KR20150086481A - Aluminum-alloy foil - Google Patents

Abstract

The aluminum alloy foil according to any one of claims 1 to 3, wherein the chemical composition contains Si: 0.1 to 0.6%, Fe: 0.2 to 1.5%, and Si and Fe in an amount of 0.48% And has a thickness of 20 mu m or less, a Si content of at least 700 mass ppm, a Fe content of at least 150 mass ppm, a tensile strength of at least 220 MPa, and a specific resistance measured in liquid nitrogen of 0.45 mu OMEGA Cm or more and 0.7 mu OMEGA .cm or less.

Description

Aluminum alloy foil {ALUMINUM-ALLOY FOIL}

The present invention relates to an aluminum alloy foil.

Conventionally, aluminum alloy foils have been used in various fields. In recent years, an aluminum alloy foil is used as a collector of an electrode in a power storage device such as a lithium ion battery, an electric double layer capacitor, or a lithium ion capacitor from the viewpoint of thinness and conductivity. Specifically, for example, Patent Documents 1 and 2 disclose a positive electrode of a lithium ion battery as a power storage device manufactured by the following manufacturing process. A layer containing a positive electrode active material and a binder is applied to one side of an aluminum alloy foil as a collector and dried. Thereafter, rolling is performed to improve the density of the positive electrode active material and the adhesion to the foil, thereby forming an anode.

The aluminum alloy foil includes, for example, 0.01 to 0.60 mass% of Si, 0.2 to 1.0 mass% of Fe, 0.05 to 0.50 mass% of Cu and 0.5 to 1.5 mass% of Mn in Patent Document 3, And the balance of Al and inevitable impurities, a tensile strength of 240 MPa or more, and an n value of 0.1 or more.

In addition, there are two other technical literatures preceding the present application. Patent Document 4 does not relate to an aluminum alloy foil for a lithium ion battery. This patent document discloses a steel sheet comprising 0.05 to 0.30 mass% of Si, 0.15 to 0.60 mass% of Fe, 0.01 to 0.20 mass% of Cu and 0.01 to 0.20 mass% of Cu, the balance being Al and inevitable impurities and having a tensile strength of 186 to 212 N / And a thickness of about 30 to 100 mu m.

Patent Document 5 discloses an aluminum alloy plate which can be used as a foil material and contains 0.1 to 2.5% by mass of Fe and 0.01 to 0.5% by mass of Si, the remainder being Al and inevitable impurities, ) An aluminum alloy sheet having an Fe content of 200 ppm or more and being cold-rolled without hot rolling is disclosed.

Japanese Patent Application Laid-Open No. 2007-234277 Japanese Patent Application Laid-Open No. 11-67220 Japanese Laid-Open Patent Publication No. 2011-26656 Japanese Patent Application Laid-Open No. 2006-283114 Japanese Patent Application Laid-Open No. 2008-223075

However, the conventional aluminum alloy foil has a problem in the following points. That is, as described above, the aluminum alloy foil is subjected to a compressive force by rolling or the like at the time of manufacturing a thin member such as an electrode of an electric storage device. For this reason, the aluminum alloy foil is required to have sufficient strength so as not to cause undesired deformation or breakage of such a compressive force. In recent years, further thinning of foil has been required. In order to cope with this demand, it is desired to increase the strength of the foil.

As a representative method for enhancing the strength of the foil, there is a method of adjusting the aluminum alloy component. However, with the simple adjustment of the alloy component, the resistivity of the foil increases due to the addition of an alloy component other than Al, and the conductivity decreases. As described above, the conventional aluminum alloy foil has a problem that it is difficult to intensify the strength without greatly impairing the conductivity.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing background, and an object of the present invention is to provide an aluminum alloy foil capable of achieving high strength without significantly deteriorating conductivity.

In one aspect of the present invention, there is provided a method of manufacturing a semiconductor device, characterized in that the chemical component contains Si: 0.1 to 0.6%, Fe: 0.2 to 1.5%, Si: 0.48% Wherein the thin film has a thickness of 20 占 퐉 or less, a solid content of Si of 700 mass ppm or more, a solid content of Fe of 150 mass ppm or more, a tensile strength of 220 MPa or more, Is not less than 0.45 μΩ · cm and not more than 0.7 μΩ · cm.

