High-Ti mirror surface aluminum plate and preparation method thereof
By optimizing the composition of aluminum alloy ingots and processing technology, the problems of white lines and pits in the production of mirror aluminum sheets were solved, achieving high gloss and high yield of high-Ti mirror aluminum sheets.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINALCO HENAN LUOYANG ALUMINUM FABRICATION CO LTD
- Filing Date
- 2026-02-10
- Publication Date
- 2026-05-12
AI Technical Summary
In existing technologies, mirror-finish aluminum sheets are prone to defects such as white lines and pits during the production process, resulting in low yield and difficulty in meeting the requirements of high gloss and surface aesthetics.
By optimizing the composition and processing technology of aluminum alloy ingots, including homogenization heat treatment, low hot rolling temperature, omitting intermediate annealing process, controlling cold rolling deformation and mirror rolling, combined with anodizing treatment, high-Ti mirror aluminum sheets are prepared.
It effectively reduces the white line rate, improves the yield rate, ensures the surface gloss and aesthetics of aluminum sheets, eliminates pit defects, and achieves a high gloss and material texture-free effect.
Smart Images
Figure CN122013008A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aluminum alloy processing technology, specifically to a high-Ti mirror aluminum sheet and its preparation method. Background Technology
[0002] As consumers increasingly demand higher aesthetic appeal from product packaging, mirror-finish aluminum is finding wider application due to its superior surface gloss and metallic texture. Cosmetic packaging, in particular, has extremely high requirements for surface aesthetics, demanding a gloss level of 650 GU or higher, and the absence of white lines and material textures. Furthermore, to reduce production costs and minimize mechanical polishing processes, the surface of mirror-finish aluminum must be free of pits and defects.
[0003] In the existing technology, after hot rolling and intermediate annealing, the surface hardness of mirror aluminum decreases due to softening at high temperature. In the subsequent cold rolling stage, aluminum sticking to the rolls is very likely to occur, which makes it easy for tiny pits to form on the surface of the aluminum plate. These pits are difficult to completely eliminate in subsequent processing and are eventually inherited to the surface of the finished product. At the same time, inclusions in the ingot, such as high Ti content, may increase the white line and result in a low yield. Summary of the Invention
[0004] To address the issue of high white line ratio in aluminum plates in existing technologies, this invention provides a high-Ti mirror aluminum plate and its preparation method, which reduces the white line ratio of aluminum plates and improves the yield of aluminum plates.
[0005] To achieve the above objectives, the specific solution adopted by the present invention is as follows: a high-Ti mirror aluminum sheet, composed of the following components by mass percentage: Mg: <0.01%, Fe: 0.05~0.1%, Cu: 0.05~0.1%, Si: <0.05%, Ti: 0.02~0.05%, impurity elements ≤0.04%, and the remainder being Al.
[0006] As an optimized solution for the above-mentioned high-Ti mirror aluminum sheet, the composition is: Mg: 0.001%, Fe: 0.07%, Cu: 0.07%, Si: 0.004%, Ti: 0.03%, impurity elements ≤ 0.04%, and the remainder is Al.
[0007] A method for preparing high-Ti mirror-finish aluminum sheet involves first obtaining an aluminum alloy ingot through melting and semi-continuous casting, then sequentially subjecting the aluminum alloy ingot to homogenization heat treatment, hot rolling, cold rolling, and mirror rolling to obtain an aluminum sheet. The composition of the aluminum alloy ingot is the same as that of the aluminum sheet. Furthermore, the aluminum alloy ingot undergoes homogenization heat treatment by holding it at 580-610℃ for 4-8 hours.
[0008] As an optimized method for preparing the above-mentioned high-Ti mirror aluminum sheet: in the hot rolling process, the initial rolling temperature is 460-520℃ and the final rolling temperature is 220-250℃.
[0009] As another optimized solution for the above-mentioned method of preparing high-Ti mirror aluminum sheet: in the hot rolling process, the thickness of the hot-rolled sheet is 3-5mm.
[0010] As another optimized method for preparing the above-mentioned high-Ti mirror aluminum sheet, the number of rolling passes in the hot rolling process is 13 to 17.
[0011] As another optimized solution for the above-mentioned method of preparing high-Ti mirror aluminum sheet: in the cold rolling process, the number of rolling passes is 5 to 8, and the total cold rolling deformation is 60 to 80%.
[0012] As another optimized solution for the above-mentioned method of preparing high-Ti mirror aluminum sheet: in mirror rolling, the rolling passes are 3-5, and the deformation amount per pass is ≤10%.
