An aluminum alloy material, a method for producing the same, and an application thereof to a material product

Abstract

The application discloses an aluminum alloy material and a preparation method and application in material products thereof, relates to the technical field of non-ferrous metal materials, and raw materials thereof include the following components in percentage by weight: A 0.014-4.046 wt%, mixed rare earth 0.005-7.670 wt%, unavoidable impurities total content less than or equal to 0.350 wt%, and aluminum ingot 88.000-99.999 wt%; the A is at least two of Fe, Si, Mg, Cu, Mn, Ti, Ni, Cr, Mo and Zr; the mixed rare earth is at least two of La, Ce, Pr, Nd, Pm, Sm and Eu; the aluminum alloy material is prepared through a plurality of working procedures; through optimization of raw material components and adjustment of the mixed rare earth proportion, the comprehensive performance of the aluminum alloy material is improved by adopting a composite processing mode of ultrasonic vibration first and then electromagnetic stirring, and the microstructure uniformity and compactness of the ingot are improved.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal materials technology, specifically to an aluminum alloy material, its preparation method, and its application in material products. Background Technology

[0002] Aluminum alloys, due to their low density, high specific strength, and good thermal conductivity, have become a key alternative to copper tubing in applications such as air conditioning refrigeration pipes and automotive heat exchangers. However, these applications place extremely stringent demands on the comprehensive performance of the material: on the one hand, the pipes must possess sufficient strength and excellent formability to withstand system pressure and meet the processing requirements of complex shapes; on the other hand, in harsh environments containing humid or chloride ions, the material must possess excellent corrosion resistance, especially resistance to pitting corrosion and stress corrosion cracking, to ensure long-term safety and reliability. Currently, the industry urgently needs an aluminum alloy material that can simultaneously achieve high strength, high plasticity, excellent corrosion resistance, and good processing stability.

[0003] Traditional 5-series and 6-series aluminum alloys often struggle to achieve an ideal balance between strength, ductility, and corrosion resistance. For example, increasing Cu content to improve strength often sacrifices corrosion resistance; conversely, alloy designs prioritizing high corrosion resistance often fail to meet the strength requirements of high-pressure pipelines. Existing technologies, while improved by adding rare earth elements, still have significant shortcomings: First, in compositional design, insufficient consideration is given to the synergistic effects of grain refinement, suppression of harmful phases, and regulation of second-phase morphology, limiting further improvements in overall performance. Second, in manufacturing processes, conventional casting and processing methods are frequently employed, limiting precise control over melt purity, microstructure uniformity, and final microstructure, easily leading to problems such as uneven microstructure and coarse second-phase formation, affecting performance stability.

[0004] Therefore, there is an urgent need to propose an aluminum alloy material, its preparation method, and its application in material products to solve the problem of poor performance of existing aluminum alloy materials due to defects in composition design and traditional preparation processes. Summary of the Invention

[0005] The purpose of this invention is to provide an aluminum alloy material, its preparation method, and its application in material products, in order to solve the problem of poor performance of existing aluminum alloy materials due to defects in composition design and traditional preparation processes.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an aluminum alloy material, wherein the raw materials comprise by weight percentage A 0.014-4.046wt%, mixed rare earth 0.005-7.670wt%, unavoidable impurities total content ≤0.350wt%, and aluminum ingot 88.000-99.999wt%.

[0007] Further, A is at least two of Fe, Si, Mg, Cu, Mn, Ti, Ni, Cr, Mo, and Zr; the mixed rare earth is at least two of La, Ce, Pr, Nd, Pm, Sm, and Eu.

[0008] Further, by weight percentage, the composition of A is: Fe 0.002–0.899 wt%, Si 0.002–0.6 wt%, Mg 0.001–0.899 wt%, Cu 0.001–0.699 wt%, Mn 0.001–0.399 wt%, Ti 0.001–0.150 wt%, Ni 0.001–0.150 wt%, Cr 0.005–0.250 wt%, Mo 0.001–0.150 wt%, Zr 0.001–0.150 wt%; the total content of the mixed rare earth elements is 0.05–1.798 wt%.

[0009] This invention also discloses a method for preparing aluminum alloy materials, specifically including the following steps:

[0010] S1. Heat the melting furnace to 500℃ and preheat for 30 minutes. Then add aluminum ingots to the melting furnace and heat to 730-760℃ to completely melt the aluminum ingots. Then add Fe, Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements in sequence and stir thoroughly until all are melted to obtain a composite melt.