Since the aluminum alloy foil has the above-described specific structure, the aluminum alloy foil can be made to have high strength without seriously damaging the conductivity. Therefore, the above-described aluminum alloy foil can suppress unnecessary plastic deformation even when a compressive force is applied by rolling or the like at the time of manufacturing a thin member such as an electrode of an electric storage device, for example, . In addition, the aluminum alloy foil can secure good conductivity without significantly deteriorating the conductivity even by increasing the strength. Accordingly, when the aluminum alloy foil is used as a current collector of an electrode in a power storage device such as a lithium ion battery, the power storage device can contribute to higher density and higher energy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view for explaining a rough procedure for measuring the Si high capacity and the Fe high capacity in Examples; FIG.

The significance and limitations of a specific chemical component (unit: mass%, abbreviated simply as "%" in the description of chemical components below) in the aluminum alloy foil are as follows.

Si: 0.1% or more and 0.6% or less

Si is an element necessary for improving the peel strength. If the temperature of the aluminum alloy exceeds 350 캜 at the time of manufacturing the foil, the solidified Si and Fe tend to precipitate as Al-Fe-Si compounds, thereby reducing work hardening at the time of cold rolling, It is easy to deteriorate. For this reason, it is preferable to carry out hot rolling at 350 DEG C or less without performing homogenization treatment at a high temperature exceeding 350 DEG C during the manufacture of foil. In order to increase the foil strength under these conditions and to reduce the resistivity of foil to ensure conductivity, it is necessary to set the Si content to 0.1% or more and 0.6% or less. When the Si content is less than 0.1%, the resistivity of the foil is reduced. However, the strength of the foil is not improved. If the Si content exceeds 0.6%, it is difficult to further improve the thin strength, and coarse Si single-phase particles are formed, and pinholes or thin cuts tend to occur at a thickness of 20 탆 or less. The Si content is preferably 0.12% or more. The Si content is preferably 0.4% or less.

Fe: not less than 0.2% and not more than 1.5%

Fe is an element necessary for improving the strength of the beak followed by Si. If the temperature of the aluminum alloy exceeds 350 캜 at the time of manufacturing the foil, the solidified Si and Fe tend to precipitate as Al-Fe-Si compounds, thereby reducing work hardening at the time of cold rolling, It is easy to deteriorate. Therefore, it is preferable to carry out the hot rolling under the condition of 350 DEG C or less without performing the homogenization treatment at a high temperature exceeding 350 DEG C during the manufacture of the foil. In order to increase the foil strength under these conditions and to reduce the resistivity of foil to ensure conductivity, the Fe content should be 0.2% or more and 1.5% or less. When the Fe content is less than 0.2%, the specific resistance of the foil is reduced. However, the strength of the foil is not improved. When the Fe content exceeds 1.5%, it becomes difficult to further improve the thin strength, and a coarse Al-Fe-based crystallized product (crystallized product) is formed at the time of casting. As described above, when the aluminum alloy ingot is not homogenized at a high temperature exceeding 350 캜, the Al-Fe-based sintered product formed at the casting remains in its coarse state until the final thickness. As a result, problems such as pinholes and thinning tend to occur at a thickness of 20 탆 or less. In addition, the addition of Fe more than necessary may cause an increase in manufacturing cost. The Fe content is preferably 0.30% or more. The Fe content is preferably 1.2% or less, more preferably 1.0% or less, further preferably 0.80% or less.

Sum of Si content and Fe content: 0.48% or more

The sum of the Si content and the Fe content (hereinafter sometimes referred to as " Si + Fe amount ") is important in securing a tensile strength of 220 MPa or more. When the amount of Si + Fe is less than 0.48%, a tensile strength of 220 MPa or more is not obtained and it is difficult to achieve high strength. The amount of Si + Fe is preferably 0.49% or more, more preferably 0.5% or more, still more preferably 0.52% or more, from the viewpoint of easily securing a tensile strength of 220 MPa or more. The Si + Fe content may be 1.6% or less, preferably 1.4% or less, more preferably 1.2% or less, in consideration of the Si content and the upper limit of the Fe content.

