Aluminum wrought material and method for producing the same

Abstract

To provide an aluminum wrought material composed of aluminum with a reduced amount of added alloy elements, enabling compatibility between high tensile strength and low yield strength.SOLUTION: An aluminum wrought material comprising Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01 mass% or less, and at least one element selected from the group consisting of Ni, Y, and Si, the balance being Al and unavoidable impurities, wherein the aluminum wrought material has a positron lifetime of 168 ps to 182 ps as measured by positron annihilation method.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to aluminum fabricated materials and methods for their manufacture. [Background technology]

[0002] It is known that aluminum wire (bonding wire) made of an aluminum alloy is used to form bonding connections in power semiconductors (see, for example, Patent Document 1). Patent Document 1 aims to provide an aluminum wire that can realize bonding connections with higher reliability than conventional ones in response to the technical issue of rising operating temperatures in power semiconductor devices, and to this end, it proposes a method for determining the true stress difference (Δρ t ) and the difference between the true strain (Δε t ) is controlled. Patent Document 1 also discloses that in order to manufacture aluminum wire having desired physical properties, at least a solution treatment step, a quenching step, and an aging treatment step at a temperature exceeding 250°C are carried out.

[0003] Patent Document 2 discloses an aluminum alloy wire used as a conductor for electrical wiring, etc. The document describes a method of casting and extruding an aluminum alloy billet, and then repeatedly performing wire drawing and heat treatment multiple times to obtain an aluminum alloy wire used as a conductor for electrical wiring that has higher bending fatigue properties than conventional wires, a moderately low 0.2% yield strength, and excellent mass productivity while maintaining high tensile strength and high electrical conductivity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6090721 [Patent Document 2] Patent No. 6534809 Summary of the Invention [Problem to be solved by the invention]

[0005] The use of high-purity aluminum wire for bonding is being investigated. High-purity aluminum has moderate flexibility, making it less susceptible to fatigue fracture when used as bonding wire, and is expected to enable wire bonding with excellent long-term reliability.

[0006] However, because high-purity aluminum is soft, there is a risk of wire breakage during wire drawing. Because wire breakage reduces yield, there is a need for extruded aluminum wire that is less likely to break. When extruding an aluminum billet, if the processing rate is increased to introduce a large number of structural defects into the metal structure, the tensile strength of the extruded aluminum wire increases, making it less susceptible to breakage. On the other hand, if the tensile strength of the extruded aluminum wire increases, the yield strength also increases, making it more difficult to deform, which creates the problem of making wiredrawing more difficult.

[0007] To solve these problems, there is a need for an extruded aluminum wire that is easy to draw and resistant to breakage. However, there is a correlation between tensile strength and yield strength, and it is common for both to be high or low, making it difficult to achieve high tensile strength and low yield strength.

[0008] Patent Documents 1 and 2 are directed to aluminum wire made of an aluminum alloy, and do not consider the problem of wire breakage during wire drawing that is specific to high-purity aluminum. Therefore, an object of one embodiment of the present invention is to provide an aluminum processed material, including an aluminum extruded wire, that is made of aluminum with a small amount of alloying elements added, and that can achieve both high tensile strength and low yield strength. Another embodiment of the present invention aims to provide a method for manufacturing the above-mentioned aluminum workpiece. [Means for solving the problem]

[0009] Aspect 1 of the present invention is Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less; one or more selected from the group consisting of Ni, Y, and Si; the balance being Al and unavoidable impurities, This is an aluminum processed material with a positron lifetime of 168ps to 182ps measured by positron annihilation spectroscopy.

[0010] Aspect 2 of the present invention is The aluminum processed material according to embodiment 1, which is an aluminum extrusion processed material.

[0011] Aspect 3 of the present invention is The processed aluminum material according to aspect 2 is an extruded wire having a diameter of 1 to 10 mm.

[0012] A fourth aspect of the present invention is The processed aluminum material according to any one of Aspects 1 to 3, wherein the total content of one or more elements selected from the group consisting of Ni, Y, and Si is 10 to 2000 ppm by mass.

[0013] A fifth aspect of the present invention is The processed aluminum material according to any one of Aspects 1 to 4 has a breaking elongation of 60% or more.

[0014] A sixth aspect of the present invention is preparing a billet containing Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less, and one or more elements selected from the group consisting of Ni, Y, and Si, with the balance being Al and unavoidable impurities; a step of extruding the billet at a working ratio of 90% or more to produce an extruded material; and storing the extruded material at 10°C to 40°C for 9 months or longer.

