An easily-extruded high-strength corrosion-resistant aluminum alloy and a manufacturing method and application thereof

Abstract

The present application relates to the technical field of aluminum alloy production and processing, and particularly relates to an easily-extruded high-strength corrosion-resistant aluminum alloy, a manufacturing method thereof and an application thereof. The present application realizes the purpose of improving the material performance by using a higher Zn element while ensuring the corrosion resistance of the material by reasonably adjusting the proportion of Mg, Si and Zn elements. This method can not only improve the strength of the aluminum alloy, but also improve its corrosion resistance, thereby solving the problem of adding a large amount of alloy elements in the prior art, reducing the production cost and the difficulty of alloy element recovery. By controlling the alloy composition and the total aluminum content, the present application ensures that the extrusion deformation resistance of the aluminum alloy is small, has excellent extrudability, and controls the content of some elements to reduce the quenching sensitivity, so that the alloy can produce more complex thin-walled section shapes. The aluminum alloy material of the present application can still maintain good corrosion resistance in a high-humidity and high-salinity environment.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy production and processing technology, and in particular to an easily extruded, high-strength, corrosion-resistant aluminum alloy, its manufacturing method, and its applications. Background Technology

[0002] Aluminum alloys are a widely used metallic material in various industrial fields, possessing excellent mechanical properties, superior processing performance, and outstanding corrosion resistance. In the photovoltaic (PV) mounting system manufacturing industry, aluminum alloys are widely used as the material due to their lightweight, high strength, and good weather resistance. However, to achieve higher strength and better corrosion resistance, it is usually necessary to add multiple alloying elements to aluminum alloys. This not only increases production costs but also makes the recycling of these alloying elements more difficult. Furthermore, since PV mounting systems are typically used in outdoor environments, the requirements for their corrosion resistance are extremely high, which also places higher demands on the performance of aluminum alloy materials.

[0003] In existing technologies, the strength and corrosion resistance of aluminum alloys are mainly improved by altering their composition and heat treatment processes. For example, increasing the content of magnesium and silicon can form a Mg2Si strengthening phase, thereby increasing the strength of the aluminum alloy. Simultaneously, appropriate heat treatments, such as solution treatment and aging treatment, can further enhance the mechanical properties of the aluminum alloy. Furthermore, the corrosion resistance of aluminum alloys can be improved by appropriately adding certain elements.

[0004] While existing technologies can improve the strength and corrosion resistance of aluminum alloys to some extent, several problems and drawbacks remain. First, current technologies often require the addition of large amounts of alloying elements, which not only increases production costs but also makes the recycling of these elements more difficult, especially the use of rare earth alloys, significantly increasing material costs. Second, existing technologies often require complex heat treatment processes, which not only increase production costs but also reduce production efficiency. Furthermore, the alloy materials used in current processes are generally 6005A or 6061 alloys, with a material strength of around 250 MPa, making it impossible to reduce the thickness of the profiles produced, thus hindering the reduction of raw material costs. Finally, although existing technologies can improve the strength and corrosion resistance of aluminum alloys, their corrosion resistance still cannot meet requirements in certain specific environments, such as high humidity and high salinity environments. Summary of the Invention

[0005] The purpose of this invention is to provide a low-cost, easily extruded, high-strength, and corrosion-resistant aluminum alloy profile and its manufacturing method, providing at least one or more beneficial options for solving one or more technical problems existing in the prior art.

[0006] This technical solution mainly addresses the following issues: 1) how to improve the strength and corrosion resistance of aluminum alloys without increasing production costs or reducing production efficiency, thereby enabling lighter designs and reducing material costs; 2) how to simplify the heat treatment process of aluminum alloys and improve production efficiency; and 3) how to further improve the corrosion resistance of aluminum alloys in high humidity and high salinity environments.

[0007] The present invention adopts the following technical solution.

[0008] A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy comprises the following steps.

