Aluminum alloy material for anodic oxidation, preparation method of aluminum alloy material and anodic oxidation aluminum alloy
By adjusting the aluminum alloy composition and optimizing the preparation process, the problems of color difference and black streaks in 7075 aluminum alloy during the anodizing process were solved, achieving high-quality surface effects and mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-03
AI Technical Summary
The existing 7075 aluminum alloy is prone to color difference and black streaks during the anodizing process, especially on plates with a thickness of 40~60mm, which affects the surface quality.
By adjusting the composition ratio of aluminum alloys and adopting processes such as online refining, homogenization, hot rolling, solution quenching, and artificial aging, the preparation process of aluminum alloys is optimized. In particular, the content and process parameters of elements such as Cu, Mg, Zn, and Cr are controlled to ensure that the original grains of the ingots are fine and the structure is uniform, thus eliminating chemical composition segregation.
This method achieves the absence of color difference and black streaks in aluminum alloy materials after anodizing, resulting in excellent surface quality and high mechanical properties.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of aluminum alloy technology, and in particular to an aluminum alloy material for anodizing, its preparation method, and anodized aluminum alloy. Background Technology
[0002] 7075 alloy, also known as Al-Zn-Mg-Cu series aluminum alloy, belongs to the aerospace series materials. It is a heat-treatable and super-hard aluminum alloy with outstanding advantages such as high strength, good processing and welding performance, but poor corrosion resistance, requiring surface anti-corrosion treatment.
[0003] In recent years, with the development of the high-end market, especially the increasing requirements for aerospace interior parts, the demand for high-strength, highly alloyed, heat-treatable aluminum alloys in the aerospace market has gradually increased. Anodizing is an effective method to improve the corrosion resistance and wear resistance of aluminum alloys. For aluminum alloy materials with high-quality surfaces, the surface quality after anodizing is particularly important. In existing technologies, aluminum alloy materials that have undergone anodizing may exhibit certain appearance defects, such as yellowing due to oxidation, uneven coloring, and black streaks, which can affect the normal use of the material.
[0004] With the diversification of applications in aerospace interiors, users' requirements for the thickness of anodized sheet metal are no longer limited to within 40mm, but are trending towards wider and thicker sheets. Therefore, solving the problem of color difference in appearance caused by factors such as uneven composition and microstructure in high-alloy thick sheet materials is of great significance to the aluminum alloy industry. Summary of the Invention
[0005] The technical problem solved by this invention is to provide an aluminum alloy material for anodizing, which solves the problem of color difference and black stripes in 40~60mm aluminum alloy after anodizing. The aluminum alloy material has excellent anodizing performance after anodizing.
[0006] In view of this, this application provides a method for preparing an aluminum alloy material for anodizing, comprising the following steps:
[0007] S1) After batching according to the composition ratio of aluminum alloy material for anodizing, the mixture is smelted, then refined, degassed online, filtered online, refined online, and cast to obtain an aluminum alloy ingot; the composition of the aluminum alloy ingot, by mass percentage, includes: Si≤0.10%, Fe≤0.20%, Cu1.35~1.65%, Mn≤0.03%, Mg2.20~2.60%, Cr0.18~0.30%, Zn5.30~5.70%, Ti≤0.05%, Al balance;
[0008] S2) The aluminum alloy ingot is subjected to homogenization treatment at a temperature of 470~480℃.
[0009] S3) The aluminum alloy ingot obtained in step S2) is hot rolled at a temperature of 420~480℃, in 15~25 passes, and the deformation per pass is 5~20mm.
[0010] S4) The aluminum alloy billet obtained in step S3) is subjected to solution quenching and artificial aging in sequence; the solution quenching temperature is 450~500℃, the quenching cooling rate is 100~150℃ / min, and the artificial aging temperature is 100~150℃.
[0011] In some specific embodiments, in step S2), the homogenization treatment is carried out at a temperature of 470~475℃ for 20~30h.
[0012] In some specific embodiments, the hot rolling temperature is 430~450℃, and / or the thickness of the hot-rolled billet is 40~60mm.
[0013] In some specific embodiments, the solution treatment temperature is 470~480℃ and the time is 90~150min.