[0015] A seventh aspect of the present invention is preparing a billet containing Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less, and one or more elements selected from the group consisting of Ni, Y, and Si, with the balance being Al and unavoidable impurities; a step of extruding the billet at a working ratio of 90% or more to produce an extruded material; and heat treating the extruded material at 270°C to 380°C for 10 minutes to 1 hour.

[0016] Aspect 8 of the present invention is Aspect 6 or 7 is a method for producing a processed aluminum material according to aspect 6 or 7, wherein the extruded material is an extruded wire having a diameter of 1 to 10 mm.

[0017] A ninth aspect of the present invention is Aspects 6 to 8 are a method for producing a worked aluminum product according to any one of aspects 6 to 8, wherein the billet contains one or more elements selected from the group consisting of Ni, Y, and Si in a total content of 10 to 2000 ppm by mass. [Effects of the Invention]

[0018] According to one embodiment of the present invention, it is possible to provide an aluminum processed material that is made of aluminum containing a small amount of alloying elements and that can achieve both high tensile strength and low yield strength, and a method for manufacturing the same. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a graph showing the relationship between the heat treatment temperature for an aluminum extruded wire (processing rate 90%) and the Vickers hardness HV of the aluminum extruded wire after the heat treatment. DETAILED DESCRIPTION OF THE INVENTION

[0020] The aluminum processed material (such as an aluminum extruded wire) targeted in the embodiments of the present invention is an intermediate product before wire drawing. The aluminum processed material is subjected to wire drawing and, if necessary, heat treatment to produce an aluminum wire product. Aluminum processed materials made from high-purity aluminum have the characteristics of being less likely to break during wire drawing and being easier to draw, due to the fact that they have both relatively high tensile strength and relatively low yield strength (this is called "good additional workability"). However, it is generally difficult to achieve both of these properties at the same time.

[0021] The inventors conducted extensive research to obtain processed aluminum material that can achieve both relatively high tensile strength and relatively low yield strength (i.e., good further workability). As a result, they discovered for the first time that it is possible to achieve both by controlling the amount of structural defects (point defects, line defects, and planar defects) contained in the metal structure of the processed aluminum material. The inventors introduced positron lifetime measured by positron annihilation spectroscopy as an index for determining the amount of structural defects. The processed aluminum material according to the embodiment of the present invention has a positron lifetime controlled to 168 ps to 182 ps and an appropriate amount of structural defects, and therefore has good additional workability.

[0022] Hereinafter, an aluminum processed material according to an embodiment of the present invention and a preferred method for producing the aluminum processed material will be described in order.

[0023] [Aluminum processed material] In this specification, the term "aluminum processed material" is a concept that broadly includes materials formed by machining an aluminum billet. A specific example of an aluminum processed material is an aluminum extrusion material produced by extrusion molding.

[0024] 1.Chemical composition The chemical composition of the aluminum processed material according to the embodiment is: Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less; one or more selected from the group consisting of Ni, Y, and Si; The balance consists of aluminum and inevitable impurities. Inevitable impurities refer to trace impurities contained in aluminum raw materials (primary ingots, etc.).

[0025] In the processed aluminum material according to the embodiment, specific elements are intentionally added to high-purity aluminum. The intentionally added components (sometimes referred to as "intentionally added components" or simply "added components") are Ni, Y, and Si. These elements are fine precipitation strengthening elements. The chemical components, excluding intentionally added components, include Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01 mass% or less, with the remainder being Al and unavoidable impurities. In other words, excluding the intentionally added components, the aluminum is high-purity aluminum with a purity of 4N (99.99 mass%) or higher. Aluminum extrusions (e.g., aluminum wire) made from such high-purity aluminum are suitable for bonding wires that achieve wire bonding with excellent long-term reliability.

[0026] The total content of one or more intentionally added components selected from the group consisting of Ni, Y, and Si is preferably 10 to 2000 ppm by mass, and more preferably 30 to 300 ppm by mass. Each intentionally added element is preferably contained within the following range in order to exert the effect of fine precipitation strengthening.

