Aluminum alloy material for aluminum foil blank and preparation method and application thereof

Abstract

The invention discloses an aluminum alloy material for aluminum foil blanks, a preparation method thereof and an application thereof. The chemical composition of the aluminum alloy material for aluminum foil blanks is, by mass percentage, Si≤0.25%, Fe≤0.35%, Cu≤0.2%, Zn≤0.1%, Ti≤0.05%, Sc 0.01-0.03% and Zr 0.04%-0.18%, and the remainder is aluminum and unavoidable impurities, and the impurity content is ≤0.15%. By adding a specific proportion of rare earth element Sc and chemical element Zr to the alloying components of 1235D aluminum alloy, the composite modification of 1235D aluminum alloy is achieved, the grain refinement effect of reducing the grain size is achieved, the iron-rich phase is modified, the morphology and size of the iron-rich phase are optimized, thereby optimizing the organizational structure of the aluminum alloy and improving its mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and in particular to an aluminum alloy material for aluminum foil blanks, a preparation method thereof and an application thereof. Background Art

[0002] Aluminum foil is a key component of consumer electronics, electric vehicles and large-scale energy storage systems, and its quality directly affects the performance and life of the product or energy storage system. However, during the rolling process of aluminum foil, a variety of defects may occur, including tearing, breakage, holes, inclusions and uneven thickness. These defects will seriously affect the performance and safety of the product or system. The above defects are mainly caused by the low strength of the aluminum alloy used in the aluminum foil blank, and the low strength of the alloy is its own mechanical property problem. Therefore, the defects such as tearing caused by low strength can be improved by improving the mechanical properties of the aluminum alloy.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] The object of the present invention is to provide an aluminum alloy material for aluminum foil blank and a preparation method and application thereof, so as to improve the above-mentioned technical problems.

[0005] The present invention is achieved in that:

[0006] In a first aspect, the present invention provides an aluminum alloy material for aluminum foil blanks, whose chemical composition, by mass percentage, is: Si≤0.25%, Fe≤0.35%, Cu≤0.2%, Zn≤0.1%, Ti≤0.05%, Sc 0.01~0.03% and Zr0.04%~0.18%, and the remainder is aluminum and unavoidable impurities, and the impurity content is ≤0.15%.

[0007] Optionally, its chemical composition, by mass percentage, is: Si≤0.1%, Fe 0.08~0.14%, Cu≤0.002%, Zn 0.003~0.008%, Ti 0.005~0.02%, Sc 0.015~0.025% and Zr 0.1%~0.18%, and the balance is aluminum and unavoidable impurities, and the impurity content is ≤0.15%.

[0008] In a second aspect, the present invention provides a method for preparing the aluminum alloy material for the aluminum foil blank, which comprises: according to the chemical composition of the aluminum alloy material for the aluminum foil blank, melting and casting corresponding proportions of 1235D aluminum alloy, Al-Sc master alloy and Al-Zr master alloy.

[0009] Optionally, the Al-Sc master alloy is an Al-2Sc alloy;

[0010] Optionally, the Al-Zr master alloy is an Al-5Zr alloy.

[0011] Optionally, the melting is performed using vacuum induction melting technology.

[0012] Optionally, before smelting, the vacuum induction furnace is evacuated to below 1000 Pa and then filled with inert gas;

[0013] Optionally, during melting, Al—Sc master alloy and Al—Zr alloy are placed in the middle of 1235D aluminum alloy.

[0014] Optionally, the smelting includes: heating the alloy raw material with an induction coil, raising the temperature to 780°C~800°C, keeping the temperature for 1~2 minutes, and then standing for 1min~3min.

[0015] Optionally, the alloy raw material is heated by an induction coil as follows: three stages of heating are performed in sequence using 4kW~6kW, 9kW~11kW and 14kW~16kW, wherein the time of the first stage of heating is controlled to be 1min~3min, the time of the second stage of heating is controlled to be 2min~4min, and the time of the third stage of heating is controlled to be 2min~4min.

