Aluminum profile and extrusion preparation process thereof

Abstract

The invention provides an aluminum profile and an extrusion preparation process thereof. The aluminum profile comprises the following components in percentage by mass: 1.7-2.2% of Mg, 0.6-1.2% of Si, 0.7-0.9% of Mn, 0.25-0.35% of Sc, 0.18-0.22% of Zr, less than or equal to 0.25% of Fe, less than or equal to 0.15% of Ti and the balance of aluminum, and the preparation process of the aluminum profile comprises the following steps: preheating an aluminum bar to 450-470 DEG C under the protection of inert gas, and keeping the temperature for not less than 3 hours; transferring the preheated aluminum bar into an extruder at the temperature of 420-440 DEG C, and applying extrusion pressure of 25-30 MPa and traction force of 10-15 kgf to deform and form the aluminum bar; after molding, alternately cooling to below 100 DEG C by air cooling and liquid nitrogen quenching; and finally, electromagnetic field auxiliary treatment (50Hz, 0.8-1.2 T and more than or equal to 30 minutes) and heat treatment at 170-180 DEG C are carried out. By optimizing alloy components and process control, the strength, toughness and dimensional stability of the aluminum profile are remarkably improved, the defects of tail shrinkage, slag inclusion and the like in the extrusion process are avoided, the aluminum profile is particularly suitable for production of complex structural parts such as new energy automobile battery trays, the secondary machining cost is reduced, and the product reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum profile production and processing technology, specifically to an aluminum profile and the extrusion preparation process of the aluminum profile. Background Technology

[0002] Aluminum profiles, as a low-density, high-strength metal material, are relatively lightweight and have been widely used in aerospace, transportation, and new energy fields. The surface of aluminum profiles has a dense natural oxide film, providing excellent corrosion resistance. Their good ductility also supports the production and processing of complex cross-section components, making them particularly suitable for battery trays in new energy vehicles.

[0003] A typical battery tray usually has a cross-section including cooling channels, reinforcing ribs, and sealing grooves, making its structure relatively complex. Traditional manufacturing processes, such as casting, can lead to filling defects in the cooling channels and thin-walled reinforcing ribs due to insufficient aluminum flow. Furthermore, fine structural features like the sealing grooves require secondary machining, which can affect material continuity and increase manufacturing costs. Additionally, the as-cast structure can exhibit shrinkage porosity and other issues, resulting in strength fluctuations.

[0004] The invention patent with announcement number CN108165907A provides a manufacturing process for aluminum profiles used in automotive collision energy-absorbing components and the aluminum profiles produced therefrom. Through homogenized annealing, extrusion, quenching, stretching, and aging treatments, the tensile mechanical properties of the aluminum profiles are improved without reducing their plasticity, thus achieving better compressive performance. However, when this technical solution is used for the intricate structure of battery trays, the forming effect is not stable enough, and continuous extrusion is prone to defects such as tail shrinkage, slag inclusions, and white lines.

[0005] In view of this, it is necessary to develop an aluminum profile and optimize the existing extrusion process. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an aluminum profile with a more stable extrusion molding effect.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an aluminum profile made of aluminum rods, wherein the aluminum rods comprise, by mass percentage: Mg, 1.7-2.2%; Si, 0.6-1.2%; Mn, 0.7-0.9%; Sc, 0.25-0.35%; Zr, 0.18-0.22%; Fe≤0.25%; Ti≤0.15%, with the balance being aluminum and other unavoidable impurities.

[0008] As an explanation, aluminum rod refers to a rod or bar-shaped component with a length-to-diameter ratio generally greater than or equal to 3. Parts made from aluminum rods include, but are not limited to, the extrusion process described in this invention, as well as other existing processes such as casting, pouring, powder metallurgy, electrolysis, cutting, sheet metal, etc., which produce aluminum alloys (aluminum rods) that conform to the composition of this element.

