm to less than 250 μm: B (somewhat good), 250 μm or more: C (poor).

[0038] Tables 6 to 9 below summarize the types of bare materials used, their manufacturing methods, the number of second-phase particles, strength, side crack occurrence, and corrosion resistance measurements. Tables 10 and 11 below summarize the types of core material and sacrificial material combinations applied, the manufacturing methods of the core material, and the measurement results for manufacturability and corrosion resistance.

[0039] [Table 1]

[0040] [Table 2]

[0041] [Table 3]

[0042] Table 4

[0043] Table 5

[0044] Table 6

[0045] Table 7

[0046] Table 8

[0047] Table 9

[0048] Table 10

[0049] Table 11

[0050] From the results shown in Tables 6 to 9, the composition is as follows (by mass%): Fe: 0.05-1.0%, Si: 0.5-13.0%, Mn: 0.1-2.0%, Cu: 0.1-2.0%, Mg: 0.01-2.0%. The content of Mn, Si, and Fe satisfies the relationship Mn ≤ 2 - 0.08 × Fe when Si < 1.4, and Mn ≤ -0.68ln(Si) + 2.2 + 0.03 × Fe when Si ≥ 1.4, with the remainder being Al and unavoidable impurities. Furthermore, the second phase particles have a diameter of 10 μm or more in terms of equivalent circle diameter and are 10,000 μm in size. 2 It was found that aluminum alloy bare material with fewer than 5 cracks per unit area exhibits high strength, a low incidence of side cracks, and excellent corrosion resistance.

[0051] The sample of sample type 54 shown in Table 7 uses bare material 55 with a low Fe content, resulting in high manufacturing costs during the refining of the raw materials. Sample type 55 used bare material 56 with a high Fe content, resulting in a high frequency of side crack occurrence. Sample type 56 used bare material 57 with a low Si content, resulting in a high frequency of side crack occurrence. Sample type 57 used bare material 58 with a high Si content, which resulted in the formation of large intermetallic compounds (crystallized deposits) during casting, causing fracture during rolling and making manufacturing impossible.

[0052] Sample type 58 used bare material 59 with a low Mn content, resulting in a large number of precipitated second-phase particles and a high frequency of side crack occurrence. Sample type 59 used bare material 60 with a high Mn content, which resulted in the formation of large intermetallic compounds (crystallized deposits) during casting, causing fracture during rolling and rendering it unmanufacturable. Sample type 60 used bare material 61 with a low Cu content, resulting in a large number of precipitated second-phase particles and a high frequency of side crack occurrence. Sample type 61 used a bare material 62 with a high Cu content, which resulted in the material becoming too hard and fracturing during rolling, making it unsuitable for manufacturing.

[0053] Sample type 62 used bare material 63 with a low Mg content, resulting in a large number of precipitated second-phase particles and a high frequency of side crack occurrence. Sample type 63 used bare material 64 with a high Mg content, resulting in excessively high material strength and fracture during rolling, making it unsuitable for manufacturing. Sample type 64 used bare material 65 that did not satisfy the relational equation, resulting in a large number of precipitated second-phase particles and a high frequency of side crack occurrence. Sample type 65 used a bare material 66 that did not satisfy the relational equation, resulting in a large number of precipitated second-phase particles and a high frequency of side crack occurrence.

[0054] Because sample 66 of material type used bare material 67 with a low Zn content, its corrosion resistance was slightly lower compared to samples of material types 46 to 53. Because sample 67 of material type used bare material 68 with a high Zn content, its corrosion resistance was slightly lower compared to samples of material types 46-53.

[0055] Samples of types 121 to 132 shown in Table 9 use bare material 55 to 66, and therefore, similar to sample types 54 to 65 described in Table 7, they experienced problems such as high cost, inability to manufacture, or the occurrence of side cracks. Samples 133 and 134, which use bare materials 67 and 68, exhibited slightly lower corrosion resistance compared to samples 113-20.

[0056] Samples 137-139, 142-144, 147-149, 152-154, and 157-159 were manufactured using one of the following manufacturing conditions shown in Table 5: manufacturing condition E, which involves a slow cooling rate during casting; manufacturing condition F, which involves low strain equivalent to hot rolling; or manufacturing condition G, which involves a low reduction ratio per cold rolling pass. Therefore, these samples exhibit a high number of precipitated second-phase particles and a high frequency of side crack occurrence.

[0057] The clad material samples shown in Table 10, types 1 to 21, are samples using core material 1 in combination with sacrificial materials 1 to 21. All of these samples showed good corrosion resistance. The clad material samples of types 22-24 are combinations of core material 1 and sacrificial materials 22-24. Sacrificial material 22 had too high a Cr content, sacrificial material 23 had too high a Ti content, and sacrificial material 24 had too high a Mg content. None of these clad materials could be manufactured. The clad material samples of types 47-49 use core material 1 in combination with sacrificial materials 22-24. Sacrificial material 47 has too high a Cr content, sacrificial material 48 has too high a Ti content, and sacrificial material 49 has too high a Mg content. None of these clad materials could be manufactured. [Explanation of symbols]

[0058] A...Aluminum alloy clad material, 1...Core material, 2...Sacrificial material.

Claims

1. The composition, in mass%, contains Fe: 0.05-1.0%, Si: 0.5-13.0%, Mn: 0.1-2.0%, Cu: 0.1-2.0%, and Mg: 0.01-2.0%. The content of Mn, Si, and Fe satisfies the relationship Mn ≤ 2 - 0.08 × Fe when Si < 1.4, and Mn ≤ -0.68ln(Si) + 2.2 + 0.03 × Fe when Si ≥ 1.4, with the remainder being Al and unavoidable impurities. Furthermore, the second phase particles have a diameter of 10 μm or more in terms of equivalent circular diameter and are 10,000 μm in size. ２ An aluminum alloy characterized by having fewer than 5 particles per unit area.

2. An aluminum alloy according to claim 1, characterized in that, in addition to the above composition, it contains one or more of Zr, Ti, Cr, Ni, Sn, Pb, and Sr, and the content of each individual element is 0.5% or less.

3. An aluminum alloy according to claim 1, characterized in that, in addition to the above composition, it contains Zn: 0.01 to 5.0% by mass.

4. An aluminum alloy according to claim 2, characterized in that, in addition to the above composition, it contains Zn: 0.01 to 5.0% by mass.

5. An aluminum alloy clad material characterized by having an aluminum alloy according to any one of claims 1 to 4 as the core material, and having a sacrificial material bonded to one or both sides of the core material.

6. An aluminum alloy clad material according to claim 5, characterized in that the sacrificial material contains Zn: 0.1 to 6.0% by mass, with the remainder being Al and unavoidable impurities.

7. An aluminum alloy clad material according to claim 6, characterized in that the sacrificial material contains one or more of the following by mass%, in the form of Cr: 0.05 to 0.5%, Ti: 0.05 to 0.5%, and Mg: 0.01 to 2.0%, with the remainder being Al and unavoidable impurities.

8. An aluminum alloy clad material according to claim 6, characterized in that the sacrificial material restricts Cu to 0.05% or less by mass, with the remainder consisting of Al and unavoidable impurities.

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