A recycled aluminum residual sn modified 6000 series aluminum alloy profile and a preparation method thereof

Abstract

This invention discloses a method for modifying 6000 series aluminum alloy profiles with recycled aluminum residue Sn and its preparation, belonging to the field of aluminum alloy preparation technology. The method includes the following steps: S1, melting and casting an aluminum alloy billet; S2, homogenizing the aluminum alloy billet; S3, preheating the aluminum alloy billet; S4, placing the aluminum alloy billet from step S3 into an extruder for hot extrusion forming to create an aluminum alloy profile, wherein the extruder outlet temperature is ≥525℃; S5, introducing the aluminum alloy profile from step S4 into an ultrasonic water quenching tank for 1-5 minutes of ultrasonic water quenching. This invention, through the combined process of recycling and modifying recycled aluminum residue Sn and ultrasonic quenching, not only solves the technical problem of recycling tin-containing aluminum, turning waste into treasure, but also produces extruded profiles with excellent comprehensive performance and significant economic and environmental benefits.

Description

Technical Field

[0001] This invention relates to a Sn-modified 6000 series aluminum alloy profile made from recycled aluminum residue and its preparation method, belonging to the field of aluminum alloy preparation technology. Background Technology

[0002] Currently, 6000 series (Al-Mg-Si) aluminum alloys are the mainstream material for photovoltaic module frames due to their excellent comprehensive performance. However, as the photovoltaic industry enters its end-of-life phase, the green recycling of a large number of retired modules has become an urgent need. However, during the recycling and crushing process, tin-containing components from the solder ribbons (Sn-Pb / Sn-Ag-Cu) in photovoltaic modules and waste aluminum from electronic and electrical equipment inevitably mix with recycled aluminum, leading to excessive Sn impurity content in the recycled aluminum. In traditional aluminum alloy metallurgy, Sn is generally considered a harmful impurity. Due to its low melting point and low solid solubility in aluminum, it easily segregates at grain boundaries, increasing the alloy's hot brittleness, deteriorating extrusion formability and mechanical properties, and especially severely impairing corrosion resistance.

[0003] Therefore, it is necessary to systematically control the Sn content and distribution characteristics in recycled aluminum to achieve comprehensive optimization of mechanical properties, hot workability, and corrosion resistance. Existing recycled aluminum materials often suffer from increased grain boundary brittleness, grain coarsening, and increased susceptibility to localized corrosion due to the segregation of impurities such as Sn, making it difficult to achieve comprehensive performance comparable to virgin aluminum alloys. To address this challenge, this invention proposes using trace amounts of Sn (0.05–0.10 wt.%) as a modifying component in recycled 6000 series aluminum alloys. Through precise formulation design, homogenization, preheating, hot extrusion, and ultrasonic water quenching and subsequent aging treatment at the extrusion nozzle, the intragranular distribution and grain boundary behavior of Sn are controlled. This allows Sn to be distributed in a favorable phase, promoting grain refinement and strengthening effects while suppressing increased grain boundary brittleness and corrosion susceptibility. This achieves controllable modification of residual Sn in recycled aluminum, resulting in stable and cost-effective recycled Sn-modified 6000 series aluminum alloy profiles. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a 6000 series aluminum alloy profile modified by recycled aluminum residual Sn and its preparation method. It can not only solve the technical problem of recycling aluminum containing tin by combining recycled aluminum residual Sn modification and ultrasonic quenching process, turning waste into treasure, but also produce extruded profiles with excellent comprehensive performance and significant economic and environmental benefits.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a method for preparing 6000 series aluminum alloy profiles modified with recycled aluminum residue Sn, comprising the following steps:

[0006] S1. Alloy raw materials are prepared according to the following weight percentages:

[0007] Sn: 0.05~0.10 wt.%, Mg: 0.55~0.90 wt.%, Si: 0.65~1.00 wt.%, Cu: 0.02~0.10 wt.%, Fe≤0.35 wt.%, Mn≤0.10 wt.%, Cr≤0.10 wt.%, Zn≤0.08 wt.%, the balance is Al;

[0008] The above alloy raw materials are melted and cast into aluminum alloy billets;

[0009] S2. Place the aluminum alloy billet from step S1 into a homogenizing furnace and keep it at 560℃±5℃ for 6 to 10 hours for homogenization treatment.

