Preparation method of double-zero foil blank and double-zero foil blank

Abstract

The invention provides a preparation method of a double-zero foil blank and the double-zero foil blank, and belongs to the technical field of aluminum foil manufacturing, and the preparation method comprises the following steps: step S1, heating and melting an electrolytic aluminum ingot, adding Al-50Fe and Al-10Mg, cooling, then adding Al-2Y and Al-2Sc, uniformly stirring, then adding core-shell structure alloy particles, continuously stirring, finally adding an Al-5Ti-1B refiner, performing ultrasonic treatment, introducing Ar, and cooling to obtain a blank; filtering to obtain molten aluminum; s2, the molten aluminum is injected into double-roller casting and rolling equipment for continuous casting and rolling, cooling is conducted, and a rough blank is obtained; the rough blank is subjected to soaking treatment, segmented rolling, plasma annealing and cooling, and an intermediate blank is obtained; and S3, the middle blank is subjected to cold rolling in the 0-degree direction, the 45-degree direction and the 90-degree direction correspondingly, then annealing and cooling are conducted, and the double-zero foil blank is obtained. The method can achieve the purposes that the plasticity and strength of the double-zero foil blank are balanced, the double-zero foil blank is not prone to fracture, and the surface quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum foil manufacturing, in particular to a preparation method of double-zero foil blank and double-zero foil blank. BACKGROUND

[0002] In the aluminum processing industry, double-zero aluminum foil is widely used in food packaging, medicine packaging, capacitors, tobacco packaging and other fields. Double-zero refers to a thickness usually less than 0.01mm, with extremely high thinness and excellent flexibility. Currently, in the industry, foil blank is usually prepared by hot rolling plus cold rolling, supplemented by a small amount of element (such as Fe, Si) ratio optimization to adjust the mechanical properties. However, this method has several technical bottlenecks. On the one hand, the traditional hot-rolled blank has a coarse primary crystal, and the work hardening rate is low, which is easy to produce fatigue cracks in multi-pass rolling; on the other hand, there is a lack of effective means to control the recrystallization behavior, resulting in unstable structure of the blank after medium annealing, affecting the strength and surface quality of the thin foil product, and limiting the comprehensive performance and line stability of the final foil.

[0003] The patent application file with publication number CN113305149A discloses a manufacturing method of double-zero aluminum foil blank one-time intermediate annealing, relating to the technical field of aluminum alloy foil processing. The chemical composition and mass percentage of aluminum alloy are as follows: Si 0.15-0.30%, Fe 0.70-0.90%, Cu≤0.05%, Mn≤0.03%, Mg≤0.03%, Cr≤0.02%, Zn≤0.10%, Ti 0.02-0.04%, and Al is the remainder. The finished product is made through the steps of melting, casting and rolling, cold rolling, intermediate annealing, edge cutting, secondary cold rolling, secondary edge cutting, foil rolling, slitting, and product annealing. Although the method shortens the production cycle of aluminum foil and improves production efficiency, the mechanical properties and surface quality of the aluminum foil blank prepared by the method are still insufficient.

[0004] Therefore, it is necessary to provide a preparation method of double-zero foil blank and double-zero foil blank to solve the problems existing in the prior art. SUMMARY

[0005] Therefore, the present application provides a preparation method of double-zero foil blank and double-zero foil blank, which can achieve the balance of plasticity and strength of double-zero foil blank, is not easy to break and improves the surface quality.

[0006] To achieve the above-mentioned purpose, the present application provides a preparation method of double-zero foil blank, comprising the following steps: Step S1, heat and melt the electrolytic aluminum ingot, add Al-50Fe and Al-10Mg, cool down, then add Al-2Y and Al-2Sc, after stirring uniformly, add the core-shell structure alloy particles and continue to stir, finally add Al-5Ti-1B refiner, ultrasonic treatment, Ar is introduced, filter, get the aluminum liquid; Step S2, pour the aluminum liquid into the double roll casting equipment for continuous casting, cool down, get the rough billet; heat treatment for the rough billet, then carry out segmented rolling, plasma annealing, cool down, get the intermediate billet. Step S3, cold rolling the intermediate billet in 0°, 45° and 90° directions respectively, then annealing, cool down, get the double zero foil billet.

[0007] After the aluminum ingot is completely melted, add aluminum-iron alloy and aluminum-magnesium alloy, so that Fe and Mg are dispersed in the aluminum melt, Mg atoms are in solid solution in α-Al and produce solute drag effect on dislocations and grain boundaries, which improves the deformation resistance and promotes the improvement of rolling plasticity; Fe can form fine and dense dispersion, which can pin the mother phase grain boundary through pinning effect during solidification and deformation, inhibit the growth of coarse grains and reduce pinholes. Add Al-2Y and Al-2Sc, Y has strong oxygen affinity, can react with impurities in the melt to form high melting point compounds, which is helpful to deep purification of the melt under the cooperation of ultrasonic degassing and ceramic filtration, so as to reduce inclusions and improve the cleanliness of the aluminum melt; Al3Y and Al3Sc can also be generated, Al3Y has low coarsening rate and strong thermal stability, which can continuously play the pinning effect and refine the grains; Al3Sc can provide pinning effect and nucleation promotion, while inhibiting recrystallization and coarsening, which also helps to improve the strength and thermal stability of the billet and keep good plasticity of the billet.

