High-performance aluminum foil as well as processing deformation process and application thereof

Abstract

The invention discloses a high-performance aluminum foil as well as a processing deformation process and application thereof, and belongs to the technical field of aluminum alloys. And the high-performance aluminum foil is an ultra-thin aluminum foil with the thickness of 0.006 mm to 0.01 mm. By means of the machining deformation technology, microalloy elements and rare earth elements are added at the same time, the aluminum alloy material with the tensile strength and the conductivity greatly improved is obtained, meanwhile, the ductility is slightly increased, and the aluminum alloy material can be used for producing aluminum foil for batteries with better quality. The invention further designs a four-roller casting process, the effect of simultaneously improving the strength, the elongation and the conductivity is achieved, good comprehensive mechanical properties are obtained, the tensile strength, the elongation and the conductivity of the aluminum alloy in an aging state are 194.6-210.6 MPa, 11.4-13.0% and 49.6-55.6% respectively, and the problems that aluminum alloy is low in strength, poor in mechanical properties and the like when being used as a battery foil material are solved.

Description

Technical Field

[0001] This invention relates to a high-performance aluminum foil, its processing and deformation technology and applications, and particularly to the modification and application of an aluminum alloy material for batteries, belonging to the field of aluminum alloy technology. Background Technology

[0002] Aluminum is the second most widely used metallic material after steel, and is widely used in construction, transportation, power, packaging, and aerospace. With the advancement of global energy transition (such as new energy vehicles and the photovoltaic industry), the demand for aluminum continues to grow due to its lightweight, corrosion resistance, and high conductivity. In particular, the rapid development of battery technology has placed higher demands on the performance of aluminum alloy materials. For example, aluminum alloys used in batteries require higher strength, better corrosion resistance, and excellent conductivity to meet the high energy density and long lifespan requirements of batteries. In recent years, researchers have attempted to control the microstructure of aluminum alloys through composite microalloying (such as Mn+Zr, Sc+Er, etc.) combined with deformation heat treatment processes to overcome performance bottlenecks. However, the addition of multiple components easily induces the coarsening precipitation of intermetallic compounds (such as Al6Mn, Al3Zr), resulting in decreased conductivity and deterioration of processability. Furthermore, existing processes mostly focus on optimizing single performance indicators, lacking a systematic consideration of the multi-field coupling failure mechanism (electrochemical-mechanical synergistic effect) of materials under battery conditions, leading to limited modification effects. Therefore, developing a method for modifying aluminum alloy materials based on the synergistic optimization of composite addition and processing technology, and achieving a balanced improvement in conductivity, strength and corrosion resistance by precisely designing alloy composition, precipitate distribution and grain boundary structure, while adapting to the needs of large-scale preparation, has become a key issue that urgently needs to be solved in the field of aluminum alloys for batteries.

[0003] This invention employs an improved twin-roll continuous casting and rolling process. Research on twin-roll continuous casting and rolling technology began in October 1963. In September 1964, a 10mm thick cast-rolled plate was produced at the Northeast Light Alloy Processing Plant. In 1965, a cast-rolled plate with a width of 700mm was produced. In 1982, a φ650*1600mm twin-roll continuous rolling mill was successfully developed at the North China Aluminum Processing Plant. After 40 years of effort, the twin-roll continuous casting and rolling process for aluminum sheet and strip has been rapidly promoted and popularized in my country. The twin-roll continuous rolling process for aluminum sheet and strip requires less investment and yields quick results. It is feasible for small and medium-sized aluminum sheet and strip rolling mills, significantly reducing the time from molten aluminum to ingot to hot-rolled sheet or re-rolling, and eliminating processes such as ingot casting, milling, and billet preparation.

[0004] Therefore, developing a processing technology based on the composite addition of metals and rare earth elements to high-purity aluminum is of great significance for promoting the application of aluminum alloy materials in the battery field. Summary of the Invention

[0005] The problem this invention aims to solve is that aluminum foil for batteries has low tensile strength, low elongation, and low conductivity. This invention designs a high-performance aluminum foil processing and deformation process to improve various problems of aluminum foil for batteries and to produce aluminum alloy materials with superior performance.

[0006] Meanwhile, the present invention provides a high-performance aluminum foil.

[0007] Meanwhile, this invention provides an application of high-performance aluminum foil.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention relates to a processing and deformation technology for high-performance aluminum foil, comprising the following steps: First, melt 99.9% high-purity aluminum and rare earth elements (La and Ce) in a smelting furnace, controlling the furnace temperature at 720~750℃. After the solid is completely melted, remove the slag. Add alloying elements X (Si, Cu, Ti, Sc and Zr) (Fe is an impurity element, and the Fe content is controlled within 0.3wt%) in the form of Al-10X master alloy according to the batching amount. The smelting time is 2h-3h, let it stand for about 15 minutes, and then stir for at least 5 minutes. Take a sample for testing to check whether the alloy content of the aluminum liquid is within the range required by this invention (Fe: 0.1~0.3wt%, Si: 0.1~0.15wt%, Cu: 0.01~0.05wt%, Ti≤0.05wt%, Sc: 0.05~0.2wt%, Zr: 0.05~0.2wt%, Ce≤0.1wt%, La≤0.1wt%, balance Al). If it is qualified, proceed to the next step. Then, a refining agent (zinc chloride) is added at a rate of 0.4-1.0% of the aluminum liquid mass. The mixture is pressed to the bottom with a tool until no more bubbles appear, and this process takes 10-15 minutes. This is primarily to remove hydrogen from the aluminum liquid. Afterward, the gas inside the furnace is evacuated to create a vacuum environment, with the vacuum level controlled in the medium vacuum range (10%). 2 ~10 -1 To remove gas from the molten aluminum, the waste residue is filtered through a multi-stage plate and tube filter device. After the slag is removed, expanded perlite, expanded graphite and other covering agents are sprinkled on the surface at a rate of 0.7 to 1.1 kg per ton of molten aluminum to prevent hydrogen from the air from entering the molten aluminum.

