High-strength 3-series aluminum alloy extrusion profile, preparation method thereof and application of high-strength 3-series aluminum alloy extrusion profile in energy storage device

Abstract

The invention belongs to the technical field of aluminum alloy extrusion profiles, and relates to a high-strength 3-series aluminum alloy extrusion profile, a preparation method thereof and application of the high-strength 3-series aluminum alloy extrusion profile in an energy storage device. According to the high-performance 3-series aluminum alloy and the profile preparation method thereof, when the relation that Mn + Si + Zr + Sn is larger than or equal to 1.70 wt% and smaller than or equal to 2.5 wt% is met, the tensile strength Rm of the whole 3-series aluminum alloy is larger than or equal to 150 MPa, the yield strength Rp0.2 is larger than or equal to 110 MPa, the ductility A50 is larger than or equal to 10%, remarkable technical progress is brought to the energy storage industry, the problems existing in a traditional process are solved, and the energy storage efficiency is improved. And the requirements of the industry for light weight, high strength and corrosion resistance are met, and the development of the energy storage industry is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy extruded profiles, and relates to a high-strength 3-series aluminum alloy extruded profile, a preparation method thereof, and an application in an energy storage device. Background Art

[0002] The development of the energy storage industry has promoted the demand for efficient, durable and environmentally friendly materials. In this context, 3 series aluminum alloys have become an ideal choice for key components such as heat exchangers and tanks due to their unique characteristics. The low density of 3 series aluminum alloys can effectively reduce the weight of energy storage equipment, thereby increasing the overall energy density. This is especially important for mobile energy storage devices such as electric vehicles. Good extrudability enables 3 series aluminum alloys to be processed into the required shape through a variety of forming technologies, which is suitable for the design requirements of various energy storage devices. High corrosion resistance ensures long-term and stable operation of the equipment in harsh environments. Efficient thermal conductivity helps maintain the battery cell in the optimal operating temperature range, which is crucial to improving equipment performance and safety.

[0003] In the production of battery cell shell products, 3 series aluminum alloys may have insufficient strength after extrusion molding. The typical mechanical properties of 3 series aluminum alloys after extrusion are: tensile strength 100-130MPa, yield strength 40-70MPa, which are far from meeting the requirements of energy storage products such as battery cell shells. In order to enhance its structural strength, additional cold drawing treatment is usually required. This additional step not only increases the manufacturing cost, but also reduces the yield rate. In addition to extrusion molding, there are two main production process routes for the production of battery cell shells:

[0004] Rolling + rolling + welding: Although this method can achieve more complex shapes, the need for welding makes the welds become potential weak points, increasing the risk of battery leakage and explosion-proof cracking.

[0005] Rolling + stamping: This method avoids welding problems, but is limited by the stamping process and is difficult to produce special-shaped battery cell shells that are longer or have different wall thicknesses.

[0006] With the advancement of technology, the application of 3 series aluminum alloys in the energy storage industry will become more extensive. By continuously optimizing material properties and improving production processes, it is expected to solve some existing limitations, such as improving the strength and stability of materials through new alloy formulas, or developing new molding technologies to adapt to more diverse design requirements. Summary of the invention

[0007] The purpose of the present invention is to address the above-mentioned problems existing in the prior art and propose a high-strength 3-series aluminum alloy extruded profile, which not only solves the problems of insufficient strength and complicated production process in traditional processes, but also meets the industry's demand for lightweight, high strength, corrosion resistance and other properties, injecting new vitality into the development of the energy storage industry.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A high-strength 3-series aluminum alloy extrusion profile, wherein the aluminum alloy extrusion profile raw material is composed of the following elements in percentage by mass: 0.35-0.70% Si, 1.0-1.50% Mn, 0.10-0.70% Fe, 0.05-0.28% Zr, 0.05-0.25% Sn, Cu≤0.20%, and the balance is Al and other inevitable impurity elements.

[0010] In the above-mentioned high-strength 3-series aluminum alloy extruded profile, preferably, the aluminum alloy extruded profile raw material is composed of the following elements in percentage by mass: 0.45-0.65% Si, 1.1-1.40% Mn, 0.10-0.70% Fe, 0.10-0.20% Zr, 0.08-0.15% Sn, Cu≤0.20%, and the remainder is Al and other unavoidable impurity elements.

[0011] In the above-mentioned high-strength 3-series aluminum alloy extruded profile, preferably, the inevitable impurity elements in the aluminum alloy extruded profile are less than 0.15wt%, wherein a single impurity element is less than 0.05%.