[0016] Optionally, the temperature of the alloy solution during casting is controlled to be 750° C. to 760° C.;

[0017] Optionally, during casting, the temperature of the mold is controlled to be above 200°C.

[0018] In a third aspect, the present invention also provides the use of the above-mentioned aluminum alloy material for aluminum foil blank in the preparation of aluminum foil blank.

[0019] The present invention has the following beneficial effects: by adding a specific proportion of rare earth element Sc and chemical element Zr to the alloying components of 1235D aluminum alloy, composite modification of 1235D aluminum alloy is achieved, the grain refinement effect of reducing the grain size is achieved, the iron-rich phase is modified, the morphology and size of the iron-rich phase are optimized, thereby optimizing the organizational structure of the aluminum alloy and improving its mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1This is a SEM characterization result diagram of the grain size of the 1235D alloy that has not been modified in the present invention;

[0022] Figure 2 This is a SEM characterization result diagram of the grain size of the aluminum alloy material used for the aluminum foil blank prepared in Example 4 of the present invention;

[0023] Figure 3 This is a SEM characterization result diagram of the iron-rich phase morphology of the 1235D alloy that has not been modified in the present invention;

[0024] Figure 4 This is a SEM characterization result diagram of the iron-rich phase morphology of the aluminum alloy material for the aluminum foil blank prepared in Example 4 of the present invention;

[0025] Figure 5 is a stress-strain curve diagram of the 1235D alloy which has not been modified in the present invention;

[0026] Figure 6 This is a stress-strain curve diagram of the aluminum alloy material used for the aluminum foil blank prepared in Example 4 of the present invention.

[0027] in, Figure 5 , Figure 6 Lines 1, 2, and 3 in the two figures correspond to three samples with the same composition. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0029] The following is a detailed description of an aluminum alloy material for aluminum foil blank disclosed in the present invention, and a preparation method and application thereof.

[0030] The inventors have studied the aluminum alloys used in existing aluminum foil materials and found that the problem of low strength is closely related to the raw materials themselves and the added chemical components. For example, the coarse grains of the raw materials themselves will lead to a decrease in their strength, and there are also harmful phases rich in the raw materials. The Fe element is usually present in aluminum alloys as a harmful element. The morphology and size of the iron-rich phase in the aluminum alloy greatly limit the application range of the alloy, and cause certain difficulties in the production and application of the alloy. In addition, in general, with the increase of tensile strength, the elongation of aluminum alloy materials used for aluminum foil blanks tends to decrease. Therefore, how to improve the tensile strength (tear resistance) while also improving the elongation of the aluminum alloy (better aluminum foil processing performance) is a difficult problem that needs to be solved. In view of this, the inventors specially propose the following technical solutions.

[0031] Some embodiments of the present invention provide an aluminum alloy material for aluminum foil blank, whose chemical composition, by mass percentage, is: Si≤0.25%, Fe≤0.35%, Cu≤0.2%, Zn≤0.1%, Ti≤0.05%, Sc 0.01~0.03% and Zr 0.04%~0.18%, and the balance is aluminum and unavoidable impurities, and the impurity content is ≤0.15%.

[0032] The inventors have conducted extensive research and practice on the existing aluminum alloy materials for aluminum foil blanks, and have taken the commonly used aluminum alloy for aluminum foil - 1235D aluminum alloy as the modification object, and optimized the alloy structure to achieve both good tensile strength and elongation.

[0033] Rare earth elements (Re) are known as "industrial vitamins" and can be used as a stable and efficient modifier in the production of aluminum alloys. Among the many rare earth elements, the inventors specifically selected the rare earth element Sc, which can form Al3Sc with Al at high temperature. The substance has an L12 structure that is the same as the structure of α-Al. The mismatch between Al3Sc and α-Al is only 0.9%, which can be used as a good heterogeneous nucleation site, thereby increasing the number of aluminum alloy grains and refining the grain size. The melting point of Al3Sc is 1320°C, so once Al3Sc is formed, it can be used as a stable modifier. Therefore, the rare earth element Sc can replace some elements in the iron-rich phase in the aluminum alloy, thereby changing its growth mode and changing its morphology. However, the inventors found in the research process that although the addition of the rare earth element Sc can improve the tensile strength to a certain extent, the addition amount of Sc must be large to significantly improve the tensile strength, and the more Sc is added, the greater the decrease in its elongation, which will significantly affect the use of aluminum alloy materials for aluminum foil blanks as aluminum foil materials. Since Sc is expensive, how to reduce the use of Sc element as much as possible while making its elongation reach better processing requirements is a further problem faced by the inventors.