[0009] After obtaining the molten aluminum of this invention, a four-roll casting process (FRC - Four Roll Casting) is employed to integrate solidification and deformation. An inclined injection method is used, with the inclination angle controlled at 10°-15°. After the molten aluminum enters the melting cylinder, pressure is provided by the front chamber, and precise detection and control are performed using a laser rangefinder. An electromagnetic stirrer is installed in the front chamber, with a stirring frequency of 15-20Hz. The fluid is forced into the flow channel and fed into the casting roll gap through the feed nozzle, with the pouring temperature controlled between 680~710℃.

[0010] The feed nozzle is assembled from multiple parts, with multiple block-shaped baffles placed between the upper and lower mating blocks to ensure a uniform flow rate and even distribution of molten aluminum into the inner cavity of the feed nozzle. Figure 2 .

[0011] Once inside the molten pool, the liquid metal gradually solidifies. Figure 3 The solidification curve represents the boundary between the solid and liquid states. KP represents the lowest point, with the liquid phase region above KP, the mushy region adjacent to KP, and the solid phase region below KP. For low-speed casting processes or alloys with a small solidification range (ΔT < 15 K), the size of the mushy region is significantly reduced. Therefore, based on the location of KP, the casting-rolling zone can be functionally divided into two areas: the solidification zone (transition from liquid to mushy) and the rolling zone (processing from liquid to solid). Figure 3 As shown, four temperature monitoring points (A, B, C, D) are placed at equal intervals based on the thickness of the roller sleeve to capture the evolution of the thermal gradient. The casting roll consists of a roll core and a roll sleeve. Grooves are left on the roll core, and the main grooves are connected to each other by secondary grooves, forming a grid-like shape. Figure 5 The roller core is drilled with holes to serve as cooling water inlets. The roller sleeve matches the roller core, and cooling water flows out from the shaft end. Figure 6Simultaneously, an electromagnetic vibrator is installed on the casting roll. Select areas outside the working end plates or bearing seats at both ends of the casting roll, and secure the vibrator base to the mounting surface with bolts (with a buffer pad). The electromagnetic vibrator selected is the Henan Ande Electronic Machinery ZDQ50 model, with a vibration frequency of 100–120 Hz. Vibration increases the nucleation rate during the solidification process in the molten pool. After passing through the casting roll, the molten aluminum cools and solidifies, transforming into a 2 mm thick aluminum strip, which then randomly enters the next rolling pass, making the aluminum strip even thinner. The reduction rate is controlled between 15% and 30%, and the casting speed does not exceed 70 m / min. Next, a short-term homogenization treatment (<30 min) is performed, utilizing the residual heat from melting (400℃-600℃) for homogenization. Following this, cold rolling is carried out at room temperature (cold rolling includes cold roughing and finishing; cold roughing (0.5 mm) has a single-pass reduction rate of 50%–65%, with a total of 3–5 cold rolling passes; finishing (≤0.5 mm) has a single-pass reduction rate of 25%–35%), with a rolling speed ≤800 m / min and rolling oil temperature controlled at approximately 30–60℃, producing aluminum foil ranging from 0.03 to 0.2 mm in thickness. Then, intermediate annealing is performed, with the annealing temperature controlled at T1 and the holding time at t1. Then, aluminum foil is rolled (for ultra-thin foil rolling, the single-pass reduction rate is 15%–25%, requiring double rolling). This rolling process is more precise, producing ultra-thin aluminum foil (0.006 mm–0.01 mm) according to requirements. After rolling, it is slit, and finally, it undergoes annealing and simultaneous aging treatment. The annealing temperature is T2, and the holding time is t2, yielding the finished product. The parameters are: 340℃≤T1≤400℃, 2h≤t1≤8h, 150℃≤T2≤250℃, 1h≤t2≤4h. The tensile strength, elongation, and conductivity of the high-performance aluminum foil are 194.6–210.6 MPa, 11.4–13.0%, and 49.6–55.6%, respectively.

[0012] The Sc content is 0.05~0.2wt%, the Zr content is 0.05~0.2wt%, and the total content of La and Ce does not exceed 0.2wt%.

[0013] Preferably, the intermediate annealing temperature T1 of the cold rolling is 380℃, and t1 is 6 hours; the temperature of the finished product annealing and simultaneous aging treatment T2 is 200℃, and t2 is 2 hours.

[0014] The specific composition of the alloy after adding high-purity aluminum is Fe: 0.1~0.3wt%, Si: 0.1~0.15wt%, Cu: 0.01~0.05wt%, Ti≤0.05wt%, Sc: 0.05~0.2wt%, Zr: 0.05~0.2wt%, Ce≤0.1wt%, La≤0.1wt%, with the balance being Al.

[0015] The aluminum foil product obtained by the processing and deformation process of the present invention is used as aluminum foil in battery production.

[0016] The present invention relates to the application of a high-performance aluminum foil in battery aluminum foil.

[0017] A battery aluminum foil, prepared from a high-performance aluminum foil of the present invention.