[0008] Al-5Ti-1B refiner is used for refining, and ultrasonic treatment is used. TiB2 particles in Al-5Ti-1B are insoluble heterogeneous nucleation substrates, which form an extremely thin Al3Ti film on the surface of TiB2 after entering the melt, improving the crystallographic matching and wettability with α-Al; ultrasonic treatment makes the cavitation bubbles in the liquid metal gather and collapse, producing micro-jet and high temperature and high pressure micro area, which can further scatter the oxide film and inclusions, promote the local rapid mixing of supersaturated alloy elements, significantly improve the density of primary crystal nucleus, and form fine equiaxed grains, reducing the holes and surface defects of the billet.

[0009] Plasma annealing method is used, the plasma contains a large number of high-energy electrons, ions and active free radicals, which can activate the surface atoms of the billet by bombarding the high-density point defects and dislocations on the surface of the billet, so as to improve the surface quality of the billet; at the same time, the trace oxide layer and organic contaminants on the surface of the billet can be removed, obtaining an ultra-clean surface and improving the subsequent billet forming.

[0010] Multi-directional rolling (0°, 45°, 90°) applies deformation in different directions, forces the grains to experience the start and rotation of different slip systems, disrupts the strong texture formed in a single direction, makes the grain orientation more randomly distributed in space, can significantly weaken the texture strength, reduce the anisotropy of mechanical properties, improve the deep drawing performance and transverse plasticity of the blank, and greatly reduce the risk of cracking and strip breaking caused by anisotropy during subsequent rolling of double zero foil.

[0011] Preferably, in the step S1, the temperature of heating and melting is 740-760℃; and the stirring uniformity time is 5-10min.

[0012] Preferably, in the step S1, the Ar flow rate is 6-10L / min.

[0013] Preferably, the molten aluminum includes the following raw materials in parts by weight: 100 parts of electrolytic aluminum ingot, 1.4-1.8 parts of Al-50Fe, 3-5 parts of Al-10Mg, 1-1.5 parts of Al-2Y, 0.5-0.75 parts of Al-2Sc, 0.2-0.4 parts of core-shell structure alloy particles, and 0.32-0.43 parts of Al-5Ti-1B.

[0014] Preferably, the preparation of the core-shell structure alloy particles includes the following steps: Under Ar atmosphere, the electrolytic aluminum is heated to complete melting, Al-2Sc and Al-10Hf are sequentially added and stirred, then the melt is poured on a water-cooled copper plate to obtain a rapidly cooled sheet, the sheet is heated and contacted with Al-5Er to diffuse and form a shell layer, and after cooling, it is cut into 0.5-0.8mm particles and dried to obtain the core-shell structure alloy particles.

[0015] By preparing the core-shell structure alloy particles, Al-2Sc and Al-10Hf as the core structure can preferentially produce L12 type dispersoids Al3(Sc,Hf), which is highly coherent with the matrix α-Al lattice and has a strong effect of pinning dislocations and grain boundaries, and Al-5Er can form a rich Er shell layer Al3Er by epitaxial deposition at the interface between the dispersoids and the matrix, thereby constructing a diffusion barrier outside the core and further inhibiting grain coarsening, thereby reducing the surface Ra and pinhole density and improving the surface quality of the blank.

[0016] Directly adding Al-2Sc, Al-10Hf and Al-5Er can cause simultaneous nucleation during casting and soaking, and when the nucleation density is too high for a short time, it can cause uneven distribution and increase defects; and the nucleation and growth speed is relatively fast, which can also easily cause coarsening, reduce the pinning effect, and further reduce the surface quality of the blank and cause strip breaking.

[0017] Preferably, in the step S2, the rough blank is subjected to the heat soaking treatment while a pulse magnetic field is applied, the pulse frequency is 8-12 Hz, and the magnetic field intensity is 0.8-1.2 T.

[0018] The magnetic field can induce micro-current and electromagnetic stirring in the metal liquid, can enhance the diffusion coefficient of Sc, Y, Hf and Er and other elements, can promote the uniform distribution of the elements, can form a perturbation to the solute / vacancy migration and dislocation movement, and can help the fine and uniform recrystallization nucleation; and in the process of dispersoid precipitation, the nucleation density can be improved and the coarsening can be inhibited, and in combination with the heat soaking treatment, finer and more uniform grains and higher dispersoid number density can be achieved, so that the ear height and the pinhole rate are reduced.

[0019] Preferably, in the step S2, the step-by-step rolling comprises the following steps: The first step is asynchronous warm rolling, the upper roller temperature is 200 DEG C, the lower roller temperature is 100 DEG C, and the rough blank is rolled to 3.6 mm; the second step is cold rolling, and the blank is rolled to 0.8 mm in 0 DEG, 45 DEG and 90 DEG directions.

