Aluminium foil and manufacturing method thereof
Patent Information
- Authority / Receiving Office
- TW · TW
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-04-14
- Publication Date
- 2023-10-16
- Estimated Expiration
- Not applicable · inactive patent
Smart Images
Figure TWG2TA000928524_001 
Figure TWG2TA000928524_002
Abstract
Description
[Technical Field]
[0001] This invention relates to a method for preparing aluminum foil. This invention also relates to an aluminum foil obtained by the method described above. [Previous Technology]
[0002] The drawing depth and elongation of the flexible aluminum foil used in lithium batteries are closely related. Before lamination, the flexible aluminum foil must undergo a formation process, during which it is heated and subjected to tension, causing it to stretch and deform. After the formation process, its elongation is reduced. Therefore, the heat softening resistance of the flexible aluminum foil is very important; that is, the flexible aluminum foil must maintain high strength at the formation temperature to reduce deformation caused by tensile stretching.
[0003] Therefore, how to develop a heat-resistant aluminum foil with high tensile strength and high elongation is an urgent problem to be solved in this field. [Summary of the Invention]
[0004] In order to solve the problems of the prior art, the present invention aims to provide a method for preparing aluminum foil, which obtains heat-resistant aluminum foil with good mechanical properties at both room temperature and high temperature by treating aluminum blank with a homogenization temperature within a specific range and intermediate annealing thickness within a specific range.
[0005] Another object of the present invention is to provide an aluminum foil prepared by the aluminum foil preparation method of the present invention. The aluminum foil has a tensile strength between 95 MPa and 98 MPa at room temperature or a tensile strength between 66 MPa and 69 MPa at 130°C.
[0006] To achieve the above objective, the present invention provides a method for preparing aluminum foil, comprising the steps of: providing an aluminum billet; placing the aluminum billet in a homogenizing furnace and subjecting it to homogenization heat treatment within a temperature range of 500°C to 590°C to obtain a homogenized heat-treated aluminum billet (slab); placing the homogenized heat-treated aluminum billet in a heating furnace and holding it at a temperature range of 480°C to 530°C for 1 hour to 3 hours, followed by hot rolling to obtain a hot-rolled plate with a thickness between 2.5 mm and 4.5 mm; subsequently, subjecting the hot-rolled plate to a first cold rolling step, wherein the thickness of the hot-rolled plate after the first cold rolling step is between 0.4 mm and 0.9 mm, followed by intermediate annealing treatment within a temperature range of 320°C to 390°C, and then performing a second cold rolling step to obtain a thickness between 0.03 mm and 0.04 mm. Cold-rolled aluminum foil between mm; and finally annealing the cold-rolled aluminum foil in a temperature range of 260°C to 300°C to obtain aluminum foil.
[0007] In one specific embodiment, the step of providing the aluminum billet further includes the steps of: placing the aluminum alloy in a melting furnace for melting, then placing it in a refining and purification furnace for refining, and obtaining a first aluminum broth; pouring the first aluminum broth into a flow channel and degassing it in the flow channel, while adding an Al-Ti-B grain refiner; to obtain a second aluminum broth; and pouring the second aluminum broth into a semi-continuous casting machine to obtain the aluminum billet.
[0008] In one specific embodiment, the temperature of the homogenization heat treatment is between 500°C and 550°C.
[0009] In one specific embodiment, the temperature of the homogenization heat treatment is between 550°C and 590°C.
[0010] In one specific embodiment, the temperature of the homogenization heat treatment is between 580°C and 590°C.
[0011] In one specific embodiment, the thickness of the hot-rolled plate after the first cold rolling is between 0.8 mm and 0.9 mm.
[0012] In one specific embodiment, the elemental composition of the aluminum alloy, based on the total weight of the aluminum alloy, includes iron between 1.45 wt% and 1.55 wt%.
[0013] In one specific embodiment, the elemental composition of the aluminum alloy further includes copper between 0.01 wt% and 0.05 wt%, silicon between 0.01 wt% and 0.2 wt%, and titanium between 0.02 wt% and 0.04 wt%.
[0014] The present invention also provides an aluminum foil prepared by the above-described method, wherein the aluminum foil has a tensile strength between 95 MPa and 98 MPa at room temperature, or a tensile strength between 66 MPa and 69 MPa at 130°C.
[0015] In one specific embodiment, the aluminum foil has an elongation between 19% and 23% at room temperature.
[0016] The method for preparing aluminum foil of the present invention involves treating aluminum blanks at a homogenization temperature of 500°C to 590°C and an intermediate annealing thickness of 0.4 mm to 0.9 mm to obtain heat-resistant aluminum foil with good mechanical properties at both room temperature and high temperature.