[0009] 1) Optimize the alloy element ratio by adjusting the proportions of elements such as magnesium (Mg), silicon (Si), zinc (Zn), iron (Fe), manganese (Mn), and copper (Cu). In particular, control the content of Mg to be 0.6-0.9 wt%, the content of Si to be 0.9-1.2 wt%, and the Mg / Si ratio to be between 0.7-0.9; the content of Zn to be 0.2-0.5 wt%, the content of Fe to be 0.15-0.30 wt%, the content of Mn to be 0.10-0.20 wt%, and the Fe / Mn ratio to be between 1.2-2.0; Cu < 0.05 wt%, and Al content > 97.5 wt%, in order to improve the material strength and corrosion resistance.

[0010] 2) A two-stage homogenization process is adopted: First, the primary homogenization is carried out at 240-300℃ for 2-6 hours to allow Mn elements to diffuse fully and improve the subsequent conversion effect on the Fe phase; then, the secondary homogenization is carried out at 530-570℃ for 6-12 hours to allow the internal eutectic phase to dissolve fully, while the high temperature promotes the rapid conversion of the Fe phase to avoid residual β-Fe phase causing extrusion scratches and lines, affecting surface quality and thus reducing corrosion resistance.

[0011] 3) Optimize extrusion and aging processes: During extrusion, ensure the outlet profile temperature is above 530℃ and undergo rapid cooling and quenching at >350℃ / min to below 200℃; aging is carried out within 4 hours after extrusion, using a three-stage aging process. The first stage of aging involves holding at 120-150℃ for 2-8 hours. After the first stage, the temperature is raised to the second stage holding temperature of 200-230℃ within half an hour for 0.5-2 hours. After the second stage holding time, the profile is cooled to room temperature at a rate greater than 10℃ / min, and then reheated to the third stage holding temperature of 160-190℃ for 6-12 hours. Through reasonable temperature and time control, element precipitation is promoted, forming a strengthening phase and improving the material's strength and corrosion resistance.

[0012] In this invention, due to the use of a higher proportion of zinc, more and more diverse post-consumer aluminum alloy waste can be received, making full use of recycled waste, reducing carbon emissions, and also reducing production costs. Furthermore, without increasing production costs or reducing production efficiency, the strength and corrosion resistance of aluminum alloys can be improved, material weight can be reduced to decrease raw material costs, the heat treatment process of aluminum alloys can be simplified, production efficiency can be improved, and the corrosion resistance of aluminum alloys can be further improved in high humidity and high salinity environments.

[0013] The present invention, by employing the above technical solution, has at least the following beneficial effects.

[0014] I. This invention achieves the goal of improving material performance while maintaining corrosion resistance by rationally adjusting the proportions of Mg, Si, and Zn elements, using a higher Zn content. This method not only improves the strength of aluminum alloys but also enhances their corrosion resistance, thus solving the problem of requiring the addition of large amounts of alloying elements in existing technologies, and reducing production costs and the difficulty of alloying element recycling.

[0015] Second, by controlling the alloy composition and specifying the total aluminum content, the aluminum alloy is guaranteed to have low resistance to extrusion deformation and excellent extrudability. At the same time, controlling the content of some elements reduces quenching sensitivity, enabling this alloy to produce more complex thin-walled profile shapes.

[0016] Third, the aluminum alloy material of this invention can still maintain good corrosion resistance in high humidity and high salinity environments. This is because the aluminum alloy material of this invention, through a two-stage homogenization process and a three-stage aging process, can ensure that the strength and corrosion resistance of the aluminum alloy reach a high level simultaneously, solving the problem of the previous negative correlation between strength and corrosion resistance.

[0017] IV. Environmental Advantages: The aluminum alloy material of this invention can utilize a large proportion of recycled waste, resulting in low carbon emissions from raw materials. This offers a significant advantage for future carbon tax collection in the European Union. This is because the aluminum alloy material of this invention can accept a wider variety of post-consumer aluminum alloy waste, thereby reducing the mining and smelting of new aluminum ore and lowering carbon emissions. Detailed Implementation

[0018] To facilitate a better understanding of the essence of the present invention by those skilled in the art, the specific embodiments of the present invention are described in detail below.