[0020] The upper roller temperature is significantly higher than the lower roller temperature, so that the deformation resistance of the upper and lower layers of the blank is different (the high-temperature side is soft, and the low-temperature side is hard) and the deformation rate is different. This introduces strong additional shear strain between the upper and lower surfaces, promotes the cross-slip and uniform proliferation of dislocations, refines the grain / subgrain structure; improves the deformation uniformity in the thickness direction of the plate, reduces the residual stress; and helps to improve the uniformity of the strength and plasticity of the blank, and lays a better organizational foundation for subsequent cold rolling.

[0021] Preferably, in the step S2, the pressure of the plasma treatment in the plasma annealing is 50 Pa, the power is 350 W, the temperature is 350-450 DEG C, and the time is 3-5 min.

[0022] Preferably, in the step S3, the thickness of the blank after the cold rolling is completed is 0.22-0.35 mm; the annealing temperature is 280-320 DEG C, and the time is 1-1.5 h.

[0023] The final annealing mainly carries out the recovery process, a large number of dislocations on the surface of the blank form low-energy subgrain structures by rearrangement or annihilation, which can effectively eliminate internal stress and restore the plasticity of the blank, so as to facilitate the subsequent rolling of the double-zero foil; at the same time, the grain coarsening and strength loss can be avoided to the greatest extent, and the effects of fine-grain strengthening and dispersion strengthening can be maintained.

[0024] In order to achieve the above purpose, the application also provides a double-zero foil blank prepared by the preparation method of the double-zero foil blank.

[0025] The double-zero foil blank prepared by the method of the present invention can achieve a balance between plasticity and strength, making it less prone to breakage and improving surface quality.

[0026] The above-described technical solution of the present invention has at least the following beneficial effects: 1. By adding Al-2Y and Al-2Sc to molten aluminum, Al3Y and Al3Sc can be generated, which can act as pinning agents, inhibit abnormal recrystallization, refine grains, improve the strength and plasticity of the billet, and significantly improve the thermal stability of the billet.

[0027] 2. The Al-5Ti-1B refining agent is used in conjunction with ultrasonic treatment for refining. After entering the molten metal, the Al-5Ti-1B refining agent can improve the crystallographic matching and wettability with α-Al; ultrasonic treatment promotes the generation of microjets and high-temperature and high-pressure micro-regions, thereby breaking down the oxide film and inclusions, promoting the local rapid mixing of supersaturated alloying elements, significantly increasing the density of primary crystal nuclei, forming fine equiaxed crystals, and reducing the porosity and surface defects of the billet.

[0028] 3. By adopting a multi-directional rolling method, deformation is applied in different directions to disrupt the strong texture formed by grains in a single direction, making the grain orientation more randomly distributed in space. This can significantly weaken the texture strength, reduce the anisotropy of mechanical properties, and greatly reduce the risk of cracking and strip breakage caused by anisotropy during subsequent rolling of double zero foil. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are some embodiments of the present invention, and all other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0030] Example 1 Under an Ar atmosphere, 10g of electrolytic aluminum was heated to 750℃ and completely melted. Then, 1.4g of Al-2Sc and 0.07g of Al-10Hf were added sequentially and stirred for 5 minutes. The melt was then poured onto a water-cooled copper plate to obtain a 1-2mm thick quenched sheet. The sheet was placed at 550℃ and diffused with 2.9g of Al-5Er. The temperature was maintained for 25 minutes to form a shell. After cooling, the sheet was cut into 0.5mm particles and dried at 120℃ for 2 hours to obtain core-shell structured alloy particles.

[0031] 100g of electrolytic aluminum ingot was added to a furnace and heated to 750℃ until completely melted. Then, 1.6g of Al-50Fe and 4g of Al-10Mg were added sequentially. The temperature was then lowered to 720℃, and 1g of Al-2Y and 0.75g of Al-2Sc were added. The mixture was stirred at 150rpm for 8min. 0.3g of core-shell alloy particles preheated at 400℃ for 10min were added and stirred continuously for 90s. Then, 0.38g of Al-5Ti-1B refining agent was added. The mixture was ultrasonically treated at a frequency of 20kHz and a power of 600W for 10min. Ar gas was introduced at a flow rate of 8L / min for 15min. The mixture was then allowed to stand for 5min and filtered through a 30μm ceramic filter plate to obtain molten aluminum.

[0032] Molten aluminum is injected into a twin-roll casting and rolling mill for continuous casting and rolling. The inlet temperature is 710℃, the outlet temperature is 690℃, and the casting speed is 2m / min. The roll surface temperature is 200℃. The thickness of the cast billet is 5.8-6.2mm. After casting and rolling, a closed-loop spray water cooling system is used for rapid cooling. The cooling water temperature is 18-25℃ to obtain a rough billet.

[0033] The rough billet was subjected to homogenization heat treatment while a pulsed magnetic field of 1.0T / 10Hz was applied, and the temperature was raised to 520℃ at a rate of 50℃ / min, held for 40min, then lowered to 470℃ and held for 3h. After the holding period, it was rapidly air-cooled and then subjected to segmented rolling. The lubricant used was an industrial emulsion with a viscosity of 15-25cP and 0.1% boron nitride nanosheets. The first segment used asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, to cold roll the billet to 3.6mm. The second segment was cold rolling. The billet is rolled at 0° to 2.4 mm, at 45° to 1.2 mm, and at 90° to 0.8 mm. It is then transferred to a plasma annealing furnace and subjected to plasma treatment in a vacuum environment with H2 / Ar in a 1:1 volume ratio. The pressure is 50 Pa, the power is 350 W, the temperature is 400 °C, and the treatment time is 4 min. After annealing, it is air-cooled in an inert atmosphere to obtain an intermediate billet.

