An ultrathin, highly conductive aluminum foil and its preparation method

Abstract

The present application relates to the technical field of aluminum foil preparation, and particularly relates to an ultrathin high-conductivity aluminum foil and a preparation method thereof. The composition of the aluminum foil comprises antimony, barium, iron and limited silicon elements, the rest being aluminum and impurities. The antimony element enrichment zone is distributed on the cross section of the matrix at intervals. The content of antimony in the enrichment zone is significantly higher than that of the matrix, forming a micro-conductive network arranged in a direction. The preparation method comprises the following steps: alloy smelting and purification, deep undercooling continuous casting for refining grains, multi-section temperature control hot rolling for optimizing the structure, pulse current assisted cold rolling for inducing selective migration and enrichment of antimony atoms along the dislocation wall, electromagnetic field constrained annealing for realizing directional arrangement of the enrichment zone, and ultrathin finish rolling. The method breaks through the balance contradiction between the conductivity and mechanical properties of the traditional aluminum foil by synergistically regulating the element distribution and microstructure, and simultaneously improves the electrical conductivity, tensile strength and ductility in the ultrathin state.

Description

Technical Field

[0001] This invention relates to the field of aluminum foil preparation technology, specifically to an ultrathin, highly conductive aluminum foil and its preparation method. Background Technology

[0002] Aluminum foil, as a fundamental functional metallic material, is widely used in electronic components, current collectors for new energy batteries, and other fields. Ultra-thin, highly conductive aluminum foil, typically in the micrometer range, is a high-end material that maintains its ultra-thin characteristics while possessing excellent conductivity, making it crucial for the miniaturization and high efficiency of electronic devices. However, existing ultra-thin aluminum foil manufacturing technologies have long faced the following key challenges:

[0003] Traditional aluminum foil requires controlling the total amount of alloying elements to improve conductivity, but too low an alloy content weakens the material's strength; conversely, adding strengthening elements leads to a decrease in conductivity. This contradiction in composition design is particularly pronounced in ultra-thin applications. The uniform element distribution formed by conventional processes results in intrinsic scattering effects in electron transport paths. The lack of directional control over the spatial distribution of specific elements makes it difficult to construct a low-resistance micro-conductive network. Existing cold rolling and annealing processes primarily focus on macroscopic deformation control, failing to simultaneously achieve atomic-scale selective migration and directional arrangement of enriched structures during ultra-thinning. This leads to a dual problem of decreased conductivity and reduced ductility during material thinning.

[0004] The aforementioned technical problems have resulted in a persistent performance inversion in traditional ultrathin aluminum foils: increased conductivity leads to decreased strength, and strengthening results in decreased conductivity, severely restricting their application in high-end electronic devices. Therefore, there is an urgent need to develop ultrathin, highly conductive aluminum foils and their preparation methods that address these issues. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides an ultrathin, highly conductive aluminum foil, the composition of which, by mass percentage, contains Sb: 0.1-0.3%; Ba: 0.03-0.06%; Fe: 0.3-0.6%; Si≤0.25%; the remainder being Al and impurities; the aluminum foil includes a substrate, and Sb enrichment bands are spaced apart on the cross-section of the substrate, the Sb content in the Sb enrichment bands being 1.5-2 times the Sb content in the substrate.

[0006] This invention also provides a method for preparing ultrathin, highly conductive aluminum foil, comprising the following steps:

[0007] S1: Alloy smelting and purification; High-purity aluminum ingots are smelted, Al-5Sb and Al-3Ba master alloys are added and purified;

[0008] S2: Deep supercooled continuous casting; the purified melt is injected into a water-cooled copper mold, and the cooling rate and supercooling are controlled to achieve rapid solidification and refine the grain structure.

[0009] S3: Multi-stage temperature-controlled hot rolling; After heat preservation treatment of the ingot, hot rolling is carried out in stages. The first stage uses a higher temperature and thinning rate for rough rolling, and the last stage uses a lower temperature and thinning rate for finish rolling to optimize the microstructure and mechanical properties of the plate.

