High-strength regenerated aluminum alloy profile for automobile anti-collision beam and preparation process of high-strength regenerated aluminum alloy profile

Abstract

The invention relates to the technical field of aluminum alloy materials, and discloses a high-strength regenerated aluminum alloy profile for an automobile anti-collision beam and a preparation process of the high-strength regenerated aluminum alloy profile for the automobile anti-collision beam, and the profile is 6063 alloy and comprises the following raw materials in percentage by mass: 45-55% of waste aluminum and 0.3-0.6% of Si; 0.5%-0.8% of Mg; 0 to 0.1 percent of Zn; 0 to 0.08% of Cu; 0 to 0.08% of Mn; 0.2%-0.45% of Fe; 0.01%-0.06% of Ti, and the balance Al and impurities with the content lower than 0.05%. The profile is obtained by carrying out casting, homogenization, extrusion, straightening, solid solution treatment and aging treatment on raw materials. According to the high-strength regenerated aluminum profile prepared through the scheme, the adding proportion of the waste aluminum can reach 45%-55%, the highest Fe content can reach 0.35% of the upper limit in the range of GB / T 3190-2020, the technical bottleneck that under the condition of the high waste proportion, the Fe element is excessive, thick intermetallic compounds are easily formed, and consequently the formability of the profile is poor is broken through, and harmless or beneficial conversion of the Fe element is achieved. And the section bar obtained by the scheme is a regenerated aluminum section bar with higher strength, high forming performance and low carbon emission factors, and unification of technology, economy and environment is realized.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy materials, and in particular to a high-strength recycled aluminum alloy profile for an automobile anti-collision beam and a preparation process thereof. Background Art

[0002] Automobiles are the main source of carbon emissions in transportation. At present, carbon emissions from automobiles account for about 7.5% of the total carbon emissions of the whole society and more than 80% of carbon emissions in my country's transportation sector. Energy conservation, emission reduction and safety are the main development trends of automobiles at present, and lightweighting of vehicles is one of the key ways to solve this problem. The aluminum alloy frame body contains a variety of extruded aluminum alloy bent parts with closed cross-section shapes. It has the advantages of light weight and high safety performance. It can achieve lightweighting of automobiles and achieve the purpose of energy conservation and emission reduction. It has been paid attention to by the majority of automobile manufacturers. Due to the key role of the anti-collision beam assembly in low-speed collision and pedestrian protection, it is an important research content in the field of automobile passive safety at home and abroad. At present, the application of aluminum alloy extruded profiles in automobile parts is relatively mature. The anti-collision beam assembly, front longitudinal beam and other body structural parts mainly use 6xxx series aluminum alloys.

[0003] In recent years, some domestic universities and research institutes have carried out a lot of work around 6xxx aluminum alloy profiles for automobiles. For example, patent CN 114293074B proposes an A1-Mg-Si alloy and a preparation method, which mainly solves the problem of profile size deformation and large residual stress caused by high sensitivity of aluminum alloy to quenching by designing the mass ratio of Mg and Si and controlling the amount of saturated Mg2Si per unit area, thus ensuring high yield output of profiles. However, the tensile strength of the material developed by this scheme is <300MPa, which cannot meet the performance requirements. And it requires that a single impurity is ≤0.03% and the total impurity is ≤0.15%, which severely limits the content of impurities. Patent CN 116904814A proposes a 6061 aluminum alloy profile for automobiles and a preparation method thereof, and develops a 6061 aluminum alloy profile for automobiles and a production process thereof with simple production process, large-scale application in industrial production, and high performance. The obtained 6061 aluminum alloy profile has a tensile strength of >350MPa, a yield strength of >320MPa, and an elongation A50 of >12%, which is higher than the strength of aluminum alloy profiles for automobiles on the existing market. Patent CN 104404322B proposes a 7xxx aluminum alloy profile for automobile bumper and a preparation method. The developed aluminum alloy profile has good thermal deformation, machinability, excellent corrosion resistance and welding performance, and its performance meets the various technical indicators of automobile bumpers stipulated by the state; Patent CN 106756330B proposes a 7xxx aluminum alloy profile for automobile body and a preparation method. By optimizing the composition and preparation process of 7003 alloy, an aluminum alloy energy absorption box and longitudinal beam suitable for manufacturing automobile bumper system are developed. The developed material not only has good mechanical properties, but also has good corrosion resistance, fatigue resistance and crushing performance (static and dynamic collision impact performance), and can be mass-produced.

[0004] In summary, although there are many studies on 6xxx and 7xxx aluminum alloy profiles for automobile body structural parts, the prior art still has the following technical problems: (1) There are few reports on medium- and high-strength recycled aluminum alloy 6xxx profiles for automobile bodies; (2) The above-mentioned prior art all uses original aluminum ingots rather than scrap aluminum, resulting in high costs, and; (3) In other prior art, when the Fe content in the deformed aluminum alloy exceeds 0.3% due to a high proportion of scrap aluminum added or its grade is poor, Fe is easy to combine with Si to form coarse needle-shaped, lamellar brittle β-type Fe-rich ternary phases. This type of intermetallic compound will act as a crack source to severely split the aluminum alloy matrix, causing the plasticity and toughness of the recycled aluminum alloy to decrease significantly, thereby reducing the overall performance of the aluminum alloy.

[0005] In view of this, the development of a high-aluminum-waste addition, high-performance recycled aluminum alloy profile and its preparation process can not only effectively make up for the shortcomings of the existing technology, but also effectively improve the utilization rate of waste aluminum and reduce the carbon emission factor, which is of great significance to the resource-based recycled aluminum alloy. Summary of the invention

[0006] The present invention aims to provide a high-strength recycled aluminum alloy profile for automobile anti-collision beams and a preparation process thereof, so as to solve the technical problem that the overall performance of the aluminum alloy is easily reduced when the existing waste aluminum is added in a high proportion.