[0027] When Ni is contained as an intentionally added component, the Ni content can be 10 to 1000 ppm by mass, preferably 30 to 300 ppm by mass, and particularly preferably 30 to 100 ppm by mass. When Y is contained as an intentionally added component, the Y content can be set to 10 to 2000 ppm by mass, or can also be set to 30 to 1000 ppm by mass, and is particularly preferably set to 50 to 300 ppm by mass. When Si is contained as an intentionally added component, the Si content can be set to 10 to 100 ppm by mass.

[0028] 2. Positron Lifetime Measurement In an embodiment of the present invention, the positron lifetime measured by positron annihilation spectroscopy is used as an indicator for determining the amount of structural defects (point defects, line defects, and planar defects) contained in a metal structure. Positrons, which are antiparticles of electrons, emit two annihilation gamma rays when they annihilate with electrons in the metal structure. Positrons have the property of being captured by structural defects (lattice defects) in the metal structure, and the captured positrons annihilate with electrons there and emit gamma rays. The positron lifetime depends on the electron density at the site where the positron annihilates. Because the electron density of structural defects is lower than the electron density in the bulk, the positron lifetime of positrons captured by structural defects is longer. Therefore, the greater the number of structural defects in the metal structure, the longer the positron lifetime overall. Measuring the positron lifetime provides information about the structural defect where the positron is trapped (Yoshitaka Taira et al., "Development of gamma-ray-induced positron annihilation spectroscopy," Proceedings of the 18th Annual Meeting of Particle Accelerator Society of Japan, August 9-12, 2021, QST-Takasaki Online, Japan, pp. 138-140).

[0029] The positron lifetime measured by positron annihilation spectroscopy is the time from when a positron enters an aluminum workpiece until the positron annihilates with an electron, and the positron lifetime in 5N-Al, which has absolutely no structural defects, is 160 ps (picoseconds). If structural defects exist in the metal structure of the aluminum workpiece, the positron lifetime will be longer than 160 ps. The inventors were the first to discover a correlation between the positron lifetime of an aluminum extruded wire and the further workability of the aluminum extruded wire, and conducted extensive research. As a result, they found that aluminum workpieces with a positron lifetime of 168 ps to 182 ps measured by positron annihilation spectroscopy have good further workability.

[0030] If the positron lifetime is less than 168 ps or more than 182 ps, it is believed that further processability will be reduced for the following reasons. Aluminum processed at a high processing rate (90% or more) contains many point defects, line defects, and planar defects in the metal structure, and the positron lifetime of the processed aluminum is over 182ps. Aluminum processed in this state has high tensile strength, making it less likely to break during wire drawing, but its high yield strength makes it difficult to draw and makes it less suitable for further processing.

[0031] Aluminum processed at a low processing rate, or processed at a high processing rate followed by heat treatment (for example, at 430°C for 60 minutes), has few point defects, line defects, and planar defects in the metal structure, and a positron lifetime of less than 168 ps. Aluminum processed in this state has low yield strength and is therefore easy to draw, but its low tensile strength also makes it prone to wire breakage during drawing, making it poorly suited for further processing.

[0032] In contrast, when aluminum processed at a high processing rate (90% or more) is stored at room temperature for 9 months or more (long-term room temperature storage) or heat-treated at a low temperature (low-temperature heat treatment), the positron lifetime of the aluminum processed material becomes 168ps to 182ps, and the yield strength becomes low but the tensile strength becomes high (i.e., the further processability is good).

[0033] It is not clear why aluminum processed materials processed at a high processing rate (90% or more) through long-term storage at room temperature or special processing such as low-temperature heat treatment only reduce their yield strength while maintaining their tensile strength, but it is speculated that the mechanism is as follows. Aluminum processed at a high processing rate contains many point defects, line defects, and planar defects in its metal structure. Planar defects are difficult to eliminate, so the amount of planar defects does not decrease significantly even after long-term storage at room temperature or low-temperature heat treatment. On the other hand, point defects and line defects are easy to eliminate, so it is thought that point defects and line defects are mainly reduced by long-term storage at room temperature or low-temperature heat treatment, resulting in a decrease in only the yield strength. Another reason why the tensile strength does not change is that long-term storage at room temperature or low-temperature heat treatment is unlikely to cause recrystallization in the metal structure of the processed aluminum material.