[0010] S4: Pulsed current assisted cold rolling; a parallel dislocation wall structure is formed through multi-pass cold rolling, and an intermittent pulsed current is applied to promote the migration of antimony atoms along the dislocation walls, thereby achieving selective enrichment of Sb;

[0011] S5: Enriched band directional control annealing; annealing is performed under electromagnetic field constraint, controlling the temperature gradient and time to directionally align the Sb enriched bands and strengthen the conductive structure;

[0012] S6: Ultra-thin foil rolling and finishing, the strip is rolled to a thickness of 8-12μm and then surface finished to obtain ultra-thin high-conductivity aluminum foil.

[0013] Further, the specific steps of S1 are as follows: heating high-purity aluminum ingots to a molten state in a melting furnace, adding Al-5Sb master alloy to provide antimony and Al-3Ba master alloy to provide barium; when the melt temperature stabilizes at 710-730℃, adding refining agent, and continuously purifying for 20-30 minutes using rotary argon injection to remove oxides and gas inclusions; after purification, letting stand for 5-10 minutes to homogenize the melt.

[0014] Furthermore, the specific steps of S2 are as follows: the molten material is rapidly injected into a water-cooled copper mold, and deep supercooling solidification is achieved by controlling the cooling rate; the cooling rate... Controlled by the following formula:

[0015]

[0016] in, The cooling rate at the solidification front; The solidification coefficient is taken as 0.15-0.25; The melt undercooling is controlled at 80-100°C. During operation, the undercooling is monitored and the water cooling intensity is adjusted in real time to ensure that the solidification process is completed within 10-15 seconds.

[0017] Furthermore, the specific steps of S3 are as follows: the ingot is held at 480-520°C for 2 hours before hot rolling; a segmented temperature control strategy is adopted.

[0018] First stage thinning rate Rolling temperature It can be completed in 3-5 sessions;

[0019] End-stage thinning rate Rolling temperature It can be completed in 2-4 passes;

[0020] True response Calculated using the following formula:

[0021]

[0022] in, To be truly adaptable; The total deformation should be controlled within the range of 0.60-0.80. During operation, the temperature should be measured and the roll gap adjusted after each pass to ensure uniform structure.

[0023] Furthermore, the specific steps of S4 are as follows: First, a parallel dislocation wall structure is formed through multiple cold rolling passes, controlling the total deformation. Dislocation wall spacing in the range of 0.60-0.80 It is regulated by the following formula:

[0024]

[0025] in, This refers to the spacing between dislocation walls; during operation, the deformation amount is adjusted according to the target spacing.

[0026] Secondly, apply intermittent pulse current, pulse current density Calculated using the following formula:

[0027]

[0028] in, The pulse current density; This refers to the antimony content in the matrix as a percentage by mass. This is the current thickness of the strip; For rolling speed; pulse parameters include pulse width. ,frequency The on / off ratio is 1:3; during operation, current is applied in 3-5 passes, and the cumulative pulse time for each pass is calculated. Based on calculations using pulse width, frequency, and rolling length, antimony atoms are ensured to migrate at a velocity of 1.0–1.2 μm / ms, forming an enrichment band width. and spacing .

[0029] Furthermore, the specific process of S5 is as follows: electromagnetic field-constrained annealing, magnetic field gradient... Controlled by the following formula:

[0030]

[0031] in, For magnetic field gradient; As a regulatory factor, a value of 5-8 is preferred; The melting point of the alloy; This refers to the annealing temperature. The activation energy for antimony diffusion is set at 80-85. It is the gas constant;

[0032] During operation, the annealing temperature is set to 240-280°C, and the holding time is [not specified]. With strip thickness satisfy The enrichment bands are oriented and arranged by electromagnetic field confinement.

[0033] Furthermore, the specific process of S6 is as follows: rolling the strip to a thickness of 8-12μm, with a rolling force of... Controlled by the following formula:

[0034]

[0035] in, For rolling force; The deformation resistance coefficient is taken as 0.8-1.2; The yield strength of the material; For bandwidth; Reduce the amount of material used per pass; The radius of the roll;

[0036] During operation, the rolling process is carried out in multiple passes, with the thinning amount controlled at 1-2μm per pass. After rolling, the surface is cleaned and the roll is wound up.