[0011] S2. Adjust the temperature of the composite melt to 720-735℃ and perform ultrasonic vibration treatment. Then raise the temperature to 740-750℃ and perform electromagnetic stirring treatment. Next, refine, degas, and remove slag from the composite melt. Let it stand at 720-730℃ for 30-50 minutes to obtain the melt after standing.

[0012] S3. The molten material after standing is semi-continuously cast at 620-670℃ to obtain an ingot;

[0013] S4. Homogenize the ingot at 510-540℃ for 8-15 hours, and then perform multi-pass hot rolling with an initial rolling temperature of 490℃-520℃ and a final rolling temperature of 320℃-350℃ to obtain a hot-rolled plate.

[0014] S5. The hot-rolled plate is cold-rolled with a total deformation of 40% to 65% and the deformation per pass is controlled between 10% and 25%. Then, it undergoes multi-stage aging treatment and is finally air-cooled to room temperature to obtain aluminum alloy material.

[0015] Furthermore, in S2, the applied frequency of the ultrasonic vibration treatment is 18–25 kHz, the power is 1.5–3.5 kW, and the treatment time is set to 8–15 min; the magnetic field strength of the electromagnetic stirring treatment is 0.02–0.05 T, and the stirring time is set to 8–15 min.

[0016] Furthermore, in S4, the interval between the multiple hot rolling passes is cooled by air or water mist, and the temperature drop rate of the rolled piece is controlled at 10-25℃ / min.

[0017] Furthermore, the specific steps of the multi-stage aging process in S5 are as follows: first, aging at 115-125℃ for 5-7 hours, then aging at 165-175℃ for 10-14 hours, and finally air-cooling to room temperature.

[0018] This invention also discloses the application of aluminum alloy materials in material products.

[0019] Furthermore, the material products include pipes; the pipes are at least one of the following: air conditioning and refrigeration pipes, automotive heat exchanger pipes, automotive fuel pipes or brake pipes, marine piping system pipes, chemical fluid transport pipes, food industry equipment pipes, solar collector pipes, aerospace hydraulic or fuel pipes, and building hot and cold water transport pipes.

[0020] Furthermore, the wall thickness of the pipe is 0.3 mm to 2.0 mm.

[0021] Compared with the prior art, the aluminum alloy material, its preparation method, and its application in material products provided by the present invention have the following beneficial effects:

[0022] (1) By limiting the content range of Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements, this invention further refines the microstructure and inhibits recrystallization. While ensuring solid solution strengthening and precipitation strengthening, rare earth elements can refine grains, purify melt, and modify harmful impurity phases, significantly improving the toughness, formability and corrosion resistance of the alloy.

[0023] (2) The present invention adopts a composite treatment method of ultrasonic vibration followed by electromagnetic stirring, which greatly improves the uniformity and density of the microstructure of the ingot. Ultrasonic vibration can generate cavitation effect and acoustic flow effect, effectively breaking dendrites, dispersing the second phase and removing gas; electromagnetic stirring realizes forced convection of the melt, promotes the homogenization of composition and temperature, and lays a good foundation for subsequent processing.

[0024] (3) By setting strict final rolling temperature conditions and using air cooling / water mist cooling to control the temperature drop rate, the present invention effectively controls the recovery and recrystallization process during rolling, refines the deformed structure, and avoids the problems of coarse structure or excessive work hardening caused by excessively high or low final rolling temperature.

[0025] (4) The aluminum alloy material prepared by the present invention has good strength, plasticity and corrosion resistance, and is particularly suitable for manufacturing pipes with high requirements for pressure bearing, forming and environmental corrosion resistance, such as air conditioning refrigeration pipes and automotive heat exchanger pipes, with good safety and reliability. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0027] Figure 1 This is a schematic flowchart of a method for preparing an aluminum alloy material provided by the present invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] This invention provides an aluminum alloy material, the raw materials of which, by weight percentage, comprise: Fe 0.002–0.899 wt%, Si 0.002–0.6 wt%, Mg 0.001–0.899 wt%, Cu 0.001–0.699 wt%, Mn 0.001–0.399 wt%, Ti 0.001–0.150 wt%, Ni 0.001–0.150 wt%, Cr 0.005–0.250 wt%, Mo 0.001–0.150 wt%, Zr 0.001–0.150 wt%, mixed rare earth elements 0.005–7.670 wt%, unavoidable total impurities ≤0.350 wt%, and aluminum ingots 88.000–99.999 wt%.

[0030] Si (silicon): It forms the main strengthening phase Mg2Si with Mg, which is the basis for age hardening.