[0010] S3. Preheat the aluminum alloy billet from step S2 to a temperature of 420-500℃ and hold it for ≥3.5h.

[0011] S4. The aluminum alloy billet from step S3 is placed into an extrusion press for hot extrusion forming to form an aluminum alloy profile. The outlet temperature of the extrusion press is ≥525℃.

[0012] S5. The aluminum alloy profile described in step S4 is introduced into an ultrasonic water quenching tank for ultrasonic water quenching treatment for 1 to 5 minutes.

[0013] S6. Place the aluminum alloy profile from step S5 into an aging furnace for aging treatment to obtain the final recycled aluminum residue Sn-modified 6000 series aluminum alloy profile.

[0014] The temperature inside the aging furnace is 175–190℃, and the holding time is ≤2h.

[0015] Furthermore, the ultrasonic frequency range of the ultrasonic water quenching treatment in step S5 is 15–50 kHz.

[0016] Furthermore, the ratio of water flow rate in the ultrasonic water quenching tank to that of the aluminum alloy profile is ≥3L / min·kg.

[0017] Furthermore, the ultrasonic water quenching tank is located at the outlet of the extruder, and multiple generators are evenly installed on the inner wall of the ultrasonic water quenching tank.

[0018] Furthermore, the time it takes for the aluminum alloy profile to completely enter the ultrasonic water quenching tank from the extruder is less than 15 seconds.

[0019] The present invention also provides a Sn-modified 6000 series aluminum alloy profile obtained by the above preparation method;

[0020] The chemical composition of this aluminum alloy profile is as follows: Sn: 0.05~0.10 wt.%, Mg: 0.55~0.90 wt.%, Si: 0.65~1.00 wt.%, Cu: 0.02~0.10 wt.%, Fe≤0.35 wt.%, Mn≤0.10 wt.%, Cr≤0.10 wt.%, Zn≤0.08 wt.%, with the balance being Al.

[0021] Furthermore, the aluminum alloy profile has a Vickers hardness ≥103Hv, tensile strength ≥309 MPa, yield strength ≥297 MPa, and elongation ≥9.5%.

[0022] By adopting the above technical solution, the present invention has the following beneficial effects:

[0023] In this invention, compared with the traditional 6000 series aluminum alloy composition, the residual Sn alloying scheme involved in this invention solves the technical problem of recycling tin-containing waste aluminum, turning waste into treasure;

[0024] Compared with the conventional heat treatment process for aluminum alloy ingots, the heat treatment process of this invention greatly shortens the aging time of the alloy (from 190 ℃ / 4h to 190 ℃ / 2h), achieving the goal of energy saving and improving production efficiency.

[0025] Compared with the conventional heat treatment process for aluminum alloy ingots, the heat treatment process of this invention can greatly improve the aging hardness of the alloy while ensuring the resistance to intergranular corrosion (the hardness value is increased from 90 Hv to 104 Hv). Attached Figure Description

[0026] Figure 1 This is a comparison table of the hardness and strength of aged aluminum alloys obtained in Examples 1-6 and Comparative Examples 1-2 of this invention;

[0027] Figure 2 Based on the differential thermal analysis table in this invention, the overheating temperature of 6000 series aluminum alloy ingots is determined to be 580 ℃;

[0028] Figure 3 Based on the differential thermal analysis table in this invention, the aging temperature range of 6000 series aluminum alloys is determined to be 175–190 °C.

[0029] Figure 4 The backscattered electron microscope (SEM) morphology of 6000 series aluminum alloys corresponding to Example 1 and Comparative Example 1 in this invention;

[0030] Figure 5 This is a graph showing the hardness change of 6000 series aluminum alloys aged at 190 °C in Example 1 and Comparative Example 1 of this invention.