[0007] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a high-strength recycled aluminum alloy profile for an automobile anti-collision beam, the profile is a 6063 alloy, and comprises the following raw materials in percentage by mass: 45-55% of scrap aluminum, 0.3%-0.6% of Si, 0.5%-0.8% of Mg, 0-0.1% of Zn, 0-0.08% of Cu, 0-0.08% of Mn, 0.2%-0.45% of Fe, 0.01%-0.06% of Ti, and the remainder is Al and impurities with a content of less than 0.05%.

[0008] Preferably, as an improvement, the profile is obtained by subjecting the raw material to melt casting, homogenization, extrusion, straightening, solution treatment and aging treatment.

[0009] Preferably, as an improvement, the present solution also provides a preparation process of a high-strength recycled aluminum alloy profile for an automobile anti-collision beam, comprising the following steps:

[0010] Step (1), melting and casting treatment: preparing the above raw materials, putting the above prepared materials into a smelting furnace, melting, refining, standing, and purifying, and using semi-continuous casting equipment to cast the purified aluminum melt into ingots;

[0011] Step (2), homogenization treatment: the ingot obtained in step (1) is subjected to two-stage homogenization treatment, the first-stage homogenization, the heating temperature is controlled at 440-460° C., and the holding time is 4-6 hours; the second-stage homogenization, the heating temperature is controlled at 550-570° C., and the holding time is 20-24 hours;

[0012] Step (3), extrusion treatment: extruding the ingot obtained in step (2) to obtain a profile;

[0013] Step (4), straightening treatment, straightening the profile obtained in step (3);

[0014] Step (5), solution treatment: subjecting the profile obtained in step (4) to solution treatment at a holding temperature of 540 to 560° C. for a holding time of 30 to 60 min, and then subjecting the profile to water quenching;

[0015] Step (6), aging treatment: the profile obtained in step (5) is transferred to a temperature of 160-180° C. within 6 hours and kept at this temperature for 7-10 hours for aging treatment to obtain a finished profile.

[0016] Preferably, as an improvement, in step (1), the melt is refined using high-purity argon gas without adding any chemical flux, the high-purity argon gas is introduced through air plugs evenly distributed at the bottom of the furnace, and the refining time is 30 to 60 minutes.

[0017] Preferably, as an improvement, in step (1), the standing still process is to allow the aluminum melt to stand in a standing furnace for 30 to 120 minutes.

[0018] Preferably, as an improvement, in step (1), the purification includes two-stage purification, as follows:

[0019] (a) The online degassing and purification outside the furnace adopts a double-rotor degasser, which is fed with high-purity argon gas. The working pressure of the degasser is 0.3-0.5Mpa, the gas flow rate is 1.5-3.5m3 / h, and the rotor speed is 250-450r / min;

[0020] (b) The online filtration and purification outside the furnace adopts a combination of single-stage plate filtration + deep bed filtration process, in which the accuracy of the single-stage plate filter is not less than 50ppi, and the deep bed filtration capacity is 20~40t / h.

[0021] Preferably, as an improvement, in step (2), the heating rates of the two-stage homogenization treatment are as follows: the first-stage homogenization heating rate is 60-80°C / h, and the second-stage homogenization heating rate is 20-30°C / h.

[0022] Preferably, as an improvement, in step (3), the extrusion treatment is carried out under the conditions of an ingot heating temperature of 510°C, a mold temperature of 480°C, an extrusion barrel temperature of 450°C, an extrusion ratio of 28, and an extrusion rod speed of 2 mm / s to obtain a profile.

[0023] Preferably, as an improvement, in step (4), the deformation of the profile during the straightening treatment is 1.5-3%.

[0024] Preferably, as an improvement, in step (6), the profile obtained in step (5) needs to be transferred within 3 hours and then subjected to aging treatment.

[0025] The principles and advantages of this solution are:

[0026] 1. Compared with the prior art, in which a high proportion of scrap aluminum addition easily leads to a decrease in the overall performance of the aluminum alloy, this scheme can make 80% or more of the needle-shaped or lamellar β-type Fe phase melt, or partially transform into a polygonal granular α-type Fe phase, by directional regulation of the enhanced purification of the melt and the homogenization process of the ingot, thereby effectively achieving the harmless or even beneficial transformation of the influence of the high Fe content under the condition of a high proportion of scrap aluminum. The Fe content under this process condition can reach up to 0.35%, the upper limit of the range of GB / T3190-2020, and the finished profiles produced have a carbon emission factor of less than 10tCO2e / t, a tensile strength of more than 280MPa, a yield strength of more than 260MPa, and an elongation of more than 10%, which are significantly higher than the performance requirements of 6063 aluminum alloy with a wall thickness of <10mm in the national standard "GB / T 33910-2017 Aluminum and Aluminum Alloy Extrusion Profiles for Automobiles" (specifically, tensile strength ≥215MPa, yield strength ≥170MPa, and elongation ≥6%).

[0027] 2. Compared with the existing recycled aluminum alloys with a smaller amount of scrap aluminum added, the recycled aluminum alloy in this scheme has a scrap aluminum addition amount of up to 45-55%, and then the Fe content is initially reduced to the threshold through the melt purification process, and then the corresponding components and processes are matched according to the Fe content to improve the organizational morphology of the iron-rich phase in the aluminum alloy, thereby reducing the probability of crack source initiation, and then comprehensively improving the performance of the recycled aluminum alloy with a high scrap addition ratio.