[0037] The beneficial effects achieved by this invention are as follows:

[0038] This invention designs a series of banded regions on the substrate cross-section with significantly higher antimony concentrations than the substrate itself, forming a microscopic compositional difference distribution. The directionally arranged antimony-rich bands construct efficient electron transport paths within the substrate, significantly reducing resistance loss and thus greatly improving the conductivity of the foil. Simultaneously, this microstructure design avoids loss of overall material ductility while ensuring conductivity. Furthermore, the strengthening effect of elements such as barium and iron enhances the tensile strength of the aluminum foil. The periodically enriched bands form an efficient electron conduction network within the substrate, significantly reducing resistance loss. Meanwhile, the substrate region maintains good ductility, while the addition of barium and iron further strengthens the material's strength. This allows the material to possess excellent conductivity while maintaining sufficient mechanical integrity and processing performance in an ultra-thin state, resolving the common performance contradictions of ultra-thin materials. This enables aluminum foil products to maintain ultra-thin characteristics while significantly improving conductivity, tensile strength, and elongation simultaneously, making it particularly suitable for advanced electronic devices with stringent requirements for thickness and electrical performance.

[0039] This invention designs key processes for pulsed current-assisted cold rolling and electromagnetic field-confined annealing. In the cold rolling stage, a specific parallel dislocation wall structure is formed by precisely controlling the deformation amount, and intermittent pulsed current is applied simultaneously to induce antimony atoms to selectively migrate and accumulate along dislocation channels, forming a banded region with a significantly higher antimony concentration than the matrix at the microscale. The subsequent annealing process uses an electromagnetic field of specific intensity and gradient for confinement, ensuring that these enriched bands can be oriented and structurally strengthened according to design requirements. Starting from obtaining ultrafine grains through deep supercooling rapid solidification, the microstructure and properties are optimized through segmented temperature-controlled hot rolling, combined with pulsed current-assisted cold rolling to induce selective atomic migration, and finally, electromagnetic confinement annealing is used to achieve the coupling of parameters in each stage of the oriented arrangement of enriched bands. Through the interaction of pulsed current and parallel dislocation wall structure, and the precise guidance of diffusion path by electromagnetic field, the controllable preparation of microstructure is ensured. Attached Figure Description

[0040] Figure 1 This is a microstructure diagram of an ultrathin, highly conductive aluminum foil prepared in Example 1 of the present invention;

[0041] Figure 2 This is a flowchart of the preparation method of the ultrathin highly conductive aluminum foil of the present invention. Detailed Implementation

[0042] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Reference Figure 1 This invention designs an ultrathin, highly conductive aluminum foil, the composition of which, by mass percentage, comprises:

[0044] Sb: 0.1-0.3%; Ba: 0.03-0.06%; Fe: 0.3-0.6%; Si≤0.25%; the remainder is Al and impurities;

[0045] The aluminum foil includes a substrate, and Sb enrichment bands are spaced apart on the cross-section of the substrate. The Sb content in the Sb enrichment bands is 1.5-2 times the Sb content in the substrate. Preferably, the Sb enrichment bands have the following characteristics: width w = 1-3 μm and spacing λ = 5-10 μm.

[0046] Example 1: In this example, the chemical composition of the ultra-thin high-conductivity aluminum foil, by mass percentage, includes antimony (Sb): 0.1-0.3%, barium (Ba): 0.03-0.06%, iron (Fe): 0.3-0.6%, and a silicon content limited to ≤0.25% (Si). The remainder is aluminum and trace impurities. Periodic antimony enrichment bands are uniformly distributed on the cross-section of the aluminum foil substrate. The antimony content in these enrichment bands is 1.5-2 times that of the substrate antimony content, and the width of the enrichment bands is controlled within the range of 1-3 μm. Figure 1 The spacing is 2μm, and the pitch is controlled within the range of 5-10μm. Figure 1 With a thickness of 8μm, this unique microstructure is oriented and aligned through pulsed current-assisted cold rolling and electromagnetic field-confined annealing processes, resulting in an aluminum foil thickness of 8-12μm. Figure 1 It features an ultra-thin profile of 5μm while also exhibiting significantly improved conductivity.

