High-conductivity ultrahigh-strength aluminum alloy material for aviation and preparation method thereof

Abstract

The invention belongs to the technical field of aeronautical materials, and particularly relates to an aeronautical high-conductivity ultrahigh-strength aluminum alloy material and a preparation method thereof. Through the Zr-Er-Y multi-element microalloying synergistic effect, a coherent Al3 (Zr, Er and Y) nano dispersed phase is formed, grains are remarkably refined, recrystallization is inhibited, meanwhile, the Y element optimizes the grain boundary precipitated phase form, the grain boundary binding force is improved, and a structure foundation is laid for high toughness of the alloy. A cooperative treatment strategy of isothermal forging and pressing, water quenching and two-stage aging is adopted in the process, and high-density dislocation and water quenching freezing dislocation configuration is introduced in forging and pressing so as to retain deformation stored energy. Two-stage aging promotes uniform dispersion of a precipitated phase, efficient superposition of deformation strengthening and precipitation strengthening is achieved, and the strength and fatigue resistance are remarkably improved. And finally, the strength, the electric conductivity and the fatigue limit of the alloy are synchronously improved while the high plasticity is kept, the bottleneck of mutual restriction of the strength and the corrosion resistance is effectively broken through, and the harsh requirements of aerospace on high-strength, high-electric-conductivity and high-fatigue materials are met.

Description

Technical Field

[0001] This invention belongs to the field of aerospace materials technology, specifically relating to a high-conductivity, ultra-high-strength aluminum alloy material for aerospace applications and its preparation method. Background Technology

[0002] Aluminum alloys, with their high specific strength, excellent machinability, and good corrosion resistance, have become an irreplaceable core structural material in aerospace, transportation, and other fields. Among them, the 7XXX series (Al-Zn-Mg-Cu) aluminum alloys, since the advent of alloy 7075 in the 1940s, have been the mainstream choice for lightweight aerospace structures due to their ultra-high strength.

[0003] The development of 7XXX series aluminum alloys is essentially a process of continuously pursuing the synergistic improvement of strength, toughness, and corrosion resistance, and can be roughly divided into four stages: The first generation, represented by the 7075-T6 alloy, achieves high strength through peak aging treatment, but suffers from a severe tendency to stress corrosion cracking (SCC).

[0004] Second generation: Develop over-aging processes such as T73 and T76, which significantly improve stress corrosion resistance at the cost of a small amount of strength.

[0005] The third generation: reducing the content of Fe and Si impurities and introducing Zr to replace Cr, resulting in alloys such as 7050 and 7475. The Al3Zr dispersed phase formed by Zr can inhibit recrystallization, refine grains, and significantly improve hardenability and fracture toughness, representing a major technological breakthrough in this system.

[0006] The fourth generation: By increasing the Zn content and combining it with complex deformation heat treatment, the 7055-T77 alloy was developed. Its tensile strength can reach more than 600MPa, while also taking into account excellent toughness. It represents the highest level of mass application of aerospace aluminum alloys.

[0007] Although the aforementioned alloys have been widely used, with the increasing demands for structural efficiency, reliability, and lifespan in next-generation aircraft, existing 7XXX series alloys are gradually revealing common problems: the pursuit of high strength often comes at the cost of decreased plasticity and toughness, while over-aging treatments to improve corrosion resistance lead to strength loss. This contradiction between strength, corrosion, and toughness makes it difficult for traditional alloys to simultaneously meet the comprehensive requirements of high strength, high corrosion resistance, and high fatigue life under extreme operating conditions.

[0008] To overcome the aforementioned bottlenecks, microalloying technology has become a research hotspot. Adding trace amounts of rare earth elements and transition metals to the Al-Zn-Mg-Cu base can have a profound impact on the microstructure. However, existing research mostly focuses on the addition of single or binary rare earth elements. A systematic industrial technical solution has not yet been developed for the synergistic composite addition of Zr, Er, and Y elements, and their coupling mechanism with forging deformation, two-stage aging, and other processes.

[0009] Based on this, the present invention aims to develop an aluminum alloy material that combines high strength, high conductivity and high fatigue limit by comprehensively utilizing the synergistic advantages of Zr-Er-Y multi-element microalloying, so as to meet the requirements of the next generation of aerospace equipment. Summary of the Invention

[0010] The purpose of this invention is to address existing problems by providing a high-conductivity, ultra-high-strength aluminum alloy material for aerospace applications and its preparation method.

