Optical aluminum alloy and preparation method therefor

Abstract

Provided in the present invention are an optical aluminum alloy and a preparation method therefor. The preparation method comprises: step S1, preparing an aluminum alloy starting ingot from raw materials by using a semi-continuous casting process, the semi-continuous casting process comprising heating and melting, alloying, refining, slagging-off, standing, degassing, filtering and semi-continuous water-cooled casting; step S2, performing homogenization, end cropping and skinning on the aluminum alloy starting ingot, so as to obtain a surface-treated alloy raw material; step S3, carrying out rapid solidification treatment on the surface-treated alloy raw material by means of a melt spinning method to obtain a rapidly solidified alloy strip; step S4, subjecting the rapidly solidified alloy strip to crushing treatment, and then performing encapsulation and cold pressing to obtain a cold-pressed billet; step S5, subjecting the cold-pressed billet to one to two passes of a hot extrusion process to prepare a bar stock; and step S6, carrying out solution treatment and aging treatment on the bar stock to obtain a finished aluminum alloy material. The method can refine the grain structure, and the prepared material can be machined into highly flat surfaces.

Description

Optical aluminum alloy and preparation method thereof Technical Field

[0001] The present invention relates to the technical field of aluminum alloy material preparation, and in particular to an optical aluminum alloy and a preparation method thereof. Background Art

[0002] Optical materials generally refer to metal or non-metallic materials with high optical reflectivity, resulting in a mirror-like effect. A surface reflectivity of 70% or higher for ordinary optical materials is sufficient for applications such as automotive interiors, decorative panels, and architectural decoration. However, for optical devices such as chips, radar, solar energy, LEDs, and telescopes, the surface reflectivity requirements are even higher, placing even higher demands on optical materials. Currently, materials used in optical devices are primarily divided into two categories: metals and inorganic non-metallic materials such as glass and ceramics. Compared to non-metallic materials such as SiC ceramics, metals offer better processing properties, allowing them to fully utilize existing CNC milling processes to fabricate complex optical devices.

[0003] Aluminum alloys have great potential in the manufacture of metal optical mirrors due to their light weight, corrosion resistance, and specific mechanical / thermal properties. However, high-quality optical aluminum alloys used in high-end chips and high-end optical information fields are mainly imported, and the material supply has long been monopolized by foreign manufacturers, which has greatly restricted the development of my country's semiconductor and high-end optical information industries. In recent years, China has used 6061 aluminum alloy through a series of surface processing methods such as precision grinding, magnetic flow polishing, ion beam polishing, and coating (gold / silver) to produce mirror-finished aluminum alloys with a surface optical reflectivity of ≥90%. However, this only meets the basic requirements for applications in high-end semiconductor chips and high-end optical information fields.

[0004] The main factors affecting the surface finish of aluminum alloy materials include composition uniformity, structural uniformity, uniformity of nanoprecipitated phase distribution, and residual stress control. Aluminum alloys prepared using traditional processes typically have strong chemical macrosegregation and uneven coarsening, making it difficult to achieve excellent surface finish even with ultra-high precision machining. CN113234973B provides a high-quality mirror-finish aluminum alloy material and its preparation method. Based on the composition of traditional 6061 aluminum alloy, the Si, Cu, and Mg contents in the aluminum alloy are appropriately reduced, while trace elements Ag and Pb are added. Furthermore, deep cold deformation and vibration aging are introduced during the preparation process. This effectively improves the matrix microstructure, grain morphology, and size of the alloy, resulting in a mirror-finish aluminum alloy with higher optical reflectivity. However, this technology only optimizes the original composition and preparation process, improving the material's compositional uniformity and structural uniformity, but still cannot meet the material requirements of high-precision optical aluminum alloys.

[0005] Therefore, how to further improve the surface optical reflectivity of aluminum alloy materials, break the foreign monopoly on high-quality optical aluminum alloy materials used in high-end chips and high-end optical information fields, and reduce the application cost of domestic optical materials has become a technical problem that needs to be solved urgently in this field.

[0006] Summary of the Invention

[0007] The main purpose of the present invention is to provide an optical aluminum alloy and a preparation method thereof, so as to solve the problem of low optical reflectivity of the surface of optical aluminum alloy materials in the prior art.

[0008] To achieve the above-mentioned object, according to one aspect of the present invention, a method for preparing an optical aluminum alloy is provided, which comprises: step S1, preparing an original aluminum alloy ingot from raw materials by a semi-continuous casting process, wherein the semi-continuous casting process comprises heating and melting the raw materials, alloying, refining, slagging, standing, degassing, filtering, and semi-continuous water-cooling casting; step S2, homogenizing, trimming, and lathing the original aluminum alloy ingot to obtain a surface-treated alloy raw material; step S3, rapidly solidifying the surface-treated alloy raw material by a melt spinning method to obtain a rapidly solidified alloy strip; step S4, crushing the rapidly solidified alloy strip, then jacketing and cold pressing it to obtain a cold-pressed billet; step S5, subjecting the cold-pressed billet to 1-2 hot extrusion processes to make a rod; and step S6, solution treating and aging the rod to obtain a finished aluminum alloy material.

[0009] Furthermore, the original aluminum alloy ingot includes the following components: by mass percentage, Si content is 0.40% to 0.80%, Fe content is ≤0.10%; Cu content is 0.15%-0.40%, Mn content is ≤0.10%; Mg content is 0.80%-1.20%; Cr content is 0.15%-0.30%, Ni content is ≤0.05%, Zn content is ≤0.25%, Ti content is 0.05%-0.15%, Zr content is 0.02%-0.04%, V content is ≤0.03%, Sc content is 0-0.20%, and the balance is Al and impurities, and the total amount of impurities is less than 0.15%, and the content of each impurity element is less than 0.05%.

[0010] Furthermore, the melt temperature of the alloy raw material is 730-770°C.

