Al-fe-ni-cu alloy, method for producing the same, and optical mirror

Abstract

This invention provides an Al-Fe-Ni-Cu alloy, its preparation method, and an optical reflector, relating to the field of aluminum alloy technology. The preparation method includes: Step S1, mixing the metal raw materials of the Al-Fe-Ni-Cu alloy according to a specified ratio, followed by sequential melting and casting to obtain an alloy ingot; Step S2, performing melt spinning on the ingot to obtain an alloy strip; Step S3, sequentially subjecting the alloy strip to crushing and vacuum hot pressing to obtain the Al-Fe-Ni-Cu alloy; wherein the temperature of the vacuum hot pressing is 350~600℃. The alloy obtained by this method possesses characteristics such as high elastic modulus, low coefficient of thermal expansion, and excellent structural stability, and can be applied in high-end fields such as aerospace telescopes, high-precision radar reflectors for defense, and optical components for semiconductor lithography equipment.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy technology, and more specifically, to an Al-Fe-Ni-Cu alloy, its preparation method, and an optical reflector. Background Technology

[0002] As a core component in aerospace and defense, optical mirrors need to operate for extended periods in complex environments with extreme temperature variations and strong radiation. In addition to excellent optical performance, they must also meet requirements for high elastic modulus, low coefficient of thermal expansion, and excellent structural stability. These properties directly guarantee the imaging accuracy and long-term reliability of the optical system.

[0003] Currently, materials used in optical mirrors are mainly divided into two categories: inorganic non-metallic materials and metallic materials. Among them, inorganic non-metallic materials such as SiC ceramics and fused silica have the advantages of low expansion and high stiffness, but they also have problems such as high processing difficulty, high brittleness, and high cost of forming complex structures, making them difficult to meet the requirements of precision optical devices for lightweight and complex configurations. In contrast, metallic materials, with their good plasticity and CNC milling adaptability, can efficiently realize the processing of irregular mirror structures, thus becoming an important choice for high-end optical mirrors.

[0004] Among various metallic materials, aluminum alloys exhibit irreplaceable potential in the field of optical mirror manufacturing due to their low density, excellent corrosion resistance, and relatively controllable cost. However, the traditional wrought aluminum alloys such as the 5 and 6 series, which are the mainstream materials used in China, can achieve a mirror effect with a surface reflectivity of ≥90% even after post-processing such as precision grinding, magnetic flux polishing, and ion beam coating. However, due to the inherent microstructural defects of the material itself, they are prone to thermal deformation and structural aging under extreme environments, leading to a decrease in mirror accuracy and failing to meet the long-term stability requirements of modern high-precision optical systems. For example, 5xxx series optical aluminum alloys are prone to coarse grain size during the manufacturing process. Coarse grains not only cause grain boundary scattering and uneven surface texture, resulting in uneven brightness of reflected light spots and a decrease in surface accuracy, but also generate internal micro-stress due to the anisotropic thermal expansion of grains under extreme temperature differences in aerospace environments. This leads to irregular warping of the mirror surface, seriously affecting the imaging accuracy and long-term service reliability of the optical system.

[0005] 6xxx series optical aluminum alloys, taking 6061 as an example, have an elastic modulus of only 69 GPa and a coefficient of thermal expansion of 23.6 × 10⁻⁶. -6 / ℃ (-50~200℃), with a high-temperature strength of ≤140MPa at 200℃, and a mirror finish accuracy decrease of ≥0.5μm after extreme temperature cycling. Furthermore, its thermal conductivity and hardness are difficult to adapt to complex service environments. In terms of manufacturing processes, the high-temperature melting and casting + hot / cold rolling process results in coarse grains and a high Fe content, easily forming brittle phases. Multiple post-processing steps are required to achieve a high-precision mirror finish, with post-processing costs accounting for over 30%. Regarding microstructure uniformity, 6xxx series aluminum alloys exhibit mixed grain sizes, significant compositional deviations, and a high internal defect rate. Long-term use leads to high grain growth, further exacerbating the accuracy degradation. While existing technologies attempt to optimize the performance of 6xxx series aluminum alloys through microcrystalline preparation, they often focus on improving single indicators or surface modification, failing to achieve a synergistic effect of high elastic modulus, low thermal expansion, and high thermal conductivity. These methods also suffer from complex processes, high costs, and uneven internal microstructure gradients, failing to overcome the core limitations of traditional materials.