[0034] Based on this, the inventor further studied the composite modification by combining other elements with Sc to reduce the usage of Sc element, and at the same time make the modified aluminum alloy have both high strength and elongation. The inventor creatively found that by melting Sc and Zr in a specific ratio with 1235D aluminum alloy to prepare alloy, it can achieve both tensile strength and elongation, thereby improving the performance of 1235D aluminum alloy as aluminum foil material.

[0035] Furthermore, in order to further improve the overall performance of the aluminum alloy, in some embodiments, the chemical composition of the aluminum alloy is optimized, that is, calculated by mass percentage, its chemical composition is: calculated by mass percentage, its chemical composition is: Si≤0.1%, Fe 0.08~0.14%, Cu≤0.002%, Zn0.003~0.008%, Ti 0.005~0.02%, Sc 0.015~0.025% and Zr 0.1%~0.18%, the balance is aluminum and unavoidable impurities, and the impurity content is ≤0.15%.

[0036] Further, its chemical composition can be optimized as follows: in terms of mass percentage, its chemical composition is: Si≤0.06%, Fe0.08~0.12%, Cu≤0.002%, Zn0.002~0.005%, Ti0.005~0.01%, Sc 0.015~0.025% and Zr0.09%~0.18%, and the remainder is aluminum and unavoidable impurities, and the impurity content is ≤0.15%.

[0037] Some embodiments of the present invention also provide a method for preparing the aluminum alloy material for the aluminum foil blank, which comprises: according to the chemical composition of the aluminum alloy material for the aluminum foil blank, melting and casting 1235D aluminum alloy, Al-Sc master alloy and Al-Zr master alloy with corresponding proportions.

[0038] Specifically, in some embodiments, the method for preparing the aluminum alloy material for the aluminum foil blank comprises the following steps:

[0039] S1. Batching: 1235D aluminum alloy, Al-Sc master alloy and Al-Zr master alloy are weighed and batched according to the percentage of each element of the aluminum alloy material for the aluminum foil blank, and the burning loss of rare earth elements and chemical elements during the smelting process is appropriately considered.

[0040] Specifically, the Al-Sc master alloy is an Al-2Sc alloy; and the Al-Zr master alloy is an Al-5Zr alloy. It should be noted that in other embodiments, other suitable master alloys may also be selected.

[0041] In some implementations, oxides, oil stains and impurities on the surfaces of various raw material alloys are removed to reduce the impurity content of the final aluminum alloy, thereby ensuring the performance of the aluminum alloy.

[0042] S2. Melting: The raw materials are melted by vacuum induction melting technology.

[0043] The vacuum induction melting technology is used to avoid oxidation of the melt when it comes into contact with air at high temperature during the melting process, reducing the introduction of impurities, that is, it has the effect of removing hydrogen and impurities, thereby greatly improving the performance of the aluminum alloy.

[0044] Specifically, the raw materials to be smelted are placed in a smelting container and then in a vacuum induction furnace. The mold with a pouring container and a filter screen installed is also placed in the vacuum induction furnace and placed below the smelting container. After the furnace cover is closed, the vacuum induction furnace is first evacuated to below 1000Pa and then filled with inert gas for protection.

[0045] It should be noted that the inert gas here refers to a gas that does not react with the alloy components. For example, the inert gas is high-purity argon. The pouring container is a tool for placing the molten alloy into the mold and further facilitating pouring the alloy into the mold. For example, the pouring container can be a pouring cup.