[0047] Reference Figure 2 This invention provides a method for preparing ultrathin, highly conductive aluminum foil, comprising the following steps:

[0048] S1: Alloy smelting and purification; high-purity aluminum ingots are smelted, Al-5Sb and Al-3Ba master alloys are added and purified; Al-5Sb master alloy represents an aluminum-based alloy containing 5% antimony, and Al-3Ba master alloy represents an aluminum-based alloy containing 3% barium. Both are used to precisely add trace amounts of antimony and barium elements to the aluminum melt during the smelting process.

[0049] S2: Deep supercooled continuous casting; the purified melt is injected into a water-cooled copper mold, and the cooling rate and supercooling are controlled to achieve rapid solidification and refine the grain structure.

[0050] S3: Multi-stage temperature-controlled hot rolling; After heat preservation treatment of the ingot, hot rolling is carried out in stages. The first stage uses a higher temperature and thinning rate for rough rolling, and the last stage uses a lower temperature and thinning rate for finish rolling to optimize the microstructure and mechanical properties of the plate.

[0051] S4: Pulsed current assisted cold rolling; a parallel dislocation wall structure is formed through multi-pass cold rolling, and an intermittent pulsed current is applied to promote the migration of antimony atoms along the dislocation walls, thereby achieving selective enrichment of Sb;

[0052] S5: Enriched band directional control annealing; annealing is performed under electromagnetic field constraint, controlling the temperature gradient and time to directionally align the Sb enriched bands and strengthen the conductive structure;

[0053] S6: Ultra-thin foil rolling and finishing, the strip is rolled to a thickness of 8-12μm and then surface finished to obtain ultra-thin high-conductivity aluminum foil.

[0054] The specific steps of S1 are as follows:

[0055] High-purity aluminum ingots are heated to a molten state in a melting furnace. Al-5Sb master alloy is added to provide antimony, and Al-3Ba master alloy is added to provide barium. When the melt temperature stabilizes at 710-730℃, a refining agent is added, and argon gas is continuously injected in a rotary jet for 20-30 minutes to remove oxides and gas inclusions. After purification, the melt is allowed to stand for 5-10 minutes to homogenize it.

[0056] The specific steps of S2 are as follows:

[0057] The molten metal is rapidly injected into a water-cooled copper mold, and deep supercooling solidification is achieved by controlling the cooling rate; cooling rate Controlled by the following formula:

[0058]

[0059] in, The solidification front cooling rate is °C / s; The solidification coefficient is taken as 0.15-0.25; The melt undercooling should be controlled at 80-100°C. During operation, the undercooling should be monitored and the water cooling intensity should be adjusted in real time to ensure that the solidification process is completed within 10-15 seconds.

[0060] The specific steps for S3 are as follows:

[0061] The ingot is held at 480-520°C for 2 hours before hot rolling; a segmented temperature control strategy is adopted.

[0062] First stage thinning rate Rolling temperature It can be completed in 3-5 sessions;

[0063] End-stage thinning rate Rolling temperature It can be completed in 2-4 passes;

[0064] True response Calculated using the following formula:

[0065]

[0066] in, To be truly adaptable; The total deformation should be controlled within the range of 0.60-0.80. During operation, the temperature should be measured and the roll gap adjusted after each pass to ensure uniform structure.

[0067] The specific steps of S4 are as follows:

[0068] First, a parallel dislocation wall structure is formed through multiple cold rolling processes to control the total deformation. Dislocation wall spacing in the range of 0.60-0.80 It is regulated by the following formula:

[0069]

[0070] in, The dislocation wall spacing is in μm; during operation, the deformation is adjusted according to the target spacing. hour , hour .

[0071] Secondly, apply intermittent pulse current, pulse current density Calculated using the following formula:

[0072]

[0073] in, The pulse current density is A / mm². The antimony content in the matrix is ​​0.10-0.30% by mass. The current thickness of the strip is in mm; The rolling speed is m / min; pulse parameters include pulse width. ,frequency The on / off ratio is 1:3; during operation, current is applied in 3-5 passes, and the cumulative pulse time for each pass is calculated. Based on calculations using pulse width, frequency, and rolling length, antimony atoms are ensured to migrate at a velocity of 1.0–1.2 μm / ms, forming an enrichment band width. and spacing .