[0028] 3. In the high-strength recycled aluminum profiles prepared by this scheme, the proportion of waste aluminum added can reach 45-55%, and the Fe content can reach the upper limit of 0.35% in the range of GB / T 3190-2020, breaking through the technical bottleneck that the excessive amount of Fe elements under the condition of high waste ratio is easy to form coarse intermetallic compounds and easily lead to poor profile formability, and realizing the harmless or beneficial transformation of Fe elements. At the same time, compared with the aluminum alloy performance obtained by the conventional 6063 aluminum alloy preparation process, this scheme obtains recycled aluminum profiles with higher strength and high formability, and the prepared profile products have low carbon emission factors, effectively realizing the unification of the three effects at the technical level, economic level, and environmental level.

[0029] 4. This scheme uses flux-free refining in the melting and casting stage. On the one hand, it effectively avoids the discharge of chlorine- and fluorine-containing solid wastes caused by the use of refining agents, and on the other hand, it effectively prevents the addition of refining agents from causing secondary pollution to the aluminum melt. Standing allows the iron-rich intermetallic compounds to fully settle to the bottom of the furnace and recover the clean melt; purification effectively removes hydrogen and other harmful inclusions in the aluminum liquid, ensuring the quality of the melt under the condition of high proportion of waste addition, achieving enhanced purification of the melt, and preparing high-quality ingots.

[0030] 5. The bipolar homogenization adopted in this scheme effectively controls and promotes the nucleation and growth of dispersed phases such as Al6Mn in the first stage of homogenization, so that it is convenient for them to effectively pin dislocations and grain boundaries in the subsequent processing process to inhibit the occurrence of coarse grains. The second stage of homogenization can, on the one hand, make the main alloy elements diffuse and distribute evenly without causing overburning, eliminate the segregation of solute atoms at the grain boundaries, and make the residual primary Mg2Si phase spheroidized and dissolved as much as possible, so as to ensure the best subsequent solid solution effect; on the other hand, it can melt or transform the lamellar β-type Fe phase into the polygonal granular α-type Fe phase, so as to make its adverse effects harmless or even beneficial, thereby effectively improving the performance of the product profile.

[0031] 6. This scheme controls extrusion parameters, which can not only improve surface quality and dimensional accuracy, but also is conducive to further effectively crushing the remaining coarse Fe-containing phases on the basis of centrifugal Fe removal and homogenization control of the size, morphology and distribution of the Fe-containing phase, thereby achieving three-level control of the harmful β-type Fe phase, thereby effectively improving the performance of the product profile.

[0032] 7. This scheme further limits the transfer time from solution quenching to aging treatment to less than 3 hours, which can minimize the adverse effects of the inevitable natural aging of Al-Mg-Si alloys during storage on the subsequent artificial aging. In addition, this scheme controls the process conditions of solution treatment and aging treatment, so that the solute atoms are fully dissolved through optimized heat treatment parameters and are transformed into the main strengthening precipitation phase to the greatest extent in the subsequent aging process, thereby maximizing the mechanical properties of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a scanning electron microscope image of the profile microstructure before and after homogenization in the preparation process of the high-strength recycled aluminum alloy profile for the automobile anti-collision beam in Example 1 of the present invention (the upper part is the morphology of the β-type Fe-containing phase before homogenization; the lower part is the morphology of the β-type Fe-containing phase after homogenization). DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following examples and experimental examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used can be obtained from commercial sources.

[0035] Program Overview

[0036] The present invention provides a high-strength recycled aluminum alloy profile for automobile anti-collision beams. The profile is 6063 alloy, and includes the following raw materials in mass percentage: 45-55% scrap aluminum, 0.3%-0.6% Si, 0.5%-0.8% Mg, 0-0.1% Zn, 0-0.08% Cu, 0-0.08% Mn, 0.2%-0.45% Fe, 0.01%-0.06% Ti, and the remainder is Al and impurities with a content of less than 0.05%. The profile is obtained by melting and casting, homogenizing, extruding, straightening, solution treatment and aging treatment of the raw materials.

[0037] This solution also provides a preparation process of a high-strength recycled aluminum alloy profile for an automobile anti-collision beam, comprising the following steps:

[0038] Step (1), melting and casting treatment: preparing the above raw materials, putting the above prepared materials into a smelting furnace, melting, refining, standing, and purifying, and using semi-continuous casting equipment to cast the purified aluminum melt into ingots;

[0039] As an improvement, the aluminum melt is allowed to stand in a standing furnace for 30 to 120 minutes.

[0040] As an improvement, the purification includes two stages of purification, as follows:

[0041] (a) The online degassing and purification outside the furnace adopts a double-rotor degasser, which is fed with high-purity argon gas. The working pressure of the degasser is 0.3-0.5Mpa, the gas flow rate is 1.5-3.5m3 / h, and the rotor speed is 250-450r / min;

[0042] (b) The online filtration and purification outside the furnace adopts a combination of single-stage plate filtration + deep bed filtration process, in which the accuracy of the single-stage plate filter is not less than 50ppi, and the deep bed filtration capacity is 20~40t / h.

[0043] Step (2), homogenization treatment: the ingot obtained in step (1) is subjected to two-stage homogenization treatment, the first-stage homogenization, the heating temperature is controlled at 440-460° C., and the holding time is 4-6 hours; the second-stage homogenization, the heating temperature is controlled at 550-570° C., and the holding time is 20-24 hours;

[0044] The heating rates of the two-stage homogenization treatment are as follows: the first-stage homogenization heating rate is 60-80°C / h, and the second-stage homogenization heating rate is 20-30°C / h.

[0045] Step (3), extrusion treatment: the ingot obtained in step (2) is subjected to extrusion treatment under the conditions of an ingot heating temperature of 510° C., a mold temperature of 480° C., an extrusion barrel temperature of 450° C., an extrusion ratio of 28, and an extrusion rod speed of 2 mm / s to obtain a profile;

[0046] Step (4), straightening treatment, straightening the profile obtained in step (3); the deformation of the profile during the straightening treatment is 1.5-3%.