[0006] In summary, in order to overcome the performance bottleneck of traditional wrought aluminum alloys in extreme environments and meet the core requirements of high-precision optical systems in the aerospace and defense fields for lightweight, high rigidity, and stability in extreme environments, the development of new microcrystalline aluminum alloy materials is urgently needed. Summary of the Invention

[0007] The main objective of this invention is to provide an Al-Fe-Ni-Cu alloy, its preparation method, and an optical mirror, in order to solve the problems of low elastic modulus and high coefficient of thermal expansion of aluminum alloy materials used in optical mirrors in the prior art.

[0008] To achieve the above objectives, according to one aspect of the present invention, a method for preparing an Al-Fe-Ni-Cu alloy is provided, the method comprising: step S1, mixing the metal raw materials of the Al-Fe-Ni-Cu alloy according to a formula and then sequentially melting and casting to obtain an alloy ingot; step S2, performing melt spinning on the ingot to obtain an alloy strip; and step S3, sequentially performing crushing and vacuum hot pressing on the alloy strip to obtain an Al-Fe-Ni-Cu alloy; wherein the temperature of the vacuum hot pressing is 350~600℃.

[0009] Furthermore, a cooling roller is used to cool the melt during melt spinning. The linear speed of the cooling roller is 10~60m / s, the flow rate of the cooling water in the cooling roller is 1000~4000L / h, and the temperature of the cooling water is 0~30℃.

[0010] Furthermore, the temperature of the vacuum hot pressing treatment is 400~550℃; and / or, the pressure of the vacuum hot pressing treatment is 20~250MPa; and / or, the heat preservation and pressure holding time of the vacuum hot pressing treatment is 5~120min.

[0011] Furthermore, the particle size of the crushed alloy powder is less than 5 mm.

[0012] Furthermore, the temperature of the melt in melt spinning is 700~950℃; and / or, the extrusion speed of the melt in melt spinning is 10~50m / s.

[0013] Furthermore, the thickness of the alloy strip is 20~500μm; and / or, the width of the alloy strip is 5~40mm.

[0014] Furthermore, the melting temperature is 700~950℃.

[0015] Furthermore, by mass percentage, the alloy ingot comprises the following elements: Fe content of 1.0~5.0%, Ni content of 2.0~7.0%, Cu content of 1.0~5.0%, Mn content of 0.5~1.5%, Mg content of 0.2~1.0%, Ti content of 0.2~1.0%, Zr content of 0.2~1.0%, unavoidable total impurity content ≤0.1%, single impurity content less than 0.05%, and the balance being Al.

[0016] In another aspect, the present invention provides an Al-Fe-Ni-Cu alloy, which is prepared by the aforementioned method for preparing Al-Fe-Ni-Cu alloys.

[0017] Furthermore, the Al-Fe-Ni-Cu alloys possess an equiaxed microstructure; and / or, the average grain size of the Al-Fe-Ni-Cu alloys is ≤10 μm; and / or, the average grain size of the second phase particles in the Al-Fe-Ni-Cu alloys is ≤6 μm; and / or, the density of the Al-Fe-Ni-Cu alloys is 2.80~3.10 g·cm³. -3 The yield strength of the Al-Fe-Ni-Cu alloy is 350~500MPa; the tensile strength of the Al-Fe-Ni-Cu alloy is 450~600MPa; the elongation after fracture of the Al-Fe-Ni-Cu alloy is 0.5~8.0%; the elastic modulus of the Al-Fe-Ni-Cu alloy is 75~95GPa; and the coefficient of thermal expansion of the Al-Fe-Ni-Cu alloy is 16.0~20.0℃.

[0018] In another aspect, the present invention provides an optical mirror whose material includes the aforementioned Al-Fe-Ni-Cu alloy.

[0019] Applying the technical solution of this invention, the melt spinning in this application utilizes the principle of rapid solidification to cool the alloy melt at a high speed, promoting rapid solidification and refinement of the grains and improving the uniformity of grain size. The fine and uniform grain structure helps improve the mechanical properties of the alloy and can reduce the coefficient of thermal expansion to a certain extent. It also helps improve the structural uniformity and thermal stability of the alloy. Furthermore, the high-modulus, low-thermal-expansion-coefficient second-phase particles can further improve the elastic modulus of the alloy and reduce the overall coefficient of thermal expansion. The crushing process transforms the alloy strip obtained from spinning into a powder state suitable for hot pressing, further promoting the homogeneity of the material. Subsequent vacuum hot pressing achieves high densification of the alloy powder. During this process, controlling the temperature of the vacuum hot pressing treatment to 350~600℃ helps to promote the rearrangement and bonding of the alloy powder, eliminating internal porosity and improving the density and compactness of the alloy. Through the synergistic effect of melt spinning, crushing, and vacuum hot pressing, this application enables the alloy to form a fine and uniform grain structure and dispersed second-phase particles, effectively improving the elastic modulus, thermal stability, and optical compatibility of the alloy. The resulting alloy possesses characteristics such as high elastic modulus, low coefficient of thermal expansion, excellent structural stability, and good processing performance, and can be applied in high-end fields such as aerospace space telescopes, high-precision radar reflectors for national defense, and optical components for semiconductor lithography equipment. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 EBSD diagrams of the Al-Fe-Ni-Cu alloy microstructure in Example 1 of this application are shown;