[0034] The intermediate billet is cold-rolled again, rolled at 0° to 0.6 mm, rolled at 45° to 0.4 mm, and rolled at 90° to 0.22-0.35 mm. It is then annealed again by placing the billet in an annealing furnace at 280°C for 1.5 hours and allowing it to cool naturally to obtain the double-zero foil billet.

[0035] Example 2 Under an Ar atmosphere, 10g of electrolytic aluminum was heated to 750℃ and completely melted. Then, 1.4g of Al-2Sc and 0.07g of Al-10Hf were added sequentially and stirred for 5 minutes. The melt was then poured onto a water-cooled copper plate to obtain a 1-2mm thick quenched sheet. The sheet was placed at 550℃ and diffused with 2.9g of Al-5Er. The temperature was maintained for 25 minutes to form a shell. After cooling, the sheet was cut into 0.5mm particles and dried at 120℃ for 2 hours to obtain core-shell structured alloy particles.

[0036] 100g of electrolytic aluminum ingot was added to a furnace and heated to 760℃ until completely melted. Then, 1.4g of Al-50Fe and 3g of Al-10Mg were added sequentially. The temperature was then lowered to 720℃, and 1.5g of Al-2Y and 0.75g of Al-2Sc were added. The mixture was stirred at 200rpm for 5min. 0.2g of core-shell alloy particles preheated at 400℃ for 10min were added and stirred continuously for 90s. Then, 0.43g of Al-5Ti-1B refining agent was added. The mixture was ultrasonically treated at a frequency of 20kHz and a power of 600W for 10min. Ar gas was introduced at a flow rate of 7L / min for 15min. The mixture was then allowed to stand for 5min and filtered through a 30μm ceramic filter plate to obtain molten aluminum.

[0037] Molten aluminum is injected into a twin-roll casting and rolling mill for continuous casting and rolling. The inlet temperature is 710℃, the outlet temperature is 690℃, and the casting speed is 1.9m / min. The roll surface temperature is 190℃. The thickness of the cast billet is 5.8-6.2mm. After casting and rolling, a closed-loop spray water cooling system is used for rapid cooling. The cooling water temperature is 18-25℃ to obtain a rough billet.

[0038] The rough billet was subjected to homogenization heat treatment while a pulsed magnetic field of 1.1T / 12Hz was applied, and the temperature was raised to 520℃ at a rate of 50℃ / min, held for 40min, then lowered to 470℃ and held for 3h. After the holding period, it was rapidly air-cooled and then subjected to segmented rolling. The lubricant used was an industrial emulsion with a viscosity of 15-25cP and 0.1% boron nitride nanosheets. The first segment used asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, to cold roll the billet to 3.6mm. The second segment was cold rolling. The billet is rolled at 0° to 2.4 mm, at 45° to 1.2 mm, and at 90° to 0.8 mm. It is then transferred to a plasma annealing furnace and subjected to plasma treatment in a vacuum environment with H2 / Ar in a 1:1 volume ratio. The pressure is 50 Pa, the power is 350 W, the temperature is 350 °C, and the treatment time is 5 min. After annealing, it is air-cooled in an inert atmosphere to obtain an intermediate billet.

[0039] The intermediate billet is cold-rolled again, rolled at 0° to 0.6 mm, rolled at 45° to 0.4 mm, and rolled at 90° to 0.22-0.35 mm. It is then annealed again by placing the billet in an annealing furnace at 320°C for 1 hour and allowing it to cool naturally to obtain the double-zero foil billet.

[0040] Example 3 Under an Ar atmosphere, 10g of electrolytic aluminum was heated to 750℃ and completely melted. Then, 1.4g of Al-2Sc and 0.07g of Al-10Hf were added sequentially and stirred for 5 minutes. The melt was then poured onto a water-cooled copper plate to obtain a 1-2mm thick quenched sheet. The sheet was placed at 550℃ and diffused with 2.9g of Al-5Er. The temperature was maintained for 25 minutes to form a shell. After cooling, the sheet was cut into 0.6mm particles and dried at 120℃ for 2 hours to obtain core-shell structured alloy particles.

[0041] 100g of electrolytic aluminum ingot was added to a furnace and heated to 740℃ until completely melted. Then, 1.8g of Al-50Fe and 5g of Al-10Mg were added sequentially. The temperature was then lowered to 720℃, and 1g of Al-2Y and 0.5g of Al-2Sc were added. The mixture was stirred at 100rpm for 10min. 0.4g of core-shell alloy particles preheated at 400℃ for 10min were added and stirred continuously for 90s. Then, 0.32g of Al-5Ti-1B refining agent was added. The mixture was ultrasonically treated at a frequency of 20kHz and a power of 600W for 10min. Ar gas was introduced at a flow rate of 9L / min for 15min. The mixture was then allowed to stand for 5min and filtered through a 30μm ceramic filter plate to obtain molten aluminum.