[0011] This invention is achieved through the following technical solution: A high-conductivity, ultra-high-strength aluminum alloy material for aerospace applications, with Al as the matrix, has the following chemical composition by mass percentage: Zn 6~7%, Mg 2.2~2.8%, Cu 1.3~1.7%, Zr 0.18~0.3%, Er 0.1~0.2%, Y 0.06~0.12%, Ti 0.02~0.05%, B 0.001~0.003%, with the balance being Al and unavoidable impurities; The content of Fe is ≤0.05%, Si is ≤0.05%, individual impurities are ≤0.03%, and the total amount of impurities is ≤0.12%.

[0012] Furthermore, after two-stage homogenization and two-stage aging, Zr and Er form a coherent / semi-coherent Al3(Er, Zr) composite nanoprecipitate phase, with Y element segregating at grain boundaries and phase boundaries.

[0013] A method for preparing the high conductivity ultra-high strength aluminum alloy material for aerospace applications as described in claim 1, comprising the following steps: S1. Raw material pretreatment: Industrial pure aluminum ingots, Zn ingots, Mg ingots, Cu ingots, and Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys with a purity ≥99.95% are selected, and are then surface-polished and dried for later use. S2, Smelting and Purification: Heat aluminum ingots to 740~760℃ to melt them, then add Zn ingots and Cu ingots in sequence, and hold for 20~30 minutes. Cool to 720~730℃, add Mg ingots, and stir for 5~10 minutes; Add Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys and stir for 15-20 minutes; High-purity argon gas (purity ≥ 99.99%) is introduced into the melt at a flow rate of 0.3~0.5 m³ / h. 3 / h, spray refining for 25~30min, while adding refining agent, let stand for 15~20min, remove slag to obtain pure melt; S3, Semi-continuous casting: The melt temperature was adjusted to 690~710℃, and semi-continuous casting was used to obtain aluminum alloy ingots. S4. Homogenization process: A two-stage homogenization process is adopted, and after homogenization, water mist cooling is performed to room temperature. S5. Isothermal forging pretreatment: The homogenized ingot is heated to 380~420℃ and held for 1~2 hours. It is then forged using isothermal forging. After forging, it is immediately water-quenched to room temperature to freeze the dislocations. S6. Hot extrusion forming: The forging billet is heated to 450~470℃, held for 1~3 hours, hot extruded using an extruder, and then air-cooled after extrusion. S7, Two-level timeliness processing: Perform a two-stage aging process, and then air-cool to room temperature after aging is complete.

[0014] Further, the components and corresponding weight percentages of the refining agent mentioned in step S2 are: KCl 40~50%, MgCl2 20~30%, KF 5~10%, with the balance being NaCl, and the amount added is 0.1~0.2% of the melt mass.

[0015] Furthermore, in step S3, during the semi-continuous casting process, the casting speed is controlled at 80~120 mm / min, the cooling water temperature at 20~30℃, and the cooling intensity at 15~20℃ / min.

[0016] Furthermore, the two-stage homogenization process described in step S4 specifically consists of: a first stage of holding at 400~420℃ for 4~6 hours, and a second stage of holding at 480~500℃ for 8~10 hours.

[0017] Furthermore, the water mist cooling rate described in step S4 is 35~45℃ / min.

[0018] Furthermore, during the isothermal forging described in step S5, the deformation rate is controlled at 10~20%, and the deformation speed is 2~5 mm / s.

[0019] Furthermore, in step S6, the extrusion ratio is controlled to be (20~30):1, the extrusion speed is 5~10mm / s, and the die temperature is 400~420℃ during hot extrusion.

[0020] Furthermore, the two-stage aging treatment described in step S7 is specifically as follows: the first stage of aging is maintained at 100~110℃ for 4~6 hours, and the second stage of aging is maintained at 160~170℃ for 8~12 hours.

[0021] The present invention has the following advantages over the prior art: 1. This invention achieves precise control over the microstructure of aluminum alloys by constructing a Zr-Er-Y multi-element microalloying system. Zr, Er, and Y synergistically form a coherent Al3(Zr, Er, Y) nano-dispersed phase. This phase exhibits high thermal stability, significantly refines grains in the as-cast microstructure, and strongly pins dislocations and subgrain boundaries during subsequent hot working and heat treatment, effectively suppressing recrystallization and thus preserving the deformation strengthening effect. Simultaneously, the addition of Y optimizes the morphology and distribution of grain boundary precipitates, reduces the width of grain boundary non-precipitate zones, and improves grain boundary bonding while enhancing strength, laying the microstructural foundation for the alloy to achieve high strength and high toughness.