[0018] The present invention has the following beneficial effects: In this invention, Zr is the most effective element for synergistically regulating the overall performance of aluminum alloys with Sc. The combined addition of Sc and Zr to aluminum alloys generates dispersed nanoscale Al3(Sc,Zr) precipitates with a smaller diffusion coefficient, stronger resistance to coarsening, better grain refinement, and improved recrystallization inhibition. The nanoscale precipitates formed by Sc and Zr effectively pin dislocations and grain boundaries, hindering dislocation movement during plastic deformation, thereby improving the material's strength. Simultaneously, the addition of Zr can delay the coarsening process of Sc precipitates at high temperatures, extending the material's service life. This may be related to the difference in diffusion rates between the two elements; Sc has a lower diffusion activation energy, preferentially precipitating to form nuclei, while Zr subsequently diffuses around the nuclei, forming a more stable structure. Secondly, the recrystallization temperature is increased. Aluminum alloys are prone to recrystallization at high temperatures, leading to a decrease in strength. The combined addition of Sc and Zr can significantly increase the recrystallization temperature of the alloy because the pinning effect of the precipitates at grain boundaries hinders the formation and growth of new grains.

[0019] The addition of trace amounts of rare earth elements La and Ce to the alloy forms a second phase, resulting in a finer and more uniform as-cast microstructure. Due to the genetic characteristics of the microstructure, the deformed microstructure becomes even finer and more uniform after rolling. The second-phase particles containing rare earth elements La and Ce can pin dislocations and inhibit recrystallization during rolling, which can significantly improve the deformed microstructure, making it more uniform and fine.

[0020] In this invention, rare earth elements possess unique physical and chemical properties that can significantly improve the microstructure and mechanical properties of aluminum alloys. Microalloying elements Sc and Zr can refine grains, improving the alloy's strength and toughness; while rare earth elements La and Ce can improve the alloy's corrosion resistance and thermal stability. Furthermore, the combined addition of these elements can promote the uniform distribution of the second phase in the alloy, reducing the formation of harmful phases, thereby further enhancing the alloy's overall performance.

[0021] Fe increases the strength of the alloy (yield strength can be increased by 10~20MPa), regulates the texture, promotes the formation of a favorable {001}<100> cubic texture, improves rollability, and inhibits grain coarsening.

[0022] Si is a double-edged sword element that requires strict control. Its positive effects include synergistic effects with Fe, improving work hardening rate, making aluminum foil easier to thin during cold rolling, and enhancing corrosion resistance. The negative effects are that excessive Si (0.2wt%) reduces electrical conductivity (approximately 1% IACS per 0.1% Si) and may form free Si particles, inducing microcracks.

[0023] Cu is a key strengthening element, with solid solution strengthening as its core mechanism, significantly improving strength (0.1% Cu can increase yield strength by approximately 15 MPa). Simultaneously, in terms of conductivity balancing, Cu's negative impact on conductivity is far less than that of Mg / Zn (each 0.1% Cu only reduces conductivity by 0.7% IACS), making it particularly suitable for battery foils requiring a balance between strength and conductivity. It also exhibits good corrosion resistance; trace amounts of Cu can promote uniform corrosion (rather than pitting), extending battery life.

[0024] Ti, a powerful grain refiner (essential element), undergoes heterogeneous nucleation to form Al3Ti particles, serving as the nucleation substrate for α-Al and reducing the as-cast grain size by more than 50%. It also inhibits recrystallization, forming a metastable phase with Al, delaying recrystallization during annealing and improving high-temperature stability.

[0025] This invention employs an improved twin-roll continuous casting and rolling process, which is feasible for small and medium-sized aluminum sheet and strip rolling beds. It significantly reduces the time from molten aluminum to ingot to hot-rolled sheet or re-rolling, and eliminates the processes of ingot casting, milling, and billet preparation.

[0026] This invention utilizes high-purity aluminum modified with composite alloying elements and rare earth elements, which not only meets the requirements for material strength and productivity of battery casings, but also improves battery life and safety to a certain extent.

[0027] By employing the processing and deformation technology of this invention, microalloying elements and rare earth elements are added simultaneously to obtain aluminum alloy materials with significantly improved tensile strength and electrical conductivity, while also slightly increasing elongation. These materials can be used to produce higher quality aluminum foil for batteries.

[0028] The microalloying elements added in this invention can generate dispersed nanoscale precipitates with smaller diffusion coefficients, stronger resistance to coarsening, and better grain refinement and recrystallization inhibition. This invention also designs a four-roll casting process to simultaneously improve strength, elongation, and electrical conductivity, resulting in excellent comprehensive mechanical properties. Under aging conditions, its tensile strength, elongation, and electrical conductivity are 194.6-210.6 MPa, 11.4-13.0%, and 49.6-55.6%, respectively, solving the problems of low strength and poor mechanical properties of aluminum alloys as battery foil materials. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a flowchart of the high-performance aluminum foil processing and deformation technology of the present invention; Figure 2 The diagram shows the structure of a conventional feed nozzle (top) and the structure of the feed nozzle of the present invention (bottom). Figure 3 TRC model diagram; Figure 4 This is a diagram of the traditional water-cooled roller groove structure. Figure 5 This is a structural diagram of the water-cooled roller groove of the present invention; Figure 6 This is a side view of the water-cooled roller of the present invention; Figure 7 This is a topographical view of the high-performance aluminum foil obtained by the present invention. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0032] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0033] According to embodiments of the present invention, a high-performance aluminum foil, its processing and deformation technology, and its applications are provided.