[0009] In the above technical features, the impurities in the balance aluminum include, but are not limited to, trace elements such as copper, zinc, and chromium introduced by the smelting raw materials. Preferably, the total amount of impurities accounts for less than 0.15% of the total mass of the aluminum alloy, so as to avoid its impact on the performance and forming properties of the alloy. When preparing this alloy by casting, high-purity aluminum ingots and argon refining can be used to achieve this range control.

[0010] To provide a clearer explanation, the present invention also provides an extrusion process for aluminum profiles having the above-mentioned technical features, comprising the following steps.

[0011] S1, preheat and keep the aluminum rod at a temperature under inert gas protection; S2, transfer the preheated aluminum bar into the extruder, and heat the extruder die and extrusion cylinder to the working temperature; S3, the heated mold is loaded into the extruder die sleeve, the heated aluminum rod is placed in the extrusion cylinder, the extrusion shaft of the extruder applies axial pressure to the aluminum rod, and at the same time the traction mechanism of the extruder applies traction force to the aluminum rod, so that the aluminum rod is deformed and forms an aluminum profile through the die hole. S4, the aluminum profile is subjected to aging treatment, which includes electromagnetic field assisted treatment and heating treatment.

[0012] In a preferred embodiment, in step S1, the aluminum rod is preheated to 450-470°C and held at that temperature for at least 3 hours. The preheating temperature is below the melting point of aluminum (referring to aluminum alloys) but above its recrystallization temperature. This is to ensure sufficient diffusion of alloying elements. Too low a temperature may result in segregation residue, while too high a temperature may cause the aluminum rod to melt, thus affecting subsequent extrusion molding processes. Simultaneously, the preheating holding time should not be too short to ensure sufficient diffusion of elements such as Mg, Sc, and Zr. Preheating can be performed using heating devices including, but not limited to, muffle furnaces.

[0013] In a preferred embodiment, in S2, the working temperature of the extrusion barrel and die is raised to 420-440°C by the heating unit of the extruder. The heating unit includes, but is not limited to, energized resistance wires. It is noteworthy that the temperature of the die and extrusion barrel should be slightly lower than the preheating temperature of the aluminum rod, creating a temperature gradient of 20–50°C. This prevents the aluminum rod from contacting the cold die, which could lead to rapid surface hardening and ensures continuous material flow, thereby reducing white line defects. If the temperature of the die and extrusion barrel is too low, the flow stress will be high, increasing the applied pressure. Conversely, if the temperature is too high, the pressure on the aluminum rod will lead to a decrease in yield strength.

[0014] In a preferred embodiment, in S2, the axial pressure applied to the aluminum bar in the extrusion shaft is 25-30 MPa, and the traction force of the traction mechanism is 10-15 kgf. The extrusion shaft refers to the piston component located inside the extrusion cylinder, which is usually coaxially connected to the hydraulic cylinder to maintain a stable pressure output. The traction mechanism includes, but is not limited to, an activation and clamping traction mechanism or a hydraulically driven traction mechanism, which has clamping components between itself and the aluminum profile.

[0015] In a preferred embodiment, in step S2, an argon-nitrogen mixed protective gas with a volume ratio of 7:3 is injected into the extrusion cylinder during the extrusion process, with a gas flow rate of 8-10 L / min. It should be noted that this argon-nitrogen mixed protective gas is only radially inserted through the extrusion cylinder, and the gas pressure is approximately twice atmospheric pressure, which can be quantitatively achieved using a pneumatic pump, metering pump, or other mechanical means. Simultaneously, since the cylinder is not a sealed structure, the gas escapes and dissipates through the end of the cylinder.

[0016] In a preferred embodiment, in step S3, after the aluminum rod passes through the mold hole, the aluminum profile is subjected to alternating cooling, including air cooling and liquid nitrogen quenching, cyclically repeated until the temperature of the aluminum profile drops below 100°C. The air cooling velocity is 15-20 m / s, and the liquid nitrogen quenching injection rate is 0.2-0.5 L / m. 2 ·s).