[0074] The specific process of S5 is as follows:

[0075] Electromagnetic field confinement annealing, magnetic field gradient Controlled by the following formula:

[0076]

[0077] in, The magnetic field gradient is T / m; As a regulatory factor, a value of 5-8 is preferred; The melting point of the alloy is °C; The annealing temperature is °C. The activation energy for antimony diffusion is given in kJ / mol, and is taken as 80-85. It is the gas constant;

[0078] During operation, the annealing temperature is set to 240-280°C, and the holding time is [not specified]. min and strip thickness mm satisfies The enrichment bands are oriented and arranged by electromagnetic field confinement.

[0079] The specific process of S6 is as follows:

[0080] The strip is rolled to a thickness of 8-12 μm, with rolling force... Controlled by the following formula:

[0081]

[0082] in, The rolling force is kN; The deformation resistance coefficient is taken as 0.8-1.2; The yield strength of the material is MPa; The bandwidth is in mm; The thickness reduction per pass is μm; The radius of the roll is in mm;

[0083] During operation, the rolling process is carried out in multiple passes, with the thinning amount controlled at 1-2μm per pass. After rolling, the surface is cleaned and the roll is wound up.

[0084] Example 2 illustrates the preparation method of the ultrathin high-conductivity aluminum foil of the present invention through a specific implementation example. The specific implementation process of the ultrathin high-conductivity aluminum foil preparation method is as follows:

[0085] S1: Alloy smelting and purification;

[0086] Take high-purity aluminum ingots with a purity of ≥99.99% and heat them in a smelting furnace until they are completely molten.

[0087] The addition of Al-5Sb master alloy brings the antimony content to 0.25%, and the addition of Al-3Ba master alloy brings the barium content to 0.05%; the iron content is controlled at 0.45%, and the silicon content at 0.20%.

[0088] When the melt temperature stabilizes at 725℃, sodium fluoroaluminate-based refining agent is added, and argon gas is continuously purified for 28 minutes using a rotary jet method to remove oxides and gas inclusions.

[0089] After purification, let it stand for 8 minutes to allow the melt to homogenize.

[0090] S2: Deep supercooling continuous casting;

[0091] The molten metal is rapidly injected into the water-cooled copper mold to control the degree of supercooling. The temperature is 95℃.

[0092] According to the formula Calculate the cooling rate: Take ,but .

[0093] The water cooling intensity is adjusted in real time to ensure that the solidification process is completed within 12 seconds, resulting in an ingot with a grain size ≤50μm.

[0094] S3: Multi-stage temperature-controlled hot rolling;

[0095] The ingot is held at 500℃ for 2 hours before being hot rolled.

[0096] First stage rough rolling: temperature Thinning rate The thinning rate was achieved in four passes, with each pass yielding a reduction of 11.25%.

[0097] Final finishing rolling: temperature Thinning rate The thinning rate was achieved in three passes, with each pass yielding 11.7% thinning.

[0098] Total deformation True response .

[0099] Temperature is measured and roller gap is adjusted after each pass to ensure uniform fabrication.

[0100] S4: Pulse current assisted cold rolling;

[0101] Control the total deformation According to the formula Adjust the spacing of the dislocation walls.

[0102] strip thickness Rolling speed Antimony content in the matrix .

[0103] Pulse current density .

[0104] Pulse width ,frequency The on / off ratio is 1:3.

[0105] When an electric current is applied during four cold rolling passes, the migration velocity of antimony atoms reaches 1.1 μm / ms, resulting in an enrichment band width. ,spacing .

[0106] S5: Targeted controlled annealing of enrichment zones;

[0107] Annealing temperature strip thickness Insulation time minute.

[0108] magnetic field gradient Calculate using the formula:

[0109] , , , , .

[0110] ;

[0111] Electromagnetic field confinement causes the Sb-enriched bands to align oriented along the rolling direction.

[0112] S6: Ultra-thin foil rolling and finishing;

[0113] The strip is rolled from 0.2 mm to 10 μm in 150 passes, with a reduction in thickness per pass. .

[0114] Rolling force according to control:

[0115] , ,bandwidth , Roll radius .