[0031] Figure 6This is a comparison of the intergranular corrosion depth of 6000 series aluminum alloy sections in Example 1 and Comparative Example 1 of the present invention;

[0032] Figure 7 These are the stress-strain curves of the alloys corresponding to Examples 1, 2, and Example 1 in this invention;

[0033] Figure 8 The transmission electron microscopy (TEM) characterization of intragranular precipitates and grain boundary precipitates in Example 1 and Comparative Example 1 of this invention corresponds to 6000 series aluminum alloys. Detailed Implementation

[0034] This invention provides a method for preparing 6000 series aluminum alloy profiles modified with recycled aluminum residue (Sn) and its preparation. Those skilled in the art can refer to this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and fall within the scope of this invention. The method and application of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the method and application described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0035] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0036] Example 1;

[0037] like Figure 1-8 As shown, a method for preparing Sn-modified 6000 series aluminum alloy profiles from recycled aluminum residues includes the following steps:

[0038] S1. Alloy raw materials are prepared according to the following weight percentages:

[0039] Sn: 0.05~0.10 wt.%, Mg: 0.55~0.90 wt.%, Si: 0.65~1.00 wt.%, Cu: 0.02~0.10 wt.%, Fe≤0.35 wt.%, Mn≤0.10 wt.%, Cr≤0.10 wt.%, Zn≤0.08 wt.%, the balance is Al;

[0040] The above alloy raw materials are melted and cast into aluminum alloy billets;

[0041] S2. Place the aluminum alloy billet from step S1 into a homogenizing furnace and hold it at 560°C for 8 hours for homogenization.

[0042] S3. Preheat the aluminum alloy billet from step S2 to 480°C and hold for 3.5 hours.

[0043] S4. The aluminum alloy billet from step S3 is placed into an extrusion press for hot extrusion forming to form an aluminum alloy profile. The outlet temperature of the extrusion press is 525°C.

[0044] S5. The aluminum alloy profile described in step S4 is introduced into an ultrasonic water quenching tank for 5 minutes of ultrasonic water quenching treatment.

[0045] S6. Place the aluminum alloy profile from step S5 into an aging furnace for aging treatment to obtain the final recycled aluminum residue Sn-modified 6000 series aluminum alloy profile.

[0046] Specifically, the temperature inside the aging furnace is 190°C, and the holding time is 2 hours.

[0047] Specifically, the ultrasonic frequency range of the ultrasonic water quenching treatment in step S5 is 15KHz.

[0048] In this embodiment, ultrasound can generate a strong cavitation effect in water, effectively breaking through the quenching steam insulation layer and achieving rapid cooling. If the frequency is below 15KHz, the effect will be weakened, and if it is above 50KHz, the overall cooling efficiency will decrease.

[0049] Specifically, the ratio of water flow rate in the ultrasonic water quenching tank to that of the aluminum alloy profile is 3 L / min·kg.

[0050] Specifically, the ultrasonic water quenching tank is located at the outlet of the extruder, and multiple generators are uniformly installed on the inner wall of the ultrasonic water quenching tank.

[0051] In this embodiment, the power density of the generator is 0.2~1.0 W / cm². 2 Furthermore, their arrangement in the ultrasonic water quenching tank ensures that the ultrasonic field intensity experienced by the aluminum alloy profile during the quenching process is uniform.

[0052] Specifically, the time it takes for the aluminum alloy profile to completely enter the ultrasonic water quenching tank from the extruder is less than 15 seconds.

[0053] The present invention also provides a 6000 series aluminum alloy profile modified with recycled aluminum residue Sn obtained by any of the above preparation methods;

[0054] The composition of this aluminum alloy profile is Sn: 0.05~0.10 wt.%, Mg: 0.55~0.90 wt.%, Si: 0.65~1.00 wt.%, Cu: 0.02~0.10 wt.%, Fe≤0.35 wt.%, Mn≤0.10 wt.%, Cr≤0.10 wt.%, Zn≤0.08 wt.%, with the balance being Al.