[0022] Figure 2 The image shows a SEM image of the second-phase particles in the Al-Fe-Ni-Cu alloy of Example 1 of this application. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Terminology explanation: Second phase particles refer to the small particulate phases that exist dispersedly in an alloy, excluding the matrix phase.

[0025] As analyzed in the background section of this application, aluminum alloy materials used in optical mirrors in the prior art have the problems of low elastic modulus and high coefficient of thermal expansion. In order to solve the above problems, this application provides an Al-Fe-Ni-Cu alloy, its preparation method and an optical mirror.

[0026] In a typical embodiment of this application, a method for preparing an Al-Fe-Ni-Cu alloy is provided. The method includes: step S1, mixing the metal raw materials of the Al-Fe-Ni-Cu alloy according to the formula and then melting and casting them sequentially to obtain an alloy ingot; step S2, performing melt spinning on the ingot to obtain an alloy strip; step S3, performing crushing and vacuum hot pressing on the alloy strip sequentially to obtain the Al-Fe-Ni-Cu alloy; wherein the temperature of the vacuum hot pressing is 350~600℃.

[0027] The melt spinning process in this application utilizes the principle of rapid solidification, cooling the alloy melt at a high rate to promote rapid solidification and refinement of the grains, thereby improving the uniformity of grain size. The fine and uniform grain structure helps improve the mechanical properties of the alloy and can reduce the coefficient of thermal expansion to a certain extent. It also improves the structural uniformity and thermal stability of the alloy. Furthermore, the high-modulus, low-thermal-expansion-coefficient second-phase particles further enhance the elastic modulus of the alloy and reduce the overall coefficient of thermal expansion. The crushing process transforms the spun alloy strip into a powder state suitable for hot pressing, further promoting the homogeneity of the material. Subsequent vacuum hot pressing achieves high densification of the alloy powder. During this process, controlling the vacuum hot pressing temperature at 350~600℃ helps to promote the rearrangement and bonding of the alloy powder, eliminating internal porosity and increasing the density and compactness of the alloy. Through the synergistic effect of melt spinning, crushing, and vacuum hot pressing, this application enables the alloy to form a fine and uniform grain structure and dispersed second-phase particles, effectively improving the elastic modulus, thermal stability, and optical compatibility of the alloy. The resulting alloy possesses characteristics such as high elastic modulus, low coefficient of thermal expansion, excellent structural stability, and good processing performance, and can be applied in high-end fields such as aerospace space telescopes, high-precision radar reflectors for national defense, and optical components for semiconductor lithography equipment.

[0028] In some embodiments of this application, the average cooling rate of the melt in melt spinning is 10. 4 ~10 6 K / s.

[0029] Controlling the cooling rate of the melt in melt spinning within the above range helps to further refine the grains and improve the uniformity of the second phase particle distribution, reduce macroscopic segregation of the alloy, improve the surface quality of the alloy, and thus help to improve the elastic modulus of the alloy and reduce the coefficient of thermal expansion.

[0030] In some embodiments of this application, a cooling roller is used to cool the melt in melt spinning. The rotational linear speed of the cooling roller is 10~60m / s, specifically 10m / s, 20m / s, 30m / s, 40m / s, 50m / s, 60m / s, or any value between two of these. The flow rate of cooling water in the cooling roller is 1000~4000L / h, and the temperature of the cooling water is 0~30℃.

[0031] Controlling the linear speed of the cooling roller, the flow rate of the cooling water in the cooling roller, and the temperature of the cooling water within the above-mentioned range helps to control the cooling rate of the melt in melt spinning within a suitable range, thereby helping to further improve the elastic modulus of the alloy and reduce the coefficient of thermal expansion.