Implementation Method
[0018] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can understand other advantages and effects of the present invention from the content disclosed in this specification. However, the exemplary embodiments disclosed in this invention are for illustrative purposes only and should not be considered as limiting the scope of the present invention. In other words, the present invention can also be implemented or applied through other different embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0019] Unless otherwise stated herein, the singular forms “a” and “the” used in the specification and the appended claims include the plural individuals. Unless otherwise stated herein, the term “or” used in the specification and the appended claims includes the meaning of “and / or”.
[0020] Examples 1 to 7: Preparation of the first to seventh aluminum foils
[0021] Referring to Figure 1, the method for preparing aluminum foil includes the following steps: Step 1 (S1): The aluminum alloy is placed in a melting furnace for melting, and then placed in a refining furnace for refining to obtain a first aluminum broth; the first aluminum broth is poured into a flow channel and degassed in the flow channel, while an Al-Ti-B grain refiner is added; to obtain a second aluminum broth, wherein, based on the total weight of the aluminum alloy, the elemental composition of the aluminum alloy includes iron between 1.45 wt% and 1.55 wt%, copper between 0.01 wt% and 0.05 wt%, silicon between 0.01 wt% and 0.2 wt%, and titanium between 0.02 wt% and 0.04 wt%, with the remainder being aluminum; Step 2 (S2): The second aluminum broth is poured into a semi-continuous casting machine to obtain an aluminum billet with a uniform and fine structure; Step 3 (S3): The aluminum billet is placed in a homogenizing furnace and subjected to homogenization heat treatment at a temperature range of 500°C to 590°C to obtain a homogenized aluminum billet; Step 4 (S4): The homogenized aluminum billet is placed in a heating furnace and held at a temperature range of 480°C to 530°C for 1 to 3 hours, and then hot-rolled to obtain a hot-rolled plate with a thickness between 2.5 mm and 4.5 mm; Step 5 (S5): The hot-rolled plate is first cold-rolled to a thickness between 0.4 mm and 0.9 mm, then subjected to intermediate annealing at a temperature range of 320°C to 390°C, and then subjected to a second cold rolling to obtain a cold-rolled aluminum foil with a thickness between 0.03 mm and 0.04 mm; and Step 6 (S6): The cold-rolled aluminum foil is finally annealed at a temperature range of 260°C to 300°C to obtain an aluminum foil.
[0022] The parameters of the homogenization heat treatment temperature used in step 3, the thickness of the hot-rolled plate obtained in step 4, the thickness of the hot-rolled plate used in step 5, the intermediate annealing temperature, the thickness of the cold-rolled aluminum foil obtained, and the final annealing temperature used in step 6 in Examples 1 to 7 are shown in Table 1. Table 1 Parameters for preparing aluminum foil in Examples 1 to 7 Aluminum foil Iron content (wt%) Homogenization temperature (°C) Thickness (mm) of hot-rolled sheet Intermediate annealing thickness / temperature (mm / ℃) Final annealing thickness / temperature (mm / ℃) Example 1 First aluminum foil 1.51 500 2.5 0.9 / 320 0.035 / 280 Example 2 Second aluminum foil 1.51 550 2.5 0.9 / 320 0.035 / 280 Example 3 Third aluminum foil 1.51 550 2.5 0.9 / 390 0.035 / 300 Example 4 Fourth aluminum foil 1.51 550 2.5 0.4 / 390 0.035 / 280 Example 5 Fifth aluminum foil 1.51 550 2.5 0.4 / 390 0.035 / 300 Example 6 Sixth aluminum foil 1.51 590 2.5 0.9 / 390 0.035 / 260 Example 7 Seventh aluminum foil 1.51 590 2.5 0.9 / 390 0.040 / 280
[0023] Comparative Examples 1 and 2: Preparation of the eighth and ninth aluminum foils
[0024] The methods for preparing aluminum foil in Comparative Examples 1 and 2 are generally the same as those in Examples 1 to 7. The difference is that the parameters used in Comparative Examples 1 and 2 for preparing aluminum foil, such as the temperature of the homogenization heat treatment used in step 3, the thickness of the hot-rolled plate obtained in step 4, the thickness of the hot-rolled plate used in step 5, the temperature of the intermediate annealing treatment, the thickness of the cold-rolled aluminum foil obtained, and the temperature of the final annealing treatment used in step 6, are shown in Table 2.
[0025] Table 2 Parameters for preparing aluminum foil in Comparative Examples 1 and 2 Comparative example Aluminum foil Iron content (wt%) Thickness (mm) of hot-rolled sheet Intermediate annealing thickness / temperature (mm / ℃) Final annealing thickness / temperature (mm / ℃) Comparative Example 1 Eighth aluminum foil 1.51 2.5 0.4 / 390 0.040 / 280 Comparative Example 2 Ninth Aluminum Foil 1.51 2.5 0.4 / 390 0.035 / 260
[0026] Example 2: Testing the mechanical properties of the first to ninth aluminum foils
[0027] The tensile strength (TS) and elongation (E1) of the first to ninth aluminum foils at room temperature were measured using a tensile testing machine, as well as the tensile strength of the first to ninth aluminum foils at 130°C. See Table 3. The results show that the first to seventh aluminum foils can produce more secondary precipitates when treated with a homogenization temperature of 500°C to 590°C, and can produce finer grains when treated with an intermediate annealing thickness of 0.4 mm to 0.9 mm. Based on this, the first to seventh aluminum foils with good mechanical properties at both room temperature and high temperature were obtained.