[0031] Mg (magnesium): As a key pairing element of Si, it works together to achieve core strengthening through precipitation.

[0032] Cu (copper): It participates in the formation of a multi-component strengthening phase, which enhances strength and resistance to high-temperature softening, but its content is strictly limited to balance corrosion resistance.

[0033] Fe (iron): As a controlled impurity, the harmful phases it forms can be modified through processes to mitigate the damage to performance.

[0034] Mn (manganese): provides trace solid solution strengthening and helps improve the surface treatment properties of alloys.

[0035] Mixed rare earth elements: purify the melt, refine the grains, and critically modify harmful iron-rich phases, thereby simultaneously improving the alloy's toughness, strength, and corrosion resistance.

[0036] Ti (Titanium): As a powerful grain refiner, it refines the casting structure and provides a uniform and fine initial structure for subsequent processing.

[0037] Ni (Ni): In aluminum alloys, it mainly affects the properties of the alloy by forming specific intermetallic compounds. Its functions include regulating the morphology of impurity phases, improving strength, and enhancing heat resistance.

[0038] Cr (chromium): Forms dispersed particles to inhibit recrystallization and grain growth, stabilizes the processing structure, and improves strength and toughness.

[0039] Mo (Mo): In aluminum alloys, it mainly strengthens through solid solution and forms a dispersed molybdenum-containing compound phase, which significantly increases the recrystallization temperature of the alloy and inhibits grain coarsening at high temperatures, thereby effectively improving the heat resistance and high-temperature stability of aluminum alloys.

[0040] Zirconium (Zr) is a highly efficient grain refiner and recrystallization inhibitor in aluminum alloys. During the casting process, it forms fine Al3Zr dispersed particles with aluminum, which strongly pin grain boundaries and subgrain boundaries, significantly inhibiting recrystallization. This allows the alloy to maintain its fibrous structure after processing and heat treatment, thereby improving the alloy's strength and resistance to stress corrosion.

[0041] Example 1:

[0042] Please see Figure 1 An aluminum alloy material, the raw materials of which, by weight percentage, include: Fe 0.505wt%, Si 0.401wt%, Mg 0.503wt%, Cu 0.302wt%, Mn 0.205wt%, Ti 0.080wt%, Ni 0.040wt%, Cr 0.152wt%, Mo 0.011wt%, Zr 0.013wt%, mixed rare earth 1.000wt%, wherein Ce:La=2:1, Ce 0.602wt%, La 0.301wt%, Pr 0.097wt%, unavoidable impurities total 0.171wt%, and aluminum ingot 96.617wt%.

[0043] The preparation method specifically includes the following steps:

[0044] S1. Heat the melting furnace to 500℃ and preheat for 30 minutes. Then add aluminum ingots to the melting furnace and heat to 750℃ to completely melt the aluminum ingots. Then add Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements in sequence and stir thoroughly until all are melted to obtain a composite melt.

[0045] S2. Adjust the temperature of the composite melt to 725℃ and perform ultrasonic vibration treatment with an applied frequency of 20kHz, a power of 2.5kW, and a treatment time of 12min. Then, raise the temperature to 745℃ and perform electromagnetic stirring treatment with a magnetic field strength of 0.03T and a stirring time of 10min. Next, refine and degas the composite melt, remove slag, and let it stand at 725℃ for 40min to obtain the melt after standing.

[0046] S3. The molten material after standing is semi-continuously cast at 650°C to obtain an ingot;

[0047] S4. The ingot is homogenized at 525℃ for 12 hours, and then hot rolled in multiple passes. Water mist cooling is used between each pass, and the temperature drop rate is controlled at 15℃ / min. The initial rolling temperature is 505℃, the total deformation is 80%, and the final rolling temperature is 335℃ to obtain the hot rolled plate.

[0048] S5. The hot-rolled plate is cold-rolled with a total deformation of 55% and the deformation per pass is controlled within 15%. Then, a multi-stage aging treatment is carried out. The specific steps are: first, aging at 120℃ for 6 hours, then aging at 170℃ for 12 hours, and finally air-cooled to room temperature to obtain aluminum alloy material.

[0049] The aluminum alloy material was made into a pipe with a burst pressure of 20.5 MPa.