[0046] Exemplarily, 1235D aluminum alloy, Al-2Sc alloy and Al-5Zr alloy are put into a crucible, and the mold with the pouring cup and filter installed is placed in a vacuum induction furnace, the furnace cover is closed, the vacuum is drawn to 700Pa, and high-purity argon gas is filled in for protection.

[0047] Among them, the Al-2Sc alloy and the Al-5Zr alloy are sandwiched between a large block of 1235D aluminum alloy to prevent the Al-2Sc alloy and the Al-5Zr alloy from sinking to the bottom or floating on the surface during the smelting process, thereby preventing serious element burning.

[0048] In some embodiments, before placing the mold with the installed gate container and filter into the vacuum induction furnace, preheating the mold and the gate container can avoid the thermal stress caused by the high-temperature alloy contacting the mold with a lower temperature, improve the fluidity of the alloy solution, and also avoid shrinkage pores in the alloy material caused by gas absorption on the mold surface, thereby improving the density and surface quality of the alloy. Exemplarily, the gate container is preheated to 600°C and the mold is preheated to 300°C. It should be noted that in the vacuum induction furnace, an induction coil is used to heat the raw materials in the smelting container, and the temperature of the mold and the gate container located below is continuously reduced during the smelting process.

[0049] Specifically, in some implementation methods, the smelted raw material is first heated to 780° C. to 800° C., kept warm for 1 to 2 minutes, and then allowed to stand for 1 to 3 minutes.

[0050] For reference, the specific operation of heating the alloy raw material with induction coil is: 4kW~6kW, 9kW~11kW and 14kW~16kW are used for three-stage heating in sequence, wherein the time of the first stage heating is controlled to be 1min~3min, the time of the second stage heating is controlled to be 2min~4min and the time of the third stage heating is controlled to be 2min~4min. Through multi-stage heating, heating with increasing heating power can avoid the situation that the heating rate is too fast, which may cause local overheating of the alloy raw material, uneven heating, etc., avoid thermal stress caused by excessive temperature difference, and thus avoid large burnout of Zr and rare earth element Sc, thereby improving the smelting quality and reducing the generation of inclusions in the alloy.

[0051] S3, casting: injecting the alloy solution after standing into the mold for forming.

[0052] Specifically, the temperature of the stationary aluminum alloy melt is measured by a thermocouple, and the casting temperature is 750°C~760°C; the stationary molten metal is then injected into a mold that has been pre-installed with a filter and preheated, cooled in an argon environment for 20 minutes, and then taken out and further cooled to room temperature in a natural environment.

[0053] Some embodiments of the present invention also provide the use of the above-mentioned aluminum alloy material for aluminum foil blanks in the preparation of aluminum foil blanks. Specifically, the aluminum alloy material for aluminum foil blanks is an ingot aluminum foil blank, which is subsequently subjected to processes such as homogenization heat treatment, hot rolling, cold rolling and annealing heat treatment to obtain a second-stage aluminum foil blank with a specific thickness.

[0054] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0055] The specific testing method for the aluminum alloy material used for the aluminum foil blank in the following embodiments and comparative examples is as follows: the composition test is performed using an X-ray fluorescence spectrometer (XRF); the mechanical properties are tensile tested using an Instron 5900 tensile testing machine in accordance with the national standard GB / T228.1-2021.

[0056] The 1235D aluminum alloy in the following embodiments and comparative examples was purchased from Inner Mongolia Liansheng New Energy Materials Co., Ltd., and its chemical composition was Si 0.032%, Fe 0.084%, Cu 0.002%, Mn 0.0025%, Mg 0.005%, Zn 0.007%, Ti0.0048%, and the remainder was aluminum and unavoidable impurities. The impurity content was ≤0.15%. The tensile strength obtained by the above-mentioned detection method was 47.32 MPa, and the elongation was 37.49%.

[0057] Example 1

[0058] This embodiment provides a method for preparing an aluminum alloy material for an aluminum foil blank, which comprises:

[0059] Step 1, according to the ratio of the mass percentage of rare earth element Sc and chemical element Zr of 1:3, that is, the mass percentage of rare earth element Sc is 0.02%, and the mass percentage of chemical element Zr is 0.06%, and considering the burning loss during the element smelting process, the 1235D aluminum alloy, Al-2Sc alloy, and Al-5Zr alloy are weighed and proportioned.