[0042] Molten aluminum is injected into a twin-roll casting and rolling mill for continuous casting and rolling. The inlet temperature is 710℃, the outlet temperature is 690℃, and the casting speed is 2.1m / min. The roll surface temperature is 200℃. The thickness of the cast billet is 5.8-6.2mm. After casting and rolling, a closed-loop spray water cooling system is used for rapid cooling. The cooling water temperature is 18-25℃ to obtain a rough billet.

[0043] The rough billet was subjected to homogenization heat treatment while a pulsed magnetic field of 0.9T / 9Hz was applied, and the temperature was raised to 520℃ at a rate of 50℃ / min, held for 40min, then lowered to 470℃ and held for 3h. After the holding period, it was rapidly air-cooled and then subjected to segmented rolling. The lubricant used was an industrial emulsion with a viscosity of 15-25cP and 0.1% boron nitride nanosheets. The first segment used asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, to cold roll the billet to 3.6mm. The second segment was cold rolling. The billet is rolled at 0° to 2.4 mm, at 45° to 1.2 mm, and at 90° to 0.8 mm. It is then transferred to a plasma annealing furnace and subjected to plasma treatment in a vacuum environment with H2 / Ar in a 1:1 volume ratio. The pressure is 50 Pa, the power is 350 W, the temperature is 400 °C, and the treatment time is 4 min. After annealing, it is air-cooled in an inert atmosphere to obtain an intermediate billet.

[0044] The intermediate billet is cold-rolled again, rolled at 0° to 0.6 mm, rolled at 45° to 0.4 mm, and rolled at 90° to 0.22-0.35 mm. It is then annealed again by placing the billet in an annealing furnace at 300°C for 1.5 hours and allowing it to cool naturally to obtain the double-zero foil billet.

[0045] Example 4 Under an Ar atmosphere, 10g of electrolytic aluminum was heated to 750℃ and completely melted. Then, 1.4g of Al-2Sc and 0.07g of Al-10Hf were added sequentially and stirred for 5 minutes. The melt was then poured onto a water-cooled copper plate to obtain a 1-2mm thick quenched sheet. The sheet was placed at 550℃ and diffused with 2.9g of Al-5Er. The temperature was maintained for 25 minutes to form a shell. After cooling, the sheet was cut into 0.8mm particles and dried at 120℃ for 2 hours to obtain core-shell structured alloy particles.

[0046] 100g of electrolytic aluminum ingot was added to a furnace and heated to 750℃ until completely melted. Then, 1.6g of Al-50Fe and 5g of Al-10Mg were added sequentially. The temperature was then lowered to 720℃, and 1g of Al-2Y and 0.6g of Al-2Sc were added. The mixture was stirred at 150rpm for 8min. 0.25g of core-shell alloy particles preheated at 400℃ for 10min were added and stirred continuously for 90s. Then, 0.4g of Al-5Ti-1B refining agent was added. The mixture was ultrasonically treated at a frequency of 20kHz and a power of 600W for 10min. Ar gas was introduced at a flow rate of 6L / min for 15min. The mixture was then allowed to stand for 5min and filtered through a 30μm ceramic filter plate to obtain molten aluminum.

[0047] Molten aluminum is injected into a twin-roll casting and rolling mill for continuous casting and rolling. The inlet temperature is 710℃, the outlet temperature is 690℃, and the casting speed is 1.9m / min. The roll surface temperature is 195℃. The thickness of the cast billet is 5.8-6.2mm. After casting and rolling, a closed-loop spray water cooling system is used for rapid cooling. The cooling water temperature is 18-25℃ to obtain a rough billet.

[0048] The rough billet was subjected to homogenization heat treatment while a pulsed magnetic field of 1.2T / 12Hz was applied, and the temperature was raised to 520℃ at a rate of 50℃ / min, held for 40min, then lowered to 470℃ and held for 3h. After the holding period, it was rapidly air-cooled and then subjected to segmented rolling. The lubricant used was an industrial emulsion with a viscosity of 15-25cP and 0.1% boron nitride nanosheets. The first segment used asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, to cold roll the billet to 3.6mm. The second segment was cold rolling. The billet is rolled at 0° to 2.4 mm, at 45° to 1.2 mm, and at 90° to 0.8 mm. It is then transferred to a plasma annealing furnace and subjected to plasma treatment in a vacuum environment. The furnace is filled with H2 / Ar in a 1:1 volume ratio. The pressure is 50 Pa, the power is 350 W, the temperature is 450 °C, and the treatment time is 3 min. After annealing, the billet is air-cooled in an inert atmosphere to obtain an intermediate billet.

[0049] The intermediate billet is cold-rolled again, rolled at 0° to 0.6 mm, rolled at 45° to 0.4 mm, and rolled at 90° to 0.22-0.35 mm. It is then annealed again by placing the billet in an annealing furnace at 320°C for 1 hour and allowing it to cool naturally to obtain the double-zero foil billet.