[0014] In some specific embodiments, the temperature for artificial aging is 120~130℃, and the holding time is 900~930min.
[0015] In some specific embodiments, the hot rolling process is followed by air cooling to room temperature.
[0016] In some specific embodiments, the casting speed is 40~55 mm / min, and the water flow rate is 175~200 m³ / min. 3 / h, the wiper height is 275~400mm; and / or, the online refining agent is AlTi5B1 filament, and the addition amount is 1.5~1.9kg / t.
[0017] In some specific embodiments, the thickness of the aluminum alloy material used for anodizing is 45~55mm.
[0018] This application also provides an aluminum alloy material for anodizing, comprising, by mass percentage: Si≤0.10%, Fe≤0.20%, Cu1.35~1.65%, Mn≤0.03%, Mg2.20~2.60%, Cr0.18~0.30%, Zn5.30~5.70%, Ti≤0.05%, and Al balance.
[0019] This application also provides an anodized aluminum alloy, which is obtained by anodizing aluminum alloy material, wherein the aluminum alloy material is the anodized aluminum alloy material prepared by the preparation method described above or the anodized aluminum alloy material described above.
[0020] This application provides a method for preparing aluminum alloy materials for anodizing. First, the initial aluminum alloy melt is refined, degassed online, filtered online, refined online, and cast to obtain an aluminum alloy ingot. Then, the aluminum alloy ingot is sequentially subjected to homogenization treatment, hot rolling, solution quenching, and artificial aging to obtain the aluminum alloy material. In the above-mentioned aluminum alloy material preparation process, the online grain refinement process ensures that the original grains of the ingot are fine. Homogenization treatment and the limitation of process parameters can eliminate stress and microscopic chemical composition segregation generated during casting. Solution quenching allows the strengthening phase to dissolve into the matrix, resulting in a supersaturated solid solution. Finally, artificial aging causes the re-precipitation of fine and dispersed strengthening phases in the re-dissolved supersaturated solid solution, thereby making the sheet microstructure more uniform, obtaining high mechanical properties and anodizing performance. This results in the aluminum alloy material having excellent surface quality after anodizing, with no color difference or black streaks. Attached Figure Description
[0021] Figure 1 This is a photograph of the aluminum alloy square plate prepared in Example 1 of the present invention after anodizing.
[0022] Figure 2 This is a photograph of the aluminum alloy square plate prepared in Comparative Example 1 of the present invention after anodizing.
[0023] Figure 3 This is a photograph of the aluminum alloy square plate prepared in Comparative Example 2 of the present invention after anodizing. Detailed Implementation
[0024] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.
[0025] In view of the requirements for the anodizing performance of aluminum alloy materials in the existing aerospace materials, this application provides a method for preparing aluminum alloy materials for anodizing. By adjusting the composition of the aluminum alloy and employing online refinement, casting, homogenization treatment, hot rolling, solution quenching, and artificial aging, while limiting process parameters, the method reduces macroscopic segregation and chemical composition segregation in the low-magnification structure of the ingot, solves the problem of color difference—black streaks—in anodizing 40-60mm plates, and exhibits excellent anodizing performance. Specifically, this invention discloses a method for preparing aluminum alloy materials for anodizing, including the following steps:
[0026] S1) After batching according to the composition ratio of aluminum alloy material for anodizing, the mixture is smelted, then refined, degassed online, filtered online, refined online, and cast to obtain an aluminum alloy ingot; the composition of the aluminum alloy ingot, by mass percentage, includes: Si≤0.10%, Fe≤0.20%, Cu1.35~1.65%, Mn≤0.03%, Mg2.20~2.60%, Cr0.18~0.30%, Zn5.30~5.70%, Ti≤0.05%, Al balance;
[0027] S2) The aluminum alloy ingot is subjected to homogenization treatment at a temperature of 470~480℃.
[0028] S3) The aluminum alloy ingot obtained in step S2) is hot rolled at a temperature of 420~480℃, in 15~25 passes, and the deformation per pass is 5~20mm.
[0029] S4) The aluminum alloy billet obtained in step S3) is subjected to solution quenching and artificial aging in sequence; the solution quenching temperature is 450~500℃, the quenching cooling rate is 100~150℃ / min, and the artificial aging temperature is 100~150℃.