[0022] 2. This invention employs a synergistic treatment strategy of isothermal forging, water quenching, and two-stage aging. Isothermal forging introduces high-density dislocations into the alloy, providing numerous heterogeneous nucleation sites for subsequent aging precipitation. Immediate water quenching after forging effectively freezes the dislocation configuration at high temperatures, preventing dislocation recovery and thus maximizing the preservation of deformation energy. In the subsequent two-stage aging process, the first stage of low-temperature aging promotes the formation of high-density GP regions, while the second stage of high-temperature aging promotes the transformation of GP regions into fine and dispersed η′ phases. This hierarchical precipitation mechanism results in a more uniform distribution of precipitated phases, achieving an efficient superposition of deformation strengthening and precipitation strengthening, significantly improving the alloy's strength and fatigue resistance.

[0023] 3. Based on the synergistic innovation of the above-mentioned composition and process, the aluminum alloy material prepared by this invention achieves simultaneous improvement in strength, conductivity, and fatigue limit while maintaining high plasticity. Compared with the traditional 7075 alloy, the tensile strength is increased by 5-10%, the conductivity is increased by more than 40%, and the fatigue limit is increased by 35-45%. The high conductivity indicates that the matrix solid solution elements are fully precipitated, the purity is improved, and the corresponding excellent stress corrosion resistance is achieved; the high fatigue limit reflects the uniform microstructure, low defect density, and high crack propagation resistance of the material. This comprehensive performance breakthrough effectively solves the technical bottleneck of the mutual constraint between strength and corrosion resistance in traditional 7XXX series aluminum alloys, and can meet the stringent requirements of the new generation of aerospace equipment for high-strength, high-toughness, long-life, and highly reliable structural materials. Detailed Implementation

[0024] To further explain the present invention, the following specific embodiments are described.

[0025] Example 1 Chemical composition: With Al as the base, its chemical composition by mass percentage includes: Zn 6%, Mg 2.2%, Cu 1.3%, Zr 0.18%, Er 0.1%, Y 0.06%, Ti 0.02%, B 0.001%, with the balance being Al and unavoidable impurities (Fe 0.04%, Si 0.03%).

[0026] Preparation method: S1. Raw material pretreatment: Industrial pure aluminum ingots, Zn ingots, Mg ingots, Cu ingots, and Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys with a purity ≥99.95% are selected, and are then surface-polished and dried for later use. S2, Smelting and Purification: Heat aluminum ingots to 740℃ to melt them, then add Zn ingots and Cu ingots in sequence, and keep warm for 20 minutes; Cool to 720℃, add Mg ingots, and stir for 5 minutes; Add Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys and stir for 15 minutes; High-purity argon gas (purity ≥ 99.99%) is introduced into the melt at a flow rate of 0.3 m³ / s. 3 / h, spray refining for 25min, while adding 0.1% of the melt mass of refining agent (KCl 40%, MgCl2 20%, KF 5%, balance NaCl), let stand for 15min, remove slag to obtain pure melt; S3, Semi-continuous casting: The melt temperature was adjusted to 690℃, and semi-continuous casting was adopted. The casting speed was controlled at 80mm / min, the cooling water temperature at 20℃, and the cooling intensity at 15℃ / min to obtain aluminum alloy ingots. S4. Homogenization process: A two-stage homogenization process is adopted. The first stage is held at 400℃ for 4 hours, and the second stage is held at 480℃ for 8 hours. After homogenization, the mixture is cooled to room temperature by water mist at a rate of 35℃ / min. S5. Isothermal forging pretreatment: The homogenized ingot was heated to 380℃ and held for 1 hour. It was then subjected to isothermal forging with a deformation rate of 10% and a deformation speed of 2 mm / s. After forging, it was immediately water-quenched to room temperature to freeze the dislocations. S6. Hot extrusion forming: The forging billet was heated to 450℃ and held for 1 hour. It was then hot extruded using an extrusion press with an extrusion ratio of 20:1, an extrusion speed of 5 mm / s, and a die temperature of 400℃. After extrusion, it was air-cooled. S7, Two-level timeliness processing: The process involves two stages of aging: the first stage involves holding the temperature at 100℃ for 4 hours, and the second stage involves holding the temperature at 160℃ for 8 hours. After aging, the material is air-cooled to room temperature.