[0034] Comparative Example 1

[0035] The processing and deformation technology of the aluminum foil in this comparative example uses 99.9% pure aluminum as the research object. After adding alloying elements, the composition is: Fe: 0.2wt%, Si: 0.12wt%, Cu: 0.03wt%, Ti: 0.02wt%, Sc: 0.1wt%, Zr: 0.1wt%, Ce: 0.15wt%, La: 0.1wt%, with the balance being Al. First, the 99.9% high-purity aluminum and rare earth elements are melted in a melting furnace at a temperature controlled at 735℃. After the solid is completely melted, the slag is removed. The alloying elements are added in the form of intermediate alloy according to the batching amount. The melting time is 2.5 hours, followed by standing for about 15 minutes, and then stirring for 5 minutes. Samples are taken for testing to check whether the alloy content of the aluminum liquid is within the range required by this patent. If it is qualified, the next step is performed.

[0036] Then, a refining agent (zinc chloride) is added at a rate of 0.7% of the aluminum liquid mass. The mixture is pressed down to the bottom until no more bubbles appear, a process that takes approximately 12 minutes. This is primarily to remove hydrogen from the aluminum liquid. Afterward, the gas inside the furnace is evacuated to create a vacuum environment, with the vacuum level controlled within the medium vacuum range (10). 2 Pa removes gas from the molten aluminum. Waste residue is filtered through a multi-stage plate and tube filter. After slag removal, expanded perlite and expanded graphite are sprinkled on the surface as a covering agent, at a rate of 0.9 kg per ton of molten aluminum, to prevent hydrogen from the air from entering the molten aluminum. After obtaining the molten aluminum from this method, a four-roll casting process (FRC - Four Roll Casting) is used to integrate solidification and deformation. An inclined injection method is adopted, with the inclination angle controlled at 15°. After the molten aluminum enters the melting cylinder, pressure is provided by the front box (in this comparative example, the front box does not have an electromagnetic stirrer installed), and a laser rangefinder is used for precise detection and control. The fluid is forced into the flow channel from the feed nozzle (e.g., Figure 2 (The traditional feed nozzle structure is shown in the diagram) Input casting roll gap (the structure of the casting roll is as shown in the diagram) Figure 4 The diagram shows the traditional water-cooled roller groove structure (note that the casting roller in this comparative example is not equipped with an electromagnetic vibrator), and the casting temperature is controlled at 700℃. After passing through the casting roller, the molten aluminum cools and solidifies into a 2mm thick aluminum strip, which then randomly enters the next rolling pass to make the aluminum strip even thinner. The reduction rate is controlled at 20%, and the casting speed is 70m / min. Next, a short-time homogenization treatment is performed, utilizing the residual heat of the smelting process. Following this, cold rolling is carried out at room temperature, with a rolling speed of 800m / min and the rolling oil temperature controlled at approximately 45℃, producing an aluminum foil of 0.1mm thickness. Then, intermediate annealing is performed, with the annealing temperature controlled at T1 of 370℃ and a holding time t1 of 6 hours. Finally, aluminum foil rolling is performed, this time with even finer rolling, producing extremely thin aluminum foil as required. In this comparative example, the final rolling yields an aluminum foil with a thickness of only 0.02mm. When the 0.02mm aluminum foil is further rolled, improper tension control or insufficient lubrication can cause the aluminum foil to break, wrinkle, or become unformed.

[0037] Comparative Example 2

[0038] The only difference between this comparative example and Comparative Example 1 is that: Ce: 0.1wt%, La: 0.1wt%.

[0039] In this comparative example, the final rolling process yielded an aluminum foil with a thickness of only 0.02 mm. Further rolling of this 0.02 mm foil resulted in defects such as strip breakage and wrinkling due to improper tension control or insufficient lubrication.

[0040] Comparative Example 3

[0041] The only difference between this comparative example and Comparative Example 1 is that: Different feeding nozzle devices, such as Figure 2 As shown in the figure below, the feed nozzle is assembled from multiple workpieces, with multiple block-shaped baffles set between the upper and lower mating blocks, which is not the traditional long strip shape.

[0042] In this comparative example, the final rolling process yielded an aluminum foil with a thickness of only 0.02 mm. Further rolling of this 0.02 mm foil resulted in defects such as strip breakage and wrinkling due to improper tension control or insufficient lubrication.

[0043] Comparative Example 4 The only difference between this comparative example and Comparative Example 1 is that: An electromagnetic stirrer is installed in the front compartment, with a stirring frequency of 15Hz.

[0044] In this comparative example, the final rolling process yielded an aluminum foil with a thickness of only 0.02 mm. Further rolling of this 0.02 mm foil resulted in defects such as strip breakage and wrinkling due to improper tension control or insufficient lubrication.

[0045] Comparative Example 5

[0046] The only difference between this comparative example and Comparative Example 1 is that: Applications of casting roll grooves, such as Figure 5 The "well" shape shown is not a traditional wraparound shape.

[0047] In this comparative example, the final rolling process yielded an aluminum foil with a thickness of only 0.02 mm. Further rolling of this 0.02 mm foil resulted in defects such as strip breakage and wrinkling due to improper tension control or insufficient lubrication.

[0048] Comparative Example 6

[0049] The only difference between this comparative example and Comparative Example 1 is that: The casting roll is equipped with an electromagnetic vibrator, and the vibration frequency is controlled at 110Hz.

[0050] In this comparative example, the final rolling process yielded an aluminum foil with a thickness of only 0.02 mm. Further rolling of this 0.02 mm foil resulted in defects such as strip breakage and wrinkling due to improper tension control or insufficient lubrication. Example 1

[0051] The only difference between this embodiment and Comparative Example 1 is that: Ce: 0.1wt%, La: 0.1wt%.