[0050] Example 5 Under an Ar atmosphere, 10g of electrolytic aluminum was heated to 750℃ and completely melted. Then, 1.4g of Al-2Sc and 0.07g of Al-10Hf were added sequentially and stirred for 5 minutes. The melt was then poured onto a water-cooled copper plate to obtain a 1-2mm thick quenched sheet. The sheet was placed at 550℃ and diffused with 2.9g of Al-5Er. The temperature was maintained for 25 minutes to form a shell. After cooling, the sheet was cut into 0.7mm particles and dried at 120℃ for 2 hours to obtain core-shell structured alloy particles.

[0051] 100g of electrolytic aluminum ingot was added to a furnace and heated to 740℃ until completely melted. Then, 1.8g of Al-50Fe and 4g of Al-10Mg were added sequentially. The temperature was then lowered to 720℃, and 1.5g of Al-2Y and 0.5g of Al-2Sc were added. The mixture was stirred at 200rpm for 5min. 0.35g of core-shell alloy particles preheated at 400℃ for 10min were added and stirred continuously for 90s. Then, 0.43g of Al-5Ti-1B refining agent was added. The mixture was ultrasonically treated at a frequency of 20kHz and a power of 600W for 10min. Ar gas was introduced at a flow rate of 10L / min for 15min. The mixture was then allowed to stand for 5min and filtered through a 30μm ceramic filter plate to obtain molten aluminum.

[0052] Molten aluminum is injected into a twin-roll casting and rolling mill for continuous casting and rolling. The inlet temperature is 710℃, the outlet temperature is 690℃, and the casting speed is 2m / min. The roll surface temperature is 200℃. The thickness of the cast billet is 5.8-6.2mm. After casting and rolling, a closed-loop spray water cooling system is used for rapid cooling. The cooling water temperature is 18-25℃ to obtain a rough billet.

[0053] The rough billet was subjected to homogenization heat treatment while a pulsed magnetic field of 0.8T / 8Hz was applied, and the temperature was raised to 520℃ at a rate of 50℃ / min, held for 40min, then lowered to 470℃ and held for 3h. After the holding period, it was rapidly air-cooled and then subjected to segmented rolling. The lubricant used was an industrial emulsion with a viscosity of 15-25cP and 0.1% boron nitride nanosheets. The first segment used asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, to cold roll the billet to 3.6mm. The second segment was cold rolling. The billet is rolled at 0° to 2.4 mm, at 45° to 1.2 mm, and at 90° to 0.8 mm. It is then transferred to a plasma annealing furnace and subjected to plasma treatment in a vacuum environment with H2 / Ar in a 1:1 volume ratio. The pressure is 50 Pa, the power is 350 W, the temperature is 350 °C, and the treatment time is 5 min. After annealing, it is air-cooled in an inert atmosphere to obtain an intermediate billet.

[0054] The intermediate billet is cold-rolled again, rolled at 0° to 0.6 mm, rolled at 45° to 0.4 mm, and rolled at 90° to 0.22-0.35 mm. It is then annealed again by placing the billet in an annealing furnace at 300°C for 1.2 hours and allowing it to cool naturally to obtain the double-zero foil billet.

[0055] Example 6 Under an Ar atmosphere, 10g of electrolytic aluminum was heated to 750℃ and completely melted. Then, 1.4g of Al-2Sc and 0.07g of Al-10Hf were added sequentially and stirred for 5 minutes. The melt was then poured onto a water-cooled copper plate to obtain a 1-2mm thick quenched sheet. The sheet was placed at 550℃ and allowed to diffuse in contact with 2.9g of Al-5Er. The temperature was maintained for 25 minutes to form a shell. After cooling, the sheet was cut into 1mm particles and dried at 120℃ for 2 hours to obtain core-shell structured alloy particles.

[0056] 100g of electrolytic aluminum ingot was added to a furnace and heated to 750℃ until completely melted. Then, 1.5g of Al-50Fe and 4.5g of Al-10Mg were added sequentially. The temperature was then lowered to 720℃, and 1g of Al-2Y and 0.5g of Al-2Sc were added. The mixture was stirred at 200rpm for 5min. 0.3g of core-shell alloy particles preheated at 400℃ for 10min were added and stirred continuously for 90s. Then, 0.4g of Al-5Ti-1B refining agent was added. The mixture was ultrasonically treated at a frequency of 20kHz and a power of 600W for 10min. Ar gas was introduced at a flow rate of 8L / min for 15min. The mixture was then allowed to stand for 5min and filtered through a 30μm ceramic filter plate to obtain molten aluminum.

[0057] Molten aluminum is injected into a twin-roll casting and rolling mill for continuous casting and rolling. The inlet temperature is 710℃, the outlet temperature is 690℃, and the casting speed is 2.1m / min. The roll surface temperature is 195℃. The thickness of the cast billet is 5.8-6.2mm. After casting and rolling, a closed-loop spray water cooling system is used for rapid cooling. The cooling water temperature is 18-25℃ to obtain a rough billet.