[0028] Table 3 Tensile strength and elongation of aluminum foils 1 to 9 Example Aluminum foil Mechanical properties of aluminum foil at room temperature Mechanical properties of aluminum foil at 130℃ Tensile strength (MPa) Elongation (%) Tensile strength (MPa) Example 1 First aluminum foil 97.6 20.4 68.6 Example 2 Second aluminum foil 97.0 19.8 67.9 Example 3 Third aluminum foil 96.5 20.0 67.1 Example 4 Fourth aluminum foil 95.2 19.8 66.8 Example 5 Fifth aluminum foil 96.2 19.3 66.5 Example 6 Sixth aluminum foil 95.8 21.6 67.2 Example 7 Seventh aluminum foil 97.5 22.2 68.1 Comparative Example 1 Eighth aluminum foil 90.2 20.3 60.5 Comparative Example 2 Ninth Aluminum Foil 91.5 19.5 61.2
[0029] As can be seen from the above, the aluminum foil preparation method of the present invention can obtain a heat-resistant aluminum foil with good mechanical properties at both room temperature and high temperature by treating the aluminum blank with a homogenization temperature of 500°C to 590°C and an intermediate annealing thickness of 0.4 mm to 0.9 mm.
[0030] The above embodiments are merely illustrative of the aluminum foil and its preparation method of the present invention, and are not intended to limit the present invention. Any person skilled in the art can modify and alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be as set forth in the following claims. [Simplified Explanation of the Diagram]
[0017] Figure 1 is a flowchart of the method for preparing aluminum foil according to the present invention.
Claims
1. A method for preparing aluminum foil, comprising the steps of: providing an aluminum billet; placing the aluminum billet in a homogenizing furnace and subjecting it to homogenization heat treatment at a temperature range of 500°C to 590°C to obtain a homogenized heat-treated aluminum billet; placing the homogenized heat-treated aluminum billet in a heating furnace and holding it at a temperature range of 480°C to 530°C for 1 hour to 3 hours, followed by hot rolling to obtain a hot-rolled plate with a thickness between 2.5 mm and 4.5 mm; subjecting the hot-rolled plate to a first cold rolling to a thickness between 0.4 mm and 0.9 mm, followed by intermediate annealing at a temperature range of 320°C to 390°C, and then performing a second cold rolling to obtain a cold-rolled aluminum foil with a thickness between 0.03 mm and 0.04 mm; and subjecting the cold-rolled aluminum foil to a final annealing at a temperature range of 260°C to 300°C to obtain the aluminum foil.
2. The preparation method as described in claim 1, wherein the step of providing the aluminum billet further includes the steps of: placing the aluminum alloy in a melting furnace for melting, and then placing it in a refining furnace for refining to obtain a first aluminum broth; pouring the first aluminum broth into a runner and degassing it in the runner while adding an Al-Ti-B grain refiner to obtain a second aluminum broth; and pouring the second aluminum broth into a semi-continuous casting machine to obtain the aluminum billet.
3. The preparation method as described in claim 1, wherein the temperature of the homogenization heat treatment is between 500°C and 550°C.
4. The preparation method as described in claim 1, wherein the temperature of the homogenization heat treatment is between 550°C and 590°C.
5. The preparation method as described in claim 1, wherein the temperature of the homogenization heat treatment is between 580°C and 590°C.
6. The preparation method as described in claim 4 or 5, wherein the thickness of the hot-rolled plate after the first cold rolling is between 0.8 mm and 0.9 mm.
7. The preparation method as described in claim 1, wherein the elemental composition of the aluminum alloy comprises between 1.45 wt% and 1.55 wt% iron based on the total weight of the aluminum alloy.
8. The preparation method as described in claim 7, wherein the elemental composition of the aluminum alloy further includes copper between 0.01 wt% and 0.05 wt%, silicon between 0.01 wt% and 0.2 wt%, and titanium between 0.02 wt% and 0.04 wt%.
9. An aluminum foil prepared by any one of claims 1 to 8, wherein the aluminum foil has a tensile strength between 95 MPa and 98 MPa at room temperature, or a tensile strength between 66 MPa and 69 MPa at 130°C.
10. The aluminum foil as claimed in claim 9, wherein the aluminum foil has an elongation between 19% and 23% at room temperature.