[0052] Different feeding nozzle devices, such as Figure 2 As shown in the figure below, the feed nozzle is assembled from multiple workpieces, with multiple block-shaped baffles set between the upper and lower mating blocks, which is not the traditional long strip shape.

[0053] An electromagnetic stirrer is installed in the front compartment, with a stirring frequency of 15Hz.

[0054] Applications of casting roll grooves, such as Figure 5 The "well" shape shown is not a traditional wraparound shape.

[0055] The casting roll is equipped with an electromagnetic vibrator, and the vibration frequency is controlled at 110Hz.

[0056] During aluminum foil rolling, ultra-thin aluminum foil (0.008mm) is pressed out according to requirements. After completion, it is slit and finally subjected to finished product annealing and aging treatment. The annealing temperature is 225℃ and the holding time is 2h to obtain the finished product.

[0057] The ultra-thin aluminum foil (0.008 mm) product obtained in this embodiment is as follows: Figure 7 As shown.

[0058] This embodiment describes the application of high-performance aluminum foil in battery aluminum foil.

[0059] A battery aluminum foil is prepared from a high-performance aluminum foil according to this embodiment. Example 2

[0060] like Figure 1 As shown, a processing and deformation process for high-performance aluminum foil includes the following steps: First, 99.9% high-purity aluminum and rare earth elements (La and Ce) are melted in a smelting furnace at a controlled temperature of 720℃. After the solid is completely melted, the slag is removed. Alloying elements X (Si, Cu, Ti, Sc, and Zr) are added in the form of an Al-10X master alloy according to the specified proportions. The melting time is 2 hours, followed by standing for about 30 minutes, and then stirring for 10 minutes. Samples are taken for testing to check whether the alloy content of the aluminum liquid is within the range required by this invention (Fe: 0.1wt%, Si: 0.1wt%, Cu: 0.01wt%, Ti: 0.05wt%, Sc: 0.05wt%, Zr: 0.05wt%, Ce: 0.05wt%, La: 0.08wt%, with the balance being Al). If it is qualified, proceed to the next step. Then, a refining agent (zinc chloride) is added at a rate of 0.4% of the aluminum liquid mass. The agent is pressed to the bottom with a tool until no more bubbles appear, and the treatment time is 10 minutes. This process is mainly used to remove hydrogen from the aluminum liquid. The gas inside the furnace is then evacuated to create a vacuum environment, with the vacuum level controlled within the medium vacuum range of 10. -1 To remove gas from the molten aluminum, the waste residue is filtered through a multi-stage plate and tube filter device. After the slag is removed, expanded perlite, expanded graphite and other covering agents are sprinkled on the surface at a rate of 0.7 kg per ton of molten aluminum to prevent hydrogen from the air from entering the molten aluminum.

[0061] After obtaining the molten aluminum in this embodiment, a four-roll casting process (FRC - Four Roll Casting) is employed to integrate solidification and deformation. An inclined injection method is used, with the inclination angle controlled at 10°. After the molten aluminum enters the melting cylinder, pressure is provided by the front chamber, and precise detection and control are performed using a laser rangefinder. An electromagnetic stirrer is installed in the front chamber, with a stirring frequency of 20Hz. The fluid is forced into the flow channel and fed into the casting roll gap through the feed nozzle, with the pouring temperature controlled at 680℃.

[0062] The feed nozzle is assembled from multiple parts, with multiple block-shaped baffles placed between the upper and lower mating blocks to ensure a uniform flow rate and even distribution of molten aluminum into the inner cavity of the feed nozzle. Figure 2 .

[0063] Once inside the molten pool, the liquid metal gradually solidifies. Figure 3 The solidification curve represents the boundary between the solid and liquid states. KP represents the lowest point, with the liquid phase region above KP, the mushy region adjacent to KP, and the solid phase region below KP. For low-speed casting processes or alloys with a small solidification range (ΔT < 15 K), the size of the mushy region is significantly reduced. Therefore, based on the location of KP, the casting-rolling zone can be functionally divided into two areas: the solidification zone (transition from liquid to mushy) and the rolling zone (processing from liquid to solid). Figure 3As shown, four temperature monitoring points (A, B, C, D) are placed at equal intervals based on the thickness of the roller sleeve to capture the evolution of the thermal gradient. The casting roll consists of a roll core and a roll sleeve. Grooves are left on the roll core, and the main grooves are connected to each other by secondary grooves, forming a grid-like shape. Figure 5 The roller core is drilled with holes to serve as cooling water inlets. The roller sleeve matches the roller core, and cooling water flows out from the shaft end. Figure 6 Simultaneously, an electromagnetic vibrator is installed on the casting roll. Select areas outside the working end plates or bearing seats at both ends of the roll, and secure the vibrator base to the mounting surface with bolts (with a buffer pad). The electromagnetic vibrator used is the Henan Ande Electronic Machinery ZDQ50 model, with a vibration frequency of 100Hz. Vibration increases the nucleation rate during the solidification process in the molten pool. After passing through the casting roll, the molten aluminum cools and solidifies, transforming into a 2mm thick aluminum strip, which then randomly enters the next rolling pass, making the aluminum strip even thinner. The reduction rate is controlled at 15%, and the casting speed is 50m / min. Next, a short-term homogenization treatment (20 min) is performed, utilizing the residual heat (500℃) from the smelting process for homogenization. Following this, cold rolling is carried out at room temperature (cold rolling includes cold roughing and finishing; cold roughing (0.5 mm) has a single-pass reduction rate of 50%, with a total of 5 cold rolling passes; finishing (≤0.5 mm) has a single-pass reduction rate of 25%), at a rolling speed of 700 m / min and a rolling oil temperature controlled at approximately 30℃, producing 0.2 mm aluminum foil. Next, intermediate annealing is performed at a temperature controlled at T1=380℃ for a holding time of t1=6 h. Then, aluminum foil rolling is performed (for ultra-thin foil rolling, a single-pass reduction rate of 15% is required, necessitating double rolling). This rolling process is more refined, producing ultra-thin aluminum foil (0.01 mm) as needed. After completion, the foil is slit, and finally, a simultaneous annealing and aging treatment is performed at a temperature of T2=200℃ for a holding time of t2=2 h, yielding the finished product.