[0032] In some embodiments of this application, the temperature of the vacuum hot pressing treatment is 400~550℃, specifically 400℃, 420℃, 450℃, 480℃, 500℃, 520℃, 550℃, and any range between two values; and / or, the pressure of the vacuum hot pressing treatment is 20~250MPa, specifically 20MPa, 50MPa, 80MPa, 100MPa, 120MPa, 150MPa, 180MPa, 200MPa, 220MPa, 250MPa, and any range between two values; and / or, the heat preservation and pressure holding time of the vacuum hot pressing treatment is 5~120min, specifically 5min, 10min, 30min, 60min, 120min, and any range between two values.

[0033] Controlling the temperature of vacuum hot pressing within the aforementioned range helps increase the diffusion capacity of metal atoms, eliminates interfaces between alloy powders, and promotes material densification. Simultaneously, appropriate temperatures can activate the recrystallization process, allowing grains to rearrange under stress-free conditions, forming a more uniform microstructure. It also helps suppress the abnormal growth of second-phase particles, maintaining their small size, thereby further improving the alloy's elastic modulus and reducing its coefficient of thermal expansion. Controlling the pressure of vacuum hot pressing within the aforementioned range helps increase the density of the powder material, eliminates internal porosity, promotes the full diffusion of alloying elements and the formation of a continuous and uniform alloy phase, helps refine the grain structure, resulting in a more uniform and compact internal structure and enhanced overall material performance. Controlling the holding time of vacuum hot pressing within the aforementioned range helps increase the alloy's density while reducing grain size increase.

[0034] In some embodiments of this application, the vacuum degree of the vacuum hot pressing process is less than 20 Pa.

[0035] Controlling the vacuum level in vacuum hot pressing within the aforementioned range helps reduce gas inclusions and oxidation, thereby promoting material densification and enhancing the microstructure stability of the alloy. Simultaneously, reducing porosity and oxide inclusions also helps decrease heat scattering during heat transfer and makes thermal expansion behavior more stable.

[0036] In some embodiments of this application, the particle size of the crushed alloy powder is less than 5 mm.

[0037] Controlling the particle size of the alloy powder during the crushing process within the above-mentioned range helps to provide a larger specific surface area, accelerates the contact and fusion between particles, helps to form fine and uniform equiaxed grains, reduces dead zones in the filling space, and thus helps to further improve the high elastic modulus of the alloy and reduce the coefficient of thermal expansion.

[0038] In some embodiments of this application, the temperature of the melt in melt spinning is 700~950°C; and / or, the extrusion speed of the melt in melt spinning is 10~50m / s.

[0039] Controlling the temperature and extrusion speed of the melt during melt spinning within the aforementioned range helps to give the melt better fluidity. When the melt is cooled rapidly, the good fluidity at the high melt temperature helps to form finer grains and promotes the formation of second-phase particles, thereby helping to improve the mechanical properties of the alloy.

[0040] In some embodiments of this application, the thickness of the alloy strip is 20~500μm; and / or, the width of the alloy strip is 5~40mm.

[0041] Controlling the thickness and width of the alloy strip within the aforementioned range helps the alloy melt dissipate heat rapidly upon contact with the cooling rollers during melt spinning, resulting in an ultra-fast cooling rate. This rapid cooling helps suppress grain growth, thereby obtaining a fine equiaxed grain structure, and also helps promote the uniform distribution of alloying elements within the grains, avoiding the compositional segregation phenomenon commonly found in coarse grain structures.

[0042] In some embodiments of this application, the melting temperature is 700~950°C.

[0043] Controlling the melting temperature within the above range helps promote the uniform distribution of elements in the molten state and reduces oxidation and impurity formation.

[0044] In some embodiments of this application, the alloy ingot comprises the following elements by mass percentage: Fe content of 1.0~5.0%, Ni content of 2.0~7.0%, Cu content of 1.0~5.0%, Mn content of 0.5~1.5%, Mg content of 0.2~1.0%, Ti content of 0.2~1.0%, Zr content of 0.2~1.0%, unavoidable total impurity content ≤0.1%, single impurity content less than 0.05%, and the balance being Al.

[0045] Fe, Ni, and Cu are the main elements forming strengthening phases. Their presence promotes the formation of fine and dispersed intermetallic compounds within the alloy, helping to inhibit dislocation movement and improve the alloy's hardness and strength. The addition of Mn, Mg, Ti, and Zr to the alloy helps promote the formation of grain refiners, such as Al-Mn and Al-Zr compounds, which limit grain growth through grain boundary pinning mechanisms. Controlling the element content in the alloy ingot within the aforementioned ranges helps to enhance the synergistic effect between the elements, thereby contributing to an increase in the alloy's elastic modulus and a decrease in its coefficient of thermal expansion.