[0019] Example 1

[0020] A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy includes the following steps.

[0021] Step 1: Prepare raw materials. By weight percentage, magnesium (Mg) is 0.85%, silicon (Si) is 1.02%, Mg / Si is 0.83%, zinc (Zn) is 0.23%, iron (Fe) is 0.16%, manganese (Mn) is 0.12%, Fe / Mn is 1.3%, copper (Cu) is 0.02%, the total content of other impurity elements is 0.10%, and aluminum (Al) is 97.5%.

[0022] These raw materials are put into a smelting furnace to melt and cast into aluminum rods.

[0023] Step 2: Homogenization of the aluminum rod. The cast aluminum rod is held at 280℃ for 6 hours for primary homogenization to allow the Mn element to diffuse fully. Then, it is held at 565℃ for 10 hours for secondary homogenization to allow the internal eutectic phase to dissolve fully. The aluminum rod after homogenization and holding is then rapidly cooled.

[0024] Step 3: Extrusion: The homogenized and cooled aluminum rod is extruded to an exit profile temperature of 540-550℃, and then rapidly cooled and quenched to below 200℃ at a rate of >350℃ / min.

[0025] Step 4: Aging: The extruded aluminum alloy profiles are aged over 4 hours using a three-stage aging process. Specifically, the profiles are held at 140℃ for 4 hours. After the first stage of aging, the temperature is increased to the second stage aging temperature of 220℃ within half an hour and held for 1 hour. After the second stage of aging, the profiles are cooled to room temperature at a rate greater than 10℃ / min, and then the temperature is increased again to the third stage aging temperature of 170℃ and held for 10 hours.

[0026] Step 5: Natural cooling: Allow the aged aluminum alloy profiles to cool naturally to obtain the final aluminum alloy product.

[0027] Example 2

[0028] A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy includes the following steps.

[0029] Step 1: Prepare the raw materials. By weight percentage, the composition is: magnesium (Mg) 0.65%, silicon (Si) 0.92%, Mg / Si ratio 0.7, zinc (Zn) 0.44%, iron (Fe) 0.21%, manganese (Mn) 0.12%, Fe / Mn ratio 1.75, copper (Cu) 0.02%, and the total content of other impurity elements is 0.11%. The aluminum (Al) content is 97.53%. These raw materials are then melted in a smelting furnace and cast into aluminum rods.

[0030] Step 2: Homogenization. The cast aluminum rod is held at 240℃ for 4 hours for primary homogenization to allow Mn to diffuse fully. Then, it is held at 550℃ for 8 hours for secondary homogenization to allow the internal eutectic phase to dissolve fully. The aluminum rod after homogenization and holding is then rapidly cooled.

[0031] Step 3: Extrusion: The homogenized and cooled aluminum rod is extruded to an exit profile temperature of 535-545℃, and then rapidly cooled and quenched to below 200℃ at a rate of >350℃ / min.

[0032] Step 4: Aging: The extruded aluminum alloy profiles are aged within 4 hours using a three-stage aging process. Specifically, the profiles are held at 120℃ for 6 hours. After the first stage of aging, the temperature is increased to the second stage aging temperature of 210℃ within half an hour and held for 2 hours. After the second stage of aging, the profiles are cooled to room temperature at a rate greater than 10℃ / min, and then the temperature is increased again to the third stage aging temperature of 180℃ and held for 8 hours.

[0033] Step 5: Natural cooling: Allow the aged aluminum alloy profiles to cool naturally to obtain the final aluminum alloy product.

[0034] Comparative Example 1.

[0035] A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy includes the following steps.