The chemical component may further contain, by mass%, Cu: not less than 0.01% and not more than 0.25%. The significance and limitation reason for this case are as follows.

Cu: not less than 0.01% and not more than 0.25%

Cu is an element contributing to the improvement of the strength of foil. In order to obtain the effect, the Cu content is preferably 0.01% or more. In addition, Cu of less than 0.01% may be contained as an inevitable impurity. On the other hand, if the Cu content becomes excessive, the strength of the foil increases. However, the resistivity also increases. Therefore, the Cu content is preferably 0.25% or less. The Cu content is preferably 0.02% or more. The Cu content is preferably 0.18% or less.

The chemical component may contain elements such as Mn, Mg, Cr, Zn, Ni, Ga, V and Ti as inevitable impurities. However, when Mn and Mg are contained in excess, there is a fear that the specific resistance of the foil is increased and the conductivity is deteriorated. Therefore, it is preferable that the Mn content is 0.01% or less and the Mg content is 0.01% or less. Since other elements such as Cr, Zn, Ni, Ga, V, and Ti are relatively non-contributing elements to the resistivity increase, the content of each element is preferably 0.05% or less. The total content of the total inevitable impurities is 0.15% or less, which is acceptable since it does not substantially affect the conductivity or the strength of the high-strength impurity.

In the aluminum alloy foil, the thickness is 20 占 퐉 or less. If the thickness exceeds 20 占 퐉, it can not cope with the thinning of the foil (the thickness gauge down), which is often required recently. Since the aluminum alloy foil has a thickness of 20 占 퐉 or less, the aluminum alloy foil is particularly suitable for use as a current collector for a power storage device electrode where a thin foil is required. The thickness of the aluminum alloy foil is preferably less than 20 mu m, more preferably less than 19 mu m, even more preferably less than 18 mu m, further preferably not more than 20 mu m, More preferably 17 mu m or less. On the other hand, the thickness is preferably 8 占 퐉 or more, more preferably 9 占 퐉 or more, and still more preferably 10 占 퐉 or more from the viewpoints of ease of handling, etc., 10 mu m or more.

In the aluminum alloy foil, the solid content of Si is 700 mass ppm or more and the solid content of Fe is 150 mass ppm or more. When the high-Si content is less than 700 mass ppm and the high-iron content is less than 150 mass ppm, a high strength of 220 MPa or more can not be achieved. The solubility of Si is preferably 720 mass ppm or more, more preferably 740 mass ppm or more, further preferably 760 mass ppm or more from the viewpoint of ensuring the high strength. The higher the Si content, the better. However, the upper limit can be set to 1000 mass ppm or less from the viewpoint of the actual ancestor phase, cooling rate at the time of agglomeration, and the like. On the other hand, the solubility of Fe is preferably 170 mass ppm or more, more preferably 190 mass ppm or more, further preferably 200 mass ppm or more, from the viewpoint of ensuring high strength. The higher the amount of Fe is, the more preferable it is. However, the upper limit can be set to 500 mass ppm or less from the viewpoints of the actual ancological phase and the cooling rate of the rough sieve.

The high-Si content and the high-content Fe content can basically be measured by the following methods. That is, the Al-Fe-based compound and the Al-Fe-Si-based compound contained in the test piece taken from the aluminum alloy foil are obtained as a residue by using the thermal phenol dissolution extraction method. Then, Si and Fe are dissolved from the residue by the hot phenol dissolution extraction method and quantitatively analyzed by ICP (Inductively Coupled Plasma Atomic Emission Spectrometry) to determine the amount of precipitated Si and precipitated Fe as the compound. Further, by using the hydrochloric acid dissolution extraction method, Si single-phase particles contained in the test piece collected from the aluminum alloy foil are obtained as a residue. The residue obtained by the hydrochloric acid dissolution extraction method is dissolved and quantitatively analyzed by ICP to obtain the amount of precipitated Si precipitated as Si single phase particles. The sum of the amount of Si precipitate obtained by the thermal phenol solution extraction method and the amount of Si precipitate obtained by the hydrochloric acid dissolution extraction method is taken as the total amount of Si precipitated. The precipitation amount of Fe obtained by the thermal phenol dissolution extraction method is defined as the total precipitation amount of Fe. Then, the value obtained by subtracting the Si total deposition amount from the Si component analysis value of the aluminum alloy foil is taken as the Si high capacity. Further, the value obtained by subtracting the total precipitation amount of Fe from the Fe component analysis value of the aluminum alloy foil is set to a high Fe content.