[0013] As an alternative optimization of the above-mentioned method for preparing high-Ti mirror aluminum sheet, the aluminum sheet is anodized after mirror rolling.
[0014] As an alternative optimization of the above-mentioned method for preparing high-Ti mirror aluminum sheet: during the anodizing process, an H2SO4 solution of 180~220g / L is used to generate an oxide film with a thickness of 3~5um on the surface of the aluminum sheet.
[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a high-Ti mirror-finish aluminum sheet and its preparation method. During the homogenization treatment of the aluminum alloy ingot, the Fe phase is fully dissolved, reducing the aggregation of large-sized second phases generated during semi-continuous casting. Holding at 580-610℃ for 4-8 hours allows the second phase to fully dissolve and disperse, preventing the large-sized second phase from breaking down and being inherited by the product, thus avoiding the formation of white lines after anodizing. The white line rate is reduced to 3±1%. Simultaneously, this invention's preparation method prevents excessive grain growth that could lead to grain size inhomogeneity. The high Ti content combined with homogenization treatment at 580-610℃ ensures that the aluminum alloy ingot maintains a uniform grain size after homogenization.
[0016] 2. In this invention, a low hot rolling temperature is used and the intermediate annealing process is omitted. The final hot rolling temperature is above the recrystallization temperature to prevent recrystallization and softening. Combined with the omission of the intermediate annealing process, the generation of aluminum adhesion is eliminated, and the pit defects on the surface of the aluminum sheet are eliminated. Attached Figure Description
[0017] Figure 1This is a grain diagram of the finished product from Example 1.
[0018] Figure 2 This is a diagram of the cube texture of the aluminum sheet in Example 1.
[0019] Figure 3 This is a grain diagram of the finished product from Comparative Example 1.
[0020] Figure 4 This is a diagram of the cube texture of the aluminum sheet in Comparative Example 1. Detailed Implementation
[0021] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art.
[0022] A method for preparing high-Ti mirror-finish aluminum sheet involves first obtaining an aluminum alloy ingot through smelting and semi-continuous casting. Then, the aluminum alloy ingot is sequentially subjected to homogenization heat treatment, hot rolling, cold rolling, and mirror rolling to obtain the aluminum sheet. The composition of the aluminum alloy ingot, by mass percentage, is: Mg: <0.01%, Fe: 0.05~0.1%, Cu: 0.05~0.1%, Si: <0.05%, Ti: 0.02~0.05%, impurity elements ≤0.04%, and the remainder being Al. The aluminum alloy ingot undergoes homogenization heat treatment at 580-610℃ for 4-8 hours. The specific steps include: Melting and semi-continuous casting: Melting temperature is 800℃, semi-continuous casting temperature is 750-780℃, and casting speed is 45~53mm / min.
[0023] Homogenization heat treatment: After the aluminum alloy ingot is trimmed at both ends, it is held at 580-610℃ for 4-8 hours. The mass fraction of Ti is controlled at 0.02-0.05%, and a relatively high homogenization temperature is used to fully dissolve the Fe phase, thereby reducing the aggregation of large-sized second phases generated during semi-continuous casting. The high-temperature homogenization treatment fully dissolves and disperses the second phase, preventing large-sized second phases from breaking down and being inherited by the finished product, which would lead to white lines after anodizing. At the same time, Ti is added to the alloy as a grain refiner, acting as a grain boundary pinning agent during the homogenization treatment to prevent grain growth and ensure that the aluminum alloy ingot maintains a uniform grain size after the high-temperature homogenization treatment.
[0024] Hot rolling: The initial rolling temperature is 460-520℃, the final rolling temperature is 220-250℃, the rolling passes are 13-17, and the hot-rolled plate thickness is 3-5mm. This invention adopts a low hot final rolling temperature and a small hot-rolled plate thickness, that is, the hot final rolling temperature is much lower than the recrystallization temperature, which prevents recrystallization softening and fundamentally eliminates the generation of aluminum adhesion and surface pits; at the same time, it reduces the total cold rolling deformation and realizes direct cold rolling to the finished thickness, avoiding rolling difficulties caused by work hardening during the cold rolling process.
[0025] Cold rolling: 5 to 8 rolling passes, with a total cold rolling deformation of 60-80%.
[0026] Mirror rolling: The rolling process consists of 3-5 passes, with a deformation of ≤10% per pass, until the finished thickness is reached to obtain an aluminum sheet.
[0027] After mirror rolling, the aluminum sheet is machined and then anodized. The anodizing process is as follows: alkaline washing, neutralization, electrochemical polishing, anodizing, and sealing. The anodizing process uses a 180~220g / L H2SO4 solution to generate an oxide film with a thickness of 3~5um.
