A high-strength cast aluminum alloy material for a 5G case and a preparation method thereof

Abstract

The application relates to the technical field of aluminum alloy preparation, in particular to a high-strength cast aluminum alloy material for a 5G case and a preparation method thereof. Metal raw materials are sequentially subjected to high-temperature melting, refining, degassing, casting processing, homogenization treatment and extrusion forming to obtain an aluminum alloy material. The aluminum alloy material is subjected to hot pressing of mixed materials on the surface to obtain an aluminum alloy material with a reinforcing layer; the reinforcing layer is subjected to ultrasonic micro forging treatment to obtain an aluminum alloy material with a pretreated reinforcing layer. A solidifying agent, an active diluent, a dispersing agent, a light stabilizer, fluorine-containing epoxy resin and epoxidized fiber are added to obtain corrosion-resistant paint; the corrosion-resistant paint is uniformly coated on the surface of the pretreated reinforcing layer, and solidification is carried out to obtain a finished product. The finished product prepared by the application has excellent mechanical strength, heat conduction performance and corrosion resistance, and therefore has a wide application prospect in the technical field of aluminum alloy preparation.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy preparation technology, specifically a high-strength cast aluminum alloy material for 5G chassis and its preparation method. Background Technology

[0002] In the era of booming 5G technology, high-strength cast aluminum alloy materials for 5G chassis are playing an irreplaceable role, demonstrating multifaceted modern value. Their value is particularly significant in ensuring the performance of 5G equipment. 5G technology places extremely high demands on the heat dissipation and structural stability of equipment. High-strength cast aluminum alloy materials have excellent thermal conductivity, enabling them to quickly dissipate heat generated within the 5G chassis, ensuring stable operation of the equipment in high-temperature environments and extending its lifespan. From an industrial development perspective, the application of this material promotes the coordinated development of the 5G industry chain. It drives the development of upstream industries such as aluminum alloy casting and processing, bringing new market opportunities and economic benefits to related enterprises. In terms of environmental protection and energy conservation, the recyclable nature of aluminum alloy materials aligns with the concept of sustainable development in modern society. Compared to other materials, its production and recycling processes have relatively lower energy consumption and environmental pollution, helping to reduce resource waste and environmental pressure, achieving a virtuous cycle between economic development and environmental protection.

[0003] However, 5G chassis are subjected to various external forces during production, transportation, and use, such as collisions, compression, and vibrations. If the aluminum alloy material is not strong enough, the chassis is prone to deformation or even damage, which not only affects the appearance of the chassis but also damages the delicate electronic components inside, leading to equipment failure. Therefore, by increasing the strength of the aluminum alloy material, it is possible to ensure that the chassis maintains its structural integrity in complex environments, providing reliable protection for internal electronic components and ensuring the normal operation of 5G equipment. Furthermore, 5G equipment generates a large amount of heat during operation, especially 5G base stations and high-performance terminal equipment. If the heat cannot be dissipated in time, it will cause the equipment temperature to become too high, thereby affecting the performance and lifespan of electronic components. Therefore, by further improving the thermal conductivity of the aluminum alloy material, the chassis can transfer heat to the outside environment more quickly, effectively reducing the internal temperature of the equipment, ensuring that electronic components operate in a suitable temperature environment, and improving the stability and reliability of the equipment. In addition, 5G equipment has a wide range of applications, including outdoor base stations and industrial environments. In these environments, the chassis is subject to corrosion from humid air, chemicals, salt spray, etc. If the aluminum alloy material has poor corrosion resistance, the chassis surface will rust and corrode, affecting not only its appearance but also weakening its structural strength and reducing its ability to protect internal electronic components. Therefore, improving the corrosion resistance of aluminum alloy materials can extend the service life of the chassis, reduce equipment maintenance costs, and ensure the long-term stable operation of 5G equipment in harsh environments.

[0004] To overcome the shortcomings of the prior art, the present invention provides a high-strength cast aluminum alloy material for 5G chassis and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to provide a high-strength cast aluminum alloy material for 5G chassis and its preparation method, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing a high-strength cast aluminum alloy material for 5G chassis includes the following steps:

[0008] Step 1: Heat the metal raw material to a molten state at 750-800℃, and then refine, degas, cast, homogenize, and extrude to obtain aluminum alloy material;

[0009] Step 2: Place the aluminum alloy material into the mold, then evenly add the mixture into the gap between the aluminum alloy material and the mold to obtain a hot press mold; first, hold the hot press mold at 55-60℃ for 1.0-1.5 hours, then evacuate the working environment of the hot press mold to a vacuum of 5×10⁻⁶. -4 -8×10 -4 Pa, then continue to heat to 630-670℃, then continue to pressurize to 45-50MPa and hold for 35-40min, then slowly cool to 25-30℃, then restore air pressure to obtain an aluminum alloy material with a reinforcing layer; then perform ultrasonic micro-forging on the reinforcing layer to obtain an aluminum alloy material with a pre-treated reinforcing layer.

[0010] Step 3: Pre-disperse the curing agent, reactive diluent, dispersant, and light stabilizer for 40-60 minutes, then add fluorinated epoxy resin and epoxy fiber and continue dispersing for 20-30 minutes to obtain a corrosion-resistant coating; uniformly coat the corrosion-resistant coating onto the surface of the pretreated reinforcing layer and cure at 140-160℃ for 1.5-2.5 hours to obtain the finished product.