[0058] The rough billet was subjected to homogenization heat treatment while a pulsed magnetic field of 1.0T / 10Hz was applied, and the temperature was raised to 520℃ at a rate of 50℃ / min, held for 40min, then lowered to 470℃ and held for 3h. After the holding period, it was rapidly air-cooled and then subjected to segmented rolling. The lubricant used was an industrial emulsion with a viscosity of 15-25cP and 0.1% boron nitride nanosheets. The first segment used asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, to cold roll the billet to 3.6mm. The second segment was cold rolling. The billet is rolled at 0° to 2.4 mm, at 45° to 1.2 mm, and at 90° to 0.8 mm. It is then transferred to a plasma annealing furnace and subjected to plasma treatment in a vacuum environment. The furnace is filled with H2 / Ar in a 1:1 volume ratio. The pressure is 50 Pa, the power is 350 W, the temperature is set to 400 °C, and the treatment time is 5 min. After annealing, the billet is air-cooled in an inert atmosphere to obtain an intermediate billet.

[0059] The intermediate billet is cold-rolled again, rolled at 0° to 0.6 mm, rolled at 45° to 0.4 mm, and rolled at 90° to 0.22-0.35 mm. It is then annealed again by placing the billet in an annealing furnace at 280°C for 1.5 hours and allowing it to cool naturally to obtain the double-zero foil billet.

[0060] Example 7 Under an Ar atmosphere, 10g of electrolytic aluminum was heated to 750℃ and completely melted. Then, 1.4g of Al-2Sc and 0.07g of Al-10Hf were added sequentially and stirred for 5 minutes. The melt was then poured onto a water-cooled copper plate to obtain a 1-2mm thick quenched sheet. The sheet was placed at 550℃ and diffused with 2.9g of Al-5Er. The temperature was maintained for 25 minutes to form a shell. After cooling, the sheet was cut into 0.8mm particles and dried at 120℃ for 2 hours to obtain core-shell structured alloy particles.

[0061] 100g of electrolytic aluminum ingot was added to a furnace and heated to 750℃ until completely melted. Then, 1.5g of Al-50Fe and 4.5g of Al-10Mg were added sequentially. The temperature was then lowered to 720℃, and 1g of Al-2Y and 0.5g of Al-2Sc were added. The mixture was stirred at 200rpm for 5min. 0.3g of core-shell alloy particles preheated at 400℃ for 10min were added and stirred continuously for 90s. Then, 0.4g of Al-5Ti-1B refining agent was added. The mixture was ultrasonically treated at a frequency of 20kHz and a power of 600W for 10min. Ar gas was introduced at a flow rate of 8L / min for 15min. The mixture was then allowed to stand for 5min and filtered through a 30μm ceramic filter plate to obtain molten aluminum.

[0062] Molten aluminum is injected into a twin-roll casting and rolling mill for continuous casting and rolling. The inlet temperature is 710℃, the outlet temperature is 690℃, and the casting speed is 2.1m / min. The roll surface temperature is 195℃. The thickness of the cast billet is 5.8-6.2mm. After casting and rolling, a closed-loop spray water cooling system is used for rapid cooling. The cooling water temperature is 18-25℃ to obtain a rough billet.

[0063] The rough billet was subjected to homogenization heat treatment, with the temperature increased to 520℃ at a rate of 50℃ / min and held for 40 min. It was then cooled to 470℃ and held for 3 h. After the holding period, it was rapidly air-cooled and subjected to segmented rolling. The lubricant used was an industrial emulsion with a viscosity of 15-25 cP and 0.1% boron nitride nanosheets. The first segment used asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, cold rolling the billet to 3.6 mm. The second segment was cold rolling, rolled at 0°. The billet is rolled to 2.4 mm; rolled at 45° to 1.2 mm, rolled at 90° to 0.8 mm, and then transferred to a plasma annealing furnace. Under vacuum, H2 / Ar is introduced with a volume ratio of 1:1 for plasma treatment at a pressure of 50 Pa, a power of 350 W, a temperature of 400 °C, and a treatment time of 5 min. After annealing, the billet is air-cooled in an inert atmosphere to obtain an intermediate billet.

[0064] The intermediate billet is cold-rolled again, rolled at 0° to 0.6 mm, rolled at 45° to 0.4 mm, and rolled at 90° to 0.22-0.35 mm. It is then annealed again by placing the billet in an annealing furnace at 280°C for 1.5 hours and allowing it to cool naturally to obtain the double-zero foil billet.

[0065] The present invention also includes comparative examples and related experiments.

[0066] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that Al-2Y and Al-2Sc were not added in Comparative Example 1, but Al was used instead. The other components and preparation methods were the same as in Example 1, and a double zero foil blank was prepared.

[0067] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that core-shell structured alloy particles were not used in Comparative Example 2, but Al was used instead. The other composition and preparation method were the same as in Example 1, and a double zero foil blank was prepared.

[0068] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 was not subjected to multi-directional (0°, 45°, 90°) rolling, but the other components and preparation methods were the same as those in Example 1, and a double zero foil blank was prepared.

[0069] Performance testing According to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Test method at room temperature", the tensile strength and elongation of the double-zero foil blanks prepared in Examples 1-7 and Comparative Examples 1-3 were tested. Specimens with a width of 15 mm and a gauge length of 50 mm were taken, and the strain rate was 2 mm / min. The tensile strength of the specimens was then tested. Samples were then taken at 0° and 90° along the rolling direction for elongation testing. According to GB / T 2523-2019 "Method for measuring surface roughness of cold-rolled metal sheets (strips)," the surface roughness of the double-zero foil blanks prepared in Examples 1-7 and Comparative Examples 1-3 was tested. The sampling length was 0.8 mm. Five points were randomly selected on the surface of the blank sample for measurement, and the arithmetic mean was taken. According to GB / T 3198-2020 "Aluminum and Aluminum Alloy Foil", the number of pinholes in the double-zero foil blanks prepared in Examples 1-7 and Comparative Examples 1-3 was tested using the light transmission method. The test results are summarized in Table 1.