[0011] and / or, filtering is performed using a double-stage ceramic filter disc, wherein the aperture of the first-stage filter disc of the double-stage ceramic filter disc is 35-45 mesh, and the aperture of the second-stage filter disc is 55-65 mesh;

[0012] And / or, the casting speed of the semi-continuous water-cooled casting is 20-50 mm / min, and the diameter of the aluminum alloy original ingot is 80-400 mm.

[0013] Furthermore, in step S2, homogenization includes keeping the original aluminum alloy ingot at 490-560°C for 8-16 hours; cutting off the head and tail to a length of 100-150 mm, and the depth of the car body to 5-15 mm.

[0014] Furthermore, in step S3, a rapid solidification process is performed in a belt-spinning machine, an inert gas is filled into the melting chamber of the belt-spinning machine, and the melt temperature is 780-850°C.

[0015] Furthermore, in step S3, the rotational linear speed of the copper cooling roller for rapid solidification treatment is 10-40 m / s, and preferably, the cooling water flow rate is 1000-4000 L / h.

[0016] Furthermore, in step S3, the pressure difference of the nozzle of the belt-spinning machine is 15-30 kPa, and the liquid outflow width of the nozzle is 2.0-30.0 mm.

[0017] Furthermore, in step S4, cold pressing is performed in a cold pressing mold, with a holding pressure of 100-300 MPa and a holding time of 20-600 s.

[0018] Furthermore, in step S5, the temperature of the extrusion barrel for hot extrusion is 350-470°C, the heating temperature of the cold-pressed billet is 350-560°C, and the holding time is 20-60 minutes;

[0019] And / or, the extrusion die temperature of the hot extrusion is 300-500° C., the total extrusion ratio is 4-30, and the extrusion speed is ≤6 m / min.

[0020] Further, in step S6, the temperature of the solution treatment is 510-570°C and the time is 30-120 minutes;

[0021] And / or, the aging treatment temperature is 150-200° C. and the time is 1-8 hours.

[0022] According to another aspect of the present invention, an optical aluminum alloy is provided. The optical aluminum alloy is prepared by any one of the above preparation methods.

[0023] By applying the technical solution of the present invention and utilizing rapid solidification technology, the grain structure can be significantly refined, component segregation can be reduced, a micron-level micro-grain structure can be obtained, and a highly flat surface can be processed. In addition, hot extrusion of the cold-pressed green billet prepared by rapid solidification strip can ensure the density of the finished rod and the uniform refinement of the grain structure, which plays an important role in improving the surface state of the finished optical aluminum alloy. The present invention adopts the technical route of "melt spinning-cold pressing-hot extrusion" to obtain a finished aluminum alloy material with uniform composition, uniform grain structure, and uniform dispersion of nano-precipitated phases. The optical aluminum alloy prepared by the present invention can achieve a surface roughness of less than Ra3.0nm after precision machining, thereby increasing the optical reflectivity and having excellent tensile strength and hardness. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0025] FIG1 is a process flow chart of the preparation method of Example 1 of the present invention;

[0026] FIG2 is a rapidly solidified alloy strip sample prepared in Example 1 of the present invention;

[0027] FIG3 is the microstructure of the rapidly solidified alloy strip prepared in Example 1 of the present invention;

[0028] FIG4 is a TEM microstructure of a rapidly solidified alloy strip prepared in Example 1 of the present invention;

[0029] FIG5 is a TEM microstructure of a rapidly solidified alloy strip prepared in Example 4 of the present invention;

[0030] FIG6 is a sample of the finished material prepared in Example 1 of the present invention;

[0031] FIG7 is the metallographic structure of the optical aluminum alloy material prepared in Example 1 of the present invention;

[0032] FIG8 is a metallographic structure of an optical aluminum alloy material prepared in Example 19 of the present invention;

[0033] FIG9 is a low-magnification (50x) grain structure of the finished material prepared in Example 2 of the present invention;

[0034] FIG10 is a high-magnification (500x) grain structure of the finished material prepared in Example 2 of the present invention;

[0035] FIG11 is a longitudinal cross-sectional SEM structure of the finished material of Example 1 of the present invention;

[0036] FIG12 is a longitudinal cross-sectional SEM structure of the finished material of Example 20 of the present invention;

[0037] FIG13 shows the surface roughness test results of the finished material prepared in Example 5 of the present invention after single-point diamond turning. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] Theoretical studies have shown that the optical reflectivity of aluminum alloys is mainly related to the surface finish of the alloys, and the surface finish mainly depends on the matrix structure of the alloys, the morphology and size of the grains, and the uniformity of the distribution of the second phase particles. Rapid solidification is a non-equilibrium solidification process. 4 ~10 6 A cooling rate of 10000 K / s directly and instantly condenses the liquid material into a solid state, generally generating amorphous, quasicrystals, microcrystals, or nanocrystals, resulting in a material with special properties and uses. Prior art optical aluminum alloys suffer from low surface optical reflectivity or high cost. To address this issue, the present application provides an optical aluminum alloy and a method for preparing the same, utilizing a rapid solidification process to produce an optical aluminum alloy material with high optical reflectivity.

[0040] According to a typical embodiment of the present application, a preparation method of an optical aluminum alloy is provided, which comprises: step S1, preparing an original aluminum alloy ingot from raw materials by a semi-continuous casting process, wherein the semi-continuous casting process comprises heating and melting the raw materials, alloying, refining, slagging, standing, degassing, filtering, and semi-continuous water-cooling casting; step S2, homogenizing, trimming, and lathing the original aluminum alloy ingot to obtain a surface-treated alloy raw material; step S3, rapidly solidifying the surface-treated alloy raw material by a melt spinning method to obtain a rapidly solidified alloy strip; step S4, crushing the rapidly solidified alloy strip, then jacketing and cold pressing it to obtain a cold-pressed billet; step S5, subjecting the cold-pressed billet to one or two hot extrusion processes to form a rod; and step S6, solution treating and aging the rod to obtain a finished aluminum alloy material.