[0027] Example 2 Chemical composition: Based on Al, its chemical composition by mass percentage includes: Zn 6.5%, Mg 2.5%, Cu 1.5%, Zr 0.25%, Er 0.15%, Y 0.09%, Ti 0.03%, B 0.002%, with the balance being Al and unavoidable impurities (Fe 0.03%, Si 0.02%).

[0028] Preparation method: S1. Raw material pretreatment: Industrial pure aluminum ingots, Zn ingots, Mg ingots, Cu ingots, and Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys with a purity ≥99.95% are selected, and are then surface-polished and dried for later use. S2, Smelting and Purification: Heat aluminum ingots to 750℃ to melt them, then add Zn ingots and Cu ingots in sequence, and hold for 25 minutes. Cool to 725℃, add Mg ingots, and stir for 7 minutes; Add Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys and stir for 17 minutes; High-purity argon gas (purity ≥ 99.99%) is introduced into the melt at a flow rate of 0.4 m³ / s. 3 / h, spray refining for 28min, while adding 0.15% of the melt mass of refining agent (KCl 45%, MgCl2 25%, KF 7%, balance NaCl), let stand for 17min, remove slag to obtain pure melt; S3, Semi-continuous casting: The melt temperature was adjusted to 700℃, and semi-continuous casting was adopted. The casting speed was controlled at 100mm / min, the cooling water temperature was 25℃, and the cooling intensity was 17℃ / min to obtain aluminum alloy ingots. S4. Homogenization process: A two-stage homogenization process is adopted, with the first stage being held at 410℃ for 5 hours and the second stage being held at 490℃ for 90 hours. After homogenization, the mixture is cooled to room temperature by water mist at a rate of 40℃ / min. S5. Isothermal forging pretreatment: The homogenized ingot was heated to 400℃ and held for 1.5h. It was then subjected to isothermal forging with a deformation rate controlled at 15% and a deformation speed of 3.5mm / s. After forging, it was immediately water-quenched to room temperature to freeze the dislocations. S6. Hot extrusion forming: The forging billet was heated to 460℃ and held for 2 hours. It was then hot extruded using an extrusion press with an extrusion ratio of 25:1, an extrusion speed of 7 mm / s, and a die temperature of 410℃. After extrusion, it was air-cooled. S7, Two-level timeliness processing: The process involves two stages of aging: the first stage involves holding the product at 105℃ for 5 hours, and the second stage involves holding the product at 165℃ for 10 hours. After aging, the product is air-cooled to room temperature.

[0029] Example 3 Chemical composition: With Al as the matrix, its chemical composition by mass percentage includes: Zn 7%, Mg 2.8%, Cu 11.7%, Zr 0.3%, Er 0.2%, Y 0.12%, Ti 0.05%, B 0.003%, with the balance being Al and unavoidable impurities (Fe 0.05%, Si 0.04%).

[0030] Preparation method: S1. Raw material pretreatment: Industrial pure aluminum ingots, Zn ingots, Mg ingots, Cu ingots, and Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys with a purity ≥99.95% are selected, and are then surface-polished and dried for later use. S2, Smelting and Purification: Heat aluminum ingots to 760℃ to melt them, then add Zn ingots and Cu ingots in sequence, and keep warm for 30 minutes; Cool to 730℃, add Mg ingots, and stir for 10 minutes; Add Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys and stir for 20 minutes; High-purity argon gas (purity ≥ 99.99%) is introduced into the melt at a flow rate of 0.5 m³ / s. 3 / h, spray refining for 30min, while adding 0.2% of the melt mass of refining agent (KCl 50%, MgCl2 30%, KF 10%, balance NaCl), let stand for 20min, remove slag to obtain pure melt; S3, Semi-continuous casting: The melt temperature was adjusted to 710℃, and semi-continuous casting was adopted. The casting speed was controlled at 120mm / min, the cooling water temperature was 30℃, and the cooling intensity was 20℃ / min to obtain aluminum alloy ingots. S4. Homogenization process: A two-stage homogenization process is adopted. The first stage is held at 420℃ for 6 hours, and the second stage is held at 500℃ for 10 hours. After homogenization, the mixture is cooled to room temperature by water mist at a rate of 45℃ / min. S5. Isothermal forging pretreatment: The homogenized ingot was heated to 420℃ and held for 2 hours. It was then forged using isothermal forging with a deformation rate controlled at 20% and a deformation speed of 5 mm / s. After forging, it was immediately water-quenched to room temperature to freeze the dislocations. S6. Hot extrusion forming: The forging billet was heated to 470℃ and held for 3 hours. It was then hot extruded using an extrusion press with an extrusion ratio of 30:1, an extrusion speed of 10 mm / s, and a die temperature of 420℃. After extrusion, it was air-cooled. S7, Two-level timeliness processing: The process involves two stages of aging: the first stage involves holding the product at 110℃ for 6 hours, and the second stage involves holding the product at 170℃ for 12 hours. After aging, the product is air-cooled to room temperature.