[0050] Example 2:

[0051] Please see Figure 1 This embodiment provides a technical solution based on Embodiment 1: an aluminum alloy material, the raw materials of which, by weight percentage, include: Fe 0.652wt%, Si 0.250wt%, Mg 0.602wt%, Cu 0.152wt%, Mn 0.151wt%, Ti 0.120wt%, Ni 0.103wt%, Cr 0.080wt%, Mo 0.013wt%, Zr 0.017wt%, mixed rare earth 0.627wt%, wherein Ce:La=1.5:1, Ce 0.330wt%, La 0.220wt%, Nd 0.077wt%, unavoidable impurities total 0.260wt%, and aluminum ingot 96.973wt%.

[0052] The preparation method specifically includes the following steps:

[0053] S1. Heat the melting furnace to 500℃ and preheat for 30 minutes. Then add aluminum ingots to the melting furnace and heat to 750℃ to completely melt the aluminum ingots. Then add Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements in sequence and stir thoroughly until all are melted to obtain a composite melt.

[0054] S2. Adjust the temperature of the composite melt to 725℃ and perform ultrasonic vibration treatment with an applied frequency of 22kHz, a power of 3.0kW, and a treatment time of 10min. Then, raise the temperature to 745℃ and perform electromagnetic stirring treatment with a magnetic field strength of 0.04T and a stirring time of 12min. Next, refine and degas the composite melt, remove slag, and let it stand at 725℃ for 40min to obtain the melt after standing.

[0055] S3. The molten material after standing is semi-continuously cast at 650°C to obtain an ingot;

[0056] S4. The ingot is homogenized at 525℃ for 12 hours, and then hot rolled in multiple passes with air cooling between each pass. The temperature drop rate is controlled at 20℃ / min, the initial rolling temperature is 495℃, the total deformation is 75%, and the final rolling temperature is 330℃ to obtain the hot rolled plate.

[0057] S5. The hot-rolled plate is cold-rolled with a total deformation of 60% and the deformation per pass is controlled within 15%. Then, a multi-stage aging treatment is carried out. The specific steps are: first, aging at 118℃ for 6.5 hours, then aging at 168℃ for 13 hours, and finally air-cooled to room temperature to obtain aluminum alloy material.

[0058] Example 3:

[0059] Please see Figure 1 This embodiment provides a technical solution based on Embodiment 1: an aluminum alloy material, the raw materials of which include, by weight percentage: Fe 0.303wt%, Si 0.551wt%, Mg 0.252wt%, Cu 0.505wt%, Mn 0.230wt%, Ti 0.050wt%, Ni 0.040wt%, Cr 0.202wt%, Mo 0.014wt%, Zr 0.019wt%, mixed rare earth 0.973wt%, wherein Ce:La=2.5:1, Ce 0.550wt%, La 0.220wt%, Nd 0.203wt%, unavoidable impurities total 0.272wt%, and aluminum ingot 96.589wt%.

[0060] The preparation method specifically includes the following steps:

[0061] S1. Heat the melting furnace to 500℃ and preheat for 30 minutes. Then add aluminum ingots to the melting furnace and heat to 750℃ to completely melt the aluminum ingots. Then add Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements in sequence and stir thoroughly until all are melted to obtain a composite melt.

[0062] S2. Adjust the temperature of the composite melt to 725℃ and perform ultrasonic vibration treatment with an applied frequency of 20kHz, a power of 2.5kW, and a treatment time of 12min. Then, raise the temperature to 745℃ and perform electromagnetic stirring treatment with a magnetic field strength of 0.03T and a stirring time of 10min. Next, refine and degas the composite melt, remove slag, and let it stand at 725℃ for 40min to obtain the melt after standing.

[0063] S3. The molten material after standing is semi-continuously cast at 650°C to obtain an ingot;

[0064] S4. The ingot is homogenized at 525℃ for 12 hours, and then hot rolled in multiple passes. Water mist cooling is used between each pass, and the temperature drop rate is controlled at 12℃ / min. The initial rolling temperature is 515℃, the total deformation is 82%, and the final rolling temperature is 332℃ to obtain the hot rolled plate.

[0065] S5. The hot-rolled plate is cold-rolled with a total deformation of 55% and the deformation per pass is controlled within 15%. Then, a multi-stage aging treatment is carried out. The specific steps are: first, aging at 120℃ for 6 hours, then aging at 170℃ for 12 hours, and finally air-cooled to room temperature to obtain aluminum alloy material.