[0046] In another typical embodiment of this application, an Al-Fe-Ni-Cu alloy is provided, which is prepared by the aforementioned Al-Fe-Ni-Cu alloy preparation method.

[0047] Since the Al-Fe-Ni-Cu alloy described above is prepared using the preparation method of this application, it has fine and uniform grains, which makes the alloy have high elastic modulus, low coefficient of thermal expansion, excellent structural stability and good processing performance. It is suitable for high-end applications such as space telescopes in the aerospace field, high-precision radar reflectors in the defense field, and optical components of lithography equipment in the semiconductor field.

[0048] In some embodiments of this application, the Al-Fe-Ni-Cu alloy has an equiaxed crystal microstructure; and / or, the average grain size of the Al-Fe-Ni-Cu alloy is ≤10 μm; and / or, the average grain size of the second phase particles in the Al-Fe-Ni-Cu alloy is ≤6 μm; and / or, the density of the Al-Fe-Ni-Cu alloy is 2.80~3.10 g·cm³. -3The yield strength of the Al-Fe-Ni-Cu alloy is 350~500MPa; the tensile strength of the Al-Fe-Ni-Cu alloy is 450~600MPa; the elongation after fracture of the Al-Fe-Ni-Cu alloy is 0.5~8.0%; the elastic modulus of the Al-Fe-Ni-Cu alloy is 75~95GPa; and the coefficient of thermal expansion of the Al-Fe-Ni-Cu alloy is 16.0~20.0℃.

[0049] Al-Fe-Ni-Cu alloys with the above performance parameters are better able to meet the application requirements of high-precision optical mirrors in extreme environments.

[0050] In another typical embodiment of this application, an optical reflector is provided, the material of which includes the aforementioned Al-Fe-Ni-Cu alloy.

[0051] Since the material of the aforementioned optical reflector includes the Al-Fe-Ni-Cu alloy of this application, the optical reflector can operate for a long time in complex environments such as extreme temperature changes and strong radiation.

[0052] In some embodiments of this application, the root mean square roughness of the surface of the optical mirror is 0.5~8.0 nm.

[0053] In some embodiments of this application, the method for preparing the optical mirror includes performing single-point diamond precision turning and precision polishing on an Al-Fe-Ni-Cu alloy to obtain the optical mirror.

[0054] The alloy is precision turned and polished with single-point diamond to obtain an optical mirror, which can meet the requirements of high-precision optical structural components and is suitable for high-end fields such as aerospace space telescopes, high-precision radar mirrors for national defense, and optical components for semiconductor lithography equipment.

[0055] The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0056] Example 1

[0057] Weigh pure aluminum, aluminum-iron master alloy, aluminum-nickel master alloy, aluminum-copper master alloy, aluminum-manganese master alloy, aluminum-magnesium master alloy, aluminum-titanium master alloy, and aluminum-zirconium master alloy raw materials according to the composition ratio and burn-off amount, and mix them evenly. Place the mixed raw materials in a melting equipment and melt them at a melting temperature of 750℃ to obtain an alloy melt. After casting and cooling, an alloy ingot is formed. By mass percentage, the alloy ingot contains the following elements: Fe content of 2.5%, Ni content of 5.0%, Cu content of 2.5%, Mn content of 1.0%, Mg content of 0.6%, Ti content of 0.6%, Zr content of 0.8%, unavoidable total impurity content ≤0.1%, single impurity content of less than 0.05%, and the balance is Al. The alloy ingot was fed into a planar flow casting machine for melt spinning, heated to 800℃ for remelting, and argon gas was introduced during the melting process to provide a protective atmosphere and prevent oxidation. The rotational linear speed of the copper cooling roller was set to 30 m / s, the flow rate of cooling water in the cooling roller was 2000 L / h, the temperature of the cooling water was 20℃, and the average cooling rate of the melt was 5.0 × 10⁻⁶ m / s. 5 With a melt extrusion speed of 15 m / s, an alloy strip with a thickness of 100 μm and a width of 20 mm was prepared. The alloy strip was crushed and screened to obtain alloy powder with a particle size of less than 5 mm. The alloy powder was loaded into the mold of a vacuum hot press, heated to 500 °C and subjected to a pressure of 100 MPa under a vacuum of 15 Pa. After holding at the temperature and pressure for 30 min, the vacuum hot pressing process was completed, and finally an Al-Fe-Ni-Cu alloy with a specification of Φ100×20 mm was obtained.

[0058] Example 2

[0059] The difference from Example 1 is that the linear rotational speed of the copper cooling roller is 45 m / s, and the average cooling rate of the melt is 1.0 × 10⁻⁶ m / s. 6 K / s, ultimately yielding an Al-Fe-Ni-Cu alloy.