[0060] Step 2: Preparation before smelting: remove oxides, oil stains and impurities on the surface of the alloy, and preheat the mold to 300°C and the pouring cup to 600°C.

[0061] Step 3: Place 1235D aluminum alloy, Al-2Sc alloy and Al-5Zr alloy into a crucible (Al-2Sc alloy and Al-5Zr alloy are sandwiched between a large piece of 1235D aluminum alloy), and place the mold with the pouring cup and filter installed into a vacuum induction furnace. Cover the furnace, draw the vacuum to 700Pa, and fill with high-purity argon gas for protection.

[0062] Step 4, smelting: the alloy in the crucible is heated to 780℃-800℃ with a power of 5kW (2min)-10kW (3min)-15kW (3min) in sequence. During the heating process, the electromagnetic induction in the induction coil will continuously stir the molten aluminum alloy. After the alloy is completely melted, it is kept warm with 10kW, and then the molten aluminum is left to stand for 2 minutes.

[0063] Step 5: Temperature measurement: The temperature of the stationary rare earth aluminum alloy melt is measured using a thermocouple, and the casting temperature is 750°C.

[0064] Step 6, casting: inject the molten metal after standing into the mold which has been pre-installed with filter screen and pre-heated, cool it in argon environment for 20 minutes, and then take it out and further cool it to room temperature in natural environment.

[0065] The aluminum alloy material for aluminum foil blank obtained by the above preparation method is tested for its chemical composition, and its chemical composition is Si 0.0927%, Fe 0.132%, Cu 0.0015%, Zn 0.0076%, Ti 0.0189%, Sc 0.0187% and Zr 0.0484%, and the remainder is aluminum and inevitable impurities. It has both high strength and elongation. After testing, its tensile strength is 48.1MPa and its elongation is 25.6%. Compared with the unmodified 1235D alloy, the tensile strength is increased by 1.6% and the elongation is slightly decreased.

[0066] Example 2

[0067] This embodiment provides a method for preparing an aluminum alloy material for an aluminum foil blank, which comprises:

[0068] Step 1, according to the ratio of the mass percentage of rare earth element Sc and chemical element Zr of 1:5, that is, the mass percentage of rare earth element Sc is 0.02%, the mass percentage of chemical element Zr is 0.1%, and considering the burning loss during the smelting process of the elements, the 1235D aluminum alloy, Al-2Sc alloy, and Al-5Zr alloy are weighed and proportioned.

[0069] Step 2: Preparation before smelting: remove oxides, oil stains and impurities on the surface of the alloy, and preheat the mold to 300°C and the pouring cup to 600°C.

[0070] Step 3: Place 1235D aluminum alloy, Al-2Sc alloy and Al-5Zr alloy into a crucible (Al-2Sc alloy and Al-5Zr alloy are sandwiched between a large piece of 1235D aluminum alloy), and place the mold with the pouring cup and filter installed into a vacuum induction furnace. Cover the furnace, draw the vacuum to 700Pa, and fill with high-purity argon gas for protection.

[0071] Step 4, smelting: the alloy in the crucible is heated to 780℃-800℃ with a power of 5kW (2min)-10kW (3min)-15kW (3min) in sequence. During the heating process, the electromagnetic induction in the induction coil will continuously stir the molten aluminum alloy. After the alloy is completely melted, it is kept warm with 10kW, and then the molten aluminum is left to stand for 2 minutes.

[0072] Step 5, temperature measurement: the temperature of the static rare earth aluminum alloy melt is measured by a thermocouple, and the casting temperature is 758°C.

[0073] Step 6, casting: inject the molten metal after standing into the mold which has been pre-installed with a filter and preheated, cool it in an argon environment for 20 minutes, and then take it out and further cool it to room temperature in a natural environment.