[0017] In a preferred embodiment, each air cooling cycle lasts 5-20 seconds, and each liquid nitrogen quenching cycle lasts 3-10 seconds, with a minimum of 10 cycles. In the above technical features, this invention, through alternating cycles of slow and rapid cooling, creates a periodic thermal stress field within the material, promoting dislocation slip and redistribution, and eliminating residual stress. Air cooling can be achieved using an air spray gun, which forces convection heat transfer and removes surface heat; liquid nitrogen can also be sprayed using a spray gun, which rapidly quenches and fixes the metastable phase. It is worth noting that excessively high flow rates can lead to chilling cracks, and prolonged liquid nitrogen quenching can decrease the material's toughness.

[0018] It is necessary to explain that the purpose of air cooling and liquid nitrogen rapid cooling is to cool the surface of the aluminum profile. Under the condition of surface cooling, the temperature inside the aluminum profile is still relatively high. Under the alternating action of the two cooling methods, the internal temperature of the aluminum profile repeatedly exchanges heat with the outside, thereby reducing the thermal stress of the aluminum profile, taking into account production efficiency, and improving its production quality.

[0019] In a preferred embodiment, in S4, electromagnetic field-assisted treatment is performed at a frequency of 50Hz and a magnetic field strength of 0.8-1.2T for a duration of no less than 30 minutes; the heating treatment temperature is 170-180℃, and the heating treatment time is no less than 8 hours. In this technical feature, the heating treatment can be performed using a heating furnace with a ceramic fiber lining for insulation. The bottom of the furnace is heated by a nickel-chromium alloy resistance wire, and the furnace should also be equipped with a forced convection fan at a wind speed of 2-5 m / s to maintain uniform heating, thereby activating Mg / Si atomic diffusion. The heating temperature is optimally controlled at 170-175℃. The electromagnetic coil is embedded in the inner wall of the heating furnace and insulated. It is worth noting that the introduction of the electromagnetic field should only be activated after the aluminum profile inside the heating furnace reaches 170 degrees Celsius to avoid eddy currents generated by magnetic field heating, which could lead to uneven temperature control.

[0020] In the electromagnetic field-assisted processing step, the electromagnetic field is generated by an electromagnetic coil surrounding the outside of the aluminum profile. The direction of the magnetic field is parallel to the length direction of the aluminum profile. The heating furnace for the heating process is located below the aluminum profile. An air chamber is left between the aluminum profile and the heating furnace, so that there is a space with a height of more than 30cm between the heating furnace and the aluminum profile.

[0021] The advantages and beneficial effects of this invention are as follows: 1. By adding a specific ratio of scandium and zirconium, the strength and toughness of the material are improved, and a stable precipitate phase is formed. This enables the aluminum profile to exhibit excellent resistance to deformation and dimensional stability in complex cross-section applications, effectively avoiding casting defects such as shrinkage porosity and gas pores, reducing material strength fluctuations, thereby reducing the risk of inclusions and white lines during the extrusion process, and ensuring that the formed aluminum profile has higher reliability and service life.

[0022] 2. The aluminum rod is preheated under inert gas protection. The injection of argon-nitrogen mixed protective gas during the extrusion process effectively prevents material oxidation and surface defects. On the other hand, alternating cooling reduces thermal stress and deformation cracking. At the same time, electromagnetic field assistance and heating aging treatment improve the grain uniformity and mechanical properties of the aluminum profile, ultimately achieving high stability of continuous extrusion. This avoids problems such as tail shrinkage and insufficient filling in traditional processes and reduces secondary processing costs. Attached Figure Description

[0023] Figure 1 This is a flow chart of the aluminum profile manufacturing process shown in this invention; Figure 2 This is a schematic diagram of the aluminum profile battery tray structure obtained by the present invention. Detailed Implementation

[0024] This invention provides an aluminum profile made from aluminum rods through an extrusion process. The alloy composition includes scandium (Sc) and zirconium (Zr), which form Al3(Sc,Zr) nanoscale coherent precipitates within the aluminum matrix. These coherent precipitates help suppress grain boundary migration during recrystallization, reducing grain size and preventing strength loss due to grain coarsening. This ensures structural stability during extrusion and hinders dislocation movement, thereby improving the yield strength of the aluminum profile.