In the aluminum alloy foil, the tensile strength is 220 MPa or more. When the tensile strength is less than 220 MPa, it can not be said to be the high strength mentioned in the present application. The tensile strength is preferably 223 MPa or more, more preferably 225 MPa or more, further preferably 230 MPa or more. The upper limit of the tensile strength can be determined in an optimum range in consideration of the balance with the resistivity and the like. The tensile strength can be, for example, about 340 MPa or less. The tensile strength is a value measured in accordance with JIS Z2241.

In the aluminum alloy foil, the resistivity is not less than 0.45 μΩ · cm and not more than 0.7 μΩ · cm. The resistivity is a value measured in liquid nitrogen. To measure the resistivity in liquid nitrogen is to remove the influence of the temperature of the measurement atmosphere.

The specific resistance is related to the amount of Si and Fe, which are alloying elements. When the resistivity is within the above range, the strength can be increased without seriously damaging the conductivity. When the resistivity is less than 0.45 mu OMEGA .cm, it is difficult to work harden during the manufacture of foil, and it becomes difficult to make the tensile strength 220 MPa or more. The resistivity may preferably be 0.50 占 cm, more preferably 0.55 占 cm. On the other hand, if the specific resistivity is high, the work hardens during the production of foil, and it is easy to increase the strength. However, there is a tendency that the conductivity is lowered. For this reason, it is preferable that the specific resistance is about 0.7 μΩ · cm, which is about 60% of the specific resistance of the 3003-series aluminum alloy foil to be a relatively high-strength aluminum alloy foil. The resistivity is preferably 0.69 占 占 m or less, and more preferably 0.68 占 占 m or less. On the other hand, the specific resistance can be measured by the double bridge method in accordance with JIS H0505.

The aluminum alloy foil can be used as a current collector for a power storage device electrode. In this case, the electrode active material is attached to the surface of the aluminum alloy foil as the current collector. Specifically, in this case, a layer containing an electrode active material is coated on the surface of the aluminum alloy foil, and a compressive force is applied by drying after drying. Even in such a case, the aluminum alloy foil hardly causes unnecessary plastic deformation due to the compressive force, so that the electrode active material is hardly peeled off, and furthermore, good conductivity can be secured. In addition, since the aluminum alloy foil has excellent thin strength, it is easy to cope with a demand for thinning of the foil. Therefore, in this case, it is possible to contribute to high-density and high-energy energy storage devices such as lithium ion batteries.

The aluminum alloy foil can be produced, for example, in the following manner. That is, the aluminum alloy foil can be obtained by subjecting an aluminum alloy ingot made of the specific chemical component to hot rolling, followed by cold rolling including a foil rolling.

At this time, the aluminum alloy ingot may be hot-rolled without homogenizing treatment at a high temperature exceeding 350 캜. The hot rolling is started after heating at a temperature of 350 DEG C or lower, and the temperatures at the start of hot rolling, during hot rolling, and at the end of hot rolling can all be set to 350 DEG C or less. The holding time after reaching the starting temperature of the hot rolling can be made within 12 hours from the standpoint of suppressing precipitation of the Al-Fe-Si compound. On the other hand, the hot rolling may be performed once, or may be divided into a plurality of steps such as finish rolling after rough rolling.