[0060] Example 3

[0061] The difference from Example 1 is that the linear rotational speed of the copper cooling roller is 10 m / s, and the average cooling rate of the melt is 1.0 × 10⁻⁶ m / s. 4 K / s, ultimately yielding an Al-Fe-Ni-Cu alloy.

[0062] Example 4

[0063] The difference from Example 1 is that the vacuum hot pressing pressure is 150 MPa, and the final Al-Fe-Ni-Cu alloy is obtained.

[0064] Example 5

[0065] The difference from Example 1 is that the vacuum hot pressing pressure is 50 MPa, and the final Al-Fe-Ni-Cu alloy is obtained.

[0066] Example 6

[0067] The difference from Example 1 is that the vacuum hot pressing temperature is 550°C, and the final Al-Fe-Ni-Cu alloy is obtained.

[0068] Example 7

[0069] The difference from Example 1 is that the vacuum hot pressing temperature is 400°C, and the final Al-Fe-Ni-Cu alloy is obtained.

[0070] Example 8

[0071] The difference from Example 1 is that the heat preservation and pressure holding time of the vacuum hot pressing treatment is 60 min, and the Al-Fe-Ni-Cu alloy is finally obtained.

[0072] Example 9

[0073] The difference from Example 1 is that, by mass percentage, the alloy ingot includes the following elements: 1.0% Fe, 5.0% Ni, 2.5% Cu, 1.0% Mn, 0.6% Mg, 0.6% Ti, 0.8% Zr, with unavoidable total impurities ≤0.1%, single impurity content less than 0.05%, and the balance being Al, ultimately yielding an Al-Fe-Ni-Cu alloy.

[0074] Example 10

[0075] The difference from Example 1 is that, by mass percentage, the alloy ingot includes the following elements: 2.5% Fe, 2.0% Ni, 2.5% Cu, 1.0% Mn, 0.6% Mg, 0.6% Ti, 0.8% Zr, with unavoidable total impurities ≤0.1%, single impurity content less than 0.05%, and the balance being Al, ultimately yielding an Al-Fe-Ni-Cu alloy.

[0076] Example 11

[0077] The difference from Example 1 is that, by mass percentage, the alloy ingot includes the following elements: 2.5% Fe, 5.0% Ni, 1.0% Cu, 1.0% Mn, 0.6% Mg, 0.6% Ti, 0.8% Zr, with unavoidable total impurities ≤0.1%, single impurity content less than 0.05%, and the balance being Al, ultimately yielding an Al-Fe-Ni-Cu alloy.

[0078] Example 12

[0079] The difference from Example 1 is that the linear rotational speed of the copper cooling roller is 60 m / s, and the average cooling rate of the melt is 1.5 × 10⁻⁶ m / s. 6 K / s, ultimately yielding an Al-Fe-Ni-Cu alloy.

[0080] Example 13

[0081] The difference from Example 1 is that the vacuum hot pressing pressure is 200 MPa, and the final Al-Fe-Ni-Cu alloy is obtained.

[0082] Example 14

[0083] The difference from Example 1 is that the vacuum hot pressing temperature is 350°C, and the final Al-Fe-Ni-Cu alloy is obtained.

[0084] Example 15

[0085] The difference from Example 1 is that the heat preservation and pressure holding time of the vacuum hot pressing treatment is 120 min, and the Al-Fe-Ni-Cu alloy is finally obtained.

[0086] Example 16

[0087] The difference from Example 1 is that the average particle size of the alloy powder is 6 mm, and the final Al-Fe-Ni-Cu alloy is obtained.

[0088] Comparative Example 1

[0089] The difference from Example 1 is that the vacuum hot pressing temperature is 620°C, and the final Al-Fe-Ni-Cu alloy is obtained.

[0090] Comparative Example 2

[0091] The difference from Example 1 is that the vacuum hot pressing temperature is 320°C, and the final Al-Fe-Ni-Cu alloy is obtained.