[0047] Step (5), solution treatment: subjecting the profile obtained in step (4) to solution treatment at a holding temperature of 540 to 560° C. for a holding time of 30 to 60 min, and then subjecting the profile to water quenching;

[0048] Step (6), aging treatment: the profile obtained in step (5) is transferred to 160-180°C within 6 hours and kept at this temperature for 7-10 hours for aging treatment to obtain a finished profile. In step (1), the refining is to refine the melt using high-purity argon gas without adding any chemical flux, and the high-purity argon gas is introduced through the air plugs evenly distributed at the bottom of the furnace, and the refining time is 30-60 minutes.

[0049] As an improvement, the profile obtained in step (5) needs to be transferred within 3 hours and then subjected to aging treatment.

[0050] In the development process of 6063 aluminum alloy profiles for automobile anti-collision beams, this solution achieves high strength, high forming performance, and low carbon emissions through strict control of alloy composition and preparation process, making it more suitable for automobile anti-collision beams. First, pure aluminum and various master alloys are prepared according to the ratio of aluminum ingots, scrap aluminum, master alloys and other raw materials, of which the scrap aluminum is added in a ratio of 45-55%. The above-mentioned materials are put into a smelting furnace, and after melting, refining, standing and purification, the purified aluminum melt is cast into ingots using semi-continuous casting equipment.

[0051] After the ingot is cut and milled, it is placed in a heat treatment furnace for homogenization. After the homogenization treatment, the ingot is cooled to the extrusion temperature and kept for a period of time before extrusion. After the extrusion is completed, the obtained profile is straightened, and then solid solution and water quenching are performed. Finally, the obtained profile is subjected to aging treatment to obtain the finished profile.

[0052] The following comparative examples of the present invention are described in comparison (the amount of waste aluminum added in the examples and comparative examples of the present solution is 45-55%), and the technical effects of the present invention can be further verified according to these examples and comparative examples. However, the examples listed are only preferred embodiments of the present invention, and it should not be understood that the scope of the above-mentioned subject of the present invention is limited to this. All technical solutions formed based on the technical concept of the present invention fall within the protection scope of the present invention.

[0053] Example 1

[0054] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.4%; Mg: 0.6%; Zn: 0.02%; Cu: 0.06%; Mn: 0.05%; Fe: 0.3%; Ti: 0.01%, and the remainder is Al (including 45% scrap aluminum) and normal impurities.

[0055] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 40%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 30 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 30 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.3Mpa, a gas flow rate of 3.5m3 / h, and a rotor speed of 350r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 30t / h.

[0056] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 440°C, the heating rate being 60°C / h, and the insulation time being 4 hours; the second-level homogenization temperature being 550°C, the heating rate being 20°C / h, and the insulation time being 20 hours; the homogenized ingot is extruded, with the ingot heating temperature being 480°C, the mold temperature being 480°C, the extrusion barrel temperature being 450°C, the extrusion ratio being 26, and the extrusion rod speed being 3mm / s; then a straightening treatment is performed with a deformation amount of 2.0%; then a solution treatment is performed with a solution treatment temperature of 540°C and an insulation time of 30 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 170°C within 3 hours and is kept for 8 hours for aging treatment, and finally a finished profile is obtained.

[0057] Example 2

[0058] The aluminum alloy composition is calculated by mass percentage as follows: Si: 0.45%; Mg: 0.8%; Zn: 0.02%; Cu: 0.02%; Mn: 0.02%; Fe: 0.28%; Ti: 0.03%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0059] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in a ratio of 40%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining, and the refining time is 60 minutes; the refined aluminum melt is introduced into a heat-insulating furnace and allowed to stand for 60 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.4Mpa, the gas flow rate is 2.5m3 / h, and the rotor speed is 450r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate accuracy is 60ppi, and the deep bed filtration capacity is 40t / h.

[0060] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 450°C, the heating rate being 80°C / h, and the insulation time being 5 hours; the second-level homogenization temperature being 560°C, the heating rate being 25°C / h, and the insulation time being 22 hours; the homogenized ingot is extruded, with the ingot heating temperature being 490°C, the mold temperature being 470°C, the extrusion barrel temperature being 460°C, the extrusion ratio being 24, and the extrusion rod speed being 2mm / s; then a straightening treatment is performed with a deformation amount of 1.5%; then a solution treatment is performed with a solution treatment temperature of 550°C and an insulation time of 45 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 180°C within 3 hours and is kept for 9 hours for aging treatment, and finally a finished profile is obtained.

[0061] Example 3

[0062] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.6%; Mg: 0.4%; Zn: 0.02%; Cu: 0.25%; Mn: 0.2%; Fe: 0.22%; Ti: 0.03%, and the remainder is Al (including 55% scrap aluminum) and normal impurities.

[0063] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in a ratio of 40%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 30 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 120 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.5Mpa, the gas flow rate is 1.5m3 / h, and the rotor speed is 250r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 20t / h.

[0064] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, the first-level homogenization temperature is 460°C, the heating rate is 70°C / h, and the insulation time is 4 hours; the second-level homogenization temperature is 550°C, the heating rate is 30°C / h, and the insulation time is 20 hours; the homogenized ingot is extruded, the ingot heating temperature is 480°C, the mold temperature is 470°C, the extrusion barrel temperature is 440°C, the extrusion ratio is 22, and the extrusion rod speed is 4mm / s; then a straightening treatment is performed, and the deformation amount is 3.0%; then a solution treatment is performed, the solution treatment temperature is 560°C, the insulation time is 60min, and then water quenching is performed; the water-quenched profile is transferred to a temperature of 180°C within 3 hours and is kept for 7 hours for aging treatment, and finally a finished profile is obtained.