[0041] This application utilizes rapid solidification technology, which can significantly refine the grain structure, reduce component segregation, obtain a micron-level micro-grain structure, and process a highly flat surface. In addition, hot extrusion of the cold-pressed green billet prepared by rapid solidification strip can ensure the uniform refinement of the density and grain structure of the finished rod, which plays an important role in improving the surface state of the finished optical aluminum alloy. The present invention adopts the technical route of "melt spinning-cold pressing-hot extrusion", which can obtain a finished aluminum alloy material with uniform composition, uniform grain structure, and uniform dispersion of nano-precipitated phase. The optical aluminum alloy prepared by the present invention can achieve a surface roughness of less than Ra3.0nm after precision machining, thereby increasing the optical reflectivity and having excellent tensile strength and hardness.

[0042] In some typical embodiments of the present application, the above-mentioned aluminum alloy original ingot includes the following components: by mass percentage, Si content 0.40% to 0.80%, Fe content ≤0.10%; Cu content 0.15%-0.40%, Mn content ≤0.10%; Mg content 0.80%-1.20%; Cr content 0.15%-0.30%, Ni content ≤0.05%, Zn content ≤0.25%, Ti content 0.05%-0.15%, Zr content 0.02%-0.04%, V content ≤0.03%, Sc content 0-0.20%, and the balance is Al and impurities, and the total impurity content is less than 0.15%, and the content of each impurity element is less than 0.05%.

[0043] By designing the composition of optical aluminum alloy materials, strictly reducing the content of the impurity element Fe, and improving the purity of the aluminum alloy melt, the volume of the insoluble Fe phase in the aluminum matrix can be effectively reduced. This can prevent the surface roughness caused by large second phases during high-precision surface processing of the finished material, thereby ensuring the surface finish of the optical aluminum material. On the other hand, by optimizing the composition content of the main alloying elements Si and Mg based on the composition of conventional Al-Mg-Si aluminum alloy materials, the atomic ratio and size of the precipitated phase are controlled to ensure the dimensional stability of the nano-precipitated phase of the finished material. In addition, precise control of the Mn element content is conducive to promoting the transformation of the alloy from the AlFeSi phase to the AlFeMnSi phase. On this basis, trace alloying elements such as Cr, Ti, and Zr are added to improve the surface activity between the alloy phase boundaries and the hardness of the aluminum matrix, thereby increasing the yield rate of the material's mirror precision processing.

[0044] In some embodiments of the present application, the Fe content in the above-mentioned aluminum alloy original ingot is ≤0.08% by mass; in some embodiments of the present application, the Fe content in the above-mentioned aluminum alloy original ingot is ≤0.06% by mass; in some embodiments of the present application, the Fe content in the above-mentioned aluminum alloy original ingot is ≤0.04% by mass.

[0045] In the above-mentioned aluminum alloy original ingot, the Si content, calculated as a percentage by mass, can be listed as 0.40%, 0.45%, 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.75%, 0.80% or any range therebetween.

[0046] In the above-mentioned aluminum alloy original ingot, the Mg content, calculated as a percentage by mass, can be listed as 0.80%, 0.85%, 0.90%, 0.95%, 1.00%, 1.05%, 1.10%, 1.15%, 1.20% or any range therebetween.

[0047] In the above aluminum alloy original ingot, the Cr content, by mass percentage, can be 0.15%, 0.20%, 0.25%, 0.30% or any range therebetween.

[0048] In the above aluminum alloy original ingot, the Zr content, calculated as a percentage by mass, can be 0.02%, 0.025%, 0.03%, 0.035%, 0.04% or any range therebetween.

[0049] In some embodiments of the present application, the Mn content in the above-mentioned aluminum alloy original ingot is ≤0.09% by mass; in some embodiments of the present application, the Mn content in the above-mentioned aluminum alloy original ingot is ≤0.07% by mass; in some embodiments of the present application, the Mn content in the above-mentioned aluminum alloy original ingot is ≤0.06% by mass; in some embodiments of the present application, the Mn content in the above-mentioned aluminum alloy original ingot is ≤0.04% by mass.

[0050] In the above-mentioned aluminum alloy original ingot, the Sc content can be listed as 0, 0.02%, 0.0 / 4%, 0.06%, 0.08%, 0.10%, 0.12%, 0.14%, 0.16%, 0.18%, 0.20% or any range therebetween, by mass percentage. The raw materials used for semi-continuous casting can be selected from corresponding metal elements or alloys according to the composition of the alloy. In some typical embodiments of the present application, the raw materials include: 99.9% industrial pure aluminum, industrial pure magnesium, aluminum-copper master alloy, aluminum-zirconium master alloy, aluminum-silicon master alloy, aluminum-manganese master alloy, aluminum-chromium master alloy, industrial pure zinc, aluminum-titanium master alloy, aluminum-vanadium master alloy, and aluminum-scandium master alloy.

[0051] In some embodiments of the present application, the melt temperature of the alloy raw material is 730-770° C. In some embodiments of the present application, the temperature of the molten aluminum in the crystallizer during semi-continuous casting is 675-695° C., and the casting speed during semi-continuous water-cooled casting is preferably 20-50 mm / min. The diameter of the prepared aluminum alloy raw ingot is 80-400 mm.

[0052] In some embodiments of the present application, the above-mentioned filtration is performed using a two-stage ceramic filter disc. The aperture of the first-stage filter disc of the two-stage ceramic filter disc is 35-45 mesh, and the aperture of the second-stage filter disc is 55-65 mesh. The filtering effect is good, which is beneficial to improving the surface smoothness of the final aluminum alloy product.

[0053] In some typical embodiments of the present application, in step S2, homogenization includes holding the original aluminum alloy ingot at 490-560°C for 8-16 hours, which has a good homogenization effect on the aluminum alloy of the present application. In some embodiments of the present application, the length of the head and tail cut off is 100-150 mm, and the depth of the car body is 5-15 mm.

[0054] The above-mentioned "rapid solidification" refers to the fact that when the molten alloy raw material comes into contact with the rapidly rotating cooling wheel, the temperature drops rapidly, thereby obtaining a metal strip. After the obtained metal strip is subjected to subsequent densification processing, a micron-level micro-grain structure is obtained, and a highly flat surface can be processed.