[0116]

[0117] After rolling, the aluminum foil is alkali washed, passivated, and then wound up to obtain a thickness of 10 μm.

[0118] Comparative Example 1: In this comparative example, the same composition as in Example 2 was used: Sb 0.25%, Ba 0.05%, Fe 0.45%, and Si 0.20%. The preparation process followed conventional steps.

[0119] Smelting and purification: Same as S1 of this invention.

[0120] Casting: The cooling rate for ordinary continuous casting is 100℃ / s.

[0121] Hot rolling: single-segment rolling at a constant temperature of 400℃, with a total deformation of 64.2%.

[0122] Cold rolling: No pulse current, total deformation 75%.

[0123] Annealing: Ordinary box annealing at 260℃ for 13 minutes, without magnetic field.

[0124] Rolled to 10 μm.

[0125] Table 1 Performance test results of Example 2 and Comparative Example 1

[0126] Test metrics Embodiment 2 of the present invention conventional process Performance improvement Electrical conductivity (%IACS) 66.5 58.2 +14.3% Tensile strength (MPa) 188 182 +3.3% Elongation (%) 3.8 3.2 +18.8% enrichment zone characteristics directional enrichment bands exist Uniform distribution /

[0127] As can be seen from the comparative test results in Table 1, the ultrathin high-conductivity aluminum foil prepared by the patented process in Example 2 of this invention is significantly superior to the conventional process product of Comparative Example 1 in several key performance indicators. Specifically, the conductivity reaches 66.5%, an increase of 14.3 percentage points compared to 58.2% of the conventional process; the tensile strength is 188 MPa, a slight increase of 3.3 percentage points compared to 182 MPa of the conventional process; and the elongation reaches 3.8%, a significant increase of 18.8 percentage points compared to 3.2% of the conventional process. These performance differences stem from the essential difference in microstructure. Example 2 formed a directional antimony enrichment band structure through a specific process, while Comparative Example 1 only obtained a uniformly distributed elemental structure.

[0128] The pulsed current-assisted cold rolling and electromagnetic field-confined annealing process designed in this invention promotes the directional migration of antimony atoms along dislocation walls, ultimately forming a periodic enrichment band structure with a width of 1 to 3 micrometers and a spacing of 5 to 10 micrometers. This constructs an optimized electron transport path in the matrix, thereby significantly improving conductivity.

[0129] Comprehensive test data demonstrates that this invention successfully achieves a synergistic breakthrough in the conductivity and mechanical properties of ultrathin aluminum foil. The combination of high conductivity and good ductility resolves a long-standing performance contradiction in this field, providing a new technical pathway for the industrial preparation of ultrathin, highly conductive aluminum foil.

[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An ultrathin, highly conductive aluminum foil, characterized by: The aluminum foil has a thickness of 8-12 μm and contains, by mass percentage: Sb: 0.1-0.3%; Ba: 0.03-0.06%; Fe: 0.3-0.6%; Si≤0.25%; the rest being Al and impurities; The aluminum foil comprises a base body, and the base body is provided with an Sb element enrichment zone at intervals in the cross section, and the content of Sb in the Sb element enrichment zone is 1.5-2 times the content of Sb in the base body.