[0092] Comparative Example 3

[0093] Aluminum alloys were prepared using the preparation method described in Example 1 of Chinese Patent Application Publication No. CN116809934A. Specifically, the alloy raw materials comprised the following components by mass percentage: Si: 0.72%; Fe: 0.063%; Cu: 0.33%; Mn: 0.069%; Mg: 0.92%; Cr: 0.24%; Zn: 0.13%; Ti: 0.11%; Zr: 0.03%; Sc: 0%, with the balance being Al and impurities. The original ingots with the above composition were prepared using semi-continuous casting. The ingots were homogenized at 520°C for 24 hours, and after trimming the ends by 150mm and machining a 5mm layer, they were fed into a single-roller strip spinning machine for rapid solidification of the strip material. The vacuum degree of the melting chamber was 2×10⁻⁶. -3 The solution is heated to 820℃ using a medium-frequency induction heating crucible, with a copper cooling roller rotational speed of 18m / s, a cooling water flow rate of 2000L / h, a nozzle pressure difference of 20kPa, and a liquid outflow width of 10.0mm. The resulting strip has a thickness of 40-80μm and a width of 7.0-16.0mm. The solidified strip is then mechanically sheared and placed into a pre-prepared mold for cold pressing at a holding pressure of 200MPa for 100s, producing a strip 300mm long and 2... A cold-pressed billet, 0.00 mm in diameter and 200 mm in height, is then clad in a 2 mm thick pure aluminum sheet and welded shut. Following this, it undergoes four cold rolling passes at a speed of 0.5 m / s, with a 6% reduction per pass and a total reduction of 22%. After decladding, it is hot-rolled at 480℃ at a speed of 1 m / s, four times, with a 15% reduction per pass. This is followed by five cold rolling passes at a speed of 2 m / s, with a 20% reduction per pass and a total reduction of 67%. Finally, the cold-rolled sheet undergoes solution treatment and aging: solution treatment at 520℃ for 60 minutes, and aging at 175℃ for 2 hours to obtain an aluminum alloy.

[0094] Materials Testing

[0095] Microstructure: According to the standard GB / T 13298-2015 Test Method for Microstructure of Metals, the average grain size of the material and the average particle size of the second phase particles are measured.

[0096] Density: The density of the material was measured in accordance with the standard GB / T 3850-2015 "Method for Determination of Density of Dense Sintered Metallic Materials and Hard Alloys".

[0097] Mechanical properties: The mechanical properties of the material were tested in accordance with GB / T 228.1-2021 Metallic materials - Tensile testing - Part 1 - Tensile method at room temperature, to obtain tensile strength, yield strength and elongation after fracture.

[0098] Elastic modulus: The elastic modulus of the material was tested using the dynamic method according to GB / T 22315-2008 Test Method for Elastic Modulus and Poisson's Ratio of Metallic Materials.

[0099] Thermal expansion coefficient test: The thermal expansion coefficient of the alloy was tested in accordance with GB / T 4339-2008 Determination of thermal expansion characteristic parameters of metallic materials.

[0100] Root mean square roughness of surface: The root mean square roughness of the surface of the optical mirror was tested in accordance with the "GB / T 3505-2009 Product Geometric Technical Specification (GPS) Surface Structure Profile Method Terminology, Definitions and Surface Structure Parameters".

[0101] The alloys prepared in the examples and comparative examples were tested for density, average grain size, average particle size of the second phase, yield strength, tensile strength, elongation after fracture, elastic modulus, and coefficient of thermal expansion. The test results for density, average grain size, average particle size of the second phase, yield strength, tensile strength, and elongation after fracture are shown in Table 1, and the test results for elastic modulus and coefficient of thermal expansion are shown in Table 2.

[0102] The alloys prepared in the examples and comparative examples were subjected to single-point diamond precision turning and precision polishing to produce optical mirrors. The root mean square roughness of the surface of the optical mirrors was measured, and the results are shown in Table 2.

[0103] Table 1

[0104]

[0105] Table 2

[0106]

[0107] Figure 1 The EBSD image of the Al-Fe-Ni-Cu alloy microstructure in Example 1 of this application is shown below. Figure 1 It can be seen that the grain size uniformity is high, the structure is equiaxed, and the average grain size is measured to be 7.2 μm.

[0108] Figure 2 This is a SEM image of the second-phase particles in the Al-Fe-Ni-Cu alloy of Example 1 of this application. Figure 2 It can be seen that the second phase particles have high size uniformity, and the average particle size of the second phase particles is measured to be 3.0 μm.