[0030] In the preparation method of aluminum alloy material for anodizing provided in this application, in step S1, the materials are batched according to the composition ratio of the aluminum alloy material for anodizing and then smelted, followed by refining, online degassing, online filtration, online fine refining, and casting to obtain an aluminum alloy ingot. The composition of the aluminum alloy ingot, by mass percentage, includes: Si≤0.10%, Fe≤0.20%, Cu1.35~1.65%, Mn≤0.03%, Mg2.20~2.50%, Cr0.18~0.25%, Zn5.30~5.70%, Ti≤0.05%, and Al balance. In the above process, the raw materials for batching can be selected according to those well known to those skilled in the art, and this application does not impose any special restrictions on them. The smelting, refining, online degassing, and online filtration are carried out in a manner well known to those skilled in the art, and this application does not impose any special restrictions on them. During the online grain refinement process, the refining agent is AlTi5B1 wire, added at a rate of 1.5~1.9 kg / t; specifically, the amount of the refining agent added is 1.65~1.85 kg / t. These limitations on the refining agent and its dosage ensure that the original grains of the ingot are fine. During the casting process, the casting speed is 40~55 mm / min, and the water flow rate is 175~200 m³ / min. 3The water flow rate is 178-185 m³ / h, the wiper height is 275-400 mm, specifically, the casting speed is 45-50 mm / min, and the water flow rate is 178-185 m³ / min. 3 / h, with a wiper height of 290~380mm. The above casting process helps to reduce macroscopic microstructure segregation and chemical composition segregation in the ingot.
[0031] In step S2, the aluminum alloy ingot is subjected to a homogenization treatment at a temperature of 470-480°C for 20-30 hours, specifically at a temperature of 470-475°C for 24-28 hours. This homogenization treatment aims to eliminate stress and microscopic chemical segregation generated during the casting process.
[0032] After the above homogenization treatment, the obtained ingot is hot-rolled. During this process, the hot rolling temperature is 420-480℃, the number of hot rolling passes is 15-25, and the deformation per pass is 5-20 mm. Specifically, the hot rolling temperature is 430-450℃, the number of hot rolling passes is 18-23, and the deformation per pass is 10-18 mm; more specifically, the hot rolling temperature is 440-445℃, the number of hot rolling passes is 20-22, and the deformation per pass is 12-15 mm. After hot rolling, the ingot is air-cooled to room temperature. The thickness of the aluminum alloy billet obtained after hot rolling is 40-60 mm, specifically 45-55 mm, which is the thickness of the aluminum alloy material used for anodizing.
[0033] After hot rolling, in step S4, the hot-rolled aluminum alloy billet is sequentially subjected to solution quenching and artificial aging to obtain anodized aluminum alloy material. During this process, the solution quenching temperature is 450~500℃, and the quenching cooling rate is 100~150℃ / min. Specifically, the solution quenching temperature is 470~480℃, the holding time is 90~150min, and the quenching cooling rate is 120~140℃ / min. More specifically, the solution quenching temperature is 470~475℃, the holding time is 100~120min, and the cooling rate is 120~130℃ / min. The solution treatment allows the reinforcing phase to dissolve into the matrix, and the quenching process forms a supersaturated solid solution in the aluminum alloy matrix. The artificial aging temperature is 100~150℃, and the holding time is 900~930min. Specifically, the artificial aging temperature is 120~130℃, and the holding time is 910~920min. This artificial aging process causes the re-precipitation of fine, dispersed reinforcing phases in the re-dissolved supersaturated solid solution, resulting in a more uniform microstructure of the sheet material and thus achieving high mechanical and anodizing properties.
[0034] This application also provides an aluminum alloy material for anodizing, comprising, by mass percentage: Si≤0.10%, Fe≤0.20%, Cu1.35~1.65%, Mn≤0.03%, Mg2.20~2.50%, Cr0.18~0.30%, Zn5.30~5.70%, Ti≤0.05%, and Al balance.
[0035] For aluminum alloys, Cu has the greatest impact on the surface quality after anodizing. Especially if Cu is enriched, during the oxidation process, Cu is oxidized to CuO or Cu₂O, or exists as metallic particles in the anodized film, forming dark gray or black spots or streaks. In this application, the Cu content is specifically 1.45~1.60%, more specifically 1.49~1.55%, and even more specifically 1.50~1.52%.