2. A method for preparing an ultrathin, highly conductive aluminum foil as described in claim 1, characterized in that, The method comprises the following steps: S1: alloy smelting and purification; high-purity aluminum ingots are smelted, Al-5Sb and Al-3Ba intermediate alloys are added, and purification treatment is performed; S2: deep undercooling continuous casting; the purified melt is injected into a water-cooled copper mold, the cooling rate and the undercooling degree are controlled, rapid solidification is realized to refine the grain structure; S3: multi-stage temperature control hot rolling; after heat preservation treatment of the cast ingot, hot rolling is implemented in stages, rough rolling is performed at a higher temperature and a thinning rate in the first stage, and finish rolling is performed at a lower temperature and a thinning rate in the last stage, so as to optimize the microstructure and mechanical properties of the plate; S4: pulse current assisted cold rolling; parallel dislocation wall structures are formed through multi-pass cold rolling, and intermittent pulse current is applied to promote the migration of antimony atoms along the dislocation walls, so as to realize selective enrichment of Sb; The specific steps of S4 are: First, parallel dislocation wall structure is formed by multi-pass cold rolling to control the total deformation in the range of 0.60-0.80, for total deformation, dimensionless; dislocation wall spacing is regulated by the following formula: ； wherein, is the dislocation wall spacing in μm; during operation, the deformation is adjusted according to the target spacing; Second, intermittent pulse current is applied, the pulse current density calculated from the following equation: ； wherein, is the pulse current density in A / mm2; is the mass percentage content of Sb in the base; is the current strip thickness in mm; is the rolling speed in m / min; Pulse parameters include pulse width , Pulse width, in μs; frequency , Frequency, in Hz; current on-off ratio 1:3; In operation, current is applied in 3-5 passes, with cumulative pulse time per pass Based on pulse width, frequency and rolling length calculations; ensure that antimony atoms migrate at 1.0-1.2 μm / ms to form enriched band width , For enriched band width, in μm; and spacing , For dislocation wall spacing, in μm; S5: enrichment zone directional regulation annealing; annealing is performed under the constraint of an electromagnetic field, the temperature gradient and the time are controlled, the Sb enrichment zone is arranged in a directional manner, and the conductive structure is strengthened; The specific process of S5 is: Using electromagnetic field confinement annealing, magnetic field gradient Controlled by the following equation: ； wherein is the magnetic field gradient in T / m; is the control factor, dimensionless; is the alloy melting point in °C; is the annealing temperature in °C; is the antimony diffusion activation energy in kJ / mol; is the gas constant in kJ / (mol K); In operation, the annealing temperature is set to 240-280°C, the holding time with the strip thickness satisfies , is the holding time, in min; is the strip thickness, in mm; the enriched band is directionally arranged by electromagnetic field confinement; S6: ultra-thin foil rolling and finishing; the strip is rolled to a thickness of 8-12 μm, and surface finishing treatment is performed, so as to obtain an ultra-thin high-conductivity aluminum foil; The specific process of S6 is: The strip is rolled to a thickness of 8-12 μm, the rolling force controlled by the equation: ； wherein, F is the rolling force in kN; is the deformation resistance coefficient, dimensionless; is the material yield strength in MPa; is the strip width in mm; is the pass reduction in pm; is the roll radius in mm; During operation, the strip is rolled in multiple passes, the thinning amount of each pass is controlled to be 1-2 μm, and surface cleaning and coiling are performed after rolling.

3. The production method according to claim 2, wherein The specific steps of S1 are: High-purity aluminum ingots are heated to a molten state in a smelting furnace, Al-5Sb intermediate alloy is added to provide antimony elements, and Al-3Ba intermediate alloy is added to provide barium elements; when the melt temperature is stabilized at 710-730°C, a refining agent is added, and continuous purification is performed for 20-30 minutes by using a rotary argon blowing method, so as to remove oxide and gas inclusions; after purification, the melt is uniformly homogenized after standing for 5-10 minutes.

4. The production method according to claim 2, wherein The specific steps of S2 are: The melt is rapidly injected into a water-cooled copper mold, and deep undercooling solidification is achieved by controlling the cooling rate controlled by the following equation: ； wherein, is the solidification front cooling rate in °C / s; is the solidification coefficient, dimensionless; is the melt undercooling in °C; controlled at 80-100 °C; during operation, the undercooling is monitored and the water cooling intensity is adjusted in real time to ensure that the solidification process is completed within 10-15 seconds.

5. The production method according to claim 2, wherein The specific steps of S3 are: The cast ingot is hot-rolled after heat preservation at 480-520°C for 2 hours; a segmented temperature control strategy is adopted: first pass reduction ratio , first pass reduction ratio, dimensionless; rolling temperature , first pass rolling temperature, in °C; completed in 3-5 passes final reduction ratio , final reduction ratio, dimensionless; rolling temperature , final rolling temperature, in °C; completed in 2-4 passes true strain calculated from the equation: ； wherein, true strain, dimensionless; total deformation, dimensionless; controlled in the range of 0.60-0.80; during operation, the temperature was measured after each pass and the roll gap was adjusted to ensure uniform structure.

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