[0012] In the above-mentioned high-strength 3-series aluminum alloy extruded profile, preferably, Mn, Si, Zr, and Sn need to satisfy the following relationship: 1.70wt%≤Mn+Si+Zr+Sn≤2.5wt%.

[0013] The present invention also provides a method for preparing the above-mentioned high-strength 3-series aluminum alloy extruded profile, the method comprising the following steps:

[0014] S1. Prepare raw materials;

[0015] S2, melting and casting the raw materials into aluminum bars, and then homogenizing them;

[0016] S3, then preheating the aluminum rod, and then using a hot extrusion die to produce an extruded profile;

[0017] S4. Quench the extruded profile and straighten it after cooling to room temperature.

[0018] In the above-mentioned method for preparing a high-strength aluminum alloy extruded profile for an energy storage device, the homogenization treatment temperature in step S2 is 350-550° C. and the time is 2-24 hours.

[0019] In the above-mentioned method for preparing a high-strength aluminum alloy extruded profile for an energy storage device, the quenching temperature in step S4 is 480-560°C.

[0020] In the above-mentioned method for preparing a high-strength aluminum alloy extruded profile for an energy storage device, the quenching in step S4 is performed under air cooling or wind cooling conditions.

[0021] In the above method for preparing a high-strength aluminum alloy extruded profile for an energy storage device, the straightening rate in step S4 is 0.5-3%.

[0022] The present invention also provides an energy storage device, comprising the above-mentioned high-strength 3-series aluminum alloy extruded profile or the high-strength 3-series aluminum alloy extruded profile prepared by the above-mentioned method.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention adjusts the composition ratio of the 3-series aluminum alloy, especially the ratio of manganese (Mn), silicon (Si), zirconium (Zr) and silicon (Sn), as well as the homogenization treatment and quenching treatment, so that sufficient mechanical strength can be obtained without an additional cold drawing process after extrusion molding, thereby simplifying the production process and improving efficiency, which directly increases the yield rate and reduces production costs.

[0025] 2. The present invention provides a high-performance 3-series aluminum alloy and a method for preparing the same. When manganese (Mn), silicon (Si), zirconium (Zr) and silicon (Sn) satisfy the relationship of 1.70wt%≤Mn+Si+Zr+Sn≤2.5wt%, the entire 3-series aluminum alloy reaches a tensile strength of Rm≥150MPa, a yield strength of Rp0.2≥110MPa, and an elongation of A50≥10%, which brings significant technological progress to the energy storage industry, not only solves the problems existing in traditional processes, but also meets the industry's needs for lightweight, high strength and corrosion resistance, and promotes the development of the energy storage industry.

[0026] 3. By reasonably setting the Fe and Cu contents, the alloy material has good extrudability and can be formed into complex shapes without sacrificing strength. DETAILED DESCRIPTION

[0027] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0028] The 3 series aluminum alloy of the present invention is composed of the following elements in percentage by mass:

[0029] 0.35-0.70% Si, 1.0-1.50% Mn, 0.10-0.70% Fe, 0.05-0.28% Zr, 0.05-0.25% Sn, Cu≤0.20%, the balance is Al and other inevitable impurity elements. Among them, in the preferred embodiment, Mn, Si, Zr, Sn need to satisfy the following relationship: 1.70wt%≤Mn+Si+Zr+Sn≤2.5wt%.

[0030] Mn is the main additive element of 3 series aluminum alloy, mainly forming Al6Mn second phase. In the presence of Si, it can promote the precipitation of high-density submicron Al-Mn-Si and Al-(Fe, Mn)-Si based dispersed phases on the alloy matrix, effectively improving the strength of the alloy.

[0031] When Mn is less than 1.0wt%, the strengthening effect is insufficient, and when the Mn content exceeds 1.5wt%, the plasticity deteriorates, the extrudability decreases and it is difficult to produce. Therefore, the appropriate range of Mn is 1.0-1.5wt%.

[0032] When Si is less than 0.35wt%, the strengthening effect is insufficient, and when the Si content exceeds 0.70wt%, the strengthening effect is too high, the alloy becomes hard, the extrudability decreases and it is difficult to produce. Therefore, the appropriate range of Si is 0.35-0.70wt%.