[0055] In some embodiments of the present application, in step S3, a rapid solidification process is performed in a belt spinning machine, and an inert gas is filled into the melting chamber of the belt spinning machine. The melt temperature is 780-850°C, which can improve the surface finish of the finished aluminum alloy and prepare a rapid solidification strip with a smoother surface and more uniform thickness. The above-mentioned inert gas can be any one or more of nitrogen, argon and helium. In some embodiments of the present application, the vacuum degree of the melting chamber of the belt spinning machine is first set to 2×10 -3 -5×10 -3 Pa, and then argon gas is introduced into the melting chamber for protection to ensure the argon concentration in the melting chamber and further improve the surface finish of the aluminum alloy.

[0056] In some embodiments of the present application, in step S3, the copper cooling roller used in the rapid solidification process rotates at a linear speed of 10-40 m / s. Preferably, the cooling water flow rate is 1000-4000 L / h. By selecting an appropriate cooling roller rotational speed and cooling water flow rate, the surface smoothness and thickness uniformity of the rapidly solidified strip are further improved. Preferably, the nozzle pressure difference of the strip spinner is 15-30 kPa, and the liquid outflow width of the nozzle is 2.0-30.0 mm, which significantly improves the production of rapidly solidified alloy strips with smooth surfaces and uniform thickness.

[0057] In some embodiments of the present application, in the above step S3, the thickness of the prepared strip is 15-100 μm, the width of the strip is 2.0-30.0 mm, and the cooling rate during the preparation process is relatively high, which is conducive to obtaining an aluminum alloy material with better performance.

[0058] In some typical embodiments of the present application, step S4 includes pulverizing the rapidly solidified alloy strip using a shearing machine, ultrasonically cleaning and drying the strip with alcohol, then placing the strip into a prefabricated package, and cold-pressing the strip using a press in a cold-pressing mold. In some embodiments of the present application, cold pressing is performed in a cold-pressing mold with a holding pressure of 100-300 MPa and a holding time of 20-600 seconds. This helps improve the density of the cold-pressed blank, reduces porosity and porosity defects, and thereby enhances the surface finish of the finished optical aluminum alloy product. In some embodiments of the present application, the resulting cold-pressed green blank has a diameter of 150-400 mm.

[0059] In some preferred embodiments of the present application, in step S5 above, the extrusion barrel temperature for hot extrusion is 300-500°C, the heating temperature for the cold-pressed billet is 400-500°C, and the holding time is 20-60 minutes; the extrusion die temperature for hot extrusion is 300-500°C, the total extrusion ratio is 4-30, and the extrusion speed is ≤6 m / min. By properly controlling the extrusion temperature and extrusion ratio, the density of the finished bar and the uniform refinement of the grain structure are further promoted, which has a significant effect on improving the surface condition of the optical aluminum alloy product and increasing the optical reflectivity. In some embodiments of the present application, extruded bars with a diameter of 20-120 mm are obtained by hot extrusion.

[0060] In step S6, to further improve the overall performance of the finished aluminum alloy, the solution treatment temperature is preferably 510-570°C for 30-120 minutes. In some embodiments of the present application, the aging treatment temperature is 150-200°C for 1-8 hours to better control the grain size of the finished material and the mechanical properties of the alloy.

[0061] According to another typical embodiment of the present application, an optical aluminum alloy is provided. The optical aluminum alloy is prepared by any one of the above-mentioned preparation methods.

[0062] The optical efficiency alloy obtained by the above method in this application has excellent surface processing performance by effectively controlling key indicators such as the grain size, recrystallization volume fraction, precipitate phase size and distribution, and mechanical properties of the finished material. Optical aluminum alloy materials with a surface roughness of less than Ra3nm can be obtained through single-point diamond precision turning, precision polishing technology and other means.

[0063] The beneficial effects that can be achieved by the present application will be further illustrated below with reference to examples and comparative examples.

[0064] Example 1

[0065] The process flow of the preparation method of optical aluminum alloy is shown in Figure 1.

[0066] The alloy raw material includes the following components in mass percentage: Si: 0.67%; Fe: 0.075%; Cu: 0.30%, Mn: 0.084%; Mg: 0.90%; Cr: 0.21%, Ni: 0.03%, Zn: 0.11%, Ti: 0.086%; Zr: 0.028%, V: 0.013%, Sc: 0%, and the balance is Al and impurities. The above raw materials are prepared, and then subjected to heating, melting, alloying, refining, slagging, standing, degassing, filtering, and semi-continuous water-cooling casting to obtain an aluminum alloy original ingot, wherein the melt temperature is 740°C, the aluminum liquid temperature in the crystallizer is 695°C, the ingot diameter is 178 mm, and the casting speed is 30 mm / min; a two-stage ceramic filter is used for filtration, and the filter mesh numbers are 45 mesh and 55 mesh respectively; the alloy ingot is homogenized at 560°C for 8 hours, and after being rolled and trimmed by 10 mm, it is added to a single-roll strip spinning machine, that is, a single-roll melt is rotated to prepare a rapid solidification strip, and the vacuum degree of the melting chamber is 2×10 -3 Pa, and argon protection; melt temperature 800 ° C, copper cooling roller rotation speed 17 m / s, cooling water flow 2000 L / h, nozzle pressure difference 20 kPa, liquid outflow width 10.0 mm, the prepared strip thickness 40-60 μm, strip width 7.0-16.0 mm; the alloy strip was mechanically sheared, cleaned and dried with alcohol, and then jacketed and cold pressed with a holding pressure of 200 MPa and a holding time of 30 seconds to produce a 250 mm diameter cold-pressed billet; the cold-pressed billet was then subjected to one hot extrusion pass with an extrusion barrel temperature of 400 ° C, a green billet heating temperature of 490 ° C, and a holding time of 30 minutes; the extrusion die temperature was 450 ° C, the extrusion ratio was 17.4, and the extrusion speed was 3 m / min to obtain a 60 mm diameter extruded bar; finally, the bar was subjected to solid solution and aging treatment with a solid solution temperature of 530 ° C and a solid solution time of 60 minutes; and an aging temperature of 175 ° C and an aging time of 2 hours.