[0031] Comparative Example 1 Comparative Example 1 uses existing 7075 aluminum alloy.

[0032] Element: Zn 6.0%, Mg 2.5%, Cu 1.6%, Cr 0.2%, balance Al and impurities. Process: Conventional smelting → casting → homogenization → extrusion → single-stage aging (120℃×24h).

[0033] Comparative Example 2 Comparative Example 2 has the same composition as Example 2, but it is air-cooled after forging and not water-quenched. Other steps and parameters are the same as in Example 2.

[0034] Comparative Example 3 Comparative Example 3 has the same composition as Example 2, uses single-stage aging at 165°C for 12 hours, and other steps and parameters are the same as in Example 2.

[0035] Comparative Example 4 Compared with Example 2, Comparative Example 4 does not contain Er, has a Zr content of 0.25%, and is prepared using the same method as Example 2.

[0036] Comparative Example 5 Compared with Example 2, Comparative Example 5 does not contain Y in its composition, but the preparation method is the same as that of Example 2.

[0037] Aluminum alloy materials were prepared using the methods described in Examples 1-3 and Comparative Examples 1-5, respectively. The performance of these aluminum alloy materials was then tested. The testing methods are as follows.

[0038] 1. Room temperature tensile properties test The test was conducted in accordance with GB / T 228.1-2021 "Metallic materials, tensile testing - Part 1: Test at room temperature".

[0039] Sample preparation: Samples are taken from the heat-treated aluminum alloy profile along the extrusion (longitudinal direction) and processed into standard circular or rectangular samples. Three parallel samples are taken from each material group.

[0040] Testing equipment: Electronic universal testing machine.

[0041] Test parameters: Determining tensile strength (R) m (MPa), specified plastic elongation strength (R) p0.2 The test parameters are yield strength (MPa) and elongation at break (A, %). The test rate is controlled at 2~6 mm / min.

[0042] Results processing: The arithmetic mean of three parallel samples was taken as the final result.

[0043] The test results are shown in Table 1 below.

[0044] Table 1

[0045] As shown in Table 1 above, the tensile strength and yield strength of Examples 1-3 are significantly higher than those of the conventional 7075 aluminum alloy. Comparative Example 2 has the same composition as Example 2, but it was not water-quenched (air-cooled) after forging. Its strength (538 MPa) is significantly lower than that of Example 2 (572 MPa). This is because during air cooling, dislocations recover and rearrange, reducing the dislocation density and weakening the effect of subsequent age hardening. This proves the necessity of the process design of immediate water quenching after forging to freeze dislocations. Comparative Example 3 uses single-stage aging, and its strength (545 MPa) is lower than that of the two-stage aging of Example 2 (572 MPa). The first stage of two-stage aging usually forms a high-density GP region at low temperature, and the second stage promotes the transformation of the GP region into a more stable and dispersed η' phase. This two-stage system results in smaller and more uniformly distributed precipitated phases than direct high-temperature aging, thus achieving higher strength. Comparative Example 4 (containing only Zr, excluding Er) and Comparative Example 5 (containing only Y) have basically the same composition as Example 1, except that they lack key microalloying elements. Their mechanical properties (tensile strength and yield strength) are significantly worse than those of Example 1, further verifying the synergistic necessity of the Zr-Er-Y ternary microalloying system.

[0046] 2. Conductivity test The test was conducted in accordance with GB / T 12966-2022, "Eddy Current Test Method for Electrical Conductivity of Aluminum and Aluminum Alloys".