[0036] Step 1: Prepare the raw materials. By weight percentage, the composition is: magnesium (Mg) 0.65%, silicon (Si) 0.92%, Mg / Si ratio 0.7, zinc (Zn) 0.44%, iron (Fe) 0.21%, manganese (Mn) 0.12%, Fe / Mn ratio 1.75, copper (Cu) 0.02%, and the total content of other impurity elements is 0.11%. The aluminum (Al) content is 97.53%. These raw materials are then melted in a smelting furnace and cast into aluminum rods.

[0037] Step 2: Homogenization: The cast aluminum rod is held at 240℃ for 4 hours for primary homogenization to allow sufficient diffusion of Mn. Secondary homogenization is then carried out at 550℃ for 8 hours to allow the internal eutectic phase to fully dissolve. The homogenized aluminum rod is then rapidly cooled.

[0038] Step 3: Extrusion: The homogenized and cooled aluminum rod is extruded to an exit profile temperature of 535-545℃, and then rapidly cooled and quenched to below 200℃ at a rate of >350℃ / min.

[0039] Step 4: Aging Treatment: The extruded aluminum alloy profiles are aged within 4 hours using a two-stage aging process. Specifically, the profiles are held at 120℃ for 6 hours, and after the first stage of aging, the temperature is increased to the second stage aging temperature of 180℃ within half an hour and held for 8 hours.

[0040] Step 5: Natural cooling: Allow the aged aluminum alloy profiles to cool naturally to obtain the final aluminum alloy product.

[0041] Comparative Example 2.

[0042] A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy includes the following steps.

[0043] Step 1: Prepare the raw materials. By weight percentage, the composition is: magnesium (Mg) 0.65%, silicon (Si) 0.92%, Mg / Si ratio 0.7, zinc (Zn) 0.44%, iron (Fe) 0.21%, manganese (Mn) 0.12%, Fe / Mn ratio 1.75, copper (Cu) 0.02%, and the total content of other impurity elements is 0.11%. The aluminum (Al) content is 97.53%. These raw materials are then melted in a smelting furnace and cast into aluminum rods.

[0044] Step 2: Homogenization. The cast aluminum rod is held at 240℃ for 4 hours for primary homogenization to allow Mn to diffuse fully. Then, it is held at 550℃ for 8 hours for secondary homogenization to allow the internal eutectic phase to dissolve fully. The aluminum rod after homogenization and holding is then rapidly cooled.

[0045] Step 3: Extrusion. The homogenized and cooled aluminum rod is extruded to an exit profile temperature of 535-545℃, and then rapidly cooled and quenched to below 200℃ at a rate of >350℃ / min.

[0046] Step 4 involves aging the extruded aluminum alloy profiles over a period of 4 hours using a two-stage aging process. Specifically, the profiles are held at 210℃ for 2 hours, then rapidly cooled to room temperature after the holding time, and finally reheated to the secondary holding temperature of 180℃ for 8 hours.

[0047] Step 5: Natural cooling: Allow the aged aluminum alloy profiles to cool naturally to obtain the final aluminum alloy product.

[0048] Comparative Example 3.

[0049] A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy includes the following steps.

[0050] Step 1: Prepare the raw materials. By weight percentage, the composition is: magnesium (Mg) 0.75%, silicon (Si) 0.95%, Mg / Si ratio 0.79, zinc (Zn) 0.02%, iron (Fe) 0.28%, manganese (Mn) 0.17%, Fe / Mn ratio 1.65, copper (Cu) 0.12%, other impurity elements total 0.10%, and aluminum (Al) 97.61%. Melt these raw materials in a smelting furnace and cast them into aluminum rods.

[0051] Step 2: Homogenization. The cast aluminum rod is held at 240℃ for 4 hours for primary homogenization to allow sufficient diffusion of Mn. Secondary homogenization is then carried out at 550℃ for 8 hours to allow the internal eutectic phase to fully dissolve. The homogenized aluminum rod is then rapidly cooled.