[0064] This embodiment describes the application of high-performance aluminum foil in battery aluminum foil.

[0065] A battery aluminum foil is prepared from a high-performance aluminum foil according to this embodiment. Example 3

[0066] A processing and deformation technology for high-performance aluminum foil includes the following steps: First, 99.9% high-purity aluminum and rare earth elements (La and Ce) are melted in a smelting furnace at a temperature controlled at 750℃. After the solid is completely melted, the slag is removed. Alloying elements X (Si, Cu, Ti, Sc, and Zr) are added in the form of an Al-10X master alloy according to the specified proportions. The smelting time is 3 hours, followed by standing for about 20 minutes, and then stirring for 5 minutes. Samples are taken for testing to check whether the alloy content of the aluminum liquid is within the range required by this invention (Fe: 0.3wt%, Si: 0.15wt%, Cu: 0.05wt%, Ti: 0.01wt%, Sc: 0.2wt%, Zr: 0.2wt%, Ce: 0.03wt%, La: 0.1wt%, with the balance being Al). If it is qualified, proceed to the next step. Then, a refining agent (zinc chloride) is added at a rate of 1.0% of the aluminum liquid mass. The agent is pressed to the bottom with a tool until no more bubbles appear, and the treatment time is 15 minutes. This is mainly to remove hydrogen from the aluminum liquid. The gas inside the furnace is then evacuated to create a vacuum environment, with the vacuum level controlled within the medium vacuum range of 10. -1 To remove gas from the molten aluminum, the waste residue is filtered through a multi-stage plate and tube filter device. After the slag is removed, expanded perlite, expanded graphite and other covering agents are sprinkled on the surface at a rate of 1.1 kg per ton of molten aluminum to prevent hydrogen from the air from entering the molten aluminum.

[0067] After obtaining the molten aluminum in this embodiment, a four-roll casting process (FRC - Four Roll Casting) is employed to integrate solidification and deformation. An inclined injection method is used, with the inclination angle controlled at 15°. After the molten aluminum enters the melting cylinder, pressure is provided by the front chamber, and precise detection and control are performed using a laser rangefinder. An electromagnetic stirrer is installed in the front chamber, with a stirring frequency of 15Hz. The fluid is forced into the flow channel and fed into the casting roll gap through the feed nozzle, with the pouring temperature controlled between 7 and 10°C.

[0068] The feed nozzle is assembled from multiple parts, with multiple block-shaped baffles placed between the upper and lower mating blocks to ensure a uniform flow rate and even distribution of molten aluminum into the inner cavity of the feed nozzle. Figure 2 .

[0069] Once inside the molten pool, the liquid metal gradually solidifies. Figure 3 The solidification curve represents the boundary between the solid and liquid states. KP represents the lowest point, with the liquid phase region above KP, the mushy region adjacent to KP, and the solid phase region below KP. For low-speed casting processes or alloys with a small solidification range (ΔT < 15 K), the size of the mushy region is significantly reduced. Therefore, based on the location of KP, the casting-rolling zone can be functionally divided into two areas: the solidification zone (transition from liquid to mushy) and the rolling zone (processing from liquid to solid). Figure 3As shown, four temperature monitoring points (A, B, C, D) are placed at equal intervals based on the thickness of the roller sleeve to capture the evolution of the thermal gradient. The casting roll consists of a roll core and a roll sleeve. Grooves are left on the roll core, and the main grooves are connected to each other by secondary grooves, forming a grid-like shape. Figure 5 The roller core is drilled with holes to serve as cooling water inlets. The roller sleeve matches the roller core, and cooling water flows out from the shaft end. Figure 6 Simultaneously, an electromagnetic vibrator is installed on the casting roll. Select areas at both ends of the casting roll that are not on the working end plates or bearing seats, and secure the vibrator base to the mounting surface with bolts (with a buffer pad). The electromagnetic vibrator selected is the Henan Ande Electronic Machinery ZDQ50 model, with a vibration frequency of 120Hz. Vibration increases the nucleation rate during the solidification process in the molten pool. After passing through the casting roll, the molten aluminum cools and solidifies, transforming into a 2mm thick aluminum strip, which then randomly enters the next rolling pass, making the aluminum strip even thinner. The reduction rate is controlled at 30%, and the casting speed is 70m / min. Next, a short-term homogenization treatment (30 min) is performed, utilizing the residual heat (600℃) from the smelting process. Following this, cold rolling is carried out at room temperature (cold rolling includes cold roughing and finishing; cold roughing (0.5 mm) has a single-pass reduction rate of 65%, with a total of 3 cold rolling passes; finishing (≤0.5 mm) has a single-pass reduction rate of 35%). The rolling speed is 800 m / min, and the rolling oil temperature is controlled at approximately 60℃, producing 0.08 mm thick aluminum foil. Then, intermediate annealing is performed, with the annealing temperature controlled at T1=340℃ and the holding time t1=2 h. Then, aluminum foil rolling is performed (the single-pass reduction rate for ultra-thin foil rolling is 25%, and double rolling is required). At this time, the rolling is more refined, and ultra-thin aluminum foil (0.007mm) is pressed out according to the requirements. After completion, it is slit, and finally, the finished product is annealed and aged simultaneously. The annealing temperature is T2=150℃, and the holding time is t2=1h to obtain the finished product.

