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CN-121992253-A - Ductile aluminum alloy and aluminum foil

CN121992253ACN 121992253 ACN121992253 ACN 121992253ACN-121992253-A

Abstract

The invention discloses a ductile aluminum alloy and an aluminum foil, wherein the aluminum alloy comprises, by mass, fe0.4110.424%, si0.2710.276%, ga0.0190.021%, ti0.0190.023%, cu <0.001%, mg <0.001%, and the balance of aluminum and impurities, and the Fe/Si ratio is preferably controlled to be 1.481.56, and the Ga/Ti ratio is 0.881.10. The invention also provides a method for rolling the aluminum foil by the aluminum alloy, which comprises the steps of continuously rolling the slab to the target thickness through multiple passes, and no intermediate annealing is needed in the whole rolling process. The aluminum alloy composition design ensures that the material has excellent cold rolling processability by controlling the second phase and promoting dynamic recovery, and can stably produce aluminum foil without intermediate annealing, thereby shortening the process flow and reducing the energy consumption and the cost.

Inventors

  • ZENG CHAOLIN
  • WANG ANXIANG
  • ZHENG LINKE

Assignees

  • 江阴新仁铝箔科技有限公司

Dates

Publication Date
20260508
Application Date
20251231

Claims (10)

  1. 1. A ductile aluminum alloy is characterized by comprising, by mass, 0.411-0.424% of Fe, 0.271-0.276% of Si, 0.019-0.021% of Ga, 0.019-0.023% of Ti, 0.001% of Mg, 0.001% of Cu, more than 99% of aluminum accounting for the total mass of the aluminum alloy, and the balance of unavoidable impurities.
  2. 2. The ductile aluminum alloy according to claim 1, wherein the Cu is <0.0006 wt%, the Mg is <0.0006 wt%.
  3. 3. The ductile aluminum alloy according to claim 1 further comprising, in mass%, mn, 0.0012 to 0.0034%, zn, 0.0040 to 0.0045%.
  4. 4. A ductile aluminum alloy according to claim 1 to 3, wherein the mass ratio of Fe element to Si element in the aluminum alloy is 1.48 to 1.56, and/or The mass ratio of Ga element to Ti element in the aluminum alloy is 0.88-1.10.
  5. 5. The ductile aluminum alloy according to claim 4, wherein the mass ratio of Fe element to Si element is 1.50 to 1.54, and/or The mass ratio of Ga element to Ti element is 0.90-1.05.
  6. 6. The ductile aluminum alloy according to claim 5 having, as measured according to GB/T228 standard: tensile strength of 215MPa or more, and/or Maximum elongation at force of 2.8% or more, and/or Tensile strength of 240MPa or more, and/or Elongation at break of 4.2% or more.
  7. 7. The ductile aluminum alloy according to claim 5 having an electrical conductivity of 60.5% iacs or more as measured according to GB/T12966-2022.
  8. 8. An aluminum foil, characterized by being rolled from the ductile aluminum alloy according to any one of claims 1 to 7.
  9. 9. The aluminum foil according to claim 8, wherein the rolling method comprises the steps of: s10, obtaining an aluminum alloy plate blank conforming to the content of the corresponding element; S20, rolling the aluminum alloy plate blank for multiple times to obtain an aluminum plate blank foil blank with the thickness of less than 280 mu m; S30, carrying out continuous multi-pass foil rolling on the aluminum plate blank foil blank, wherein the deformation of each pass of foil rolling is controlled to be 45-55%; s40, obtaining the finished aluminum foil with the thickness of 10-25 mu m.
  10. 10. The aluminum foil according to claim 9, wherein in the step S30, the aluminum foil comprises: s31, rolling the aluminum plate blank foil blank for the first time, wherein the rolling rate is controlled to be 52% -56%, and the rolling speed is set to be 600-800m/min; s32, rolling the foil subjected to the S31 rolling for the second pass, wherein the rolling rate is controlled to be 57% -61%, and the rolling speed is set to be 800-1200m/min; S33, rolling the foil subjected to S32 for the third time, wherein the rolling rate is controlled to be 46% -50%, and the rolling speed is set to be 800-1200m/min; And S34, performing fourth-pass rolling on the foil subjected to S33 rolling, controlling the rolling reduction to be 43% -47%, setting the rolling speed to be 500% -700 m/min, and obtaining the finished aluminum foil with the thickness of 12-16 mu m after rolling.