[0052] Step 3: Extrusion. The homogenized and cooled aluminum rod is extruded to an exit profile temperature of 535-545℃, and then rapidly cooled and quenched to below 200℃ at a rate of >350℃ / min.

[0053] Step 4, aging treatment, involves aging the extruded aluminum alloy profiles within 4 hours using a three-stage aging process. Specifically, the profiles are held at 120℃ for 6 hours. After the first stage of aging, the temperature is increased to the second stage aging temperature of 210℃ within half an hour and held for 2 hours. After the second stage of aging, the profiles are quickly cooled to room temperature and then reheated to the third stage aging temperature of 180℃ and held for 8 hours.

[0054] The process involves natural cooling of the aged aluminum alloy profiles to obtain the final aluminum alloy product.

[0055] Comparative Example 4.

[0056] A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy includes the following steps.

[0057] Step 1: Prepare the raw materials. By weight percentage, the composition is: magnesium (Mg) 0.77%, silicon (Si) 0.94%, Mg / Si ratio 0.82, zinc (Zn) 0.43%, iron (Fe) 0.31%, manganese (Mn) 0.02%, Fe / Mn ratio 15.5, copper (Cu) 0.03%, and the total content of other impurity elements is 0.12%. The aluminum (Al) content is 97.38%. These raw materials are then melted in a smelting furnace and cast into aluminum rods.

[0058] Step 2: Homogenization treatment. The cast aluminum rod is kept at 550℃ for 8 hours for primary homogenization. After homogenization and heat preservation, the aluminum rod is rapidly cooled.

[0059] Step 3: Extrusion. The homogenized and cooled aluminum rod is extruded to an exit profile temperature of 535-545℃, and then rapidly cooled and quenched to below 200℃ at a rate of >350℃ / min.

[0060] Step 4, aging treatment, involves aging the extruded aluminum alloy profiles within 4 hours using a three-stage aging process. Specifically, the profiles are held at 120℃ for 6 hours. After the first stage of aging, the temperature is increased to the second stage aging temperature of 210℃ within half an hour and held for 2 hours. After the second stage of aging, the profiles are quickly cooled to room temperature and then reheated to the third stage aging temperature of 180℃ and held for 8 hours.

[0061] Step 5: Natural cooling: Allow the aged aluminum alloy profiles to cool naturally to obtain the final aluminum alloy product.

[0062] Performance testing.

[0063] To better demonstrate the technological advancements of this invention, the performance of the aluminum alloy products obtained in Examples 1-2 and Comparative Examples 1-4 was tested, and the results are shown in Table 1.

[0064] Table 1. Comparison of Performance Tests for Aluminum Alloy Products

[0065] Tensile strength MPa Yield strength MPa Hardness HV Intergranular corrosion level Peeling corrosion level Extrusion surface effect Example 1 353 324 127 Level 2 PA qualified Example 2 342 318 123 Level 2 PA qualified Comparative Example 1 360 322 129 Level 4 PB qualified Comparative Example 2 323 292 118 Level 2 PA qualified Comparative Example 3 358 325 128 Level 4 PC qualified Comparative Example 4 349 320 123 Level 2 PA Linear burrs are substandard .

[0066] As can be seen from Table 1, the aluminum alloy products prepared by this invention can better balance the product's strength, corrosion resistance, and extrusion effect, solving the previous problem that strength and corrosion resistance were negatively correlated.

[0067] Due to the advanced technology of this invention, it has wide applications in fields such as aluminum alloy material manufacturing, photovoltaic bracket manufacturing, and metal corrosion protection. Firstly, the novel low-cost, easily extruded, high-strength, corrosion-resistant photovoltaic bracket aluminum alloy material of this invention, through the rational adjustment of the Mg, Si, and Zn element ratios, achieves the goal of improving material performance while maintaining corrosion resistance using a higher Zn element, significantly reducing production costs and improving production efficiency. Secondly, the aluminum alloy material of this invention has excellent corrosion resistance and does not require additional surface treatment, further reducing production costs. Finally, the aluminum alloy material of this invention can use a large proportion of recycled waste, resulting in low carbon emissions from raw materials, meeting current environmental protection requirements, and possessing a significant market competitive advantage. Therefore, the aluminum alloy material of this invention has broad application prospects in photovoltaic bracket manufacturing, building structural materials, and automotive parts manufacturing.