[0025] The alloy composition also includes magnesium (Mg) and silicon (Si). During the aging stage, the two can precipitate as Mg2Si strengthening phases to provide a certain amount of matrix strength. It also contains manganese (Mn), which plays a role in inhibiting the formation of coarse β-AlFeSi phases by Fe impurities, reducing stress concentration points, and increasing the recrystallization temperature to avoid abnormal grain growth during extrusion deformation.

[0026] The present invention also provides an extrusion preparation process for such aluminum profiles. In this process, the aluminum rod is preheated in a scorching atmosphere to fully homogenize the aluminum rod and eliminate casting segregation. The mold temperature is slightly lower than the preheating temperature of the aluminum rod to form a directional thermal gradient, which avoids the aluminum rod surface from becoming too cold and causing a sudden change in flow stress, thereby reducing the risk of inclusions.

[0027] During the extrusion of aluminum rods, a pressure of 25-30 MPa and a traction force of 10-15 kgf are applied. The high pressure ensures the material fully fills the complex cavity of the die, while the traction force balances the base velocity and the rheological properties of the material, reducing or preventing tailing. During the extrusion process, the extruder barrel is also connected to an argon-nitrogen mixer for protection. Nitrogen reduces the oxygen partial pressure within the barrel, while argon prevents the oxidation of metal elements during the high-temperature process, thereby reducing or preventing the formation of white lines on the surface.

[0028] For aluminum profiles extruded from the die holes, the present invention also employs an alternating cooling method for stress regulation. Slow cooling with air cooling is used to reduce thermal stress, while rapid cooling with liquid nitrogen is used to accelerate local delivery to fix the metastable phase structure. Alternating cooling induces dislocation recombination in the alloy material, thereby releasing residual stress.

[0029] On the other hand, considering that traditional aging treatments are difficult to balance strength and higher blade shape of alloy materials, an electromagnetic field is also introduced. Through the coupling effect of electromagnetic field and heating, the electromagnetic field induces eddy current effect, which on the one hand accelerates the enrichment of Mg / Si solute atoms into the precipitated phase, and on the other hand drives dislocation slip, refining the subgrain structure.

[0030] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0031] Example 1 An extrusion process for aluminum profiles includes the following steps: S1, a material containing 1.7%Mg, 0.9%Si, 0.8%Mn, 0.30%Sc, 0.18%Zr, 0.25%Fe, 0.15%Ti and the balance Al is melted and cast into an aluminum rod. The aluminum rod is preheated to 450℃ and held for 3 hours under argon protection at 5L / min.

[0032] S2, set the heating unit of the extruder to heat the extrusion cylinder and die to 440°C, transfer the preheated and heat-insulated aluminum rod to the extruder, apply an extrusion pressure of 25MPa and a traction force of 10kgf to the aluminum rod, and at the same time inject a protective gas mixture of argon and nitrogen with a volume ratio of 7:3 into the extrusion cylinder at a gas flow rate of 8L / min.

[0033] S3. After the aluminum rod is extruded from the die hole, it is immediately subjected to air cooling and liquid nitrogen quenching, which are alternated in a cycle. The air cooling is carried out at a wind speed of 15 m / s, and each cycle lasts for 3 seconds. The liquid nitrogen quenching spray rate is 0.2 L / (m³). 2 Each cooling cycle lasts for 3 seconds, and the air cooling and liquid nitrogen rapid cooling cycles alternate 20 times to reduce the temperature of the aluminum profile to below 100℃.

[0034] S4. Place the aluminum profile cooled to below 100°C on a heating table and keep it at 170°C for 8 hours. When the aluminum profile is heated to 170°C, apply an electromagnetic field to it for auxiliary treatment. The direction of the electromagnetic field is parallel to the length axis of the aluminum profile. Use a frequency of 50Hz and a magnetic field strength of 0.8T for 30 minutes.