[0036] The Mg content is specifically 2.25~2.57%, more specifically 2.45~2.50%. The Cr content is specifically 0.21~0.27%, more specifically 0.23~0.25%. The Zn content is specifically 5.38~5.66%, more specifically 5.40~5.55%.
[0037] The synergistic effect of the aforementioned Mg, Zn, Cr, and Cu elements causes Cu to form more S phase (Al2CuMg) and less Al2Cu, thereby reducing the influence of Cu on anodizing.
[0038] The contents of S, Fe, Mn, and Ti need to be strictly limited: S ≤ 0.05%, specifically, S ≤ 0.03%, more specifically, S ≤ 0.02%; Fe ≤ 0.15%, specifically, Fe ≤ 0.12%, more specifically, Fe ≤ 0.09%; Mn ≤ 0.02%, more specifically, Mn ≤ 0.01%; Ti ≤ 0.03%, specifically, Ti ≤ 0.025%, more specifically, Ti ≤ 0.02%.
[0039] This application also provides an anodized aluminum alloy, which is obtained by anodizing aluminum alloy material, wherein the aluminum alloy material is the anodized aluminum alloy material prepared by the preparation method described above or the anodized aluminum alloy material described above.
[0040] The aluminum alloy material for anodizing provided by this invention improves the comprehensive mechanical properties and chemical milling performance of the product through optimized chemical composition design. At the same time, by designing casting process parameters, the size of coarse compounds is reduced, resulting in a dispersed distribution of compounds and a uniform and fine microstructure. Furthermore, through the combination of homogenization treatment, solution quenching, and artificial aging, macroscopic microstructure segregation is reduced and microscopic chemical composition segregation is eliminated. The resulting aluminum alloy material has a low-magnification grain size of no more than 1.5 grade, and no obvious macroscopic segregation is observed on the low-magnification surface, with a macroscopic segregation level ≤ 1 grade. This ensures that the cross-section of the plate after anodizing is free of color difference and black streaks, exhibiting excellent surface quality.
[0041] To further understand the present invention, the following detailed description of the aluminum alloy material for anodizing and its preparation method provided by the present invention is provided in conjunction with the embodiments. The scope of protection of the present invention is not limited by the following embodiments.
[0042] Example 1
[0043] The composition of the aluminum alloy material used for anodizing in this embodiment, by mass percentage, includes: Si 0.03%, Fe 0.12%, Cu 1.45%, Mn 0.01%, Mg 2.45%, Cr 0.21%, Zn 5.38%, Ti 0.025%, with the balance being Al;
[0044] The raw materials are prepared using primary aluminum ingots of Al99.70 and above, pure metals, master alloys, and 7075 alloy head and tail sawn remelting materials. Cu can be prepared using Cu plates or AlCu40 and AlCu20. Cr is prepared using AlCr4 master alloy, Mg is prepared using Mg ingots, and Zn is prepared using Zn ingots.
[0045] Smelting: The raw materials after the above batching are mixed and smelted to obtain aluminum alloy melt;
[0046] Melt purification: The aluminum alloy melt is sequentially refined, degassed online, and filtered online;
[0047] Grain refinement: The melt that has been purified is refined online using AlTi5B1 wire, with a refining agent addition of 1.59 kg / t;
[0048] Casting process: A semi-continuous casting method was adopted to cast four ingots from the above-mentioned molten aluminum alloy; the casting speed was set to 40 mm / min, and the water flow rate was set to 178 m³ / min. 3 / h, the scraper height is set to 380mm, and the temperature of the aluminum liquid at the end of the flow plate is controlled at 695~705℃. During the casting process, cooling water is used for cooling, and the cooling water temperature is controlled at 22~24℃.
[0049] Homogenization process: The above four ingots are heated to a uniform heat holding temperature of 475℃, held at this temperature for 20 hours, air-cooled to room temperature, and the head and tail are removed to obtain the raw ingot material.