[0070] This embodiment describes the application of high-performance aluminum foil in battery aluminum foil.

[0071] A battery aluminum foil is prepared from a high-performance aluminum foil according to this embodiment. Example 4

[0072] The only difference between this embodiment and Embodiment 1 is that: Short-term homogenization treatment (30 min) is performed using the residual heat (400℃) from melting.

[0073] T1=400℃, t1=8h, T2=250℃, t2=4h.

[0074] During aluminum foil rolling, extremely thin aluminum foil (0.006mm) is pressed out according to requirements. Example 5

[0075] The only difference between this embodiment and Embodiment 1 is that: During aluminum foil rolling, extremely thin aluminum foil (0.009mm) is pressed out according to requirements.

[0076] Performance testing:

[0077] Alloy samples obtained from the aluminum alloys of the comparative examples and embodiments using different aging processes were subjected to room temperature tensile property tests and room temperature electrical conductivity tests. The room temperature tensile property test method is as follows: A Zwick / RollZ030TH electronic universal tensile testing machine was used, with a tensile rate of 1 mm / min. Before the experiment, the worktable of the Zwick / RollZ030TH electronic universal tensile testing machine was raised by approximately 10 mm to eliminate the influence of the worktable system's self-weight. Three parallel samples were used for comparison in each group of experiments to reduce experimental errors. The electrical conductivity test method is as follows: An M4900C eddy current conductivity meter was used. Samples were prepared according to standard requirements, ensuring the sample surface was flat, free of oil stains, and free of oxide layers. The instrument was calibrated using a standard block to ensure the accuracy and reliability of the measurement results. The sample was placed on the sensor, the instrument was started for measurement, and the measurement results were recorded after stabilization. Necessary corrections and calculations were performed based on the measurement results to obtain the final electrical conductivity value. The tensile property test results and electrical conductivity values ​​of the alloys of the comparative examples and embodiments are shown in Table 1.

[0078] Table 1. Results of tensile property tests and electrical conductivity values

[0079] As can be seen from the test results in Table 1, the difference between Comparative Example 1 and Comparative Example 3 lies in the different feed nozzles, such as... Figure 2 As shown in Comparative Example 1, the feed nozzle is usually composed of two two-piece devices at the top and bottom, with a long strip baffle arranged in the middle. This solution uses multiple block baffles, which makes the temperature field and flow rate of the aluminum liquid more uniform in the feed nozzle, effectively reducing the gaps caused by thermal stress during casting and rolling, and to a certain extent reducing centerline segregation, resulting in better alloy performance.

[0080] The difference between Comparative Example 4 and Comparative Example 1 lies in the addition of an electromagnetic stirrer to the front chamber. Electromagnetic stirring promotes the transformation of columnar crystals into equiaxed crystals and significantly refines the grain size. This is because electromagnetic stirring accelerates and alters the motion of the melt. This motion, on the one hand, continuously cools the melt at the mold walls, and on the other hand, brings hot metal back from the center region of the melt, causing the crystallization front to remelt. Therefore, electromagnetic stirring significantly reduces the temperature gradient of the melt, making the melt temperature more uniform over a larger area of ​​the crystallization front, leading to nucleation and crystallization extending towards the central region. Without electromagnetic stirring, as the percentage of solids increases, the viscosity of the mixture rises rapidly, fluidity decreases, and the growing dendrites easily connect with the outer shell, hindering not only the transport of metal particles during solidification but also the flow of the melt in the final stage of solidification. With electromagnetic stirring, the grain shape and size of the casting structure are altered, and the grains are significantly refined, thereby enhancing the alloy properties.

[0081] Comparative Example 5 differs from Comparative Example 1 in that the internal grooves of the water-cooled roller are shaped like a "well". Compared with traditional casting rollers, the cooling water can pass through the casting roller more evenly and stably, improving the cooling efficiency and reducing surface segregation, such as point segregation and strip segregation. This makes the alloy's properties more stable and its strength is improved to a certain extent.

[0082] The difference between Comparative Example 6 and Comparative Example 1 lies in the electromagnetic vibration process. Compared to the electromagnetic stirrer installed in the front chamber, electromagnetic vibration is more effective. It breaks up larger grains through vibration, provides activation energy to promote recrystallization, and can also release some stress to improve segregation. Electromagnetic vibration and electromagnetic stirring can also produce a synergistic effect, transforming the metallographic structure on the surface of the billet from the original columnar crystals to fine equiaxed crystals, achieving the best equiaxed grain refinement effect. This indicates that the grains broken up by vibration can rapidly diffuse into the melt under the action of electromagnetic stirring force, where they undergo complex processes such as friction, scouring, and local melting in the high-temperature liquid, causing the straight edges and sharp corners to disappear. Therefore, under the combined action of electromagnetic vibration and electromagnetic stirring, a large number of crystal nuclei can be generated in the liquid at the solidification front, greatly enhancing the inhibition of columnar crystals and significantly improving the alloy properties.