[0035] Example 2 An extrusion process for aluminum profiles includes the following steps: S1, a material containing 2.2%Mg, 1.2%Si, 0.9%Mn, 0.35%Sc, 0.20%Zr, 0.10%Fe, 0.05%Ti and the balance Al is melted and cast into an aluminum rod. The aluminum rod is preheated to 470℃ and held at that temperature for 3.5 hours under argon protection at a rate of 5L / min.

[0036] S2, set the heating unit of the extruder to heat the extrusion cylinder and the die to 420°C, transfer the preheated and heat-insulated aluminum rod to the extruder, apply an extrusion pressure of 30MPa and a traction force of 15kgf to the aluminum rod, and at the same time inject a protective gas mixture of argon and nitrogen with a volume ratio of 7:3 into the extrusion cylinder at a gas flow rate of 10L / min.

[0037] S3. After the aluminum rod is extruded from the die hole, it is immediately subjected to air cooling and liquid nitrogen quenching, which are alternated in a cycle. The air cooling is carried out at a wind speed of 20 m / s, and each cycle lasts for 20 seconds. The liquid nitrogen quenching spray rate is 0.5 L / (m³). 2 Each cooling cycle lasts for 10 seconds, and the air cooling and liquid nitrogen rapid cooling cycles alternate 15 times to reduce the temperature of the aluminum profile to below 80°C.

[0038] S4. Place the aluminum profile cooled to below 80°C on a heating table and keep it at 180°C for 10 hours. When the aluminum profile is heated to 170°C, apply an electromagnetic field to it for auxiliary treatment. The direction of the electromagnetic field is parallel to the length axis of the aluminum profile. Use a frequency of 50Hz and a magnetic field strength of 1.2T for 35 minutes.

[0039] Example 3 An extrusion process for aluminum profiles includes the following steps: S1, a material containing 2.0%Mg, 0.6%Si, 0.8%Mn, 0.35%Sc, 0.22%Zr, 0.15%Fe, 0.10%Ti and the balance Al is melted and cast into an aluminum rod. The aluminum rod is preheated to 450℃ and held for 4 hours under argon protection at 5L / min.

[0040] S2, set the heating unit of the extruder to heat the extrusion cylinder and die to 430°C, transfer the preheated and heat-insulated aluminum rod to the extruder, apply an extrusion pressure of 26MPa and a traction force of 15kgf to the aluminum rod, and at the same time inject a protective gas mixture of argon and nitrogen with a volume ratio of 7:3 into the extrusion cylinder at a gas flow rate of 9L / min.

[0041] S3. After the aluminum rod is extruded from the die hole, it is immediately subjected to air cooling and liquid nitrogen quenching, which alternately cycle. Air cooling is performed at a wind speed of 18 m / s, with each cycle lasting 12 seconds. The liquid nitrogen quenching spray rate is 0.2 L / (m³). 2 Each cooling cycle lasts for 6 seconds, and the air cooling and liquid nitrogen rapid cooling cycles alternate 12 times to reduce the temperature of the aluminum profile to below 95℃.

[0042] S4. Place the aluminum profile cooled to below 95°C on a heating table and keep it at 175°C for 10 hours. When the aluminum profile is heated to 175°C, apply an electromagnetic field to it for auxiliary treatment. The direction of the electromagnetic field is parallel to the length axis of the aluminum profile. Use a frequency of 50Hz and a magnetic field strength of 1.0T for 60 minutes.

[0043] Example 4 An extrusion process for aluminum profiles includes the following steps: S1, a material containing 1.8%Mg, 0.8%Si, 0.7%Mn, 0.25%Sc, 0.18%Zr, 0.25%Fe, 0.15%Ti and the balance Al is melted and cast into an aluminum rod. The aluminum rod is preheated to 460℃ and held for 3 hours under argon protection at 5L / min.

[0044] S2, set the heating unit of the extruder to heat the extrusion cylinder and die to 440°C, transfer the preheated and heat-insulated aluminum rod to the extruder, apply an extrusion pressure of 28MPa and a traction force of 10kgf to the aluminum rod, and at the same time inject a protective gas mixture of argon and nitrogen with a volume ratio of 7:3 into the extrusion cylinder at a gas flow rate of 8L / min.