[0067] The rapidly solidified alloy strip formed during the preparation process is shown in the photograph of Figure 2, the microstructure is shown in Figure 3, and the TEM structure is shown in Figure 4. The finished optical aluminum alloy material obtained after the above treatment is shown in Figure 6, the metallographic structure is shown in Figure 7, and the longitudinal cross-section SEM structure is shown in Figure 11.

[0068] Example 2

[0069] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.63%; Fe: 0.077%; Cu: 0.30%, Mn: 0.083%; Mg: 0.85%; Cr: 0.22%, Ni: 0.03%, Zn: 0.11%, Ti: 0.078%; Zr: 0.033%, V: 0.015%, Sc: 0%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 750°C, the aluminum liquid temperature in the crystallizer was 700°C, the ingot diameter was 254 mm, and the casting speed was 25 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 530°C for 16 h, the head and tail were cut, and the car body was 10 mm thick. It was then added to a single-roller stripping machine for rapid solidification strip preparation, and the vacuum degree of the melting chamber was 3×10 -3 Pa, and argon protection; melt temperature 810 ° C, copper cooling roller rotation speed 30 m / s, cooling water flow 3500 L / h, nozzle pressure difference 20 kPa, liquid outflow width 10.0 mm, prepared strip thickness 40-60 μm, strip width 7.0-16.0 mm; the alloy strip is crushed, alcohol cleaned and dried, and then jacketed and cold pressed with a holding pressure of 200 MPa and a holding time of 40 s to produce a 150 mm Ø cold-pressed billet; the cold-pressed billet is then subjected to one hot extrusion pass with an extrusion barrel temperature of 400 ° C, a green billet heating temperature of 450 ° C, and a holding time of 30 min; the extrusion die temperature is 450 ° C, the extrusion ratio is 9, and the extrusion speed is 4 m / min to obtain a 50 mm Ø extruded bar; finally, the bar is subjected to solid solution and aging treatment with a solid solution temperature of 530 ° C and a solid solution time of 60 min; and an aging temperature of 175 ° C and an aging time of 2 h. The low-magnification (50x) and high-magnification (500x) grain structures of the finished material of this embodiment are shown in Figures 9 and 10, respectively.

[0070] Example 3

[0071] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.71%; Fe: 0.068%; Cu: 0.34%, Mn: 0.085%; Mg: 0.86%; Cr: 0.22%, Ni: 0.015%, Zn: 0.11%, Ti: 0.02%; Zr: 0.02%, V: 0.015%, Sc: 0.02%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 740°C, the aluminum liquid temperature in the crystallizer was 695°C, the ingot diameter was 254 mm, and the casting speed was 20 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 560°C for 8 hours, and after cutting the head, tail, and car body by 10 mm, it was added to a single-roller strip spinning machine, that is, a single-roller melt was rotated to prepare a rapidly solidified strip. The vacuum degree of the melting chamber was 2×10 -3 Pa, and argon protection; melt temperature 820 ° C, copper cooling roller rotation speed 17 m / s, cooling water flow 2000 L / h, nozzle pressure difference 20 kPa, liquid outflow width 10.0 mm, prepared strip thickness 40-60 μm, strip width 7.0-16.0 mm; the alloy strip was mechanically sheared, cleaned and dried with alcohol, then jacketed and cold pressed with a holding pressure of 200 MPa and a holding time of 30 seconds to produce a 240 mm diameter cold-pressed billet; the cold-pressed billet was then subjected to one hot extrusion pass with an extrusion barrel temperature of 420 ° C, a green billet heating temperature of 530 ° C, and a holding time of 30 minutes; the extrusion die temperature was 480 ° C, the extrusion ratio was 16, and the extrusion speed was 1.5 m / min to obtain a 60 mm diameter extruded bar; finally, the bar was subjected to solid solution and aging treatment with a solid solution temperature of 560 ° C and a solid solution time of 90 minutes; and an aging temperature of 175 ° C and an aging time of 2 hours.

[0072] Example 4

[0073] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.69%; Fe: 0.072%; Cu: 0.32%, Mn: 0.089%; Mg: 0.83%; Cr: 0.20%; Ni: 0.01%; Zn: 0.10%, Ti: 0.01%; Zr: 0.03%, V: 0.01%, Sc: 0.13%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 740°C, the aluminum liquid temperature in the crystallizer was 695°C, the ingot diameter was 254 mm, and the casting speed was 20 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 540°C for 8 h, and after cutting the head, tail, and car body by 10 mm, it was added to a single-roller strip spinning machine, that is, a single-roller melt was rotated to prepare a rapidly solidified strip. The vacuum degree of the melting chamber was 2×10 -3 Pa, and argon protection; melt temperature 830 ° C, copper cooling roller rotation speed 17m / s, cooling water flow 2000L / h, nozzle pressure difference 20kPa, liquid outflow width 10.0mm, the prepared strip thickness 40-60μm, strip width 7.0-16.0mm, its TEM structure is shown in Figure 5; the alloy strip is mechanically sheared, washed and dried with alcohol, and then jacketed and cold pressed. The holding pressure is 200MPa. The cold-pressed billet was subjected to one hot extrusion process, with the extrusion barrel temperature at 420°C, the green billet heating temperature at 530°C, and the holding time at 30 min. The extrusion die temperature was 480°C, the extrusion ratio was 16, and the extrusion speed was 1.5 m / min to obtain a Ø60 mm extruded bar. Finally, the bar was subjected to solution treatment and aging treatment, with the solution temperature at 560°C and the solution time at 90 min. The aging temperature was 175°C and the aging time was 2 h.