[0050] Hot rolling of ingots: The ingot blanks are heated to 440°C and rolled through 15 passes with a deformation of 5~20mm per pass to obtain 7075 alloy plates with a thickness of 55mm. After hot rolling, the plates are air-cooled to room temperature.
[0051] Solution quenching: Heat a 55mm thick 7075 alloy plate that has been air-cooled to room temperature to 470~480℃, hold it at this temperature for 90min, and then rapidly cool it to room temperature at a rate of 120℃ / min.
[0052] Artificial aging: After solution quenching, the plate is heated to the aging temperature of 120℃ and held at this temperature for 900 minutes to obtain anodized aluminum alloy plate.
[0053] Through the above process, the low-magnification grain size of the four ingots obtained does not exceed grade 1.5, and there is no obvious macroscopic segregation on the low-magnification inspection surface, with a macroscopic segregation grade ≤ grade 1; the aluminum alloy sheet for anodizing prepared above, after anodizing, has no color difference or black streaks in its cross-section, such as Figure 1 As shown.
[0054] Example 2
[0055] The composition of the aluminum alloy material used for anodizing in this embodiment, by mass percentage, includes: Si 0.05%, Fe 0.15%, Cu 1.49%, Mn 0.02%, Mg 2.50%, Cr 0.25%, Zn 5.40%, Ti 0.03%, with the balance being Al;
[0056] The raw materials are prepared using primary aluminum ingots of Al99.70 and above, pure metals, master alloys, and 7075 alloy head and tail sawn remelting materials. Cu can be prepared using Cu plates or AlCu40 and AlCu20. Cr is prepared using AlCr4 master alloy, Mg is prepared using Mg ingots, and Zn is prepared using Zn ingots.
[0057] Smelting: The raw materials after the above batching are mixed and smelted to obtain aluminum alloy melt;
[0058] Melt purification: The aluminum alloy melt is sequentially refined, degassed online, and filtered online;
[0059] Grain refinement: The melt that has been purified is refined online using AlTi5B1 wire, with a refining agent addition of 1.65 kg / t;
[0060] Casting process: Semi-continuous casting method is adopted, casting 4 ingots; the casting speed is set to 45mm / min, and the water flow rate is set to 185m³ / min. 3 / h, the scraper height is set to 380mm, and the temperature of the molten aluminum at the end of the flow plate is controlled at 695~705℃. During the casting process, cooling water is used for cooling; the cooling water temperature is controlled at 22~24℃.
[0061] Homogenization process: The above 4 ingots are heated to a uniform heat holding temperature of 470℃, held at this temperature for 24 hours, air-cooled to room temperature, and the head and tail are removed to obtain the raw ingot material.
[0062] Hot rolling of ingots: The ingot blanks are heated to 445°C and rolled through 20 passes, with a deformation of 5~20mm per pass, to obtain 7075 alloy plates with a thickness of 60mm. After hot rolling, the plates are air-cooled to room temperature.
[0063] Solution hardening: A 60mm thick 7075 alloy plate, which has been air-cooled to room temperature, is heated to 475℃ and held at this temperature for 150min; after holding, it is rapidly cooled to room temperature at a cooling rate of 120℃ / min.
[0064] Artificial aging: After solution quenching, the plate is heated to the aging temperature of 130℃ and held at this temperature for 930 minutes to obtain anodized aluminum alloy plate.
[0065] Through the above process, the low-magnification grain size of the four ingots obtained does not exceed grade 1.5, the low-magnification detection surface has no obvious macro segregation, and the macro segregation grade is ≤ grade 1; the aluminum alloy sheet for anodizing prepared above has no color difference and black stripes in the cross section after anodizing.
[0066] Example 3
[0067] The composition of the aluminum alloy material used for anodizing in this embodiment, by mass percentage, includes: Si 0.02%, Fe 0.09%, Cu 1.52%, Mn 0.01%, Mg 2.57%, Cr 0.27%, Zn 5.66%, Ti 0.02%, with the balance being Al.
[0068] The raw materials are prepared using primary aluminum ingots of Al99.70 and above, pure metals, master alloys, and 7075 alloy head and tail sawn remelting materials. Cu can be prepared using Cu plates or AlCu40 and AlCu20. Cr is prepared using AlCr4 master alloy, Mg is prepared using Mg ingots, and Zn is prepared using Zn ingots.