[0066] Comparative Example 1:

[0067] An aluminum alloy material, the raw materials of which, by weight percentage, comprise: Fe 0.505wt%, Si 0.401wt%, Mg 0.503wt%, Cu 0.302wt%, Mn 0.205wt%, Ti 0.080wt%, Ni 0.040wt%, Cr 0.152wt%, Mo 0.011wt%, Zr 0.013wt%, unavoidable impurities totaling 0.171wt%, and aluminum ingots 97.617wt%; unlike Example 1, the raw materials do not contain mixed rare earth elements. The preparation process of this aluminum alloy material is exactly the same as that of Example 1.

[0068] Comparative Example 2:

[0069] An aluminum alloy material comprises the following raw materials by weight percentage: Fe 0.505wt%, Si 0.401wt%, Mg 0.503wt%, Cu 0.302wt%, Mn 0.205wt%, Ti 0.080wt%, Ni 0.040wt%, Cr 0.152wt%, Mo 0.011wt%, Zr 0.013wt%, and mixed rare earth elements 0.660wt%, wherein Ce:La = 5:1, Ce 0.550wt%, La 0.110wt%, and the total unavoidable impurities content is 0.171wt%, with aluminum ingots comprising 96.957wt%. Unlike Example 1, the mass ratio of Ce to La in the mixed rare earth elements is adjusted to 5:1, and no other light rare earth elements are added. The preparation process of this aluminum alloy material is exactly the same as that of Example 1.

[0070] Comparative Example 3:

[0071] An aluminum alloy material, the raw materials of which, by weight percentage, comprise: Fe 0.505wt%, Si 0.401wt%, Mg 0.503wt%, Cu 0.302wt%, Mn 0.205wt%, Ti 0.080wt%, Ni 0.040wt%, Cr 0.152wt%, Mo 0.011wt%, Zr 0.013wt%, mixed rare earth 1.000wt%, wherein Ce:La = 2:1, Ce 0.602wt%, La 0.301wt%, Pr 0.097wt%, unavoidable impurities total 0.171wt%, and aluminum ingot 96.617wt%. Compared with Example 1, the preparation method of this aluminum alloy material does not involve ultrasonic vibration and electromagnetic stirring, but only conventional mechanical stirring. The preparation method specifically includes the following steps:

[0072] S1. Heat the melting furnace to 500℃ and preheat for 30 minutes. Then add aluminum ingots to the melting furnace and heat to 750℃ to completely melt the aluminum ingots. Then add Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements in sequence and stir thoroughly until all are melted to obtain a composite melt.

[0073] S2. Adjust the temperature of the composite melt to 725℃, mechanically stir for 22 minutes, then refine and degas the composite melt, remove slag, and let it stand at 725℃ for 40 minutes to obtain the melt after standing.

[0074] S3. The molten material after standing is semi-continuously cast at 650°C to obtain an ingot;

[0075] S4. The ingot is homogenized at 525℃ for 12 hours, and then hot rolled in multiple passes. Water mist cooling is used between each pass, and the temperature drop rate is controlled at 15℃ / min. The initial rolling temperature is 505℃, the total deformation is 80%, and the final rolling temperature is 335℃ to obtain the hot rolled plate.

[0076] S5. The hot-rolled plate is cold-rolled with a total deformation of 55% and the deformation per pass is controlled within 15%. Then, a multi-stage aging treatment is carried out. The specific steps are: first, aging at 120℃ for 6 hours, then aging at 170℃ for 12 hours, and finally air-cooled to room temperature to obtain aluminum alloy material.

[0077] Comparative Example 4:

[0078] An aluminum alloy material, the raw materials of which, by weight percentage, comprise: Fe 0.505wt%, Si 0.401wt%, Mg 0.503wt%, Cu 0.302wt%, Mn 0.205wt%, Ti 0.080wt%, Ni 0.040wt%, Cr 0.152wt%, Mo 0.011wt%, Zr 0.013wt%, mixed rare earth 1.000wt%, wherein Ce:La = 2:1, Ce 0.602wt%, La 0.301wt%, Pr 0.097wt%, unavoidable impurities total 0.171wt%, and aluminum ingot 96.617wt%. Compared with Example 1, the preparation method of this aluminum alloy material does not involve multi-stage aging, but only single-stage aging. The preparation method specifically includes the following steps:

[0079] S1. Heat the melting furnace to 500℃ and preheat for 30 minutes. Then add aluminum ingots to the melting furnace and heat to 750℃ to completely melt the aluminum ingots. Then add Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements in sequence and stir thoroughly until all are melted to obtain a composite melt.