[0068] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Parts not described in the specific embodiments are all prior art or common knowledge.

[0070] It should also be noted that the detailed description of preferred embodiments and included examples in the description of this invention facilitate a better understanding of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In case of any discrepancy, the definitions in this specification shall prevail.

[0071] In this invention, the term "prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof, as used in this invention, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus comprising the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such a composition, step, method, article, or apparatus.

[0072] In this invention, when a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1 to 5” is disclosed, the described range should be interpreted as including ranges “1 to 4”, “1 to 3”, “1 to 2”, “1 to 2 and 4 to 5”, “1 to 3 and 5”, etc. When numerical ranges are described in this invention, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0073] Furthermore, the indefinite articles “a” and “an” preceding the elements or components of this invention do not impose any limitation on the quantity requirement (i.e., the number of times) of the elements or components. Therefore, “an” or “a” should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers to the singular form.

Claims

1. A method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy, characterized in that, Includes the following steps: 1) Aluminum rod casting: by weight percentage, Mg: 0.6-0.9%, Si: 0.9-1.2%, Zn: 0.2-0.5%, Fe: 0.15-0.30%, Mn: 0.10-0.20%, Cu < 0.05%, with the balance being Al; the Mg / Si ratio is controlled between 0.7 and 0.9, and the Fe / Mn ratio is controlled between 1.2 and 2.0; the Al content is greater than 97.5 wt%; these raw materials are put into a melting furnace for melting and casting into aluminum rods; 2) Homogenization treatment: First, perform primary homogenization by holding the temperature at 240-300℃ for 2-6 hours, and then perform secondary homogenization by holding the temperature at 530-570℃ for 6-12 hours. 3) Extrusion: During the extrusion process, the outlet profile temperature is higher than 530℃, and it is rapidly cooled and quenched to below 200℃ at a rate of >350℃ / min. 4) Aging treatment: Aging is carried out within 4 hours after extrusion. The aging process is three-stage aging. The first stage of aging is held at a temperature of 120-150℃ for 2-8 hours. After the first stage of aging, the temperature is raised to the second stage of aging at a temperature of 200-230℃ within half an hour for 0.5-2 hours. After the second stage of aging, the profile is cooled to room temperature at a rate of more than 10℃ / min, and then the temperature is raised to the third stage of aging at a temperature of 160-190℃ for 6-12 hours. 5) Natural cooling: Allow the aged aluminum alloy profiles to cool naturally.

2. The method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy according to claim 1, characterized in that, In step 1), the aluminum rod casting process is carried out with the following weight percentages: magnesium 0.65%, silicon 0.92%, zinc 0.44%, iron 0.21%, manganese 0.12%, copper 0.02%, and other impurity elements totaling 0.11%, with aluminum at 97.53%.

3. The method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy according to claim 1, characterized in that, In step 3), the extrusion step, the outlet profile temperature is 540-550℃ during the extrusion process.

4. The method for manufacturing an easily extruded, high-strength, corrosion-resistant aluminum alloy according to claim 1, characterized in that, In step 3), the extrusion step, the outlet profile temperature is 535-545℃ during the extrusion process.

5. A high-strength, corrosion-resistant aluminum alloy that is easily extruded, characterized in that, It is prepared by the manufacturing method of an easily extruded high-strength corrosion-resistant aluminum alloy as described in any one of claims 1-4.

6. The application of the easily extruded high-strength corrosion-resistant aluminum alloy as described in claim 5 in photovoltaic brackets, building structural components, or automotive parts.