Description

Ductile aluminum alloy and aluminum foil Technical Field The invention relates to the field of aluminum alloy materials, in particular to a ductile aluminum alloy and an aluminum foil. Background The application field of aluminum foil as a basic metal material is expanding with the rise of new energy industry. Among them, the battery aluminum foil for lithium ion batteries has become a core class of high-end aluminum foil products. Unlike conventional packaging aluminum foil, battery aluminum foil not only requires a thickness typically between 10-20 microns, but also has nearly stringent requirements on the mechanical properties, surface quality, electrical conductivity and dimensional stability of the product. This determines that the aluminum alloy used therein should have high purity, excellent rolling plasticity and specific microstructure to meet the requirements of high-speed coating, mechanical strength and stable electrical conductivity during battery cycling. The production process flow of the battery aluminum foil mainly comprises the procedures of hot rolling, cold rolling, intermediate annealing, finished product finish rolling and the like. Among them, the annealing process is critical to control the microstructure of the aluminum foil, eliminate work hardening, and obtain the required strength and maximum force elongation. However, in order to achieve the balance between the extremely thin thickness and the strict energy index of the battery foil, multiple intermediate anneals are often required in the conventional process, which directly results in lengthy production flow, high energy consumption and increased cost, and becomes a bottleneck restricting the improvement of production efficiency and the control of cost. In the rolling process, when the production of the battery aluminum foil, particularly reaches the ultra-thin specification of 13 microns or below, the rolling mill is required to have extremely high precision and stability, and is extremely sensitive to the control of rolling process parameters. 1100 series aluminium alloy belongs to the category of industrial pure aluminium (aluminium content is more than or equal to 99.0%), and the addition amount of alloy elements is small. It is considered that the presence of metal impurities scatters electrons, reducing conductivity. The high purity characteristics allow 1100 series to have the most excellent conductivity and plasticity among the commonly used aluminum alloys. The 1100 series alloy shows excellent cold rolling processing performance, can bear higher rolling reduction, realizes stable rolling from blank to ultrathin foil, and is more suitable for battery aluminum foil. However, the 1100 series aluminum alloy has relatively high content of iron and silicon elements, and coarse or hard and brittle second phase particles are relatively easy to form. Under severe rolling deformation, these hard particles tend to initiate microcracks in the aluminum matrix or become stress concentration points, increasing the risk of rolling strip breakage. At the same time, they may also form minute bumps or scratches on the foil surface, affecting the finish and uniformity of the final product surface. In addition, 1100 series aluminum alloys tend to be work-hardened more strongly, and more complex or precise annealing regimes are often required to control grain size and texture in order to obtain soft finished products that meet the post-coating requirements. Chinese patent application (CN 118880086 a) discloses a method for preparing a battery aluminum foil. The method is technically characterized in that a casting-rolling blank-feeding mode is adopted to produce 1080-system aluminum alloy (Al is more than 99.80%), and the quantity and the size of harmful second-phase particles are reduced by strictly controlling the contents of Fe and Si and adding trace Cu and Ti and combining an intermediate complete annealing process under the protection of nitrogen. The scheme has the core advantages of effectively reducing the rolling breakage rate and simultaneously guaranteeing the high conductivity and good comprehensive mechanical properties of the product. However, the patent document still requires an annealing process to achieve a good rolling effect, and the process is long and high in cost. Chinese patent application (CN 116967284 a) discloses a medium-high voltage electronic aluminum foil for aluminum electrolytic capacitor and its preparation method. The aluminum raw material with extremely high purity is adopted, the hot rolling process is optimized again, the microstructure of the finished aluminum foil is improved by reducing the rolling pass and increasing the average pass reduction rate, and the linear aggregation of non-cubic grains is avoided. According to the scheme, excellent recrystallization texture is obtained through plastic processing technology regulation and control, so that the extremely high requirement of the electrolytic