[0069] Smelting: The raw materials after the above batching are mixed and smelted to obtain aluminum alloy melt;
[0070] Melt purification: The aluminum alloy melt is sequentially refined, degassed online, and filtered online;
[0071] Grain refinement: The purified melt is refined online using AlTi5B1 wire, with a refining agent addition of 1.85 kg / t;
[0072] Casting process: Semi-continuous casting method is adopted, casting 4 ingots; the casting speed is set to 45mm / min, and the water flow rate is set to 200m³ / min. 3 / h, the scraper height is set to 380mm, and the temperature of the aluminum liquid at the end of the flow plate is controlled at 695~705℃. During the casting process, cooling water is used for cooling; the cooling water temperature is controlled at 22~24℃.
[0073] Homogenization process: The four ingots formed above are heated to a uniform heat holding temperature of 475℃, held at this temperature for 28 hours, air-cooled to room temperature, and the head and tail are removed to obtain the raw ingot material.
[0074] Hot rolling of ingots: The ingot blanks are heated to 445°C and rolled through 25 passes, with a deformation of 5~20mm per pass, to obtain 7075 alloy plates with a thickness of 45mm. After hot rolling, the plates are air-cooled to room temperature.
[0075] Solution hardening: 45mm thick 7075 alloy plate, which has been air-cooled to room temperature, is heated to 475℃ and held at this temperature for 120min; after holding, it is rapidly cooled to room temperature at a cooling rate of 120℃ / min.
[0076] Artificial aging: After solution quenching, the plate is heated to the aging temperature of 125℃ and held at this temperature for 900 minutes to obtain anodized aluminum alloy plate.
[0077] Through the above process, the low-magnification grain size of the four ingots obtained does not exceed grade 1.5, the low-magnification detection surface has no obvious macro segregation, and the macro segregation grade is ≤ grade 2; the aluminum alloy sheet for anodizing prepared above has no color difference and black stripes in the cross section after anodizing.
[0078] Comparative Example 1
[0079] The preparation method is basically the same as in Example 1, except that:
[0080] The composition of the aluminum alloy material used for anodizing in this comparative example, by mass percentage, includes: Si 0.05%, Fe 0.15%, Cu 1.49%, Mn 0.02%, Mg 2.50%, Cr 0.25%, Zn 5.40%, Ti 0.02%, with the balance being Al.
[0081] Grain refinement: AlTi5B1 wire is added online to the melt after melt purification treatment, with a grain refiner addition amount of 1.35 kg / t;
[0082] Casting process: Semi-continuous casting method is adopted, casting 4 ingots; the casting speed is set to 45mm / min, and the water flow rate is set to 185m³ / min. 3 / h, the scraper height is set to 380mm, and the temperature of the molten aluminum at the end of the flow plate is controlled at 695~705℃. During the casting process, cooling water is used for cooling; the cooling water temperature is controlled at 22~24℃.
[0083] Homogenization process: Heat the above 4 ingots to a holding temperature of 350℃, hold at this temperature for 4 hours, air cool to room temperature, and remove the head and tail to obtain the raw ingot material.
[0084] Through the above process, the low-magnification grain size of the four ingots obtained does not exceed grade 1.5, and there is no obvious macroscopic segregation on the low-magnification inspection surface, with a macroscopic segregation grade of 2. The aluminum alloy sheet prepared above for anodizing, after anodizing, exhibits color difference and black streaks in its cross-section. Figure 2 As shown.
[0085] Comparative Example 2
[0086] The preparation method is basically the same as in Example 1, except that:
[0087] Hot rolling of ingots: The ingot blanks are heated to 440°C and rolled through 10 passes with a deformation of 5~20mm per pass to obtain 7075 alloy plates with a thickness of 55mm. After hot rolling, the plates are air-cooled to room temperature.
[0088] Solution hardening: A 55mm thick 7075 alloy plate, which has been air-cooled to room temperature, is heated to 465℃ and held at this temperature for 90 minutes; after holding, it is rapidly cooled to room temperature at a cooling rate of 120℃ / min.
[0089] Artificial aging: After solution quenching, the plate is heated to the aging temperature of 150℃ and held at that temperature for 900 minutes.