[0074] The aluminum alloy material for aluminum foil blank obtained by the above preparation method is subjected to component detection, and its chemical composition is Si 0.0546%, Fe 0.0889%, Cu 0.0014%, Zn 0.003%, Ti 0.0093%, Sc 0.0192% and Zr 0.0912%, and the remainder is aluminum and inevitable impurities. It has both high strength and elongation. After testing, its tensile strength is 48.97MPa and its elongation is 26.57%. Compared with the unmodified 1235D alloy, the tensile strength is increased by 3.4%, and the elongation is improved compared with Example 1.

[0075] Example 3

[0076] This embodiment provides a method for preparing an aluminum alloy material for an aluminum foil blank, which comprises:

[0077] Step 1, according to the ratio of the mass percentage of rare earth element Sc and chemical element Zr of 1:7, that is, the mass percentage of rare earth element Sc is 0.02%, and the mass percentage of chemical element Zr is 0.14%, and considering the burning loss during the element smelting process, the 1235D aluminum alloy, Al-2Sc alloy, and Al-5Zr alloy are weighed and proportioned.

[0078] Step 2: Preparation before smelting: remove oxides, oil stains and impurities on the surface of the alloy, and preheat the mold to 300°C and the pouring cup to 600°C.

[0079] Step 3: Place 1235D aluminum alloy, Al-2Sc alloy and Al-5Zr alloy into a crucible (Al-2Sc alloy and Al-5Zr alloy are sandwiched between a large piece of 1235D aluminum alloy), and place the mold with the pouring cup and filter installed into a vacuum induction furnace. Cover the furnace, draw the vacuum to 700Pa, and fill with high-purity argon gas for protection.

[0080] Step 4, smelting: the alloy in the crucible is heated to 780℃-800℃ with a power of 5kW (2min)-10kW (3min)-15kW (3min) in sequence. During the heating process, the electromagnetic induction in the induction coil will continuously stir the molten aluminum alloy. After the alloy is completely melted, it is kept warm with 10kW, and then the molten aluminum is left to stand for 2 minutes.

[0081] Step 5, temperature measurement: the temperature of the static rare earth aluminum alloy melt is measured by a thermocouple, and the casting temperature is 751°C.

[0082] Step 6, casting: inject the molten metal after standing into the mold which has been pre-installed with a filter and preheated, cool it in an argon environment for 20 minutes, and then take it out and further cool it to room temperature in a natural environment.

[0083] The aluminum alloy material for aluminum foil blank obtained by the above preparation method is subjected to component detection, and its chemical composition is Si 0.0554%, Fe 0.104%, Zn 0.0028%, Ti 0.0064%, Sc 0.0194 and Zr 0.126, and the remainder is aluminum and inevitable impurities. It has both high strength and elongation. After testing, its tensile strength is 48.97MPa and its elongation is 26.57%. Compared with the unmodified 1235D alloy, the tensile strength is increased by 3.4%, and the elongation is improved compared with Example 1.

[0084] Example 4

[0085] This embodiment provides a method for preparing an aluminum alloy material for an aluminum foil blank, which comprises:

[0086] Step 1, according to the ratio of the mass percentage of rare earth element Sc and chemical element Zr of 1:9, that is, the mass percentage of rare earth element Sc is 0.02%, and the mass percentage of chemical element Zr is 0.18%, and considering the burning loss during the element smelting process, the 1235D aluminum alloy, Al-2Sc alloy, and Al-5Zr alloy are weighed and proportioned.

[0087] Step 2: Preparation before smelting: remove oxides, oil stains and impurities on the surface of the alloy, and preheat the mold to 300°C and the pouring cup to 600°C.

[0088] Step 3: Place 1235D aluminum alloy, Al-2Sc alloy and Al-5Zr alloy into a crucible (Al-2Sc alloy and Al-5Zr alloy are sandwiched between a large piece of 1235D aluminum alloy), and place the mold with the pouring cup and filter installed into a vacuum induction furnace. Cover the furnace, draw the vacuum to 700Pa, and fill with high-purity argon gas for protection.