[0109] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0110] The melt spinning process in this application utilizes the principle of rapid solidification, cooling the alloy melt at a high rate to promote rapid solidification and refinement of the grains, thereby improving the uniformity of grain size. The fine and uniform grain structure helps improve the mechanical properties of the alloy and can reduce the coefficient of thermal expansion to a certain extent. It also improves the structural uniformity and thermal stability of the alloy. Furthermore, the high-modulus, low-thermal-expansion-coefficient second-phase particles further enhance the elastic modulus of the alloy and reduce the overall coefficient of thermal expansion. The crushing process transforms the spun alloy strip into a powder state suitable for hot pressing, further promoting the homogeneity of the material. Subsequent vacuum hot pressing achieves high densification of the alloy powder. During this process, controlling the vacuum hot pressing temperature at 350~600℃ helps to promote the rearrangement and bonding of the alloy powder, eliminating internal porosity and increasing the density and compactness of the alloy. Through the synergistic effect of melt spinning, crushing, and vacuum hot pressing, this application enables the alloy to form a fine and uniform grain structure and dispersed second-phase particles, effectively improving the elastic modulus, thermal stability, and optical compatibility of the alloy. The resulting alloy possesses characteristics such as high elastic modulus, low coefficient of thermal expansion, excellent structural stability, and good processing performance, and can be applied in high-end fields such as aerospace space telescopes, high-precision radar reflectors for national defense, and optical components for semiconductor lithography equipment.

[0111] The above are merely embodiments of the present invention and are not intended to limit the invention. Those skilled in the art will recognize that the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for producing an Al-Fe-Ni-Cu alloy, characterized by, The preparation method includes: Step S1: The metal raw materials of the Al-Fe-Ni-Cu alloy are mixed according to the formula and then melted and cast sequentially to obtain an alloy ingot. The alloy ingot contains the following elements by mass percentage: Fe content is 1.0~5.0%, Ni content is 2.0~7.0%, Cu content is 1.0~5.0%, Mn content is 0.5~1.5%, Mg content is 0.2~1.0%, Ti content is 0.2~1.0%, Zr content is 0.2~1.0%, the total content of unavoidable impurities is ≤0.1%, the content of a single impurity is less than 0.05%, and the balance is Al. Step S2: The ingot is melt-spun to obtain an alloy strip; wherein, a cooling roller is used to cool the melt in the melt spinning process, the linear speed of the cooling roller is 10~60m / s, the flow rate of the cooling water in the cooling roller is 1000~4000L / h, and the temperature of the cooling water is 0~30℃. Step S3: The alloy strip is subjected to crushing and vacuum hot pressing in sequence to obtain the Al-Fe-Ni-Cu alloy; wherein the temperature of the vacuum hot pressing is 400~550℃ and the pressure of the vacuum hot pressing is 50~200MPa.

2. The method for preparing the Al-Fe-Ni-Cu alloy according to claim 1, characterized in that, The heat preservation and pressure holding time for the vacuum hot pressing treatment is 5~120 minutes.

3. The method of producing an Al-Fe-Ni-Cu alloy according to claim 1, characterized by, The particle size of the alloy powder subjected to the crushing process is less than 5 mm.

4. The method for preparing the Al-Fe-Ni-Cu alloy according to claim 1, characterized in that, The temperature of the melt in the melt spinning process is 700~950℃; and / or, the extrusion speed of the melt in the melt spinning process is 10~50m / s.

5. The method of producing an Al-Fe-Ni-Cu alloy according to claim 1, characterized by, The thickness of the alloy strip is 20~500μm; and / or the width of the alloy strip is 5~40mm.

6. The method of producing an Al-Fe-Ni-Cu system alloy according to claim 1, characterized by, The melting temperature is 700~950℃.

7. An Al-Fe-Ni-Cu based alloy, characterized by comprising, in mass %, The Al-Fe-Ni-Cu alloy is prepared by the method for preparing Al-Fe-Ni-Cu alloy as described in any one of claims 1 to 6.

8. The Al-Fe-Ni-Cu-based alloy according to claim 7, characterized by The Al-Fe-Ni-Cu alloy has an equiaxed crystal microstructure; and / or, the average grain size of the Al-Fe-Ni-Cu alloy is ≤10 μm; and / or, the average grain size of the second phase particles of the Al-Fe-Ni-Cu alloy is ≤6 μm; and / or, the density of the Al-Fe-Ni-Cu alloy is 2.80~3.10 g·cm³. -3 The Al-Fe-Ni-Cu alloy has a yield strength of 350-500 MPa; the Al-Fe-Ni-Cu alloy has a tensile strength of 450-600 MPa; the Al-Fe-Ni-Cu alloy has an elongation at break of 0.5-8.0%; the Al-Fe-Ni-Cu alloy has an elastic modulus of 75-95 GPa; and the Al-Fe-Ni-Cu alloy has a coefficient of thermal expansion of 16.0-20.0 °C.

9. An optical mirror, characterized by The material of the optical mirror includes the Al-Fe-Ni-Cu alloy as described in claim 7 or 8.

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