[0011] In a more optimized manner, in step one, the content of each component of the metal raw material is as follows (by mass fraction): 4.3-4.5% Zn, 0.13-0.15% Si, 0.02-0.04% Cu, 0.13-0.15% Fe, 0.20-0.25% Mn, 0.75-0.77% Mg, 0.10-0.12% Ti, 0.15-0.17% Zr, 0.12-0.15% Cr, with the balance being Al; the casting temperature is 770-780℃, the casting speed is 90-100 mm / s; and the thickness of the aluminum alloy material is 1.5-2.0 mm.

[0012] In a more optimized manner, the preparation process of the mixture in step two is as follows: the diamond powder is surface-cleaned, and after cleaning, copper metal is sputtered onto the surface of the diamond powder by magnetron sputtering in an argon atmosphere to obtain metallized diamond powder; then the metallized diamond powder and aluminum powder are mixed, and anhydrous ethanol is added dropwise, and the mixture is mixed evenly to obtain the mixture; wherein the mass ratio of metallized diamond powder to aluminum powder is (0.8-1.0):1; the magnetron sputtering process parameters are: working pressure is 1.0-1.5Pa, power is 110-130W, and time is 25-30min.

[0013] In a more optimized manner, the ultrasonic micro-forging process parameters in step two are: ultrasonic amplitude of 5-8μm, forging force of 270-300N, heating temperature of 750-800℃, and forging time of 5-7s.

[0014] In a more optimized manner, in step three, the content of each component of the corrosion-resistant coating is as follows (by mass): 50-70 parts fluorinated epoxy resin, 15-18 parts epoxy fiber, 10-15 parts curing agent, 15-20 parts reactive diluent, 1-2 parts dispersant, and 0.5-0.8 parts light stabilizer; wherein the curing agent is diethylenetriamine, the reactive diluent is toluene glycidyl ether, the dispersant is sodium dodecyl sulfate, and the light stabilizer is UV-320; the thickness of the pretreatment reinforcement layer is 0.15-0.20 mm, and the thickness of the corrosion-resistant coating is 40-50 μm.

[0015] A more optimized preparation process for epoxidized fibers is as follows:

[0016] S1: Dissolve aluminum isopropoxide in deionized water and heat and stir at 55-60℃ for 18-20 h to obtain alumina sol; add the alumina sol to N,N-dimethylformamide, stir until dissolved, then add polyacrylonitrile and continue stirring for 20-25 h to obtain spinning solution; subject the spinning solution to electrospinning, drying, and carbonization in sequence to obtain composite fiber;

[0017] S2: Add epoxy resin and triethylenetetramine to anhydrous ethanol, stir thoroughly to dissolve, then add composite fiber and sodium dodecylbenzenesulfonate, continue stirring for 20-25 minutes, after stirring, keep the temperature at 60-70℃ for 2-3 hours, after the reaction is completed, filter, wash and dry to obtain epoxy fiber.

[0018] In a more optimized manner, in step S1, the electrospinning parameters are: working voltage of 12.5-13.0kV, spinning speed of 0.02-0.03mm / min, and spinning distance of 12-15cm; drying parameters: drying at 75-80℃ for 25-30h; carbonization parameters: under a nitrogen atmosphere, first slowly raise the temperature to 230-250℃ and hold for 1.5-2.0h, then raise the temperature to 750-800℃ and hold for 2-3h to obtain composite fibers.

[0019] In a more optimized manner, in step S1, the mass-to-volume ratio of aluminum isopropoxide to deionized water is (5-7) g: 50 mL; and the mass-to-volume ratio of alumina sol, polyacrylonitrile, and N,N-dimethylformamide is (3-4) g: 1.5 g: 20 mL.

[0020] In a more optimized manner, in step S2, the reaction mass ratio of epoxy resin, composite fiber, and triethylenetetramine is (1-2):10:0.15.

[0021] The beneficial effects of this invention are:

[0022] The key feature of this invention is that in step two, copper metal is sputtered onto the surface of diamond powder by magnetron sputtering to obtain metallized diamond powder. The metallized diamond powder and aluminum powder are then mixed, and anhydrous ethanol is added dropwise and mixed thoroughly to obtain a mixture. This mixture is then hot-pressed onto the surface of an aluminum alloy material to obtain an aluminum alloy material with a reinforcing layer. Diamond, possessing extremely high hardness and strength, is an excellent reinforcing phase. After metallization (copper plating) of the diamond powder surface by magnetron sputtering, it can better mix with the aluminum powder and form a good bond with the aluminum alloy matrix during hot pressing. Therefore, when the aluminum alloy is subjected to external forces, the reinforcing layer can effectively hinder dislocation movement, improve the overall strength and hardness of the material, and thus enhance the aluminum alloy's resistance to deformation and damage. In addition, diamond has extremely high thermal conductivity. After introducing metallized diamond powder into aluminum alloy, these diamond particles can form efficient heat conduction channels on the surface of the aluminum alloy matrix. After further magnetron sputtering copper plating on the diamond surface, the copper layer not only improves the interfacial bonding between diamond and aluminum alloy matrix, but also reduces the interfacial thermal resistance. The lower interfacial thermal resistance allows heat to be transferred more smoothly from diamond particles to aluminum alloy matrix, further improving the thermal conductivity of the material.