[0089] Step 4, smelting: the alloy in the crucible is heated to 780℃-800℃ with a power of 5kW (2min)-10kW (3min)-15kW (3min) in sequence. During the heating process, the electromagnetic induction in the induction coil will continuously stir the molten aluminum alloy. After the alloy is completely melted, it is kept warm with 10kW, and then the molten aluminum is left to stand for 2 minutes.

[0090] Step 5, temperature measurement: the temperature of the static rare earth aluminum alloy melt is measured by a thermocouple, and the casting temperature is 753°C.

[0091] Step 6, casting: inject the molten metal after standing into the mold which has been pre-installed with filter screen and pre-heated, cool it in argon environment for 20 minutes, and then take it out and further cool it to room temperature in natural environment.

[0092] The aluminum alloy material for aluminum foil blank obtained by the above preparation method is subjected to component detection, and its chemical composition is Fe 0.0115%, Cu 0.0017%, Zn 0.0041%, Ti 0.0098%, Sc 0.0188% and Zr0.168%, and the remainder is aluminum and inevitable impurities. It has both high strength and elongation. After testing, its tensile strength is 51.35MPa and its elongation is 31.28%. Compared with the unmodified 1235D alloy, the tensile strength is increased by 8.5%, and the elongation is improved compared with Example 3.

[0093] Comparative Example 1

[0094] The only difference between this comparative example and Example 1 is that in step 1, only 1235D aluminum alloy and Al-2Sc alloy with a mass percentage content of Sc element of 0.2% are prepared, and in step 3, the 1235D aluminum alloy and Al-2Sc alloy are put into a crucible (the Al-2Sc alloy is sandwiched between a large piece of 1235D aluminum alloy).

[0095] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 74.73 MPa and an elongation of 20.41% after testing.

[0096] Comparative Example 2

[0097] The only difference between this comparative example and Example 1 is that in step 1, only 1235D aluminum alloy and Al-2Sc alloy with a mass percentage content of 0.3% of Sc element are prepared, and in step 3, the 1235D aluminum alloy and Al-2Sc alloy are put into a crucible (the Al-2Sc alloy is sandwiched between a large piece of 1235D aluminum alloy).

[0098] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 82.96 MPa and an elongation of 18.85% after testing.

[0099] Comparative Example 3

[0100] The only difference between this comparative example and Example 1 is that in step 1, only Er element with a mass percentage content of 0.05% is added to the 1235D aluminum alloy.

[0101] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 44.32 MPa and an elongation of 13.28% after testing.

[0102] Comparative Example 4

[0103] The only difference between this comparative example and Example 1 is that in step 1, only Er element with a mass percentage content of 0.1% is added to the 1235D aluminum alloy.

[0104] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 40.17 MPa and an elongation of 19.49% after testing.

[0105] Comparative Example 5

[0106] The only difference between this comparative example and Example 1 is that in step 1, only 0.05% by mass of Ce element is added to 1235D aluminum alloy.

[0107] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 40.96 MPa and an elongation of 11.05% after testing.

[0108] Comparative Example 6

[0109] The only difference between this comparative example and Example 1 is that in step 1, only 0.1% by mass of Ce element is added to 1235D aluminum alloy.

[0110] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 43.92 MPa and an elongation of 21.2% after testing.

[0111] Comparative Example 7

[0112] The only difference between this comparative example and Example 1 is that in step 1, the Al-5Zr alloy and the 1235D aluminum alloy are mixed according to the mass percentage content of the Zr element of 0.05%.

[0113] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 46.33 MPa and an elongation of 18.0% after testing.

[0114] Comparative Example 8

[0115] The only difference between this comparative example and Example 1 is that in step 1, the Al-5Zr alloy and the 1235D aluminum alloy are mixed according to the mass percentage content of the Zr element of 0.1%.

[0116] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 54.03 MPa and an elongation of 20.72% after testing.

[0117] Comparative Example 9

[0118] The only difference between this comparative example and Example 1 is that in step 1, the Al-5Zr alloy and the 1235D aluminum alloy are mixed according to the mass percentage content of the Zr element of 0.15%.

[0119] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 50.73 MPa and an elongation of 25.45% after testing.