[0034] Furthermore, the results of the preliminary experiment shown in Figure 1 confirmed that high-purity aluminum processed at a high processing rate can be softened by heat treatment at a relatively low temperature (i.e., the yield strength can be reduced by long-term storage at room temperature or low-temperature heat treatment). Figure 1 is a graph showing the results of measuring the Vickers hardness (HV) of aluminum processed at a processing rate of 90% (4N-Al) after heat treatment at various temperatures. The heat treatment temperature was within the range of 25°C to 400°C, and the heat treatment time was 3 hours. The Vickers hardness was measured under a load of 50 gf. As shown in Figure 1, when the horizontal axis is the heat treatment temperature and the vertical axis is the Vickers hardness, it can be seen that the Vickers hardness drops sharply when the heat treatment temperature exceeds 100°C. Therefore, high-purity aluminum processed at a high processing rate can be sufficiently softened at a heat treatment temperature significantly lower than the conventional heat treatment conditions (430°C).

[0035] The measurement conditions for the positron annihilation method are as follows: As the electron beam source, for example, the beamline UVSOR BL1U at the Extreme Ultraviolet Research Facility of the Institute for Molecular Science is used. Gamma ray-induced positron annihilation lifetime spectroscopy (GiPAS) Positrons: Positron generation by gamma rays generated by inverse Thomson scattering (ITS) of a laser and an electron beam (laser wavelength: 800 nm, electron beam: 750 MeV) Gamma rays: Ultrashort pulse gamma rays with a maximum energy of 6.6 MeV Gamma ray pulse width: subpicoseconds to picoseconds Positron lifetime: Measured as the time difference between the gamma ray (6.6 MeV) emitted from the source and the annihilation gamma ray (0.511 MeV) emitted from the sample.

[0036] 3. Breaking elongation The processed aluminum material according to the embodiment preferably has a breaking elongation of 60% or more, which results in an aluminum material with particularly excellent further processability. The breaking elongation is more preferably 65% ​​or more, even more preferably 70% or more, and particularly preferably 72% or more. The higher the elongation at break, the more preferable it is, and there is no particular upper limit to the elongation at break. For example, the upper limit may be 100%, 90%, or 80%. The breaking elongation is determined from a tensile test carried out in accordance with JIS Z 2241:2011.

[0037] 4.Other The processed aluminum material can be formed into any desired size and shape depending on the application. For example, when the processed aluminum material is an extruded material, it may be an extruded wire (wire or rod) having a diameter of 1 to 10 mm. The aluminum processed material according to the embodiment is suitable for use as a bonding wire, as well as for electric wires such as overhead power transmission lines, superconducting stabilizers, and for use after being processed into fine wires. It is preferable to control the type and content of intentionally added components added to the processed aluminum material according to the intended use.

[0038] [Method of manufacturing aluminum processed materials] Two methods for manufacturing the extruded aluminum wire according to the embodiment of the present invention will be described below. It should be noted that a person skilled in the art who has access to the disclosure of the present application may arrive at different methods for manufacturing the extruded aluminum wire according to the embodiment based on the descriptions.

[0039] <First manufacturing method> The first manufacturing method includes the following steps. (i) billet preparation step: a step of preparing a billet containing Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less, and one or more elements selected from the group consisting of Ni, Y, and Si, with the balance being Al and unavoidable impurities (ii) Extrusion step: A step of extruding the billet at a processing rate of 90% or more to produce an extruded material. (iii) Long-term room temperature storage step: a step of storing the extruded material at 10°C to 40°C for 9 months or more.

[0040] Each step will be described in detail.

[0041] (i) Billet preparation process A predetermined amount of intentionally added elements (one or more of Ni, Y, and Si) is added to a raw material of high-purity aluminum (for example, Al with a purity of 99.99% (4N) or higher), and the mixture is stirred and held in solution. An ingot is then cast using a standard method, and further processed to produce an extrusion billet (sometimes simply referred to as a "billet") of the desired dimensions. The billet contains one or more elements selected from the group consisting of Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn, and Ni, Y, and Si, with a total content of 0.01% by mass or less, and the remainder consisting of Al and unavoidable impurities. The intentional additives contained in the billet are preferably one or more selected from the group consisting of Ni, Y, and Si, with the total content being in the range of 10 to 2000 mass ppm.