[0023] Furthermore, the reinforcing layer is subjected to ultrasonic micro-forging to obtain an aluminum alloy material with a pre-treated reinforcing layer. The high-frequency vibrations and impact loads generated during ultrasonic micro-forging cause the grains within the reinforcing layer to break down and refine, resulting in higher strength in the bonding area between the reinforcing layer and the matrix. In addition, during micro-forging, a certain degree of plastic deformation occurs between the diamond particles in the reinforcing layer and the aluminum alloy matrix, increasing their contact area and strengthening the bonding force. This tight bonding can more effectively transfer loads and improve the overall mechanical properties of the material. Moreover, ultrasonic micro-forging can create a suitable roughness on the surface of the reinforcing layer, allowing the coating to better penetrate these microscopic irregularities during the subsequent coating process, forming a mechanical interlocking effect and thus improving the adhesion between the coating and the reinforcing layer surface.

[0024] The key feature of this invention is that, in step three, aluminum isopropoxide and deionized water are first added to obtain an alumina sol; then, using the alumina sol, N,N-dimethylformamide, and polyacrylonitrile as raw materials, a spinning solution is obtained; the spinning solution is then subjected to electrospinning, drying, and carbonization sequentially to obtain composite fibers. Alumina possesses high hardness and strength, and the carbon fibers formed after carbonization of polyacrylonitrile also exhibit excellent mechanical properties. In the composite fiber, alumina and carbon fibers combine to form a high-strength skeletal structure. When this composite fiber is added to a corrosion-resistant coating, it can effectively bear external loads, disperse stress, and reduce deformation and cracking of the coating under stress, thereby improving the tensile strength, fracture toughness, and other mechanical properties of the coating. Furthermore, the composite fiber forms a three-dimensional network structure in the coating, which effectively prevents the penetration and diffusion of corrosive media. Alumina and carbon fibers themselves have good chemical stability and can resist the erosion of some chemical substances, providing an additional protective barrier for the coating and thus improving its corrosion resistance.

[0025] Furthermore, by adding epoxy resin, triethylenetetramine, anhydrous ethanol, composite fibers, and sodium dodecylbenzenesulfonate, epoxy resin is coated onto the surface of the composite fibers to obtain epoxy fibers. The epoxy groups on the surface of the epoxy fibers have similar reactivity to those in the fluorinated epoxy resin. During subsequent mixing and curing, they can undergo similar chemical reactions with curing agents to form a uniform cross-linked network structure. This matching reactivity ensures that the epoxy fibers can be uniformly dispersed in the fluorinated epoxy resin and fully bonded with it, improving the overall performance of the material.

[0026] Finally, a corrosion-resistant coating is obtained by adding a curing agent, reactive diluent, dispersant, light stabilizer, fluorinated epoxy resin, and epoxy fibers. This corrosion-resistant coating is then uniformly applied to the surface of the pretreated reinforcing layer and cured to obtain the finished product. In summary, the network structure formed by the epoxy fibers in the coating and the cross-linked network formed by the fluorinated epoxy resin intertwine to form a dense composite protective system, effectively preventing the penetration and diffusion of corrosive media and providing more comprehensive and effective protection for aluminum alloy materials. Simultaneously, the pretreated reinforcing layer itself also possesses certain corrosion resistance properties, which, in synergy with the corrosion-resistant coating layer, further improve the corrosion resistance of the aluminum alloy material, enabling it to be used for extended periods in complex environments. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Raw material source:

[0029] Diamond, 150 mesh size; aluminum powder, 15μm particle size; polyacrylonitrile, provided by Hubei Shineng Chemical Technology Co., Ltd., molecular weight 100,000; epoxy resin, provided by Shanghai Xusen Halogen-Free Flame Retardant Co., Ltd., specifically E51; fluorinated epoxy resin, provided by Hubei Xinyuhong Biomedical Technology Co., Ltd., model N / A; by mass parts, one part is 1g.

[0030] Example 1: Step 1: The metal raw material is heated to molten state at 800℃, then refined, degassed, cast, homogenized, and extruded to obtain aluminum alloy material; the content of each component of the metal raw material is as follows (by mass fraction): 4.5% Zn, 0.15% Si, 0.04% Cu, 0.15% Fe, 0.25% Mn, 0.77% Mg, 0.12% Ti, 0.17% Zr, 0.15% Cr, with the balance being Al; the casting temperature is 780℃, and the casting speed is 100 mm / s; the thickness of the aluminum alloy material is 2.0 mm.

[0031] Step 2: The diamond powder is surface-cleaned. After cleaning, copper metal is sputtered onto the surface of the diamond powder by magnetron sputtering in an argon atmosphere to obtain metallized diamond powder. The metallized diamond powder and aluminum powder are then mixed, and anhydrous ethanol is added dropwise. After mixing evenly, a mixture is obtained. The mass ratio of metallized diamond powder to aluminum powder is 0.9:1. The magnetron sputtering process parameters are: working pressure 1.5 Pa, power 130 W, and time 30 min.

[0032] Aluminum alloy material is placed in a mold, and then the mixture is evenly added into the gap between the aluminum alloy material and the mold to obtain a hot press mold. The hot press mold is first held at 60℃ for 1.5 hours, and then the working environment of the hot press mold is evacuated to 8×10. - 4 The pressure is increased to 670℃, then increased to 50MPa and held for 40 minutes, then slowly cooled to 30℃, and then the pressure is restored to obtain an aluminum alloy material with a reinforcing layer. The reinforcing layer is then subjected to ultrasonic micro-forging to obtain an aluminum alloy material with a pre-treated reinforcing layer. The ultrasonic micro-forging process parameters are: ultrasonic amplitude of 8μm, forging force of 300N, heating temperature of 800℃, and forging time of 7s.