[0074] Example 5

[0075] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.76%; Fe: 0.079%; Cu: 0.33%, Mn: 0.077%; Mg: 0.84%; Cr: 0.22%, Ni: 0.01%, Zn: 0.10%, Ti: 0.04%; Zr: 0.026%, V: 0.01%, Sc: 0.01%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 740°C, the aluminum liquid temperature in the crystallizer was 695°C, the ingot diameter was 254 mm, and the casting speed was 20 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 560°C for 8 h, and after cutting the head, tail, and car body by 10 mm, it was added to a single-roller strip spinning machine, that is, a single-roller melt was rotated to prepare a rapidly solidified strip. The vacuum degree of the melting chamber was 2×10 -3 Pa, and argon protection; melt temperature 810 ° C, copper cooling roller rotation speed 23m / s, cooling water flow 2500L / h, nozzle pressure difference 18kPa, liquid outflow width 23.0mm, prepared strip thickness 40-80μm, strip width 15.0-28.0mm; the alloy strip is mechanically shredded, washed and dried with alcohol, then jacketed and cold pressed, with a holding pressure of 120MPa, The holding time is 30s to produce a Ø405mm cold-pressed billet; the cold-pressed billet is then subjected to two hot extrusion passes, with the first pass having an extrusion barrel temperature of 300°C, a green billet heating temperature of 350°C, and a holding time of 30min; the extrusion die temperature of 300°C, an extrusion ratio of 2.62, and an extrusion speed of 0.5m / min to obtain a Ø250mm extruded rod; the second pass having an extrusion barrel temperature of 420°C, a green billet heating temperature of 520°C, and a holding time of 30min; the extrusion die temperature of 450°C, an extrusion ratio of 6.25, and an extrusion speed of 1.2m / min to obtain a Ø100mm extruded rod; finally, the bar is subjected to solid solution and aging treatment, with a solid solution temperature of 560°C, a solid solution time of 90min, an aging temperature of 175°C, and an aging time of 2h.

[0076] The surface roughness test results of the finished material after single-point diamond turning are shown in Figure 13.

[0077] Example 6

[0078] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.63%; Fe: 0.077%; Cu: 0.30%, Mn: 0.083%; Mg: 0.85%; Cr: 0.22%, Ni: 0.03%, Zn: 0.11%, Ti: 0.078%; Zr: 0.033%, V: 0.015%, Sc: 0%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 750°C, the aluminum liquid temperature in the crystallizer was 700°C, the ingot diameter was 254 mm, and the casting speed was 25 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh numbers of 45 and 55, respectively. The alloy ingot was homogenized at 560°C for 12 h, the head and tail were cut, and the car body was 10 mm thick. It was then added to a single-roller strip-spinning machine for rapid solidification strip preparation, and the vacuum degree of the melting chamber was 3×10 -3 Pa, and argon protection; melt temperature 810 ° C, copper cooling roller rotation speed 30 m / s, cooling water flow 3500 L / h, nozzle pressure difference 20 kPa, liquid outflow width 10.0 mm, prepared strip thickness 40-60 μm, strip width 7.0-16.0 mm; the alloy strip is crushed, alcohol cleaned and dried, and then jacketed and cold pressed with a holding pressure of 200 MPa and a holding time of 40 s to produce a 150 mm Ø cold-pressed billet; the cold-pressed billet is then subjected to one hot extrusion pass with an extrusion barrel temperature of 400 ° C, a green billet heating temperature of 450 ° C, and a holding time of 30 min; the extrusion die temperature is 450 ° C, the extrusion ratio is 9, and the extrusion speed is 4 m / min to obtain a 50 mm Ø extruded bar; finally, the bar is subjected to solid solution and aging treatment with a solid solution temperature of 530 ° C and a solid solution time of 60 min; and an aging temperature of 175 ° C and an aging time of 6 h.

[0079] Example 7

[0080] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.67%; Fe: 0.075%; Cu: 0.30%, Mn: 0.084%; Mg: 0.90%; Cr: 0.21%, Ni: 0.03%, Zn: 0.11%, Ti: 0.086%; Zr: 0.028%, V: 0.013%, Sc: 0%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 750°C, the aluminum liquid temperature in the crystallizer was 700°C, the ingot diameter was 254 mm, and the casting speed was 25 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 530°C for 16 h, the head and tail were cut, and the car body was 10 mm thick. It was then added to a single-roller stripping machine for rapid solidification strip preparation, and the vacuum degree of the melting chamber was 3×10 -3 Pa, and argon protection; melt temperature 810 ° C, copper cooling roller rotation speed 15 m / s, cooling water flow 2000 L / h, nozzle pressure difference 20 kPa, liquid outflow width 10.0 mm, prepared strip thickness 40-60 μm, strip width 7.0-16.0 mm; the alloy strip was crushed, cleaned with alcohol, and dried, and then jacketed and cold pressed with a holding pressure of 200 MPa and a holding time of 40 s to produce a 150 mm Ø cold-pressed billet; the cold-pressed billet was then subjected to one hot extrusion pass with an extrusion barrel temperature of 400 ° C, a green billet heating temperature of 450 ° C, and a holding time of 30 min; the extrusion die temperature was 450 ° C, the extrusion ratio was 9, and the extrusion speed was 4 m / min to obtain a 50 mm Ø extruded bar; finally, the bar was subjected to solid solution and aging treatment with a solid solution temperature of 530 ° C and a solid solution time of 60 min; and an aging temperature of 175 ° C and an aging time of 2 h.

[0081] Example 8

[0082] The difference from Example 1 is that the alloy ingot is homogenized at 430° C. for 8 hours.

[0083] Example 9

[0084] The difference from Example 1 is that the mass percentage of Si in the alloy raw material is 0.3%.

[0085] Example 10

[0086] The difference from Example 1 is that the mass percentage of Si in the alloy raw material is 1.0%.

[0087] Example 11

[0088] The difference from Example 1 is that the mass percentage of Mg in the alloy raw material is 0.5%.

[0089] Example 12

[0090] The difference from Example 1 is that the mass percentage of Mg in the alloy raw material is 1.5%.

[0091] Example 13

[0092] The difference from Example 1 is that the alloy raw material does not contain Zr.

[0093] Example 14

[0094] The difference from Example 1 is that the nozzle pressure difference is 30 kPa.