[0042] (ii) Extrusion process The extrusion billet is heated to a billet preheating temperature and then extruded in an extrusion device to obtain an extruded material. The billet preheating temperature may be set within the range of temperatures used in general extrusion molding. The heating temperature of the container of the extrusion device is set to the same temperature as the billet preheating temperature (within a temperature difference of 40°C). The working rate in the extrusion process is set to 90% or more. This allows the production of extruded material with a sufficient amount of structural defects in the metal structure. Here, the working rate is the percentage obtained by dividing the difference between the cross-sectional area A0 of the billet and the cross-sectional area A1 of the extruded material by the cross-sectional area A0 of the billet, and is calculated using the following formula. Machining rate (%)=(A0-A1) / A0×100

[0043] The extruded material is, for example, an extruded wire having a diameter of 1 to 10 mm.

[0044] (iii) Long-term room temperature storage process The resulting extruded material is stored at 10°C to 40°C for a long period of time, at least nine months. This reduces the point and line defects in the metal structure over time, resulting in a decrease in yield strength. However, since planar defects in the metal structure are difficult to reduce, the decrease in tensile strength is suppressed. The atmosphere during long-term storage at room temperature may be any of air, inert gas, and vacuum. If the storage period is short, the yield strength will not decrease sufficiently and further workability will not be improved. Generally, the period before extruded material is processed into wire is several months, or at most six months, and such a storage period is not enough to reduce the yield strength. The storage period is preferably 12 months or more, more preferably 18 months or more, even more preferably 24 months or more, and particularly preferably 28 months or more.

[0045] <Second manufacturing method> The second manufacturing method includes (i) a billet preparation step and (ii) an extrusion step, similar to the first manufacturing method, but does not include the (iii) long-term room temperature storage step, and instead includes (iv) a heat treatment step. Only the heat treatment step (iv), which is different from the first manufacturing method, will be explained below.

[0046] (iv) Heat treatment process The heat treatment step involves heat treating the extruded material obtained in the extrusion step at 270°C to 380°C for 10 minutes to 1 hour. This allows the yield strength to be reduced while suppressing a decrease in tensile strength in a significantly shorter time than the (iii) long-term room temperature storage step in the first manufacturing method. Although point defects and line defects can be reduced even at heat treatment temperatures below 270°C, the time required for heat treatment increases significantly, so the lower limit of the heat treatment temperature is set to 270°C. Heat treatment temperatures above 380°C may promote the elimination of planar defects, resulting in a decrease in tensile strength, so the upper limit of the heat treatment temperature is set to 380°C. The heat treatment temperature is preferably in the range of 280°C to 370°C, more preferably in the range of 290°C to 360°C, and particularly preferably in the range of 300°C to 355°C.

[0047] Depending on the heat treatment conditions (heat treatment temperature and heat treatment time), the processed aluminum material obtained by the heat treatment may have lower yield strength and higher tensile strength than the processed aluminum material obtained after long-term storage at room temperature. In other words, by selecting optimal heat treatment conditions, the processed aluminum material obtained by the second production method may have better additional workability. [Example]

[0048] Measurement samples of processed aluminum material (extruded wire) were prepared using the following procedure, and various measurements were performed.

[0049] (1) Preparation of measurement samples High-purity aluminum (purity 99.999% Al (5N-Al)) obtained by triple-layer electrolysis was used as the Al raw material. High-purity aluminum raw material was placed in a graphite crucible and melted at 760°C. Ni was added as an intentionally added component, and the mixture was stirred and degassed (700°C for 2 hours while held in a vacuum). It was then cast at 740°C using a graphite mold with an inner diameter of 100 mm (inner diameter 100 mm x inner height 230 mm).

[0050] The resulting ingot was processed to produce an extrusion billet measuring φ70 mm and length 180 mm. The extrusion billet was then extruded with the billet temperature set to 350-390°C and the container temperature set to within ±40°C of the billet temperature to obtain an aluminum processed material (extruded wire) measuring φ2 mm and length approximately 50 m.

[0051] The contents of 12 elements in the obtained extruded wires were measured by solid-state emission spectroscopy. All extruded wires had a Ni content of 50 ppm by mass, a total content of Si, Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn of 18 ppm by mass, and the remainder being high-purity aluminum (4N-Al) consisting of Al and unavoidable impurities.

[0052] For Samples Nos. 1 to 3, the extruded wires were stored in the atmosphere at about 10°C to about 30°C for the periods shown in Table 1. For Samples Nos. 4 and 5, the extruded wires were heat treated at the heat treatment temperatures and for the heat treatment times shown in Table 1. After storage or heat treatment, 2 m of the extrusion start was cut out from each of Samples Nos. 1 to 5 to prepare a measurement sample.