[0028] The aluminum sheet prepared using the above method has no pitting defects on its surface, an average grain size of 90~130µm, a cube texture ratio of 0.2~2%, a gloss level ≥700GU, tensile strength >145MPa, yield strength >130MPa, and elongation ≥6%. After anodizing, the maximum valley depth Rv on the surface is ≤0.2µm. The white line rate on the surface is ≤3±1%, and there are no material streaks. Example 1
[0029] A method for preparing a high-Ti mirror-finish aluminum sheet, wherein the aluminum sheet comprises, by mass percentage: Mg: 0.001%, Fe: 0.05%, Cu: 0.05%, Si: 0.003%, Ti: 0.03%, impurity elements 0.04%, and the remainder being Al. The method includes the following steps: Melting and semi-continuous casting: Melting temperature is 800℃, semi-continuous casting temperature is 760℃, and casting speed is 45mm / min.
[0030] Homogenization heat treatment: After the aluminum alloy ingot is cut off at both ends, it is held at 580℃ for 4 hours.
[0031] Hot rolling: The initial rolling temperature is 460℃, the final rolling temperature is 220℃, the rolling passes are 15, and the thickness of the hot-rolled plate is 3mm.
[0032] Cold rolling: 8 rolling passes, total cold rolling deformation is 80%.
[0033] Mirror rolling: The rolling process consists of 3 passes, with a deformation of 9% per pass, until the finished thickness is achieved, resulting in an aluminum sheet.
[0034] After mirror rolling, the aluminum sheet is machined and then anodized. The anodizing process uses a 180g / L H2SO4 solution to generate an oxide film with a thickness of 3~5um.
[0035] The properties of the aluminum sheets prepared by the above method are shown in Table 1. Example 2
[0036] A method for preparing a high-Ti mirror-finish aluminum sheet, wherein the aluminum sheet comprises, by mass percentage: Mg: 0.001%, Fe: 0.01%, Cu: 0.1%, Si: 0.004%, Ti: 0.02%, impurity elements 0.02%, and the remainder being Al. The method includes the following steps: Melting and semi-continuous casting: The melting temperature is 800℃, and the semi-continuous casting temperature is 780℃.
[0037] Homogenization heat treatment: After the aluminum alloy ingot is cut off, it is held at 610℃ for 8 hours.
[0038] Hot rolling: The initial rolling temperature is 520℃, the final rolling temperature is 250℃, the rolling passes are 17, and the thickness of the hot-rolled plate is 5mm.
[0039] Cold rolling: 5 rolling passes, 60% total cold rolling deformation.
[0040] Mirror rolling: The rolling process consists of 3 passes, with a deformation of 8% per pass, until the finished thickness is achieved, resulting in an aluminum sheet.
[0041] After mirror rolling, the aluminum sheet is machined and then anodized using a 220g / L H2SO4 solution to generate an oxide film with a thickness of 3µm.
[0042] The properties of the aluminum sheets prepared by the above method are shown in Table 1. Example 3
[0043] A method for preparing a high-Ti mirror-finish aluminum sheet, wherein the aluminum sheet comprises, by mass percentage: Mg: 0.001%, Fe: 0.1%, Cu: 0.1%, Si: 0.004%, Ti: 0.05%, impurity elements 0.02%, and the remainder being Al. The method includes the following steps: Melting and semi-continuous casting: Melting temperature is 800℃, semi-continuous casting temperature is 780℃, and casting speed is 50mm / min.
[0044] Homogenization heat treatment: After the aluminum alloy ingot is cut off at both ends, it is held at 600℃ for 6 hours.
[0045] Hot rolling: The initial rolling temperature is 480℃, the final rolling temperature is 240℃, the rolling passes are 13, and the thickness of the hot-rolled plate is 4mm.
[0046] Cold rolling: 6 rolling passes, total cold rolling deformation is 70%.
[0047] Mirror rolling: In mirror rolling, there are 3 rolling passes, with a deformation of 8% per pass, until the finished thickness is reached to obtain aluminum sheet.
[0048] After mirror rolling, the aluminum sheet is machined and then anodized using a 200g / L H2SO4 solution, resulting in an oxide film thickness of 5μm.
[0049] The properties of the aluminum sheets prepared by the above method are shown in Table 1. Example 4
[0050] A method for preparing a high-Ti mirror-finish aluminum sheet, wherein the aluminum sheet comprises, by mass percentage: Mg: 0.001%, Fe: 0.03%, Cu: 0.03%, Si: 0.004%, Ti: 0.04%, impurity elements 0.02%, and the remainder being Al. The method includes the following steps: Melting and semi-continuous casting: Melting temperature is 800℃, semi-continuous casting temperature is 780℃, and casting speed is 50mm / min.