In the cold rolling, annealing is not performed on the way, and the thickness of the cold rolling is set to 20 占 퐉 or less. If the annealing is performed in the middle, precipitation of the Al-Fe-Si based compound is promoted, and the work hardening property in cold rolling is lowered, resulting in a decrease in the thin strength. The final annealing after completion of the cold rolling is preferably not carried out for the same reasons as annealing during the cold rolling. The final rolling rate in the cold rolling including the foil rolling is preferably 95% or more, more preferably 96% or more, and even more preferably 97% or more from the viewpoint of achieving a high strength of 220 MPa or more in tensile strength . The final rolling ratio is a value calculated from 100 占 (plate thickness of the hot rolled plate before cold rolling - thickness of the aluminum alloy foil after the final cold rolling) / (plate thickness of the hot rolled plate before cold rolling).

Example

The aluminum alloy foil according to the embodiment will be described below.

(Example 1)

An aluminum alloy ingot having the chemical components listed in Table 1 was subjected to semi-continuous casting and surface machining to prepare an aluminum alloy ingot. Of the aluminum alloys of the chemical components shown in Table 1, the alloys A to H are aluminum alloys of chemical compositions suitable for the examples, and the alloys I to O are aluminum alloys of chemical compositions as comparative examples.

The prepared aluminum alloy ingot was hot-rolled without homogenizing treatment to obtain a hot-rolled plate having a thickness of 2 mm. At this time, the hot rolling was roughly carried out by rough rolling and finish rolling. In the hot rolling, the aluminum alloy ingot before being subjected to rough rolling was heated to 330 캜 and held for 6 hours to set the starting temperature (hot rolling starting temperature) of the rough rolling to 330 캜. The end temperature (hot rolling temperature) of the rough rolling was 310 占 폚, and the finish temperature of the finish rolling (hot rolling end temperature) was 270 占 폚. As described above, in this example, not only the start temperature and the end temperature of the hot rolling, but also the finish temperature of the rough rolling, that is, the starting temperature of the finish rolling,

Subsequently, after the temperature was returned to room temperature, the cold rolling including the thin rolled steel was repeatedly carried out without annealing in the middle to obtain an aluminum alloy foil having a thickness of 12 탆. The final rolling ratio in the cold rolling was 100 占 (plate thickness of the hot rolled plate before cold rolling: 12 占 퐉) / (thickness of the aluminum alloy foil after final cold rolling) / (hot rolled plate before cold rolling) Plate thickness 2000 占 퐉) = 99.4%.

Next, tensile strength, proof stress and elongation, resistivity (electrical resistivity), Si high-density and Fe high-density were measured by using the obtained aluminum alloy foil as a test material. Specifically, the tensile strength, the proof stress and the stretching were measured in accordance with JIS Z2241 by taking the JIS No. 5 test piece from the test material and measuring n = 2. The specific resistance was measured by the double bridge method in accordance with JIS H0505. Further, in order to remove the influence of the atmospheric temperature, the measurement of the resistivity was carried out in liquid nitrogen.

The measurement of the Si high capacity and the Fe high capacity was carried out by the following procedure. Will be described with reference to Fig. Fig. 1 shows a method for analyzing the total amount of precipitated Si and the total amount of precipitated Fe in the aluminum alloy foil from the residue obtained by the hot phenol solution extraction method and the residue obtained by the hydrochloric acid dissolution extraction method. The method of analyzing the amount of precipitated Si and the amount of precipitated Fe is described in the article "Sato, Izumi: Lecture summary of the 68th Spring Meeting of the Japan Institute of Light Metals, (1985), 55.", Muramatsu, Matsuo, Komatsu et al. (1989), 51., which is incorporated herein by reference in its entirety.