[0065] Example 4

[0066] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.55%; Mg: 0.6%; Zn: 0.02%; Cu: 0.02%; Mn: 0.03%; Fe: 0.3%; Ti: 0.02%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0067] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 50%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 45 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 60 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.3Mpa, a gas flow rate of 3.5m3 / h, and a rotor speed of 350r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 60ppi, and the deep bed filtration capacity is 40t / h.

[0068] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, the first-level homogenization temperature is 440°C, the heating rate is 80°C / h, and the insulation time is 6 hours; the second-level homogenization temperature is 570°C, the heating rate is 25°C / h, and the insulation time is 24 hours; the homogenized ingot is extruded, the ingot heating temperature is 500°C, the mold temperature is 490°C, the extrusion barrel temperature is 460°C, the extrusion ratio is 32, and the extrusion rod speed is 3mm / s; then a straightening treatment is performed, and the deformation amount is 2.0%; then a solution treatment is performed, the solution treatment temperature is 540°C, the insulation time is 60min, and then water quenching is performed; the water-quenched profile is transferred to a temperature of 160°C for 2 hours and the profile is kept for 10 hours for aging treatment, and finally a finished profile is obtained.

[0069] Example 5

[0070] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.55%; Mg: 0.6%; Zn: 0.02%; Cu: 0.02%; Mn: 0.03%; Fe: 0.32%; Ti: 0.02%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0071] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in a proportion of 50%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 45 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 30 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.3Mpa, the gas flow rate is 3.5m3 / h, and the rotor speed is 350r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 20t / h.

[0072] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 450°C, the heating rate being 60°C / h, and the insulation time being 4 hours; the second-level homogenization temperature being 550°C, the heating rate being 25°C / h, and the insulation time being 20 hours; the homogenized ingot is extruded, with the ingot heating temperature being 480°C, the mold temperature being 480°C, the extrusion barrel temperature being 450°C, the extrusion ratio being 34, and the extrusion rod speed being 2mm / s; then a straightening treatment is performed with a deformation amount of 1.5%; then a solution treatment is performed with a solution treatment temperature of 550°C and an insulation time of 45 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 170°C for 2 hours and the profile is kept at a temperature of 170°C for 7 hours for aging treatment, and finally a finished profile is obtained.

[0073] Example 6

[0074] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.5%; Mg: 0.6%; Zn: 0.02%; Cu: 0.02%; Mn: 0.02%; Fe: 0.35%; Ti: 0.02%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0075] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 50%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 30 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 60 minutes; after standing, the aluminum melt flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.4Mpa, a gas flow rate of 2.5m3 / h, and a rotor speed of 450r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 20t / h.

[0076] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 450°C, the heating rate being 80°C / h, and the insulation time being 6 hours; the second-level homogenization temperature being 560°C, the heating rate being 30°C / h, and the insulation time being 20 hours; the homogenized ingot is extruded, with the ingot heating temperature being 480°C, the mold temperature being 480°C, the extrusion barrel temperature being 450°C, the extrusion ratio being 30, and the extrusion rod speed being 4mm / s; then a straightening treatment is performed with a deformation amount of 2.0%; then a solution treatment is performed with a solution treatment temperature of 550°C and an insulation time of 60min, followed by water quenching; the water-quenched profile is transferred to a temperature of 170°C for 1h and the profile is kept for 8h for aging treatment, and finally a finished profile is obtained.

[0077] Example 7

[0078] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.55%; Mg: 0.6%; Zn: 0.02%; Cu: 0.03%; Mn: 0.01%; Fe: 0.35%; Ti: 0.02%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0079] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 50%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 60 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 90 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.5Mpa, the gas flow rate is 1.5m3 / h, and the rotor speed is 250r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 60ppi, and the deep bed filtration capacity is 30t / h.

[0080] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, the first-level homogenization temperature is 460°C, the heating rate is 70°C / h, and the insulation time is 5 hours; the second-level homogenization temperature is 560°C, the heating rate is 30°C / h, and the insulation time is 22 hours; the homogenized ingot is extruded, the ingot heating temperature is 490°C, the mold temperature is 490°C, the extrusion barrel temperature is 460°C, the extrusion ratio is 28, and the extrusion rod speed is 3mm / s; then a straightening treatment is performed, and the deformation amount is 2.0%; then a solution treatment is performed, the solution treatment temperature is 560°C, the insulation time is 60min, and then water quenching is performed; the water-quenched profile is transferred to 180°C for 1h and the insulation time is 9h for aging treatment, and finally a finished profile is obtained.

[0081] Example 8

[0082] The aluminum alloy composition is calculated by mass percentage as follows: Si: 0.6%; Mg: 0.7%; Zn: 0.01%; Cu: 0.02%; Mn: 0.02%; Fe: 0.35%; Ti: 0.015%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0083] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 60%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 45 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 60 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.4Mpa, a gas flow rate of 2.5m3 / h, and a rotor speed of 450r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 60ppi, and the deep bed filtration capacity is 40t / h.

[0084] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, the first-level homogenization temperature is 460°C, the heating rate is 60°C / h, and the insulation time is 5 hours; the second-level homogenization temperature is 570°C, the heating rate is 20°C / h, and the insulation time is 22 hours; the homogenized ingot is extruded, the ingot heating temperature is 490°C, the mold temperature is 490°C, the extrusion barrel temperature is 440°C, the extrusion ratio is 22, and the extrusion rod speed is 4mm / s; then a straightening treatment is performed, and the deformation amount is 3.0%; then a solution treatment is performed, the solution treatment temperature is 540°C, the insulation time is 30min, and then water quenching is performed; the water-quenched profile is transferred to 180°C for 2 hours and the insulation time is 10 hours for aging treatment, and finally a finished profile is obtained.

[0085] Example 9

[0086] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.45%; Mg: 0.6%; Zn: 0.01%; Cu: 0.02%; Mn: 0.02%; Fe: 0.35%; Ti: 0.015%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0087] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 60%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 45 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 90 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.3Mpa, a gas flow rate of 3.5m3 / h, and a rotor speed of 350r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 30t / h.