[0033] Fe is an impurity element in 3 series aluminum alloys, which is not good for the plasticity and extrudability of the material. When Fe is less than 0.10wt%, it is not recommended because the high purity will increase the product cost. When Fe is greater than 0.7wt%, a coarse Al-(Fe, Mn)-Si-based crystal phase will be formed in the alloy during casting, and the plasticity will deteriorate and the extrudability will decrease. Therefore, the appropriate range of Fe is 0.10-0.7wt%.

[0034] Cu can produce solid solution strengthening in 3 series aluminum alloys as supplementary strengthening. At the same time, the presence of trace amounts of Cu can also promote the transformation of material corrosion from pitting corrosion to uniform corrosion. When the Cu content exceeds 0.20wt%, the intergranular corrosion performance deteriorates. Therefore, the appropriate range of Cu is ≤0.20wt%.

[0035] Zr forms a nano-scale fully coherent Al3Zr phase in the aluminum matrix, which can improve the strength of the alloy. When Zr is less than 0.05wt%, the strengthening effect is insufficient. When the Zr content exceeds 0.28wt%, a coarse Al3Zr equilibrium phase is easily formed, and the strengthening effect is no longer obvious. Therefore, the appropriate range of Zr is 0.05-0.28wt%.

[0036] The presence of Sn can significantly reduce the size of Al-Mn-Si and Al-(Fe, Mn)-Si based dispersed phases, while increasing the number density, which has a significant effect on improving the strength of the alloy. When Sn is less than 0.05wt%, the strengthening effect is insufficient. When the Sn content exceeds 0.25wt%, the strength increase is not obvious when the Sn content is increased. Therefore, the appropriate range of Sn is 0.05-0.25wt%.

[0037] Practice shows that although Mn, Si, Zr and Sn have the effect of significantly improving strength, they will deteriorate the extrudability of the alloy. Therefore, when Mn, Si, Zr and Sn exist at the same time, the relationship of 1.70wt% ≤ Mn + Si + Zr + Sn ≤ 2.5wt% must be satisfied in the preferred scheme to better balance high mechanical properties and good extrudability.

[0038] Embodiment 1-11:

[0039] S1. The aluminum alloy profile compositions of Examples 1-11 are configured as shown in Table 1;

[0040] S2. Add the prepared alloy raw materials into a smelting furnace and smelt them at 775°C to make them all melt into liquid to form aluminum melt. After they are all melted into liquid, keep them warm for about half an hour to remove slag and refine the aluminum melt. After the components are adjusted to the required standard, reduce the temperature of the aluminum melt to 710°C, and perform standing, slag removal and casting in sequence to obtain round cast bars, and then perform homogenization treatment at 368°C for 18 hours.

[0041] S2, then preheating the aluminum rod at 523°C, and then using a hot extrusion die to produce an extruded profile;

[0042] S3. The extruded profile is then quenched at 540°C, then air-cooled to room temperature, and finally straightened, wherein the straightening rate is 1%.

[0043] Comparative Examples 1-5:

[0044] S1. The aluminum alloy profile compositions of Comparative Examples 1-5 are configured as shown in Table 1;

[0045] S2. Add the prepared alloy raw materials into a smelting furnace and smelt them at 775°C to make them all melt into liquid to form aluminum melt. After they are all melted into liquid, keep them warm for about half an hour to remove slag and refine the aluminum melt. After the components are adjusted to the required standard, reduce the temperature of the aluminum melt to 710°C, and perform standing, slag removal and casting in sequence to obtain round cast bars, and then perform homogenization treatment at 368°C for 18 hours.

[0046] S2, then preheating the aluminum rod at 523°C, and then using a hot extrusion die to produce an extruded profile;

[0047] S3. The extruded profile is then quenched at 540°C, then air-cooled to room temperature, and finally straightened, wherein the straightening rate is 1%.

[0048] Table 1: Elemental composition of aluminum alloy profiles prepared in Examples 1-11 and Comparative Examples 1-5

[0049]

[0050]

[0051] Table 2: Performance test results of aluminum alloy profiles prepared in Examples 1-11 and Comparative Examples 1-5

[0052]

[0053] The extrudability (a measure of the difficulty of industrial production) is expressed by the breakthrough pressure, and the upper limit is generally 280 Bar. Production cannot be carried out if the pressure exceeds this value.