[0080] S2. Adjust the temperature of the composite melt to 725℃ and perform ultrasonic vibration treatment with an applied frequency of 20kHz, a power of 2.5kW, and a treatment time of 12min. Then, raise the temperature to 745℃ and perform electromagnetic stirring treatment with a magnetic field strength of 0.03T and a stirring time of 10min. Next, refine and degas the composite melt, remove slag, and let it stand at 725℃ for 40min to obtain the melt after standing.

[0081] S3. The molten material after standing is semi-continuously cast at 650°C to obtain an ingot;

[0082] S4. The ingot is homogenized at 525℃ for 12 hours, and then hot rolled in multiple passes. Water mist cooling is used between each pass, and the temperature drop rate is controlled at 15℃ / min. The initial rolling temperature is 505℃, the total deformation is 80%, and the final rolling temperature is 335℃ to obtain the hot rolled plate.

[0083] S5. The hot-rolled plate is cold-rolled with a total deformation of 55% and the deformation per pass is controlled within 15%. Then, a single-stage aging treatment is performed at 170℃ for 18 hours. Finally, it is air-cooled to room temperature to obtain aluminum alloy material.

[0084] Performance testing:

[0085] Based on the aluminum alloy materials provided in Examples 1 to 3 and Comparative Examples 1 to 4, their mechanical properties (tensile strength, yield strength, elongation) and corrosion resistance (average corrosion rate) were tested to verify the influence of different composition designs and processing on the comprehensive performance of aluminum alloy materials.

[0086] (a) Mechanical property testing

[0087] 1. Sample preparation: Process each sample into a standard tensile specimen. Prepare 3 parallel specimens for each group. Sand the surface of the specimens with sandpaper to ensure that there are no scratches, cracks and impurities attached.

[0088] 2. Equipment debugging: Start the electronic universal testing machine, preheat the equipment (preheating time 30min), calibrate the force sensor and displacement measurement system, and set the tensile rate to 2mm / min.

[0089] 3. Specimen installation: Clamp the tensile specimen in the upper and lower jaws of the testing machine, ensuring that the specimen axis is aligned with the direction of force to avoid eccentric loading.

[0090] 4. Test procedure: Start the testing machine and conduct a room temperature tensile test, recording the force-displacement curve in real time until the specimen breaks.

[0091] 5. Data Recording and Processing: Read the yield strength (Rp0.2) and tensile strength (Rm) from the force-displacement curve, measure the gauge length after the specimen breaks, and calculate the elongation (A). Take the average value of 3 parallel specimens in each group as the final test result.

[0092] Table 1 Mechanical performance test results

[0093] sample Tensile strength (MPa) Yield strength (MPa) Elongation (%) Example 1 195±2.1 165±1.8 28.0±0.5 Example 2 188±1.8 158±1.5 26.5±0.4 Example 3 205±2.3 172±2.0 25.5±0.6 Comparative Example 1 185±2.5 155±2.2 20.0±0.8 Comparative Example 2 190±2.0 160±1.9 24.0±0.5 Comparative Example 3 175±3.0 148±2.5 22.0±0.7 Comparative Example 4 180±2.2 152±2.0 23.0±0.6

[0094] The experimental results are shown in Table 1. The strength and plasticity of the aluminum alloy materials in each embodiment are superior to those in the comparative examples. Example 3 exhibits the highest tensile strength and yield strength, but its elongation is slightly lower than that of Example 1. Example 1 maintains high strength while possessing the best elongation, demonstrating the optimal balance between strength and plasticity. In contrast, the elongation of Comparative Example 1, without rare earth elements, drops significantly to 20.0%, and its strength is the lowest. Comparative Example 3, lacking ultrasonic vibration and electromagnetic stirring, exhibits the worst mechanical properties, indicating that this process plays a crucial role in achieving homogenization and performance improvement. Comparative Example 4, using only single-stage aging, also shows lower strength and plasticity than Example 1, which uses multi-stage aging. Therefore, the reasonable addition of mixed rare earth elements, the application of melt treatment processes combining ultrasonic vibration and electromagnetic stirring, and multi-stage aging are effective ways to obtain high-strength, high-toughness aluminum alloy materials.

[0095] (ii) Corrosion resistance test (average corrosion rate in 3.5% NaCl aqueous solution)

[0096] 1. Sample preparation: The samples of each experimental group were processed into standard corrosion samples, and three parallel samples were prepared for each group. The sample surface was wiped with acetone to remove oil stains, rinsed with distilled water, dehydrated with anhydrous ethanol, and dried. The initial mass (m0) of the sample was weighed using an analytical balance (accuracy 0.1 mg), and the sample dimensions were measured with vernier calipers. The sample surface area (S) was calculated.