[0090] Through the above process, the low-magnification grain size of the four ingots obtained does not exceed grade 1.5, and there is no obvious macroscopic segregation on the low-magnification inspection surface, with a macroscopic segregation grade ≤ grade 1. The aluminum alloy sheet prepared above for anodizing, after anodizing, exhibits color difference and black streaks in its cross-section, but the degree is slightly less than that of Comparative Example 1. Figure 3 As shown.
[0091] Comparative Example 3
[0092] The preparation method is basically the same as in Example 1, except that:
[0093] Hot rolling of ingots: The ingot blanks are heated to 380°C and rolled through 15 passes with a deformation of 5~20mm per pass to obtain 7075 alloy plates with a thickness of 55mm. After hot rolling, the plates are air-cooled to room temperature.
[0094] Solution hardening: A 55mm thick 7075 alloy plate, which has been air-cooled to room temperature, is heated to 465℃ and held at this temperature for 90 minutes; after holding, it is rapidly cooled to room temperature at a cooling rate of 360℃ / min.
[0095] Artificial aging: After solution quenching, the plate is heated to the aging temperature of 120℃ and held at that temperature for 960 minutes.
[0096] Through the above process, the low-magnification grain size of the four ingots obtained does not exceed grade 1.5, the low-magnification detection surface has no obvious macro segregation, and the macro segregation grade is ≤ grade 1; after anodizing, the aluminum alloy sheet prepared above has a slight color difference in the cross section.
[0097] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
[0098] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing an aluminum alloy material for anodizing, comprising the following steps: S1) After batching according to the composition ratio of aluminum alloy material for anodizing, the materials are smelted, then refined, degassed online, filtered online, refined online and cast to obtain aluminum alloy ingots; The composition of the aluminum alloy ingot, by mass percentage, includes: Si≤0.10%, Fe≤0.20%, Cu1.35~1.65%, Mn≤0.03%, Mg2.20~2.60%, Cr0.18~0.30%, Zn5.30~5.70%, Ti≤0.05%, Al balance; S2) The aluminum alloy ingot is subjected to homogenization treatment at a temperature of 470~480℃. S3) The aluminum alloy ingot obtained in step S2) is hot rolled at a temperature of 420~480℃, in 15~25 passes, and the deformation per pass is 5~20mm. S4) The aluminum alloy billet obtained in step S3) is subjected to solution quenching and artificial aging in sequence; the solution quenching temperature is 450~500℃, the quenching cooling rate is 100~150℃ / min, and the artificial aging temperature is 100~150℃.
2. The preparation method according to claim 1, characterized in that, In step S2), the homogenization treatment is carried out at a temperature of 470~475℃ for 20~30h.
3. The preparation method according to claim 1, characterized in that, The hot rolling temperature is 430~450℃, and / or the thickness of the hot-rolled billet is 40~60mm.
4. The preparation method according to claim 1, characterized in that, The solution treatment temperature is 470~480℃, and the time is 90~150min.
5. The preparation method according to claim 1, characterized in that, The temperature for artificial aging is 120~130℃, and the holding time is 900~930min.
6. The preparation method according to claim 1, characterized in that, The hot rolling process is followed by air cooling to room temperature.
7. The method according to any one of claims 1 to 6, characterized in that, The casting speed is 40~55 mm / min, and the water flow rate is 175~200 m³ / min. 3 / h, the wiper height is 275~400mm; and / or, the online refining agent is AlTi5B1 filament, and the addition amount is 1.5~1.9kg / t.
8. The preparation method according to claim 7, characterized in that, The thickness of the aluminum alloy material used for anodizing is 45~55mm.
9. An aluminum alloy material for anodizing, comprising, by weight percentage: Si≤0.10%, Fe≤0.20%, Cu1.35~1.65%, Mn≤0.03%, Mg2.20~2.60%, Cr0.18~0.30%, Zn5.30~5.70%, Ti≤0.05%, Al balance.
10. An anodized aluminum alloy, obtained by anodizing an aluminum alloy material, wherein the aluminum alloy material is an anodized aluminum alloy material prepared by the preparation method according to any one of claims 1 to 8 or an anodized aluminum alloy material according to claim 9.