[0070] Table 1

[0071] As shown in Table 1, the tensile strength and elongation of the billet prepared in Comparative Example 1 decreased significantly compared with that in Example 1, indicating that Al-2Y and Al-2Sc can generate Al3Y and Al3Sc, exerting a pinning effect and refining the grains, thereby improving the strength and plasticity of the billet. Compared with Example 1, Comparative Example 2 showed a significant increase in the number of pinholes, indicating that the core-shell structure alloy particles help to suppress grain coarsening, thereby reducing pinholes and improving the surface quality of the billet. Compared with the billet prepared in Example 1, the elongation of the billet prepared in Comparative Example 3 at 90° of the rolling direction decreased significantly, indicating that multi-directional rolling helps to weaken the texture strength, reduce the anisotropy of mechanical properties, and improve the plasticity of the billet.

[0072] The difference between Example 7 and Example 6 is that no magnetic field was applied during the homogenization heat treatment in Example 7. As a result, the test results of various properties of the billet obtained in Example 7 were all lower than those in Example 6. This indicates that the magnetic field can enhance the diffusion coefficient of elements such as Sc, Y, Hf and Er, promote the uniform distribution of elements, obtain finer and more uniform grains and higher dispersion number density, thereby reducing pinholes.

[0073] The above are preferred embodiments of the present invention. Those skilled in the art can make several improvements and modifications 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 method for preparing a double-zero foil blank, characterized in that, Includes the following steps: Step S1: Heat and melt the electrolytic aluminum ingot, add Al-50Fe and Al-10Mg, cool down, then add Al-2Y and Al-2Sc, stir evenly, add core-shell structured alloy particles and continue stirring, finally add Al-5Ti-1B refining agent, sonicate, introduce Ar, filter, and obtain aluminum liquid. Step S2: Inject molten aluminum into a twin-roll casting and rolling mill for continuous casting and rolling, and then cool it to obtain a rough billet; The rough billet is subjected to homogenization heat treatment, followed by segmented rolling, plasma annealing, and cooling to obtain the intermediate billet; Step S3: The intermediate billet is cold rolled at 0°, 45° and 90° respectively, then annealed and cooled to obtain a double zero foil billet.

2. The method for preparing a double-zero foil blank according to claim 1, characterized in that, In step S1, the heating and melting temperature is 740-760℃; the stirring time is 5-10 minutes.

3. The method for preparing a double-zero foil blank according to claim 1, characterized in that, In step S1, the Ar flow rate is 6-10 L / min.

4. The method for preparing a double-zero foil blank according to claim 1, characterized in that, The molten aluminum comprises the following raw materials in parts by weight: 100 parts of electrolytic aluminum ingot, 1.4-1.8 parts of Al-50Fe, 3-5 parts of Al-10Mg, 1-1.5 parts of Al-2Y, 0.5-0.75 parts of Al-2Sc, 0.2-0.4 parts of core-shell structured alloy particles, and 0.32-0.43 parts of Al-5Ti-1B.

5. The method for preparing a double-zero foil blank according to claim 1, characterized in that, The preparation of the core-shell structured alloy particles includes the following steps: Under an Ar atmosphere, electrolytic aluminum is heated to complete melting, and Al-2Sc and Al-10Hf are added sequentially and stirred. The melt is then poured onto a water-cooled copper plate to obtain a rapidly cooled thin plate. The thin plate is then heated and diffused with Al-5Er to form a shell. After cooling, it is cut into 0.5-0.8 mm particles, dried, and core-shell structured alloy particles are obtained.

6. The method for preparing a double-zero foil blank according to claim 1, characterized in that, In step S2, while the billet is subjected to homogenization heat treatment, a pulsed magnetic field is also applied, with a pulse frequency of 8-12Hz and a magnetic field strength of 0.8-1.2T.

7. The method for preparing a double-zero foil blank according to claim 1, characterized in that, In step S2, the segmented rolling process includes the following steps: The first stage uses asynchronous warm rolling, with the upper roll temperature at 200℃ and the lower roll temperature at 100℃, rolling the rough billet to 3.6mm; the second stage uses cold rolling, which is performed in the 0°, 45° and 90° directions respectively, rolling the billet to 0.8mm.

8. The method for preparing a double-zero foil blank according to claim 1, characterized in that, In step S2, the plasma treatment pressure during plasma annealing is 50 Pa, the power is 350 W, the temperature is 350-450 °C, and the time is 3-5 min.

9. The method for preparing a double-zero foil blank according to claim 1, characterized in that, In step S3, the thickness of the billet after cold rolling is 0.22-0.35 mm; the annealing temperature is 280-320℃ and the time is 1-1.5 h.

10. A double-zero foil blank, characterized in that, It is prepared by the method for preparing a double-zero foil blank according to any one of claims 1-9.

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