[0088] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, the first-level homogenization temperature is 460°C, the heating rate is 80°C / h, and the insulation time is 6 hours; the second-level homogenization temperature is 560°C, the heating rate is 30°C / h, and the insulation time is 24 hours; the homogenized ingot is extruded, the ingot heating temperature is 500°C, the mold temperature is 470°C, the extrusion barrel temperature is 450°C, the extrusion ratio is 24, and the extrusion rod speed is 4mm / s; then a straightening treatment is performed, and the deformation amount is 3.0%; then a solution treatment is performed, the solution treatment temperature is 560°C, the insulation time is 45min, and then water quenching is performed; the water-quenched profile is transferred to 160°C for 2h and the insulation time is 8h for aging treatment, and finally a finished profile is obtained.

[0089] Example 10

[0090] The aluminum alloy components are calculated in mass percentage as follows: Si: 0.5%; Mg: 0.6%; Zn: 0.01%; Cu: 0.01%; Mn: 0.02%; Fe: 0.35%; Ti: 0.015%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0091] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 60%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 60 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 120 minutes; after standing, the aluminum melt flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.5Mpa, a gas flow rate of 1.5m3 / h, and a rotor speed of 250r / min; the aluminum liquid flows through a filtration system, with a single-stage plate filter plate accuracy of 50ppi and a deep bed filtration capacity of 30t / h.

[0092] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, the first-level homogenization temperature is 460°C, the heating rate is 70°C / h, and the insulation time is 5 hours; the second-level homogenization temperature is 570°C, the heating rate is 30°C / h, and the insulation time is 24 hours; the homogenized ingot is extruded, the ingot heating temperature is 500°C, the mold temperature is 470°C, the extrusion barrel temperature is 450°C, the extrusion ratio is 26, and the extrusion rod speed is 3mm / s; then a straightening treatment is performed, and the deformation amount is 2.0%; then a solution treatment is performed, the solution treatment temperature is 550°C, the insulation time is 45min, and then water quenching is performed; the water-quenched profile is transferred to a temperature of 170°C for 0.5h and the profile is kept for 10h for aging treatment, and finally a finished profile is obtained.

[0093] Comparative Example 1

[0094] The aluminum alloy components are calculated in mass percentage as follows: Si: 0.5%; Mg: 0.6%; Zn: 0.01%; Cu: 0.01%; Mn: 0.02%; Fe: 0.35%; Ti: 0.015%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0095] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in a ratio of 40%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 30 minutes; introduce the refined aluminum melt into a holding furnace and let it stand for 180 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.3Mpa, the gas flow rate is 3.5m3 / h, and the rotor speed is 350r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 20t / h.

[0096] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 440°C, the heating rate being 60°C / h, and the insulation time being 4 hours; the second-level homogenization temperature being 550°C, the heating rate being 20°C / h, and the insulation time being 20 hours; the homogenized ingot is extruded, with the ingot heating temperature being 480°C, the mold temperature being 480°C, the extrusion barrel temperature being 450°C, the extrusion ratio being 26, and the extrusion rod speed being 3mm / s; then a straightening treatment is performed with a deformation amount of 2.0%; then a solution treatment is performed with a solution treatment temperature of 540°C and an insulation time of 30 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 170°C within 3 hours and is kept for 8 hours for aging treatment, and finally a finished profile is obtained.

[0097] Comparative Example 2

[0098] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.45%; Mg: 0.6%; Zn: 0.01%; Cu: 0.02%; Mn: 0.02%; Fe: 0.35%; Ti: 0.015%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0099] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 40%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 45 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 60 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.2Mpa, the gas flow rate is 0.5m3 / h, and the rotor speed is 150r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 20t / h.

[0100] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 450°C, the heating rate being 60°C / h, and the insulation time being 5 hours; the second-level homogenization temperature being 560°C, the heating rate being 25°C / h, and the insulation time being 22 hours; the homogenized ingot is extruded, with the ingot heating temperature being 490°C, the mold temperature being 470°C, the extrusion barrel temperature being 460°C, the extrusion ratio being 24, and the extrusion rod speed being 2mm / s; then a straightening treatment is performed with a deformation amount of 1.5%; then a solution treatment is performed with a solution treatment temperature of 550°C and an insulation time of 45 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 180°C within 3 hours and insulation time being 9 hours for aging treatment, and finally a finished profile is obtained.

[0101] Comparative Example 3

[0102] The aluminum alloy composition is calculated by mass percentage as follows: Si: 0.45%; Mg: 0.8%; Zn: 0.02%; Cu: 0.02%; Mn: 0.02%; Fe: 0.28%; Ti: 0.03%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0103] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in a ratio of 40%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 30 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 60 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.5Mpa, the gas flow rate is 1.5m3 / h, and the rotor speed is 250r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 40ppi, and the deep bed filtration capacity is 10t / h.

[0104] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, the first-level homogenization temperature is 460°C, the heating rate is 70°C / h, and the insulation time is 4 hours; the second-level homogenization temperature is 550°C, the heating rate is 30°C / h, and the insulation time is 20 hours; the homogenized ingot is extruded, the ingot heating temperature is 480°C, the mold temperature is 470°C, the extrusion barrel temperature is 440°C, the extrusion ratio is 22, and the extrusion rod speed is 4mm / s; then a straightening treatment is performed, and the deformation amount is 3.0%; then a solution treatment is performed, the solution treatment temperature is 560°C, the insulation time is 60min, and then water quenching is performed; the water-quenched profile is transferred to a temperature of 180°C within 3 hours and is kept for 7 hours for aging treatment, and finally a finished profile is obtained.