[0033] Step 3: S1: Dissolve aluminum isopropoxide in deionized water and heat and stir at 60℃ for 20h to obtain alumina sol; add the alumina sol to N,N-dimethylformamide, stir and dissolve thoroughly, then add polyacrylonitrile and continue stirring for 25h to obtain spinning solution; subject the spinning solution to electrospinning, drying, and carbonization sequentially to obtain composite fibers; electrospinning parameters: working voltage 13.0kV, spinning speed 0.03mm / min, spinning distance 15cm; drying parameters: drying at 80℃ for 30h; carbonization parameters: under nitrogen atmosphere, first slowly heat to 250℃ and hold for 2.0h, then heat to 800℃ and hold for 3h to obtain composite fibers; the mass-to-volume ratio of aluminum isopropoxide to deionized water is 6g:50mL; the mass-to-volume ratio of alumina sol, polyacrylonitrile, and N,N-dimethylformamide is 3.5g:1.5g:20mL;

[0034] S2: Epoxy resin and triethylenetetramine were added to anhydrous ethanol and stirred thoroughly to dissolve. Then, composite fiber and sodium dodecylbenzenesulfonate were added and stirred for another 25 minutes. After stirring, the mixture was kept at 70°C for 3 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain epoxy fiber. The mass ratio of epoxy resin, composite fiber, and triethylenetetramine was 1.5:10:0.15.

[0035] S3: The curing agent, reactive diluent, dispersant, and light stabilizer are pre-dispersed for 60 minutes, then fluorinated epoxy resin and epoxy fiber are added and dispersed for another 30 minutes to obtain a corrosion-resistant coating. The corrosion-resistant coating is uniformly coated onto the surface of the pretreated reinforcing layer and cured at 160℃ for 2.5 hours to obtain the finished product. The content of each component of the corrosion-resistant coating is as follows (by mass): 70g fluorinated epoxy resin, 18g epoxy fiber, 15g curing agent, 20g reactive diluent, 2g dispersant, and 0.8g light stabilizer. The curing agent is diethylenetriamine, the reactive diluent is toluene glycidyl ether, the dispersant is sodium dodecyl sulfate, and the light stabilizer is UV-320. The thickness of the pretreated reinforcing layer is 0.15mm, and the thickness of the corrosion-resistant coating is 40μm.

[0036] Example 2: Step 1: The metal raw material is heated to a molten state at 770℃, and then refined, degassed, cast, homogenized, and extruded to obtain an aluminum alloy material; the content of each component of the metal raw material is as follows (by mass fraction): 4.5% Zn, 0.15% Si, 0.04% Cu, 0.15% Fe, 0.25% Mn, 0.77% Mg, 0.12% Ti, 0.17% Zr, 0.15% Cr, with the balance being Al; the casting temperature is 775℃, and the casting speed is 95 mm / s; the thickness of the aluminum alloy material is 2.0 mm.

[0037] Step 2: The diamond powder is surface-cleaned. After cleaning, copper metal is sputtered onto the surface of the diamond powder by magnetron sputtering in an argon atmosphere to obtain metallized diamond powder. The metallized diamond powder and aluminum powder are then mixed, and anhydrous ethanol is added dropwise. After mixing evenly, a mixture is obtained. The mass ratio of metallized diamond powder to aluminum powder is 0.9:1. The magnetron sputtering process parameters are: working pressure 1.2 Pa, power 120 W, and time 27 min.

[0038] Aluminum alloy material is placed in a mold, and then the mixture is evenly added into the gap between the aluminum alloy material and the mold to obtain a hot press mold. The hot press mold is first held at 57℃ for 1.3 hours, and then the working environment of the hot press mold is evacuated to 7×10. - 4 The pressure is increased to 650℃, then increased to 47MPa and held for 37 minutes, then slowly cooled to 27℃, and then the pressure is restored to obtain an aluminum alloy material with a reinforcing layer. The reinforcing layer is then subjected to ultrasonic micro-forging to obtain an aluminum alloy material with a pre-treated reinforcing layer. The ultrasonic micro-forging process parameters are: ultrasonic amplitude of 6μm, forging force of 285N, heating temperature of 775℃, and forging time of 6s.

[0039] Step 3: S1: Dissolve aluminum isopropoxide in deionized water and heat and stir at 57℃ for 19h to obtain alumina sol; add the alumina sol to N,N-dimethylformamide, stir until fully dissolved, then add polyacrylonitrile and continue stirring for 23h to obtain spinning solution; subject the spinning solution to electrospinning, drying, and carbonization sequentially to obtain composite fibers; electrospinning parameters: working voltage 12.7kV, spinning speed 0.025mm / min, spinning distance 14cm; drying parameters: drying at 77℃ for 27h; carbonization parameters: under nitrogen atmosphere, first slowly heat to 240℃ and hold for 1.7h, then heat to 770℃ and hold for 2.5h to obtain composite fibers; the mass-to-volume ratio of aluminum isopropoxide to deionized water is 6g:50mL; the mass-to-volume ratio of alumina sol, polyacrylonitrile, and N,N-dimethylformamide is 3.5g:1.5g:20mL;

[0040] S2: Epoxy resin and triethylenetetramine were added to anhydrous ethanol and stirred thoroughly to dissolve. Then, composite fiber and sodium dodecylbenzenesulfonate were added and stirred for another 23 minutes. After stirring, the mixture was kept at 65°C for 2.5 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain epoxy fiber. The mass ratio of epoxy resin, composite fiber, and triethylenetetramine was 1.5:10:0.15.