[0095] Example 15

[0096] The difference from Example 1 is that the nozzle pressure difference is 15 kPa.

[0097] Example 16

[0098] The difference from Example 1 is that the liquid outflow width is 5.0 mm.

[0099] Example 17

[0100] The difference from Example 1 is that the liquid outflow width is 30.0 mm.

[0101] Example 18

[0102] The difference from Example 1 is that the liquid outflow width is 35.0 mm.

[0103] Example 19

[0104] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.69%; Fe: 0.56%; Cu: 0.31%, Mn: 0.086%; Mg: 0.89%; Cr: 0.21%, Ni: 0.03%, Zn: 0.12%, Ti: 0.09%; Zr: 0.02%, V: 0.015%, Sc: 0%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 740°C, the aluminum liquid temperature in the crystallizer was 695°C, the ingot diameter was 178 mm, and the casting speed was 30 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 560°C for 8 h, and after cutting the head, tail, and car body by 10 mm, it was added to a single-roller strip spinning machine, i.e., a single-roller melt was rotated to prepare a rapidly solidified strip. The vacuum degree of the melting chamber was 2×10 -3Pa, and argon protection; melt temperature 800 ° C, copper cooling roller rotation speed 17 m / s, cooling water flow 2000 L / h, nozzle pressure difference 20 kPa, liquid outflow width 10.0 mm, the prepared strip thickness 40-60 μm, strip width 7.0-16.0 mm; the alloy strip was mechanically sheared, cleaned and dried with alcohol, and then jacketed and cold pressed with a holding pressure of 200 MPa and a holding time of 30 seconds to produce a 250 mm diameter cold-pressed billet; the cold-pressed billet was then subjected to one hot extrusion pass with an extrusion barrel temperature of 400 ° C, a green billet heating temperature of 490 ° C, and a holding time of 30 minutes; the extrusion die temperature was 450 ° C, the extrusion ratio was 17.4, and the extrusion speed was 3 m / min to obtain a 60 mm diameter extruded bar; finally, the bar was subjected to solid solution and aging treatment with a solid solution temperature of 530 ° C and a solid solution time of 60 minutes; and an aging temperature of 175 ° C and an aging time of 2 hours.

[0105] Compared to Example 1, the alloy raw material used was commercially pure aluminum, and the resulting alloy ingot had an Fe content of 0.56%, significantly higher than the 0.075% Fe content in the alloy of Example 1. The cross-sectional microstructure of the finished material is shown in Figure 8 . It can be seen that the finished material prepared in this example contains a large number of large Fe-containing phases. These large Fe-containing phases reduce the uniformity of the material.

[0106] Example 20

[0107] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.76%; Fe: 0.079%; Cu: 0.33%, Mn: 0.077%; Mg: 0.84%; Cr: 0.22%, Ni: 0.01%, Zn: 0.10%, Ti: 0.04%; Zr: 0.026%, V: 0.01%, Sc: 0.01%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 740°C, the aluminum liquid temperature in the crystallizer was 695°C, the ingot diameter was 254 mm, and the casting speed was 20 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 560°C for 8 h, and after cutting the head, tail, and car body by 10 mm, it was added to a single-roller strip spinning machine, that is, a single-roller melt was rotated to prepare a rapidly solidified strip. The vacuum degree of the melting chamber was 2×10 -3Pa, and argon protection; melt temperature 810 ℃, copper cooling roller rotation speed 23m / s, cooling water flow 2500L / h, nozzle pressure difference 18kPa, liquid outflow width 23.0mm, prepared strip thickness 40-80μm, strip width 15.0-28.0mm; the alloy strip is mechanically cut, washed and dried with alcohol, then jacketed and cold pressed, with a holding pressure of 120MPa and a holding time of 30s to produce Ø180mm cold-pressed billet; then the cold-pressed billet is subjected to one hot extrusion, with the extrusion barrel temperature at 300℃, the green billet heating temperature at 450℃, and the holding time at 30min; the extrusion die temperature at 380℃, the extrusion ratio at 3.24, and the extrusion speed at 0.5m / min, to obtain a Ø100mm extruded bar; finally, the bar is subjected to solid solution and aging treatment, with the solid solution temperature at 560℃ and the solid solution time at 90min; the aging temperature at 165℃ and the aging time at 2h.

[0108] The longitudinal cross-sectional SEM structure of the finished material is shown in FIG12 .

[0109] Example 21

[0110] The invention discloses a method for preparing an optical aluminum alloy. The alloy raw materials include the following components in percentage by mass: Si: 0.63%; Fe: 0.077%; Cu: 0.30%, Mn: 0.083%; Mg: 0.85%; Cr: 0.22%, Ni: 0.03%, Zn: 0.11%, Ti: 0.078%; Zr: 0.033%, V: 0.015%, Sc: 0%, and the balance is Al and impurities. The raw materials were heated and melted, alloyed, refined, slag-stripped, allowed to stand, degassed, filtered, and semi-continuously water-cooled to obtain aluminum alloy primary ingots, wherein the melt temperature was 750°C, the aluminum liquid temperature in the crystallizer was 700°C, the ingot diameter was 254 mm, and the casting speed was 25 mm / min. A two-stage ceramic filter was used for filtration, with filter mesh sizes of 45 and 55, respectively. The alloy ingot was homogenized at 430°C for 12 h, the head and tail were cut, and the car body was 10 mm thick. It was then added to a single-roller strip-spinning machine for rapid solidification strip preparation, and the vacuum degree of the melting chamber was 3×10 -3Pa, and argon protection; melt temperature 810 ° C, copper cooling roller rotation speed 30 m / s, cooling water flow 3500 L / h, nozzle pressure difference 20 kPa, liquid outflow width 10.0 mm, prepared strip thickness 40-60 μm, strip width 7.0-16.0 mm; the alloy strip is crushed, alcohol cleaned and dried, and then jacketed and cold pressed with a holding pressure of 200 MPa and a holding time of 40 s to produce a 150 mm Ø cold-pressed billet; the cold-pressed billet is then subjected to one hot extrusion pass with an extrusion barrel temperature of 400 ° C, a green billet heating temperature of 450 ° C, and a holding time of 30 min; the extrusion die temperature is 450 ° C, the extrusion ratio is 9, and the extrusion speed is 4 m / min to obtain a 50 mm Ø extruded bar; finally, the bar is subjected to solid solution and aging treatment with a solid solution temperature of 530 ° C and a solid solution time of 60 min; and an aging temperature of 175 ° C and an aging time of 2 h.