[0055] Specifically, the aluminum alloy profile has a Vickers hardness ≥103Hv, tensile strength ≥309 MPa, yield strength ≥297 MPa, and elongation ≥9.5%.

[0056] Example 2;

[0057] The basic steps of this embodiment are the same as those of Embodiment 1, except that the Sn content in the alloy billet in this embodiment is 0.06 wt.%.

[0058] Example 3;

[0059] The basic steps of this embodiment are the same as those of Embodiment 1, except that the Mg content is adjusted to 0.85 wt.% and the Si content is adjusted to 1.0 wt.%.

[0060] Example 4;

[0061] The basic steps of this embodiment are the same as those of Embodiment 1, except that the ultrasonic frequency range in step S5 of this embodiment is 50 kHz and the ultrasonic time is 1 min.

[0062] Example 5;

[0063] The basic steps of this embodiment are the same as those of Embodiment 1, except that the aging temperature in step S6 of this embodiment is 175 ℃.

[0064] Comparative Example 1;

[0065] The basic steps of this comparative example are the same as those of Example 1, except that the alloy billet in this comparative example does not contain Sn alloying element.

[0066] Comparative Example 2;

[0067] The basic steps of this comparative example are the same as those of Example 1, except that in this comparative example, after extrusion molding in step S4, ordinary water quenching treatment is performed.

[0068] The aluminum ingots obtained in Examples 1-5 and Comparative Examples 1-2 were all tested under the same conditions according to GB / T 228.1 "Tensive Testing of Metallic Materials" and GB / T7998-2023 "Evaluation Method for Intergranular Corrosion Susceptibility of Aluminum Alloys". The results of hardness, tensile strength, yield strength, and elongation were obtained. Figure 1 As shown;

[0069] Depend on Figure 1 It can be seen that the hardness, tensile strength, yield strength and elongation of the 6000 series aluminum alloy obtained by the present invention are all higher than those of the comparative example.

[0070] Figure 2 Differential thermal analysis characterization of the as-cast alloys corresponding to Example 1 and Comparative Example 1, by Figure 2It can be seen that the addition of Sn has no significant effect on the homogenization temperature;

[0071] Figure 3 Differential thermal analysis characterization of the extruded alloys for Example 1 and Comparative Example 1 was performed by... Figure 3 It can be seen that the addition of Sn has no significant effect on the aging temperature;

[0072] Figure 4 Scanning electron microscopy characterization of the solid solution alloys of Example 1 and Comparative Example 1 was performed by... Figure 4 It can be seen that the addition of trace amounts of Sn did not produce the Mg2Sn phase, and it had a certain modifying effect on the morphology of the iron phase.

[0073] Figure 5 The solid solution aging curves for Example 1, Comparative Example 1, and Comparative Example 2 are provided by... Figure 5 It can be seen that the addition of trace amounts of Sn can not only shorten the aging time, but also enhance the aging hardening effect; the addition of trace amounts of Sn combined with ultrasonic quenching composite process can further enhance the aging hardening effect while shortening the time.

[0074] Figure 6 The stress-strain curves of the aged alloys corresponding to Examples 1, 2, and Comparative Example 1 are obtained from... Figure 6 It can be seen that the addition of trace amounts of Sn combined with the ultrasonic quenching process effectively improves the alloy strength while ensuring the alloy elongation.

[0075] Figure 7 The intergranular corrosion morphologies corresponding to Example 1 and Comparative Example 1 are derived from... Figure 7 It can be seen that the addition of trace amounts of Sn combined with the ultrasonic quenching composite process ensures the alloy's resistance to intergranular corrosion.