First, the thermal phenol dissolution extraction method will be described. 2 g of the test piece was taken from the aluminum alloy foil (S10). The test piece was cut out from the aluminum alloy foil and weighed to give a total of 2 g. Subsequently, a beaker containing 50 ml of phenol was placed on a hot plate, the phenol was heated to 170 to 180 ° C, and the test pieces were melted (S11). Then, the beaker containing the solution was cooled down from the hot plate (S12). Subsequently, to prevent solidification, benzyl alcohol was added to the cooled solution (S13). Subsequently, the solution to which benzyl alcohol was added was filtered (S14) with a membrane filter (pore diameter 0.1 mu m) made of polytetrafluoroethylene, and an Al-Fe-based compound and an Al- (S15). Subsequently, Si was dissolved in the 10% NaOH solution from the residue obtained by this hot phenol dissolution extraction method, and then Fe was dissolved with aqua regia (concentrated hydrochloric acid: nitric acid = 3: 1 by volume ratio) Si, and Fe was obtained. Subsequently, this mixed solution was quantitatively analyzed by inductively coupled plasma emission spectrometry (ICP) (S16). As a result, the amount of precipitated Si and the amount of deposited Fe as the Al-Fe-based compound and the Al-Fe-Si-based compound were determined.

Next, the hydrochloric acid dissolution extraction method will be described. 2 g of the test piece was taken from the aluminum alloy foil (S20). The test pieces were sampled as described above. Subsequently, test pieces were put in a beaker containing 120 ml of HCl (volume ratio of concentrated hydrochloric acid: water = 1: 1), dissolved at room temperature, and further 2 to 3 drops of hydrogen peroxide H ₂ O ₂ were added (S21). Subsequently, the solution was filtered (S24) with a membrane filter (pore diameter 0.1 mu m) made of polytetrafluoroethylene, and Si single-phase particles were obtained as a residue (S25). Subsequently, the residue obtained by this hydrochloric acid dissolution extraction method was dissolved in a 10% -NaOH solution, and then the above-mentioned water was mixed and acidified to a pH of 1 to 2. This solution was then quantitatively analyzed by inductively coupled plasma emission spectrometry (ICP) (S26). As a result, the amount of Si precipitated as Si single-phase particles was determined.

Next, the sum of the amount of Si precipitate obtained by the thermal phenol melting extraction method and the amount of Si precipitate obtained by the hydrochloric acid dissolution extraction method was defined as the total amount of precipitated Si. The amount of Fe precipitation obtained by the thermal phenol solution extraction method was defined as the total precipitation amount of Fe. The value obtained by subtracting the total deposition amount of Si from the analysis value of Si component of the aluminum alloy foil was taken as the Si high capacity. Further, a value obtained by subtracting the total precipitation amount of Fe from the Fe component analysis value of the aluminum alloy foil was set to a high Fe content.

Further, in order to investigate the condition of the thin rolled state, the occurrence of pinholes was examined together with the light leakage by illuminating the back side of the test material. Table 2 shows the above results.

As shown in these results, the test piece C1 had a low tensile strength of less than 220 MPa because the alloy I having an Si + Fe content of 0.47% was used.

The test piece C2 is made of alloy J having an Si content of less than 0.1% and an Fe content of less than 0.2%, and has a Si content of less than 700 mass ppm and a Fe content of less than 150 mass ppm. As a result, the test material C2 had a tensile strength of less than 220 MPa.

As the test piece C3, since the alloy K having an Si content exceeding 0.6% was used, coarse Si single-phase particles were formed and pinholes were generated therefrom.

The test material C4 uses an alloy L having an Fe content of less than 0.2% and has a high iron content of less than 150 mass ppm. As a result, the test piece C3 had a tensile strength of less than 220 MPa.

As the test material C5, since the alloy M having an Fe content exceeding 1.5% was used, coarse Al-Fe-based particles were formed and pinholes were generated therefrom.

On the other hand, the test materials E1 to E8 are all made of the alloys A to H having the specific chemical composition described above, and have a thickness of 20 mu m or less, a high Si content of 700 mass ppm or more, a high Fe content of 150 mass ppm Or more, and the tensile strength is 220 MPa or more. The test materials E1 to E8 all have resistivities of 0.45 占 · m or more and 0.7 占 占 · m or less as measured in liquid nitrogen. From these results, it can be understood that the test materials E1 to E8 do not exhibit a significant decrease in conductivity even though the tensile strength is higher than 220 MPa.

Therefore, according to this example, it is possible to provide an aluminum alloy foil capable of achieving high strength without significantly deteriorating the conductivity. In addition, since the aluminum alloy foil has high strength even if it is thinned, problems such as pinholes and breaks can be avoided.