[0097] 2. Preparation of test solution: Accurately weigh 35g of sodium chloride (analytical grade), add 1000mL of distilled water, stir until completely dissolved, and prepare a 3.5% NaCl aqueous solution. Control the solution temperature at 35±1℃.

[0098] 3. Immersion Test: Immerse the samples completely in a 3.5% NaCl aqueous solution, ensuring that the samples do not come into contact with each other or with the container wall. The immersion time is 30 days. Record the solution temperature daily during the immersion process to ensure that the temperature fluctuation is within ±1℃.

[0099] 4. Sample post-treatment: After soaking, take out the sample, gently remove the surface corrosion products with a brush, rinse with distilled water, dehydrate with anhydrous ethanol, air dry, and weigh the final mass of the sample (m1).

[0100] 5. Corrosion rate calculation: Calculate the average corrosion rate (V) according to the formula:

[0101]

[0102] Where v is the average corrosion rate (unit: mm / year), m0 is the initial mass of the sample (unit: g), m1 is the final mass of the sample (unit: g), and S is the surface area of ​​the sample (unit: cm²). 2), where t is the soaking time (unit: year). The average value of 3 parallel samples in each group is taken as the final test result.

[0103] Table 2 Corrosion Resistance Test Results

[0104] sample Average corrosion rate (mm / year) Self-corrosion potential (V vs. SCE) Self-corrosion current density (μA / cm²) Example 1 0.020±0.002 -0.68±0.02 0.15±0.03 Example 2 0.022±0.002 -0.70±0.03 0.18±0.04 Example 3 0.023±0.003 -0.71±0.02 0.20±0.05 Comparative Example 1 0.045±0.005 -0.85±0.04 0.52±0.08 Comparative Example 2 0.035±0.004 -0.78±0.03 0.30±0.06 Comparative Example 3 0.032±0.003 -0.75±0.03 0.28±0.05 Comparative Example 4 0.026±0.003 -0.72±0.02 0.22±0.04

[0105] The experimental results are shown in Table 2. The overall corrosion resistance of Examples 1, 2, and 3 is significantly better than that of the comparative examples. Among them, Example 1 exhibits the best corrosion resistance, with the lowest average corrosion rate of 0.020 mm / year, the highest self-corrosion potential (-0.68 V), and the lowest self-corrosion current density (0.15 μA / cm²), indicating that the passivation film formed on its surface is the most stable and has the strongest protective effect. In contrast, Comparative Example 1, which contains no rare earth elements at all, exhibited the worst corrosion resistance, with a corrosion rate as high as 0.045 mm / year. This reveals the crucial role of rare earth elements in refining the microstructure, purifying grain boundaries, and promoting the formation of a dense oxide film. Comparative Example 2 (with an unbalanced Ce:La ratio) and Comparative Example 3 (lacking melt ultrasonic and electromagnetic stirring treatment) showed improved corrosion resistance but were still significantly inferior to the Example 1. This indicates that the balanced addition of rare earth elements and the melt treatment process are indispensable for obtaining a uniform and dense microstructure and thus improving corrosion resistance. Furthermore, although Comparative Example 4, which uses single-stage aging, exhibited better corrosion resistance than the other comparative examples, it still lagged behind the best example. This confirms the advantages of multi-stage aging processes in optimizing the distribution of precipitated phases and reducing the micro-cell effect of electrochemical corrosion.

[0106] Application example:

[0107] Application of an aluminum alloy material in material products:

[0108] Using the composition and preparation process of Example 1, thin-walled pipes suitable for various harsh working conditions are manufactured through subsequent pipe processing technology. Specifically, after hot rolling and cold rolling the aluminum alloy ingot to the required thickness, pipes with an outer diameter of 6-12 mm and a wall thickness of 0.3-2.0 mm are produced through continuous drawing and high-frequency welding processes, followed by surface anodizing to form a dense oxide film. In practical applications, this pipe exhibits excellent comprehensive performance: when used in air conditioning refrigeration pipelines, its burst pressure exceeds 20.5 MPa, and it shows no significant corrosion or pitting in long-term refrigerant-containing and humid environments; when used in automotive heat exchanger pipes, it maintains high strength and resistance to stress corrosion cracking under vibration and thermal cycling loads; when used in solar collector pipelines, its surface weather resistance and thermal conductivity improve system efficiency; and when used in building hot and cold water pipes, it combines resistance to chloride ion corrosion with long service life. Compared to traditional copper pipes, the entire series of pipes reduces weight by about 60% and manufacturing costs by more than 20%. They can also be adapted to complex structural requirements through secondary processing such as bending and flaring. They achieve a balance of high strength, high plasticity, excellent corrosion resistance and good economy, fully meeting the needs of high-performance pipes in air conditioning, automotive, shipbuilding, chemical, food, solar energy, aerospace and construction industries.