[0041] S3: The curing agent, reactive diluent, dispersant, and light stabilizer are pre-dispersed for 50 minutes, then fluorinated epoxy resin and epoxy fiber are added and dispersed for another 25 minutes to obtain a corrosion-resistant coating. The corrosion-resistant coating is uniformly coated onto the surface of the pretreated reinforcing layer and cured at 150℃ for 2 hours to obtain the finished product. The content of each component of the corrosion-resistant coating is as follows (by mass): 70g fluorinated epoxy resin, 18g epoxy fiber, 15g curing agent, 20g reactive diluent, 2g dispersant, and 0.8g light stabilizer. The curing agent is diethylenetriamine, the reactive diluent is toluene glycidyl ether, the dispersant is sodium dodecyl sulfate, and the light stabilizer is UV-320. The thickness of the pretreated reinforcing layer is 0.15mm, and the thickness of the corrosion-resistant coating is 40μm.

[0042] Example 3: Step 1: The metal raw material is heated to a molten state at 750℃, and then refined, degassed, cast, homogenized, and extruded to obtain an aluminum alloy material; the content of each component of the metal raw material is as follows (by mass fraction): 4.5% Zn, 0.15% Si, 0.04% Cu, 0.15% Fe, 0.25% Mn, 0.77% Mg, 0.12% Ti, 0.17% Zr, 0.15% Cr, with the balance being Al; the casting temperature is 770℃, and the casting speed is 90 mm / s; the thickness of the aluminum alloy material is 2.0 mm.

[0043] Step 2: The diamond powder is surface-cleaned. After cleaning, copper metal is sputtered onto the surface of the diamond powder by magnetron sputtering in an argon atmosphere to obtain metallized diamond powder. The metallized diamond powder and aluminum powder are then mixed, and anhydrous ethanol is added dropwise. After mixing evenly, a mixture is obtained. The mass ratio of metallized diamond powder to aluminum powder is 0.9:1. The magnetron sputtering process parameters are: working pressure 1.0 Pa, power 110 W, and time 25 min.

[0044] Aluminum alloy material is placed in a mold, and then the mixture is evenly added into the gap between the aluminum alloy material and the mold to obtain a hot press mold. The hot press mold is first held at 55℃ for 1.0 h, and then the working environment of the hot press mold is evacuated to 5×10. - 4 The pressure is increased to 630℃, then increased to 45MPa and held for 35 minutes, then slowly cooled to 25℃, and then the pressure is restored to obtain an aluminum alloy material with a reinforcing layer. The reinforcing layer is then subjected to ultrasonic micro-forging to obtain an aluminum alloy material with a pre-treated reinforcing layer. The ultrasonic micro-forging process parameters are: ultrasonic amplitude of 5μm, forging force of 270N, heating temperature of 750℃, and forging time of 5s.

[0045] Step 3: S1: Dissolve aluminum isopropoxide in deionized water and heat and stir at 55℃ for 18 hours to obtain alumina sol; add the alumina sol to N,N-dimethylformamide, stir until fully dissolved, then add polyacrylonitrile and continue stirring for 20 hours to obtain spinning solution; subject the spinning solution to electrospinning, drying, and carbonization sequentially to obtain composite fibers; electrospinning parameters: working voltage 12.5kV, spinning speed 0.02mm / min, spinning distance 12cm; drying parameters: drying at 75℃ for 25 hours; carbonization parameters: under a nitrogen atmosphere, first slowly heat to 230℃ and hold for 1.5 hours, then heat to 750℃ and hold for 2 hours to obtain composite fibers; the mass-to-volume ratio of aluminum isopropoxide to deionized water is 6g:50mL; the mass-to-volume ratio of alumina sol, polyacrylonitrile, and N,N-dimethylformamide is 3.5g:1.5g:20mL.

[0046] S2: Epoxy resin and triethylenetetramine were added to anhydrous ethanol and stirred thoroughly to dissolve. Then, composite fiber and sodium dodecylbenzenesulfonate were added and stirred for another 20 minutes. After stirring, the mixture was kept at 60°C for 2 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain epoxy fiber. The mass ratio of epoxy resin, composite fiber, and triethylenetetramine was 1.5:10:0.15.

[0047] S3: The curing agent, reactive diluent, dispersant, and light stabilizer are pre-dispersed for 40 minutes, then fluorinated epoxy resin and epoxy fiber are added and dispersed for another 20 minutes to obtain a corrosion-resistant coating. The corrosion-resistant coating is uniformly coated onto the surface of the pretreated reinforcing layer and cured at 140℃ for 1.5 hours to obtain the finished product. The content of each component of the corrosion-resistant coating is as follows (by mass): 70g fluorinated epoxy resin, 18g epoxy fiber, 15g curing agent, 20g reactive diluent, 2g dispersant, and 0.8g light stabilizer. The curing agent is diethylenetriamine, the reactive diluent is toluene glycidyl ether, the dispersant is sodium dodecyl sulfate, and the light stabilizer is UV-320. The thickness of the pretreated reinforcing layer is 0.15mm, and the thickness of the corrosion-resistant coating is 40μm.