[0053] (Tensile test) A 200 mm long piece was cut out from the measurement sample and processed to obtain a tensile test piece (test material). The shape and dimensions of the tensile test piece were the same as those of No. 4 test piece in JIS Z 2241:2011.

[0054] The tensile test was performed in accordance with JIS Z 2241:2011. Both ends of the tensile test piece were held in a chuck at 50 mm, and the tensile test was performed at a tensile speed of 20 mm / min. The tensile test method was performed in accordance with JIS Z 2241:2011. From the results of the tensile test, the tensile strength, yield strength, and elongation at break were determined and are shown in Table 1. A tensile strength of 50 MPa or more is considered good, and a yield strength of 38 MPa or less is considered good.

[0055] (Positron lifetime measurement) A 25 mm long piece was cut out from the measurement sample, embedded in resin, and the cross section was polished and etched. The cross section was used as the measurement surface, and positron lifetime measurements were performed using the positron annihilation method. The measurement conditions for the positron annihilation method were as follows: The beamline UVSOR BL1U at the Extreme Ultraviolet Research Facility of the Institute for Molecular Science was used as the electron beam source. Gamma-ray-induced positron annihilation spectroscopy (GiPAS) Positrons: Positron generation by gamma rays generated by inverse Thomson scattering (ITS) of a laser and an electron beam (laser wavelength: 800 nm, electron beam: 750 MeV) Gamma rays: Ultrashort pulse gamma rays with a maximum energy of 6.6 MeV Gamma ray pulse width: subpicoseconds to picoseconds The results of the positron lifetime measurements are shown in Table 1.

[0056] [Table 1]

[0057] Consider the results in Table 1. Samples Nos. 2 to 4, which met all the conditions of this embodiment, had a tensile strength of 50 MPa or more and a yield strength of 38 MPa or less, confirming that they had good additional workability. Furthermore, when comparing the results of Samples No. 2 and No. 3, which had been stored at room temperature for a long period of time, Sample No. 3, which had been stored for 30 months, had better additional workability than Sample No. 2, which had been stored for 9 months. When comparing Sample No. 3, which had been stored for 30 months, with Sample No. 4, which had been heat-treated, it was found that Sample No. 4, which had been heat-treated, had better additional workability.

[0058] Sample No. 1 was stored for a short period of one month, which is thought to have resulted in a long positron lifetime and high yield strength. It is believed that sample No. 5 had a short positron lifetime and low tensile strength due to the high heat treatment temperature. Therefore, it is believed that neither Sample No. 1 nor Sample No. 5 exhibited excellent additional processability.

Claims

1. Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less; and one or more selected from the group consisting of Ni, Y, and Si; the balance consisting of Al and unavoidable impurities, An aluminum processed material having a positron lifetime of 168 ps to 182 ps as measured by positron annihilation spectroscopy.

2. The aluminum product according to claim 1 , which is an aluminum extrusion product.

3. The aluminum processed material according to claim 2, which is an extruded wire having a diameter of 1 to 10 mm.

4. The aluminum processed material according to claim 1, wherein the total content of one or more elements selected from the group consisting of Ni, Y, and Si is 10 to 2000 ppm by mass.

5. The aluminum processed material according to any one of claims 1 to 4, wherein the breaking elongation is 60% or more.

6. preparing a billet containing Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less, and one or more elements selected from the group consisting of Ni, Y, and Si, with the balance being Al and inevitable impurities; a step of extruding the billet at a working ratio of 90% or more to produce an extruded material; and storing the extruded material at 10°C to 40°C for 9 months or more.

7. preparing a billet containing Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V, and Zn in a total content of 0.01% by mass or less, and one or more elements selected from the group consisting of Ni, Y, and Si, with the balance being Al and inevitable impurities; a step of extruding the billet at a working ratio of 90% or more to produce an extruded material; and heat treating the extruded material at 270°C to 380°C for 10 minutes to 1 hour.

8. The method for manufacturing an aluminum processed product according to claim 6 or 7, wherein the extruded material is an extruded wire having a diameter of 1 to 10 mm.

9. The method for producing an aluminum processed material according to claim 6 or 7, wherein the total content of one or more elements selected from the group consisting of Ni, Y, and Si contained in the billet is 10 to 2000 ppm by mass.

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