[0111] The aluminum alloy product obtained in the above embodiment was tested, and the testing method is as follows:

[0112] Grain size test: The finished material is made into a smooth metallographic specimen, which is mechanically ground and polished, and then anodic coated. The specimen is then observed and photographed under a metallographic microscope, and the average grain size is measured according to the straight line intercept method in GB / T 6394-2002.

[0113] Micro Vickers hardness test: The finished material is made into a metallographic specimen of appropriate size. After mechanical grinding and polishing, the hardness test is carried out on a micro Vickers hardness tester. Ten hardness points are measured for each sample, and the average value is taken.

[0114] Precision polishing surface roughness test: Take the finished material of corresponding diameter, after mechanical turning, perform precision turning on a single-point diamond lathe, and use a high-precision roughness tester to test the precision turning surface roughness.

[0115] The test results of the above indicators are shown in Table 1 below.

[0116] Table 1

[0117] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: by utilizing the rapid solidification technology, the grain structure can be significantly refined, the component segregation can be reduced, a micron-level microscopic grain structure can be obtained, and a highly flat surface can be processed. In addition, hot extrusion of the cold-pressed green billet prepared by the rapid solidification strip can ensure the uniform refinement of the density of the finished rod and the grain structure, which plays an important role in improving the surface state of the finished optical aluminum alloy. The present invention adopts the technical route of "melt spinning-cold pressing-hot extrusion", which can obtain a finished aluminum alloy material with uniform composition, uniform grain structure, and uniform dispersion of nano-precipitated phases. The optical aluminum alloy prepared by the present invention can achieve a surface roughness of less than Ra3.0nm after precision machining, thereby increasing the optical reflectivity and having excellent tensile strength and hardness.

[0118] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing an optical aluminum alloy, characterized in that: include: Step S1, preparing an aluminum alloy original ingot by using a semi-continuous casting process on the raw materials, wherein the semi-continuous casting process includes heating and melting the raw materials, alloying, refining, slagging, standing, degassing, filtering, and semi-continuous water-cooling casting; Step S2, homogenizing, cutting the head and tail, and lathing the original aluminum alloy ingot to obtain a surface-treated alloy raw material; Step S3, using a melt spinning method to rapidly solidify the surface treated alloy raw material to obtain a rapidly solidified alloy strip; Step S4, encapsulating and cold pressing the rapidly solidified alloy strip after crushing to obtain a cold pressed billet; Step S5, subjecting the cold pressed blank to 1-2 hot extrusion processes to make a rod; Step S6, subjecting the bar material to solution treatment and aging treatment to obtain a finished aluminum alloy material.

2. The preparation method according to claim 1, characterized in that: The aluminum alloy original ingot comprises the following components: by mass percentage, Si content is 0.40% to 0.80%, Fe content is ≤0.10%; Cu content is 0.15%-0.40%, Mn content is ≤0.10%; Mg content is 0.80%-1.20%; Cr content is 0.15%-0.30%, Ni content is ≤0.05%, Zn content is ≤0.25%, Ti content is 0.05%-0.15%, Zr content is 0.02%-0.04%, V content is ≤0.03%, Sc content is 0-0.20%, and the balance is Al and impurities, and the total amount of impurities is less than 0.15%, and the content of each impurity element is less than 0.05%.

3. The preparation method according to claim 1 or 2, characterized in that: The melt temperature of the alloy raw material is 730-770°C. And / or, the filtering is performed using a double-stage ceramic filter, the aperture of the first-stage filter of the double-stage ceramic filter is 35-45 mesh, and the aperture of the second-stage filter is 55-65 mesh; And / or, the casting speed of the semi-continuous water-cooling casting is 20-50 mm / min, and the diameter of the original aluminum alloy ingot is 80-400 mm.

4. The preparation method according to claim 1 or 2, characterized in that: In step S2, the homogenization includes keeping the original aluminum alloy ingot at 490-560°C for 8-16 hours; the length of the cut ends is 100-150 mm, and the depth of the car skin is 5-15 mm.

5. The preparation method according to claim 1 or 2, characterized in that: In step S3, the rapid solidification process is carried out in a belt-spinning machine, the melting chamber of the belt-spinning machine is filled with an inert gas, and the melt temperature is 780-850°C.

6. The preparation method according to claim 1, characterized in that: In step S3, the rotation linear speed of the copper cooling roller in the rapid solidification treatment is 10-40 m / s, and the cooling water flow rate is 1000-4000 L / h.

7. The preparation method according to claim 5, characterized in that: In step S3, the pressure difference of the nozzle of the belt-spinning machine is 15-30 kPa, and the liquid outflow width of the nozzle is 2.0-30.0 mm.

8. The preparation method according to claim 1, characterized in that: In step S4, the cold pressing is performed in a cold pressing mold, the holding pressure is 100-300 MPa, and the holding time is 20-600 s.

9. The preparation method according to claim 1, characterized in that: In step S5, the temperature of the hot extrusion barrel is 350-470°C, the heating temperature of the cold pressed blank is 350-560°C, and the holding time is 20-60min; And / or, the extrusion die temperature of the hot extrusion is 300-500° C., the total extrusion ratio is 4-30, and the extrusion speed is ≤6 m / min.

10. The preparation method according to claim 1, characterized in that: In step S6, the temperature of the solution treatment is 510-570°C and the time is 30-120min; And / or, the aging treatment is performed at a temperature of 150-200° C. and for a time of 1-8 h.

11. An optical aluminum alloy, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 10.

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