[0045] S3. After the aluminum rod is extruded from the die hole, it is immediately subjected to air cooling and liquid nitrogen quenching, which are alternated in a cycle. The air cooling is carried out at a wind speed of 15 m / s, and each cycle lasts for 6 seconds. The liquid nitrogen quenching spray rate is 0.2 L / (m³). 2 Each cooling cycle lasts for 3 seconds, and the air cooling and liquid nitrogen rapid cooling cycles alternate 15 times to reduce the temperature of the aluminum profile to below 85°C.

[0046] S4. Place the aluminum profile cooled to below 85°C on a heating table and keep it at 170°C for 10 hours. When the aluminum profile is heated to 170°C, apply an electromagnetic field to it for auxiliary treatment. The direction of the electromagnetic field is parallel to the length axis of the aluminum profile. Use a frequency of 50Hz and a magnetic field strength of 0.9T for 40 minutes.

[0047] Example 5 An extrusion process for aluminum profiles includes the following steps: S1, a material containing 1.8%Mg, 0.9%Si, 0.7%Mn, 0.25%Sc, 0.21%Zr, 0.25%Fe, 0.15%Ti and the balance Al is melted and cast into an aluminum rod. The aluminum rod is preheated to 460℃ and held for 3 hours under argon protection at 5L / min.

[0048] S2, set the heating unit of the extruder to heat the extrusion cylinder and die to 440°C, transfer the preheated and heat-insulated aluminum rod to the extruder, apply an extrusion pressure of 30MPa and a traction force of 15kgf to the aluminum rod, and at the same time inject a protective gas mixture of argon and nitrogen with a volume ratio of 7:3 into the extrusion cylinder at a gas flow rate of 10L / min.

[0049] S3. After the aluminum rod is extruded from the die hole, it is immediately subjected to air cooling and liquid nitrogen quenching, which are alternated in a cycle. The air cooling is carried out at a wind speed of 15 m / s, and each cycle lasts for 3 seconds. The liquid nitrogen quenching spray rate is 0.5 L / (m³). 2Each cooling cycle lasts for 3 seconds, and the air cooling and liquid nitrogen rapid cooling cycles alternate 20 times to reduce the temperature of the aluminum profile to below 100℃.

[0050] S4. Place the aluminum profile cooled to below 100°C on a heating table and keep it at 170°C for 10 hours. When the aluminum profile is heated to 170°C, apply an electromagnetic field to it for auxiliary treatment. The direction of the electromagnetic field is parallel to the length axis of the aluminum profile. Use a frequency of 50Hz and a magnetic field strength of 1.2T for 40 minutes.

[0051] Comparative Example 1 An extrusion process for aluminum profiles differs from that in Example 1 in that the aluminum rod does not contain Sc, and the corresponding material gap is filled by Al.

[0052] Comparative Example 2 An extrusion process for aluminum profiles differs from that in Example 1 in that the aluminum rod does not contain Zr, and the corresponding material gap is filled by Al.

[0053] Comparative Example 3 An extrusion process for aluminum profiles differs from Example 1 in that the aluminum rod is individually air-cooled in step S3 without liquid nitrogen cooling, and the air-cooling wind speed is 20 m / s.

[0054] Comparative Example 4 An extrusion process for aluminum profiles differs from that in Example 1 in that the aluminum rod is heated separately in S4 without electromagnetic field assistance.