(Example 2)

The aluminum alloy A having the chemical composition shown in Table 1 was subjected to semi-continuous casting and was ground to prepare an aluminum alloy ingot. Further, a 1050 alloy (alloy N) and a 3003 alloy (alloy O) of the conventional alloy described in Table 1 were subjected to semi-continuous casting and ground to obtain a comparative aluminum alloy ingot.

Using the aluminum alloy ingot thus prepared, an aluminum alloy foil having a thickness of 12 占 퐉 was produced under the production conditions shown in Table 3. The cold rolling in Table 3 was started after returning to room temperature. The tensile strength, proof stress and elongation, resistivity (electric resistivity), Si high content and Fe high content were measured for the obtained aluminum alloy foil in the same manner as in Example 1, and the thin rolled state (presence or absence of pinholes) was examined. The results are shown in Table 4.

As shown in Table 4, in the test materials C6 to C8, since the starting temperature of the hot rolling at the time of hot rolling exceeds 350 deg. C, the formation of the Al-Fe-Si based compound is promoted, Was less than 700 mass ppm and the Fe solubility was less than 150 mass ppm and the tensile strength was as low as less than 220 MPa.

The test material C9 was produced by homogenizing at 520 DEG C before the start of the hot rolling. As a result, the test material C9 promoted the formation of the Al-Fe-Si compound, the Si high-dose amount was less than 700 mass ppm, the Fe high-dose amount was less than 150 mass ppm, and the tensile strength was as low as less than 220 MPa.

Test material C10 has a starting temperature of hot rolling of 340 占 폚. However, during the cold rolling, when the plate thickness is 1 mm, annealing is carried out at 380 ° C. As a result, the test material C10 promoted the formation of the Al-Fe-Si compound, the Si high-dose amount was less than 700 mass ppm, the Fe high-dose amount was less than 150 mass ppm, and the tensile strength was as low as less than 220 MPa.

The test materials C11 and C12 were produced by using a 1050 alloy (alloy N) and a 3003 alloy (alloy O), which are conventional alloys, and a homogenization treatment at a high temperature of 520 DEG C exceeding 350 DEG C before the start of hot rolling will be. The test material C11 had a chemical composition lower than 220 MPa because it was the same as the conventional alloy 1050 alloy (alloy N). The test material C12 had a resistivity of 1.2 μΩ · cm or more, which was too high, and the conductivity was inferior because the chemical component was the same as that of the conventional alloy 3003 (alloy O).

On the contrary, the test materials E9 and E10 are all made of alloy A having the above-mentioned specific chemical composition, and have a thickness of 20 mu m or less, a high Si content of 700 mass ppm or more, a high Fe content of 150 mass ppm or more, The tensile strength is 220 MPa or more. The test materials E9 and E10 have a specific resistance of 0.45 占 · m or more and 0.7 占 占 m or less as measured in liquid nitrogen. From these results, it can be seen that the test materials E9 and E10 do not exhibit a significant decrease in conductivity even though the tensile strength is higher than 220 MPa.

Therefore, according to this example, it is possible to provide an aluminum alloy foil capable of achieving high strength without significantly deteriorating the conductivity.

Although the embodiment has been described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of not damaging the gist of the present invention.

Claims (3)

The steel sheet according to any one of claims 1 to 3, wherein the chemical component contains Si: 0.1 to 0.6%, Fe: 0.2 to 1.5%, Si: 0.48% or more in total and Al and inevitable impurities Lt; / RTI &
The foil has a thickness of 20 mu m or less,
(Solid solution amount) of Si is 700 mass ppm or more, a high solubility of Fe is 150 mass ppm or more,
A tensile strength of 220 MPa or more,
Wherein a specific resistance measured in liquid nitrogen is 0.45 占 · m or more and 0.7 占 占 m or less. The aluminum alloy foil according to claim 1, wherein the chemical component further contains, by mass%, Cu: not less than 0.01% and not more than 0.25%. The aluminum alloy foil according to claim 1 or 2, wherein the aluminum alloy foil is for a current collector of the power storage device electrode.

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