[0054] The aluminum alloy profiles in Examples 1-11, when meeting specific chemical composition ratios (such as the specific contents of elements such as Mn, Si, Fe, Cu, Zr, Sn, etc. in the examples), can obtain higher tensile strength (Rm) and yield strength (R0.2), while maintaining a certain elongation (A50), which indicates that the material has good mechanical properties. In particular, Examples 5-11 not only maintain good mechanical properties, but also ensure that the breakthrough pressure is within a reasonable range, achieving the best balance between mechanical properties and extrudability. The breakthrough pressures of Examples 1-11 are all below 280 Bar, indicating that these samples have good extrudability and are suitable for industrial production.

[0055] Comparative Examples 1-4 fail to strictly control the content of certain elements (Sn, Mn, Si, Zr), and their mechanical properties are inferior to those of the samples in the examples. The Mn and Si contents in Comparative Example 5 exceed the upper limits specified in the present invention. Although it has the highest tensile strength and yield strength, its breakthrough pressure reaches 280 Bar, which indicates that it may encounter great resistance in the actual production process, resulting in increased production costs or failure to produce normally.

[0056] In summary, the present invention precisely controls the alloy composition and optimizes the preparation process, so that the profile can meet the required strength requirements (Rm≥140MPa, Rp0.2≥110MPa, A50≥5%) without additional cold drawing treatment after extrusion, thereby simplifying the production process and improving efficiency;

[0057] The parts of the embodiments herein that are not exhaustive of the midpoint values ​​of the technical scope claimed for protection by the present invention and the new technical solutions formed by equivalent replacement of single or multiple technical features in the technical solutions of the embodiments are also within the scope claimed for protection by the present invention; at the same time, in all the listed or unlisted embodiments of the scheme of the present invention, each parameter in the same embodiment merely represents an example of its technical solution (i.e., a feasible solution), and there is no strict coordination and limitation relationship between the parameters, wherein the parameters can be replaced with each other without violating the axioms and the claims of the present invention, unless otherwise stated.

[0058] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above technical means, but also include technical schemes composed of any combination of the above technical features. The above is a specific implementation of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as the protection scope of the present invention.

[0059] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A high-strength 3-series aluminum alloy extrusion profile, characterized in that: The aluminum alloy extruded profile raw material is composed of the following elements in percentage by mass: 0.35-0.70% Si, 1.0-1.50% Mn, 0.10-0.70% Fe, 0.05-0.28% Zr, 0.05-0.25% Sn, Cu≤0.20%, and the remainder is Al and other inevitable impurity elements.

2. The high-strength 3-series aluminum alloy extruded profile according to claim 1, characterized in that: The aluminum alloy extruded profile raw material is composed of the following elements in percentage by mass: 0.45-0.65% Si, 1.1-1.40% Mn, 0.10-0.70% Fe, 0.10-0.20% Zr, 0.08-0.15% Sn, Cu≤0.20%, and the remainder is Al and other inevitable impurity elements.

3. The high-strength 3-series aluminum alloy extruded profile according to claim 1, characterized in that: The inevitable impurity elements in the aluminum alloy extruded profile are less than 0.15wt%, of which a single impurity element is less than 0.05%.

4. The high-strength 3-series aluminum alloy extruded profile according to claim 1, characterized in that: Mn, Si, Zr, and Sn must satisfy the following relationship: 1.70wt%≤Mn+Si+Zr+Sn≤2.5wt%.

5. A method for preparing the high-strength 3-series aluminum alloy extruded profile as claimed in claim 1, characterized in that: The method comprises the following steps: S1. Prepare raw materials; S2, melting and casting the raw materials into aluminum bars, and then homogenizing them; S3, then preheating the aluminum rod, and then using a hot extrusion die to make an extruded profile; S4. Quench the extruded profile and straighten it after cooling to room temperature.

6. The method for preparing a high-strength 3-series aluminum alloy extruded profile for an energy storage device according to claim 5, characterized in that: The homogenization temperature in step S2 is 350-550°C and the time is 2-24h.

7. The method for preparing a high-strength 3-series aluminum alloy extruded profile for an energy storage device according to claim 5, characterized in that: The preheating temperature in step S3 is 420-570°C.

8. The method for preparing a high-strength 3-series aluminum alloy extruded profile for an energy storage device according to claim 5, characterized in that: The quenching temperature in step S4 is 480-560°C.

9. The method for preparing a high-strength 3-series aluminum alloy extruded profile for an energy storage device according to claim 5, characterized in that: The quenching cooling method in step S4 is air cooling or wind cooling.

10. An energy storage device, characterized in that: It includes the high-strength 3 series aluminum alloy extruded profile described in claim 1 or the high-strength 3 series aluminum alloy extruded profile prepared by the method described in claim 5.

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