[0055] The technical effects of the above embodiments and comparative examples were analyzed. The elongation at break, tensile strength, and yield strength were tested according to the ASTM E8 / E8M-2021 standard test method for tensile strength of metallic materials. Standard cylindrical specimens with a gauge length of 50 mm and a diameter of 6 mm were cut along the extrusion direction and subjected to a tensile rate of 2 mm / min at room temperature (23 ± 1 °C). The forming effect was assessed visually according to ISO 6361-2:2021 Classification of Defects in Extruded Aluminum and Aluminum Alloys. The test results are shown in the table below. As shown in the table above, the performance differences between Comparative Examples 1 and 2 and the Examples indicate that the addition of scandium (Sc) and zirconium (Zr) to the aluminum profile alloy increases the elongation at break, suggesting that the addition of these two elements is beneficial for improving the toughness of the alloy. The average tensile strength of the Examples is approximately 270 MPa, which is higher than that of the Comparative Examples. This indicates that the Sc-Zr composite strengthening helps reduce grain coarsening, ensures dimensional stability, and reduces the risk of shrinkage porosity and gas porosity in the casting state. Meanwhile, the difference between Comparative Example 3 and the Examples shows that the alternating cooling process contributes to thermal stress control and defect reduction. Alternating cooling prevents local overcooling or lattice distortion through cyclic temperature control, improves strength stability, and avoids shrinkage cavities caused by uneven thermal shrinkage after extrusion. In addition, based on the effects of Comparative Example 4 (without electromagnetic field assistance) and the Examples, it is shown that electromagnetic field treatment promotes dislocation movement and recrystallization through electromagnetic oscillation, improves toughness, accelerates phase precipitation, improves grain boundary purity, and reduces forming defects.

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An aluminum material made of an aluminum bar, characterized by The following components are included by mass percentage: Mg, 1.7-2.2%; Si, 0.6-1.2%; Mn, 0.7-0.9%; Sc, 0.25-0.35%; Zr, 0.18-0.22%; Fe ≤0.25%; Ti ≤0.15%; balance of aluminum and other unavoidable impurities.

2. An extrusion preparation process of the aluminum profile according to claim 1, comprising the following steps: S1, preheating and holding the aluminum bar under inert gas protection; S2, transferring the preheated aluminum bar to the extruder, heating the extruder die and extrusion cylinder to working temperature; S3, loading the heated die into the extruder die sleeve, placing the heated aluminum bar into the extrusion cylinder, applying axial pressure to the aluminum bar through the extrusion shaft, and applying traction to the aluminum bar through the traction mechanism, so that the aluminum bar is deformed and forms an aluminum profile through the die hole; S4, aging treatment of the aluminum profile, including electromagnetic field assisted treatment and heating treatment.

3. The extrusion production process according to claim 2, characterized in that, In S1, the aluminum bar is preheated to 450-470℃, and the holding time is not less than 3 hours.

4. The extrusion process according to claim 2, characterized in that In S2, the working temperature of the extrusion cylinder and the die is 420-440℃.

5. The extrusion process of claim 2, wherein, In S2, the pressure applied by the extrusion shaft to the aluminum bar is 25-30MPa, and the traction force of the traction mechanism is 10-15kgf.

6. The extrusion process of claim 2, wherein, In S2, argon-nitrogen mixed protective gas with a volume ratio of 7:3 is injected into the extrusion cylinder during the extrusion process, and the gas flow rate is 8-10L / min.

7. The extrusion process of claim 2, wherein, In S3, after the aluminum bar passes through the mold hole to form the aluminum profile, the aluminum profile is alternately cooled, including air cooling and liquid nitrogen quenching, and the cycle is performed until the temperature of the aluminum profile is reduced to below 100°C; wherein the air cooling speed is 15-20 m / s, and the liquid nitrogen quenching spray amount is 0.2-0.5 L / (m 2 ·s).

8. The extrusion production process according to claim 7, characterized in that, In the alternate cooling, the time for each air cooling is 5-20 seconds, the time for each liquid nitrogen quenching is 3-10 seconds, and the cycle number is not less than 10 times.

9. The extrusion process of claim 2, wherein, In S4, the electromagnetic field assisted treatment uses a frequency of 50Hz, a magnetic field strength of 0.8-1.2T, and a treatment time of not less than 30 minutes.

10. The extrusion process of claim 2, wherein, In S4, the heating treatment temperature is 170-180℃, and the heating treatment time is not less than 8 hours.

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