[0109] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An aluminum alloy material, characterized in that, Its raw materials include, by weight percentage: A 0.014~4.046wt%, mixed rare earth 0.005~7.670wt%, unavoidable impurities total content ≤0.350wt%, and aluminum ingot 88.000~99.999wt%.

2. The aluminum alloy material according to claim 1, characterized in that, The A is at least two of Fe, Si, Mg, Cu, Mn, Ti, Ni, Cr, Mo, and Zr; the mixed rare earth is at least two of La, Ce, Pr, Nd, Pm, Sm, and Eu.

3. The aluminum alloy material according to claim 2, characterized in that, The composition of A, by weight percentage, is as follows: Fe 0.002–0.899 wt%, Si 0.002–0.6 wt%, Mg 0.001–0.899 wt%, Cu 0.001–0.699 wt%, Mn 0.001–0.399 wt%, Ti 0.001–0.150 wt%, Ni 0.001–0.150 wt%, Cr 0.005–0.250 wt%, Mo 0.001–0.150 wt%, Zr 0.001–0.150 wt%; the total content of the mixed rare earth elements is 0.05–1.798 wt%.

4. A method for preparing an aluminum alloy material, characterized in that, It is used to prepare an aluminum alloy material according to any one of claims 1-3, and the preparation method specifically includes the following steps: S1. Heat the melting furnace to 500℃ and preheat for 30 minutes. Then add aluminum ingots to the melting furnace and heat to 730-760℃ to completely melt the aluminum ingots. Then add Fe, Si, Mg, Cu, Fe, Mn, Ti, Ni, Cr, Mo, Zr and mixed rare earth elements in sequence and stir thoroughly until all are melted to obtain a composite melt. S2. Adjust the temperature of the composite melt to 720-735℃ and perform ultrasonic vibration treatment. Then raise the temperature to 740-750℃ and perform electromagnetic stirring treatment. Next, refine, degas, and remove slag from the composite melt. Let it stand at 720-730℃ for 30-50 minutes to obtain the melt after standing. S3. The molten material after standing is semi-continuously cast at 620-670℃ to obtain an ingot; S4. Homogenize the ingot at 510-540℃ for 8-15 hours, and then perform multi-pass hot rolling with an initial rolling temperature of 490℃-520℃ and a final rolling temperature of 320℃-350℃ to obtain a hot-rolled plate. S5. The hot-rolled plate is cold-rolled with a total deformation of 40% to 65% and the deformation per pass is controlled between 10% and 25%. Then, it undergoes multi-stage aging treatment and is finally air-cooled to room temperature to obtain aluminum alloy material.

5. The method for preparing an aluminum alloy material according to claim 4, characterized in that, The ultrasonic vibration treatment in S2 is applied at a frequency of 18–25 kHz, with a power of 1.5–3.5 kW and a treatment time of 8–15 min; the electromagnetic stirring treatment has a magnetic field strength of 0.02–0.05 T and a stirring time of 8–15 min.

6. The method for preparing an aluminum alloy material according to claim 4, characterized in that, In the S4 process, the interval between multiple hot rolling passes is cooled by air or water mist, and the temperature drop rate of the rolled piece is controlled at 10-25℃ / min.

7. The method for preparing an aluminum alloy material according to claim 4, characterized in that, The specific steps of the multi-stage aging process in S5 are as follows: first, aging at 115-125℃ for 5-7 hours, then aging at 165-175℃ for 10-14 hours, and finally air cooling to room temperature.

8. The application of an aluminum alloy material according to any one of claims 1-3 in material products.

9. The application of an aluminum alloy material according to claim 8 in material products, characterized in that, The material products include pipes; the pipes are at least one of the following: air conditioning and refrigeration pipes, automotive heat exchanger pipes, automotive fuel pipes or brake pipes, marine piping system pipes, chemical fluid transport pipes, food industry equipment pipes, solar collector pipes, aerospace hydraulic or fuel pipes, and building hot and cold water transport pipes.

10. The application of an aluminum alloy material according to claim 9 in material products, characterized in that, The wall thickness of the pipe is 0.3mm to 2.0mm.

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