[0083] It should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the above description of exemplary embodiments of the invention. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in fewer than all the features of the foregoingly disclosed embodiments. Therefore, the claims, following the detailed description, are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0084] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-performance aluminum foil, characterized in that, Extremely thin aluminum foil with a thickness of 0.006 mm to 0.01 mm.

2. The high-performance aluminum foil according to claim 1, characterized in that, It includes the following components: Fe: 0.1~0.3wt%, Si: 0.1~0.15wt%, Cu: 0.01~0.05wt%, Ti≤0.05wt%, Sc: 0.05~0.2wt%, Zr: 0.05~0.2wt%, Ce≤0.1wt%, La≤0.1wt%, with the balance being Al.

3. The high-performance aluminum foil according to claim 1, characterized in that, The tensile strength, elongation, and electrical conductivity of the high-performance aluminum foil are 194.6-210.6 MPa, 11.4-13.0%, and 49.6-55.6%, respectively.

4. The processing and deformation process for a high-performance aluminum foil according to any one of claims 1 to 3, characterized in that, Includes the following steps: First, 99.9% high-purity aluminum and rare earth elements La and Ce are melted in a smelting furnace, with the furnace temperature controlled at 720~750℃. After the solid is completely melted, the slag is removed. Alloy element X is added in the form of Al-10X master alloy according to the amount of ingredients. Alloy element X includes Si, Cu, Ti, Sc and Zr. The melting time is 2h-3h, let stand for 15-30 minutes, stir for at least 5 minutes, take a sample for testing, and test whether the alloy content of the aluminum liquid is within the range of claim 2. If it is qualified, proceed to the next step to obtain aluminum liquid one. Then add a refining agent at a rate of 0.4-1.0% of the aluminum liquid's mass, pressing it to the bottom until no more bubbles appear. The processing time is 10-15 minutes. The gas inside the furnace is then evacuated to create a vacuum environment, with the vacuum level controlled within the medium vacuum range of 10. 2 ~10 -1 Then filter the waste residue. After cleaning the residue, sprinkle a covering agent on the surface. Use 0.7 to 1.1 kg per ton of aluminum liquid to obtain aluminum liquid two. The second aluminum liquid is cast using a four-roll casting process, which integrates solidification and deformation. It adopts an inclined injection method with the inclination angle controlled at 10°-15°. After the second aluminum liquid enters the melting cylinder, the pressure is provided by the front box, which is equipped with an electromagnetic stirrer with a stirring frequency of 15-20Hz. The second aluminum liquid is then pumped into the flow channel and fed into the casting roll gap from the feed nozzle. The pouring temperature is controlled between 680 and 710℃. Multiple block-shaped baffles are set between the upper and lower opposing blocks of the feed nozzle; After the second molten aluminum enters the molten pool, the liquid metal of the second molten aluminum gradually solidifies. The casting roll consists of a roll core and a roll sleeve. The roll core has main grooves and secondary grooves. The main grooves are connected to each other by the secondary grooves to form a grid shape. The roll core is drilled with holes as cooling water inlet holes. The roll sleeve matches the roll core. Cooling water flows out from the end of the roll core shaft. At the same time, an electromagnetic vibrator is installed on the casting roll with a vibration frequency of 100-120Hz. Vibration is used to increase the nucleation rate of the solidification process in the molten pool zone. After passing through the casting rolls, the aluminum liquid undergoes secondary cooling and solidification to form a 2 mm thick aluminum strip. Then it proceeds to the next rolling stage, with the reduction rate controlled between 15% and 30%, and the casting speed not exceeding 70m / min; Next, a short-time homogenization process is carried out, which utilizes the residual heat from melting for homogenization, followed by cold rolling. Cold rolling includes cold roughing and cold finishing; the single-pass reduction rate of cold roughing is 50% to 65%, the total number of cold rolling passes is 3 to 5, the rolling speed is ≤800m / min, the rolling oil temperature is controlled at 30~60℃, and a 0.5mm thick aluminum strip is obtained after cold roughing. The single-pass reduction rate of finishing rolling is 25% to 35%, the rolling speed is ≤800m / min, the rolling oil temperature is controlled at 30~60℃, and aluminum foil with a thickness of 0.03 to 0.2mm is pressed out after finishing rolling. Next, intermediate annealing is performed, with the annealing temperature controlled at T1 and the holding time at t1. Then aluminum foil rolling is performed, with a single pass reduction rate of 15% to 25%, and double rolling is used to press out extremely thin aluminum foil with a thickness of 0.006 mm to 0.01 mm. After the ultra-thin aluminum foil is finished, it is slit and then subjected to annealing and aging treatment. The annealing temperature is T2 and the holding time is t2 to obtain the finished product. Where 340℃≤T1≤400, 2h≤t1≤8h, 150℃≤T2≤250℃, and 1h≤t2≤4h.

5. The processing deformation process according to claim 4, characterized in that, Refining agents include zinc chloride.

6. The processing deformation process according to claim 4, characterized in that, The covering agent includes expanded perlite or expanded graphite.

7. The processing deformation process according to claim 4, characterized in that, The short-time homogenization process takes less than 30 minutes, which means that the residual heat from the melting process at 400℃-600℃ is used for homogenization.

8. The processing deformation process according to claim 4, characterized in that, The intermediate annealing temperature T1 for cold rolling is 380℃, and t1 is 6 hours; the temperature for simultaneous annealing and aging of the finished product is 200℃, and t2 is 2 hours.

9. The application of a high-performance aluminum foil according to any one of claims 1 to 3 in battery aluminum foil.

10. A battery aluminum foil, prepared from a high-performance aluminum foil as described in any one of claims 1 to 3.

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