[0048] Comparative Example 1: The pre-treatment reinforcing layer was removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: The metal raw material was heated to molten state at 800℃, and then refined, degassed, cast, homogenized, and extruded to obtain aluminum alloy material; the content of each component of the metal raw material was as follows (by mass fraction): 4.5% Zn, 0.15% Si, 0.04% Cu, 0.15% Fe, 0.25% Mn, 0.77% Mg, 0.12% Ti, 0.17% Zr, 0.15% Cr, with the balance being Al; the casting temperature was 780℃, and the casting speed was 100 mm / s; the thickness of the aluminum alloy material was 2.0 mm.

[0049] Step 2: S1: Dissolve aluminum isopropoxide in deionized water and heat and stir at 60℃ for 20h to obtain alumina sol; add the alumina sol to N,N-dimethylformamide, stir and dissolve thoroughly, then add polyacrylonitrile and continue stirring for 25h to obtain spinning solution; subject the spinning solution to electrospinning, drying, and carbonization sequentially to obtain composite fibers; electrospinning parameters: working voltage 13.0kV, spinning speed 0.03mm / min, spinning distance 15cm; drying parameters: drying at 80℃ for 30h; carbonization parameters: under nitrogen atmosphere, first slowly heat to 250℃ and hold for 2.0h, then heat to 800℃ and hold for 3h to obtain composite fibers; the mass-to-volume ratio of aluminum isopropoxide to deionized water is 6g:50mL; the mass-to-volume ratio of alumina sol, polyacrylonitrile, and N,N-dimethylformamide is 3.5g:1.5g:20mL;

[0050] S2: Epoxy resin and triethylenetetramine were added to anhydrous ethanol and stirred thoroughly to dissolve. Then, composite fiber and sodium dodecylbenzenesulfonate were added and stirred for another 25 minutes. After stirring, the mixture was kept at 70°C for 3 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain epoxy fiber. The mass ratio of epoxy resin, composite fiber, and triethylenetetramine was 1.5:10:0.15.

[0051] S3: The curing agent, reactive diluent, dispersant, and light stabilizer are pre-dispersed for 60 minutes, then fluorinated epoxy resin and epoxy fiber are added and dispersed for another 30 minutes to obtain a corrosion-resistant coating. The corrosion-resistant coating is uniformly coated onto the surface of the aluminum alloy material and cured at 160℃ for 2.5 hours to obtain the finished product. The content of each component of the corrosion-resistant coating is as follows (by mass): 70g fluorinated epoxy resin, 18g epoxy fiber, 15g curing agent, 20g reactive diluent, 2g dispersant, and 0.8g light stabilizer. The curing agent is diethylenetriamine, the reactive diluent is toluene glycidyl ether, the dispersant is sodium dodecyl sulfate, and the light stabilizer is UV-320. The thickness of the corrosion-resistant coating is 40μm.

[0052] Comparative Example 2: The epoxidized fiber was removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: The metal raw material was heated to molten state at 800℃, and then refined, degassed, cast, homogenized, and extruded to obtain aluminum alloy material; the content of each component of the metal raw material was as follows (by mass fraction): 4.5% Zn, 0.15% Si, 0.04% Cu, 0.15% Fe, 0.25% Mn, 0.77% Mg, 0.12% Ti, 0.17% Zr, 0.15% Cr, with the balance being Al; the casting temperature was 780℃, and the casting speed was 100 mm / s; the thickness of the aluminum alloy material was 2.0 mm.

[0053] Step 2: The diamond powder is surface-cleaned. After cleaning, copper metal is sputtered onto the surface of the diamond powder by magnetron sputtering in an argon atmosphere to obtain metallized diamond powder. The metallized diamond powder and aluminum powder are then mixed, and anhydrous ethanol is added dropwise. After mixing evenly, a mixture is obtained. The mass ratio of metallized diamond powder to aluminum powder is 0.9:1. The magnetron sputtering process parameters are: working pressure 1.5 Pa, power 130 W, and time 30 min.

[0054] Aluminum alloy material is placed in a mold, and then the mixture is evenly added into the gap between the aluminum alloy material and the mold to obtain a hot press mold. The hot press mold is first held at 60℃ for 1.5 hours, and then the working environment of the hot press mold is evacuated to 8×10. - 4 The pressure is increased to 670℃, then increased to 50MPa and held for 40 minutes, then slowly cooled to 30℃, and then the pressure is restored to obtain an aluminum alloy material with a reinforcing layer. The reinforcing layer is then subjected to ultrasonic micro-forging to obtain an aluminum alloy material with a pre-treated reinforcing layer. The ultrasonic micro-forging process parameters are: ultrasonic amplitude of 8μm, forging force of 300N, heating temperature of 800℃, and forging time of 7s.