[0120] Comparative Example 10

[0121] The only difference between this comparative example and Example 1 is that in step 1, the Al-5Zr alloy and the 1235D aluminum alloy are mixed according to the mass percentage content of the Zr element of 0.20%.

[0122] The aluminum alloy material for aluminum foil blank obtained by the above preparation method has a tensile strength of 50.92 MPa and an elongation of 23.62% after testing.

[0123] The purchased 1235D aluminum alloy and the aluminum foil blank obtained in the embodiment were subjected to microstructure testing using aluminum alloy materials. The results are as follows: Figure 1-Figure 4 As shown, from Figure 1 and Figure 2 It can be seen that the grain state of the unmodified 1235D alloy is mainly in a coarse state, while the grain state of the modified 1235D alloy is mainly in a fine state after being strengthened by fine grains. Figure 3 and Figure 4 It can be seen that the unmodified 1235D alloy is composed of long strips, needles and granules of iron-rich phases, which are large in size and unevenly distributed. The microstructure of the modified 1235D alloy is mainly composed of granules and a small amount of short rods of iron-rich phases, and the phases are small in size and evenly distributed.

[0124] In summary, the embodiments of the present invention innovatively utilize the rare earth element Sc and the chemical element Zr to reduce the grain size in the aluminum alloy to achieve grain refining effect, which has a metamorphic effect on the iron-rich phase, optimizes the morphology and size of the iron-rich phase, thereby optimizing the organizational structure of the aluminum alloy and improving its mechanical properties.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An aluminum alloy material for aluminum foil blank, characterized in that: The aluminum alloy material for the aluminum foil blank is an ingot aluminum foil blank, and its chemical composition, by mass percentage, is: Si≤0.1%, Fe 0.08~0.14%, Cu≤0.002%, Zn 0.003~0.008%, Ti 0.005~0.02%, Sc 0.015~0.025% and Zr 0.1%~0.18%, and the balance is aluminum and unavoidable impurities, and the impurity content is ≤0.15%.

2. A method for preparing an aluminum alloy material for aluminum foil blank according to claim 1, characterized in that: It includes: According to the chemical composition of the aluminum alloy material for the aluminum foil blank, 1235D aluminum alloy, Al-Sc master alloy and Al-Zr master alloy with corresponding proportions are melted and cast.

3. The method for preparing the aluminum alloy material for aluminum foil blank according to claim 2, characterized in that: The Al-Sc master alloy is an Al-2Sc alloy; And / or, the Al-Zr master alloy is Al-5Zr alloy.

4. The method for preparing the aluminum alloy material for aluminum foil blank according to claim 2 or 3, characterized in that: The melting is carried out by vacuum induction melting technology.

5. The method for preparing the aluminum alloy material for aluminum foil blank according to claim 4, characterized in that: Before smelting, the vacuum induction furnace is evacuated to below 1000Pa and then filled with inert gas; And / or, during smelting, the Al-Sc master alloy and the Al-Zr master alloy are placed in the middle of the 1235D aluminum alloy.

6. The method for preparing the aluminum alloy material for aluminum foil blank according to claim 4, characterized in that: The smelting comprises: heating the alloy raw material by using an induction coil, raising the temperature to 780° C. to 800° C., keeping the temperature for 1 to 2 minutes, and then standing for 1 to 3 minutes.

7. The method for preparing the aluminum alloy material for aluminum foil blank according to claim 5, characterized in that: The alloy raw material is heated by an induction coil as follows: three stages of heating are performed in sequence using 4kW~6kW, 9kW~11kW and 14kW~16kW, wherein the time of the first stage of heating is controlled to be 1min~3min, the time of the second stage of heating is controlled to be 2min~4min, and the time of the third stage of heating is controlled to be 2min~4min.

8. The method for preparing the aluminum alloy material for aluminum foil blank according to claim 2, characterized in that: The temperature of the alloy solution during casting is controlled at 750℃~760℃; And / or, during casting, the temperature of the mold is controlled to be above 200°C.

9. Use of the aluminum alloy material for aluminum foil blank as claimed in claim 1 in preparing aluminum foil blank.

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