[0105] Comparative Example 4

[0106] The aluminum alloy composition is calculated by mass percentage as follows: Si: 0.6%; Mg: 0.4%; Zn: 0.02%; Cu: 0.25%; Mn: 0.2%; Fe: 0.22%; Ti: 0.03%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0107] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 50%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 30 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 60 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.4Mpa, a gas flow rate of 2.5m3 / h, and a rotor speed of 450r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate has an accuracy of 50ppi, and the deep bed filtration capacity is 30t / h.

[0108] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 440°C, the heating rate being 60°C / h, and the insulation time being 4 hours; the second-level homogenization temperature being 530°C, the heating rate being 20°C / h, and the insulation time being 20 hours; the homogenized ingot is extruded, with the ingot heating temperature being 480°C, the mold temperature being 480°C, the extrusion barrel temperature being 450°C, the extrusion ratio being 26, and the extrusion rod speed being 3mm / s; then a straightening treatment is performed with a deformation amount of 2.0%; then a solution treatment is performed with a solution treatment temperature of 540°C and an insulation time of 30 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 170°C within 3 hours and is kept for 8 hours for aging treatment, and finally a finished profile is obtained.

[0109] Comparative Example 5

[0110] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.55%; Mg: 0.6%; Zn: 0.02%; Cu: 0.02%; Mn: 0.03%; Fe: 0.3%; Ti: 0.02%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0111] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in a proportion of 50%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 30 minutes; introduce the refined aluminum melt into a holding furnace and let it stand for 45 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, and the working pressure of the degasser is 0.5Mpa, the gas flow rate is 1.5m3 / h, and the rotor speed is 250r / min; the aluminum liquid flows through the filtration system, the single-stage plate filter plate accuracy is 60ppi, and the deep bed filtration capacity is 20t / h.

[0112] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 440°C, the heating rate being 60°C / h, and the insulation time being 4 hours; the second-level homogenization temperature being 550°C, the heating rate being 20°C / h, and the insulation time being 16 hours; the homogenized ingot is extruded, with the ingot heating temperature being 480°C, the mold temperature being 480°C, the extrusion barrel temperature being 450°C, the extrusion ratio being 26, and the extrusion rod speed being 3mm / s; then a straightening treatment is performed with a deformation amount of 2.0%; then a solution treatment is performed with a solution treatment temperature of 540°C and an insulation time of 30 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 170°C within 3 hours and is kept for 8 hours for aging treatment, and finally a finished profile is obtained.

[0113] Comparative Example 6

[0114] The aluminum alloy components are calculated by mass percentage as follows: Si: 0.5%; Mg: 0.6%; Zn: 0.02%; Cu: 0.02%; Mn: 0.02%; Fe: 0.35%; Ti: 0.02%, and the remainder is Al (including 50% scrap aluminum) and normal impurities.

[0115] Prepare aluminum ingots, scrap aluminum, intermediate alloy and other raw materials according to the above-mentioned composition ratio, with scrap aluminum added in an amount of 50%. Put the above-mentioned materials into a smelting furnace for melting, and introduce high-purity argon gas into the smelting furnace for refining for 45 minutes; introduce the refined aluminum melt into a heat-insulating furnace and let it stand for 60 minutes; the aluminum melt after standing flows into a double-rotor degasser outside the furnace for degassing and purification, with a working pressure of 0.4Mpa, a gas flow rate of 2.5m3 / h, and a rotor speed of 450r / min; the aluminum liquid flows through a filtration system, with a single-stage plate filter plate accuracy of 60ppi and a deep bed filtration capacity of 20t / h.

[0116] The refined and purified aluminum melt is cast into an ingot using a semi-continuous casting device; the ingot is subjected to homogenization treatment after head cutting and surface milling, with the first-level homogenization temperature being 440°C, the heating rate being 60°C / h, and the insulation time being 4 hours; the second-level homogenization temperature being 550°C, the heating rate being 20°C / h, and the insulation time being 20 hours; the homogenized ingot is extruded, with the ingot heating temperature being 480°C, the mold temperature being 480°C, the extrusion barrel temperature being 450°C, the extrusion ratio being 26, and the extrusion rod speed being 3mm / s; then a straightening treatment is performed with a deformation amount of 2.0%; then a solution treatment is performed with a solution treatment temperature of 540°C and an insulation time of 30 minutes, followed by water quenching; the water-quenched profile is transferred to a temperature of 170°C within 10 hours and is kept for 8 hours for aging treatment, and finally a finished profile is obtained.

[0117] Experimental Example 1: Performance Testing

[0118] 1. Microstructure analysis:

[0119] The microstructures before and after homogenization were observed using an optical microscope and a scanning electron microscope equipped with an EDS spectrometer. Figure 1 shown.

[0120] 2. Mechanical properties test:

[0121] Tensile specimens were cut from the finished profile along the extrusion direction. The specimen size was processed according to the standard GB6397-86, and the gauge length was 50mm×12.5mm×2mm. In order to confirm the repeatability of the data, the average value of the test results of three tensile specimens was taken for each state. The tensile strength (UTS), yield strength (YS) and elongation (EL) of the material were tested according to GB / T228, and the test results are listed in Table 1.

[0122] Table 1: Mechanical properties test results of examples and comparative examples

[0123]

[0124]

[0125] Note: na means that relevant data cannot be obtained due to problems such as extrusion cracking;

[0126] As can be seen from Table 1, the profiles prepared by using the raw materials of Examples 1 to 10 have a yield strength of 260 to 268 MPa, a tensile strength of 281 to 290 MPa, and an elongation of ≥10.5%, which can meet the requirements of recycled aluminum extrusion profiles for automobile anti-collision beams. According to the latest "Technical Specifications for Passenger Vehicle Life Cycle Carbon Emission Accounting", the raw material acquisition stage, vehicle production stage, and use stage of passenger vehicles are included in the life cycle carbon emission accounting scope, and the application of recycled aluminum is an important measure for aluminum alloy materials to reduce the carbon emission factor of the entire life cycle. The amount of scrap aluminum added in this solution is 45 to 55% (for example, 50%), so that the carbon emission factor in this solution is less than 10t CO2e / t, which significantly improves the application effect of recycled aluminum.