[0055] Step 3: Pre-disperse the curing agent, reactive diluent, dispersant, and light stabilizer for 60 minutes, then add fluorinated epoxy resin and continue dispersing for 30 minutes to obtain a corrosion-resistant coating; uniformly coat the corrosion-resistant coating onto the surface of the pretreated reinforcing layer, and cure at 160℃ for 2.5 hours to obtain the finished product; the content of each component of the corrosion-resistant coating is as follows (by mass): 70g fluorinated epoxy resin, 15g curing agent, 20g reactive diluent, 2g dispersant, and 0.8g light stabilizer; the curing agent is diethylenetriamine, the reactive diluent is toluene glycidyl ether, the dispersant is sodium dodecyl sulfate, and the light stabilizer is UV-320; the thickness of the pretreated reinforcing layer is 0.15mm, and the thickness of the corrosion-resistant coating is 40μm.

[0056] Comparative Example 3: The corrosion-resistant coating was removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: The metal raw material was heated to molten state at 800℃, and then refined, degassed, cast, homogenized, and extruded to obtain aluminum alloy material; the content of each component of the metal raw material was as follows (by mass fraction): 4.5% Zn, 0.15% Si, 0.04% Cu, 0.15% Fe, 0.25% Mn, 0.77% Mg, 0.12% Ti, 0.17% Zr, 0.15% Cr, with the balance being Al; the casting temperature was 780℃, and the casting speed was 100 mm / s; the thickness of the aluminum alloy material was 2.0 mm.

[0057] Step 2: The diamond powder is surface-cleaned. After cleaning, copper metal is sputtered onto the surface of the diamond powder by magnetron sputtering in an argon atmosphere to obtain metallized diamond powder. The metallized diamond powder and aluminum powder are then mixed, and anhydrous ethanol is added dropwise. After mixing evenly, a mixture is obtained. The mass ratio of metallized diamond powder to aluminum powder is 0.9:1. The magnetron sputtering process parameters are: working pressure 1.5 Pa, power 130 W, and time 30 min.

[0058] Aluminum alloy material is placed in a mold, and then the mixture is evenly added into the gap between the aluminum alloy material and the mold to obtain a hot press mold. The hot press mold is first held at 60℃ for 1.5 hours, and then the working environment of the hot press mold is evacuated to 8×10. - 4 Pa, then continue heating to 670℃, then continue pressurizing to 50MPa and holding for 40min, then slowly cool to 30℃, then restore air pressure to obtain an aluminum alloy material with a reinforcing layer; then the reinforcing layer is subjected to ultrasonic micro-forging to obtain the finished product; ultrasonic micro-forging process parameters: ultrasonic amplitude of 8μm, forging force of 300N, heating temperature of 800℃, forging time of 7s; the thickness of the reinforcing layer on the surface of the finished product is 0.15mm.

[0059] Testing and experimentation:

[0060] Tensile strength test: Referring to GB / T 16865-2023 "Specimens and methods for tensile testing of wrought aluminum, magnesium and their alloy processed products", the finished product prepared by this invention was cut into 90×20mm specimens, and the test temperature was 300℃.

[0061] Thermal conductivity test: First, the thermal diffusivity of the sample is tested using a J-2 thermal property tester, and then the thermal diffusivity is substituted into the thermal conductivity formula to calculate the thermal conductivity.

[0062] Corrosion resistance test: The corrosion resistance of the samples was tested according to GB / T 1771-2007 "Determination of resistance to neutral salt spray of paints and varnishes" standard, with a test duration of 2000 hours. The test results are shown in the table below:

[0063]

[0064] Conclusion: In Examples 1-3, the dosage remained unchanged, with only some reaction parameters modified. Experimental data showed no significant fluctuations in the performance of the samples.

[0065] Comparative Example 1: The pre-treatment reinforcing layer was removed, and the rest was the same as in Example 1. The experimental data showed that, compared with Example 1, the tensile strength decreased to 213.2 MPa and the thermal conductivity decreased to 206 W / (m·K). After corrosion testing, the sample surface showed large-area cracking, blistering, and peeling. The reason for this was that the pre-treatment reinforcing layer contained multiple reinforcing phases, thus exhibiting excellent mechanical properties and corrosion resistance. In addition, diamond has extremely high thermal conductivity, which can form efficient heat conduction channels. Therefore, removing the pre-treatment reinforcing layer resulted in a decrease in tensile strength and thermal conductivity.

[0066] Comparative Example 2: The epoxy fibers were removed, and the rest was the same as in Example 1. Experimental data showed that, compared to Example 1, the tensile strength decreased to 271.8 MPa. After corrosion testing, the sample surface exhibited partial cracking, blistering, and peeling. The reasons for this are: the epoxy fibers are a high-strength skeleton structure formed by the combination of alumina and carbon fibers, resulting in excellent mechanical properties; furthermore, the epoxy fibers have similar reactivity to the main resin, allowing them to form a uniform three-dimensional network structure in the coating, effectively preventing the penetration and diffusion of corrosive media; therefore, removing the epoxy fibers reduced the tensile strength and corrosion resistance.

[0067] Comparative Example 3: The corrosion-resistant coating was removed, and the rest was the same as in Example 1. The experimental data showed that the tensile strength was reduced to 254.1 MPa compared with Example 1. The surface of the sample after the corrosion test showed obvious cracking, blistering, and peeling in many places. The reason for this was that the corrosion-resistant coating was further removed from the basis of Comparative Example 2, which further reduced the tensile strength and corrosion resistance.