[0051] Homogenization heat treatment: After the aluminum alloy ingot is cut off at both ends, it is held at 580℃ for 4 hours.
[0052] Hot rolling: The initial rolling temperature is 460℃, the final rolling temperature is 250℃, the rolling passes are 14, and the thickness of the hot-rolled plate is 5mm.
[0053] Cold rolling: 7 rolling passes, 70% total cold rolling deformation.
[0054] Mirror rolling: In mirror rolling, there are 4 rolling passes, with a deformation of 8% per pass, until the finished thickness is reached to obtain aluminum sheet.
[0055] After mirror rolling, the aluminum sheet is machined and then anodized using a 200g / L H2SO4 solution, resulting in an oxide film thickness of 3μm.
[0056] Comparative Example 1 The comparative example was prepared using the same method as Example 3, except that the aluminum alloy ingot was subjected to homogenization heat treatment at 480°C for 6 hours after the ends were cut off. The properties of the aluminum sheet prepared using the above method are shown in Table 1.
[0057] Comparative Example 2 The comparative example was prepared using the same method as Example 3, except that the aluminum sheet composition by mass percentage was: Mg: 0.001%, Fe: 0.1%, Cu: 0.1%, Si: 0.004%, Ti: 0.01%, impurity elements 0.02%, and the remainder being Al. The properties of the aluminum sheet prepared using the above method are shown in Table 1.
[0058] Comparative Example 3 The comparative example was prepared using the same method as Example 3, except that: after the aluminum alloy ingot was trimmed, it was subjected to homogenization heat treatment at 480°C for 6 hours; after cold rolling, it was subjected to intermediate annealing at 320°C for 2 hours. The properties of the aluminum sheet prepared using the above method are shown in Table 1.
[0059] Table 1 Properties of Aluminum Sheets 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 high-Ti mirror-finish aluminum sheet, characterized in that: It is composed of the following components by mass percentage: Mg: <0.01%, Fe: 0.05~0.1%, Cu: 0.05~0.1%, Si: <0.05%, Ti: 0.02~0.05%, impurity elements ≤0.04%, and the remainder is Al.
2. A high-Ti mirror-finish aluminum sheet, characterized in that: The components are: Mg: 0.001%, Fe: 0.07%, Cu: 0.07%, Si: 0.004%, Ti: 0.03%, impurity elements ≤0.04%, the remainder is Al.
3. A method for preparing high-Ti mirror-finish aluminum sheet, comprising first obtaining an aluminum alloy ingot through smelting and semi-continuous casting, and then sequentially subjecting the aluminum alloy ingot to homogenization heat treatment, hot rolling, cold rolling, and mirror rolling to obtain an aluminum sheet, characterized in that: The composition of the aluminum alloy ingot is the same as that of the aluminum sheet described in claim 1; and the aluminum alloy ingot is subjected to homogenization heat treatment at 580-610℃ for 4-8 hours.
4. The method for preparing a high-Ti mirror-finish aluminum sheet as described in claim 3, characterized in that: In the hot rolling process, the initial rolling temperature is 460-520℃, and the final rolling temperature is 220-250℃.
5. The method for preparing a high-Ti mirror-finish aluminum sheet as described in claim 3, characterized in that: In the hot rolling process, the thickness of the hot-rolled plate is 3-5mm.
6. The method for preparing a high-Ti mirror-finish aluminum sheet as described in claim 3, characterized in that: In the hot rolling process, the number of rolling passes is 13 to 17.
7. The method for preparing a high-Ti mirror-finish aluminum sheet as described in claim 3, characterized in that: In the cold rolling process, the number of rolling passes is 5 to 8, and the total cold rolling deformation is 60-80%.
8. The method for preparing a high-Ti mirror-finish aluminum sheet as described in claim 3, characterized in that: In mirror rolling, the rolling passes are 3-5, and the deformation amount per pass is ≤10%.
9. The method for preparing a high-Ti mirror-finish aluminum sheet as described in claim 3, characterized in that: After mirror rolling, the aluminum sheet undergoes anodizing treatment.
10. The method for preparing a high-Ti mirror-finish aluminum sheet as described in claim 9, characterized in that: During the anodizing process, an H2SO4 solution of 180~220g / L is used to generate an oxide film with a thickness of 3~5um on the surface of the aluminum plate.