[0127] In the comparative examples, comparative examples 1 to 8 do not meet the requirements of the present invention, resulting in the following results:

[0128] A. Comparative Example 1: Since the aluminum melt was left in the furnace for too long during the smelting stage, new inclusions were generated in the melt, and the surface slag was difficult to remove, resulting in inclusions in the ingot, which cracked at the inclusions during extrusion;

[0129] B. Comparative Example 2: Due to the insufficient rotor speed of the degasser in the online purification stage, the hydrogen content of the melt was high, resulting in a high hydrogen content in the final ingot and cracking during extrusion;

[0130] C. Comparative Example 3 has low plate filtration accuracy, resulting in inclusions in the ingot, which cracks at the inclusions during extrusion;

[0131] D. Comparative Examples 4 and 5 respectively have low secondary homogenization temperature and insufficient secondary homogenization time, which results in the Fe content in the alloy not being able to be sufficiently thinned and melted, resulting in low strength of the alloy;

[0132] E. In comparative example 6, due to the long transfer time, the profile was adversely affected by natural aging to a certain extent during the storage period, and the strength after aging treatment was relatively low.

[0133] In summary, this scheme can melt 80% or more of the needle-shaped or lamellar β-type Fe phase and transform it into polygonal granular α-type Fe phase through targeted regulation of the enhanced purification of the melt and the homogenization process of the ingot, thereby effectively achieving the harmless or even beneficial transformation of the influence of high Fe element content under the condition of high proportion of scrap aluminum. The Fe content under this process condition can reach up to 0.35%, the upper limit of the range of GB / T 3190-2020, and the finished profiles produced have: carbon emission factor less than 10tCO2e / t, tensile strength greater than 280MPa, yield strength greater than 260MPa, and elongation greater than 10%.

[0134] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A high-strength recycled aluminum alloy profile for automobile anti-collision beams, characterized in that: The profile is 6063 alloy, which includes the following raw materials in percentage by mass: 45-55% of scrap aluminum, 0.3%-0.6% of Si, 0.5%-0.8% of Mg, 0-0.1% of Zn, 0-0.08% of Cu, 0-0.08% of Mn, 0.2%-0.45% of Fe, 0.01%-0.06% of Ti, and the remainder is Al and impurities with a content of less than 0.05%.

2. The high-strength recycled aluminum alloy profile for automobile anti-collision beam according to claim 1, characterized in that: The profile is obtained by subjecting raw materials to melting and casting treatment, homogenization treatment, extrusion treatment, straightening treatment, solid solution treatment and aging treatment.

3. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 2, characterized in that: The steps include: Step (1), melting and casting treatment: preparing the above raw materials, putting the above prepared materials into a smelting furnace, melting, refining, standing, and purifying, and using semi-continuous casting equipment to cast the purified aluminum melt into ingots; Step (2), homogenization treatment: the ingot obtained in step (1) is subjected to two-stage homogenization treatment, the first-stage homogenization, the heating temperature is controlled at 440-460° C., and the holding time is 4-6 hours; the second-stage homogenization, the heating temperature is controlled at 550-570° C., and the holding time is 20-24 hours; Step (3), extrusion treatment: extruding the ingot obtained in step (2) to obtain a profile; Step (4), straightening treatment, straightening the profile obtained in step (3); Step (5), solution treatment: subjecting the profile obtained in step (4) to solution treatment at a holding temperature of 540 to 560° C. for a holding time of 30 to 60 min, and then subjecting the profile to water quenching; Step (6), aging treatment: the profile obtained in step (5) is transferred to a temperature of 160-180° C. within 6 hours and kept at this temperature for 7-10 hours for aging treatment to obtain a finished profile.

4. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 3, characterized in that: In step (1), the melt is refined using high-purity argon gas without adding any chemical flux, the high-purity argon gas is introduced through the gas plugs evenly distributed at the bottom of the furnace, and the refining time is 30 to 60 minutes.

5. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 3, characterized in that: In step (1), the aluminum melt is allowed to stand in a standing furnace for 30 to 120 minutes.

6. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 3, characterized in that: In step (1), purification includes two stages of purification, as follows: (a) The online degassing and purification outside the furnace adopts a double-rotor degasser, which is fed with high-purity argon gas. The working pressure of the degasser is 0.3-0.5Mpa, the gas flow rate is 1.5-3.5m3 / h, and the rotor speed is 250-450r / min; (b) The online filtration and purification outside the furnace adopts a combination of single-stage plate filtration + deep bed filtration process, in which the accuracy of the single-stage plate filter is not less than 50ppi, and the deep bed filtration capacity is 20~40t / h.

7. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 3, characterized in that: In step (2), the heating rates of the two-stage homogenization treatment are as follows: the first-stage homogenization heating rate is 60-80°C / h, and the second-stage homogenization heating rate is 20-30°C / h.

8. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 3, characterized in that: In step (3), the extrusion treatment is carried out under the conditions of an ingot heating temperature of 510°C, a mold temperature of 480°C, an extrusion barrel temperature of 450°C, an extrusion ratio of 28, and an extrusion rod speed of 2 mm / s to obtain a profile.

9. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 3, characterized in that: In step (4), the deformation of the profile during the straightening process is 1.5 to 3%.

10. The process for preparing a high-strength recycled aluminum alloy profile for an automobile anti-collision beam according to claim 3, characterized in that: In step (6), the profile obtained in step (5) needs to be transferred within 3 hours and then subjected to aging treatment.

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