[0076] Figure 8 The intragranular and grain boundary precipitate morphologies of the alloys in Example 1 and Comparative Example 1 are shown in the transmission electron microscopy (TEM) images. Figure 8 It can be seen that the combined process of adding trace amounts of Sn and ultrasonic quenching ensures fine precipitation within the grains while narrowing the width of the precipitation zone at the grain boundaries; the above microstructure simultaneously ensures the alloy's strength and resistance to intergranular corrosion.

[0077] The Sn-modified 6000 series aluminum alloy profiles prepared by the above method exhibit Vickers hardness ≥103Hv, tensile strength ≥309 MPa, yield strength ≥297 MPa, and elongation ≥9.5%, with comprehensive mechanical properties reaching or even exceeding those of some native 6000 series aluminum alloys. More importantly, their intergranular corrosion depth is significantly reduced compared to the control samples without Sn or with ordinary quenching, demonstrating excellent corrosion resistance.

[0078] This profile is particularly suitable for structural components with strict requirements for strength, corrosion resistance and lightweight, such as photovoltaic module frames, building curtain wall support structures, new energy vehicle battery trays and body frames, high-end radiators, etc., opening up new market areas for the application of high-value recycled aluminum.

[0079] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a recycled aluminum residual Sn-modified 6000 series aluminum alloy profile, characterized by, The method comprises the following steps: S1, alloy raw materials are prepared according to the following weight percentages: Sn: 0.05-0.10 wt.%, Mg: 0.55-0.90 wt.%, Si: 0.65-1.00 wt.%, Cu: 0.02-0.10 wt.%, Fe≤0.35 wt.%, Mn≤0.10 wt.%, Cr≤0.10 wt.%, Zn≤0.08 wt.%, and the balance being Al; The alloy raw materials are melted and cast into aluminum alloy cast blanks; S2, the aluminum alloy cast blanks in step S1 are placed in a homogenizing furnace and homogenized at 560℃±5℃ for 6-10 hours; S3, the aluminum alloy cast blanks in step S2 are preheated at a temperature of 420-500℃ for≥3.5 hours; S4, the aluminum alloy cast blanks in step S3 are placed in an extruder to be hot extruded to form aluminum alloy profiles, and the outlet temperature of the extruder is≥525℃; S5, the aluminum alloy profiles in step S4 are introduced into an ultrasonic water quenching tank for ultrasonic water quenching treatment for 1-5 minutes; S6, the aluminum alloy profiles in step S5 are placed in an aging furnace for aging treatment to obtain the final recycled aluminum residual Sn modified 6000 series aluminum alloy profiles; The temperature in the aging furnace is 175-190℃, and the holding time is≤2 hours.

2. The method according to claim 1, wherein the ultrasonic frequency of the ultrasonic water quenching treatment in step S5 is 15-50 kHz.

3. The method according to claim 1, wherein the water flow rate in the ultrasonic water quenching tank is≥3 L / min·kg.

4. The method according to claim 1, wherein the ultrasonic water quenching tank is arranged at the outlet of the extruder, and a plurality of generators are evenly arranged on the inner wall of the ultrasonic water quenching tank.

5. The method according to claim 4, wherein the time for the aluminum alloy profiles to completely enter the ultrasonic water quenching tank from the extruder is less than 15 seconds.

6. A recycled aluminum residual Sn modified 6000 series aluminum alloy profile prepared by the method according to any one of claims 1-5, wherein the composition of the aluminum alloy profile is Sn: 0.05-0.10 wt.%, Mg: 0.55-0.90 wt.%, Si: 0.65-1.00 wt.%, Cu: 0.02-0.10 wt.%, Fe≤0.35 wt.%, Mn≤0.10 wt.%, Cr≤0.10 wt.%, Zn≤0.08 wt.%, and the balance being Al. ​ ​ ​ ​ ​ 7. The recycled aluminum residual Sn-modified 6000 series aluminum alloy profile according to claim 6, characterized in that: the Vickers hardness of the aluminum alloy profile is ≥ 103 Hv, the tensile strength is ≥ 309 MPa, the yield strength is ≥ 297 MPa, and the elongation is ≥ 9.5%.

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