[0068] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0069] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-strength cast aluminum alloy material for a 5G cabinet, characterized by: Includes the following steps: Step 1: Heat the metal raw material to a molten state at 750-800℃, and then refine, degas, cast, homogenize, and extrude to obtain aluminum alloy material; Step 2: Place the aluminum alloy material into the mold, then evenly add the mixture into the gap between the aluminum alloy material and the mold to obtain a hot press mold; first, hold the hot press mold at 55-60℃ for 1.0-1.5 hours, then evacuate the working environment of the hot press mold to a vacuum of 5×10⁻⁶. -4 -8×10 -4 Pa, then continue to heat to 630-670℃, then continue to pressurize to 45-50MPa and hold for 35-40min, then slowly cool to 25-30℃, then restore air pressure to obtain an aluminum alloy material with a reinforcing layer; then perform ultrasonic micro-forging on the reinforcing layer to obtain an aluminum alloy material with a pre-treated reinforcing layer. The preparation process of the mixture is as follows: the diamond powder is surface cleaned, and after cleaning, copper metal is sputtered on the surface of the diamond powder by magnetron sputtering in an argon atmosphere to obtain metallized diamond powder; then the metallized diamond powder and aluminum powder are mixed, and anhydrous ethanol is added dropwise. After mixing evenly, the mixture is obtained. The mass ratio of metallized diamond powder to aluminum powder is (0.8-1.0):1; the magnetron sputtering process parameters are: working pressure 1.0-1.5Pa, power 110-130W, and time 25-30min. Step 3: Pre-disperse the curing agent, reactive diluent, dispersant, and light stabilizer for 40-60 minutes, then add fluorinated epoxy resin and epoxy fiber and continue dispersing for 20-30 minutes to obtain a corrosion-resistant coating; uniformly coat the corrosion-resistant coating onto the surface of the pretreated reinforcing layer and cure at 140-160℃ for 1.5-2.5 hours to obtain the finished product; The components of the corrosion-resistant coating are as follows (by weight): 50-70 parts fluorinated epoxy resin, 15-18 parts epoxy fiber, 10-15 parts curing agent, 15-20 parts reactive diluent, 1-2 parts dispersant, and 0.5-0.8 parts light stabilizer; the curing agent is diethylenetriamine, the reactive diluent is toluene glycidyl ether, the dispersant is sodium dodecyl sulfate, and the light stabilizer is UV-320; the thickness of the pretreatment reinforcement layer is 0.15-0.20 mm, and the thickness of the corrosion-resistant coating is 40-50 μm. The preparation process of epoxidized fiber is as follows: S1: Dissolve aluminum isopropoxide in deionized water and heat and stir at 55-60℃ for 18-20h to obtain alumina sol; add the alumina sol to N,N-dimethylformamide, stir until dissolved, then add polyacrylonitrile and continue stirring for 20-25h to obtain spinning solution; subject the spinning solution to electrospinning, drying, and carbonization in sequence to obtain composite fiber; S2: Add epoxy resin and triethylenetetramine to anhydrous ethanol, stir thoroughly to dissolve, then add composite fiber and sodium dodecylbenzenesulfonate, continue stirring for 20-25 minutes, after stirring, keep the temperature at 60-70℃ for 2-3 hours, after the reaction is completed, filter, wash and dry to obtain epoxy fiber.

2. The preparation method of the high-strength cast aluminum alloy material for a 5G case according to claim 1, characterized in that: In step one, the content of each component of the metal raw material is as follows (by mass fraction): 4.3-4.5% Zn, 0.13-0.15% Si, 0.02-0.04% Cu, 0.13-0.15% Fe, 0.20-0.25% Mn, 0.75-0.77% Mg, 0.10-0.12% Ti, 0.15-0.17% Zr, 0.12-0.15% Cr, with the balance being Al; the casting temperature is 770-780℃, the casting speed is 90-100mm / s; and the thickness of the aluminum alloy material is 1.5-2.0mm.

3. The preparation method of the high-strength cast aluminum alloy material for a 5G case according to claim 1, characterized in that: In step two, the ultrasonic micro-forging process parameters are: ultrasonic amplitude of 5-8μm, forging force of 270-300N, heating temperature of 750-800℃, and forging time of 5-7s.

4. The preparation method of the high-strength cast aluminum alloy material for a 5G case according to claim 1, characterized in that: In the preparation of epoxidized fibers, in step S1, the electrospinning parameters are as follows: working voltage is 12.5-13.0kV, spinning speed is 0.02-0.03mm / min, and spinning distance is 12-15cm; drying parameters are: drying at 75-80℃ for 25-30h; carbonization parameters are: under a nitrogen atmosphere, first slowly raise the temperature to 230-250℃ and hold for 1.5-2.0h, then raise the temperature to 750-800℃ and hold for 2-3h to obtain composite fibers.

5. The method for preparing a high-strength cast aluminum alloy material for a 5G case according to claim 1, characterized in that: In the preparation of epoxidized fibers, in step S1, the mass-to-volume ratio of aluminum isopropoxide and deionized water is (5-7) g: 50 mL; the mass-to-volume ratio of alumina sol, polyacrylonitrile, and N,N-dimethylformamide is (3-4) g: 1.5 g: 20 mL.

6. The preparation method of the high-strength cast aluminum alloy material for a 5G case according to claim 1, characterized in that: In the preparation of epoxidized fibers, in step S2, the reaction mass ratio of epoxy resin, composite fiber, and triethylenetetramine is (1-2): 10：0.15。 7. A high-strength cast aluminum alloy material for 5G chassis, characterized in that, Prepared by the preparation method according to any one of claims 1-6.

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