[0047] Testing equipment: Eddy current conductivity meter.

[0048] Test environment: Ambient temperature controlled at 20±2℃.

[0049] Test procedure: Before using the instrument, calibrate it with a standard test block and take measurements at 5 different locations evenly on the surface of each sample.

[0050] Results processing: The arithmetic mean of 5 measurements was taken as the conductivity value of the sample, expressed in %IACS. Three samples were tested for each material group, and the final result was the average of the three samples.

[0051] 3. Fatigue performance testing The procedure was carried out in accordance with GB / T 3075-2021 "Methods for Controlling Axial Force in Fatigue Testing of Metallic Materials".

[0052] Testing equipment: High-frequency fatigue testing machine.

[0053] Test method: The conditional fatigue limit under a specified number of cycles was determined using the rise and fall method.

[0054] Stress ratio: R=0.1 or R=-1.

[0055] Loop base: 1 × 10 7 Second-rate.

[0056] Stress increment: Take 3 to 5% of the expected fatigue limit.

[0057] Number of samples: The number of valid samples shall not be less than 15, for statistical purposes of the lifting method.

[0058] Results processing: The data from the rise and fall method were processed in accordance with GB / T 3075-2021 "Statistical Scheme and Analysis Method for Fatigue Test Data of Metallic Materials" to calculate the median fatigue limit (survival rate 50%) or the safe fatigue limit (survival rate 90%, confidence level 95%).

[0059] The test results are shown in Table 2 below.

[0060] Table 2

[0061] As shown in Table 2 above, the conductivity of traditional 7075 is only 38.0% IACS, which is relatively low. The conductivity of Examples 1-3 is significantly improved to 53.1-55.2% IACS. The increase in conductivity indicates that the solid solution elements (Zn, Mg, Cu) in the matrix are fully precipitated, forming a strengthening phase and purifying the matrix. The addition of trace amounts of Zr, Er, and Y can form stable dispersed phases, reducing the scattering of electrons to the matrix, thereby improving conductivity. High conductivity usually means that the alloy has better resistance to stress corrosion cracking. The conductivity of Comparative Example 4 (without Er) and Comparative Example 5 (without Y) is slightly lower than that of Example 2, indicating that the combined addition of Er and Y helps to optimize precipitation behavior and make the matrix purer.

[0062] The fatigue limit of Example 2 was significantly higher than that of Comparative Example 1. The fatigue limits of Comparative Examples 2 and 3 were significantly lower than those of Example 2, indicating that the dislocation configuration and the size and distribution of the precipitated phase are extremely sensitive to fatigue performance. Coarse precipitated phases or dislocation-free regions easily lead to stress concentration and early crack initiation. Comparative Example 4 (without Er) had the lowest fatigue limit (238 MPa), demonstrating that Er plays a crucial role in improving microstructure uniformity and enhancing fatigue resistance.

[0063] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-conductivity, ultra-high-strength aluminum alloy material for aerospace applications, characterized in that, Based on Al, its chemical composition by mass percentage includes: Zn 6~7%, Mg 2.2~2.8%, Cu 1.3~1.7%, Zr 0.18~0.3%, Er 0.1~0.2%, Y 0.06~0.12%, Ti 0.02~0.05%, B 0.001~0.003%, with the balance being Al and unavoidable impurities; The content of Fe is ≤0.05%, Si is ≤0.05%, individual impurities are ≤0.03%, and the total amount of impurities is ≤0.12%.

2. The high conductivity ultra-high strength aluminum alloy material for aerospace applications according to claim 1, characterized in that, After two-stage homogenization and two-stage aging, Zr and Er form a coherent / semi-coherent Al3(Er, Zr) composite nanoprecipitate, with Y element segregating at grain boundaries and phase boundaries.

3. A method for preparing the high conductivity ultra-high strength aluminum alloy material for aerospace applications as described in claim 1, characterized in that, Includes the following steps: S1. Raw material pretreatment: Industrial pure aluminum ingots, Zn ingots, Mg ingots, Cu ingots, and Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys with a purity ≥99.95% are selected, and are then surface-polished and dried for later use. S2, Smelting and Purification: Heat aluminum ingots to 740~760℃ to melt them, then add Zn ingots and Cu ingots in sequence, and hold for 20~30 minutes. Cool to 720~730℃, add Mg ingots, and stir for 5~10 minutes; Add Al-Zr, Al-Er, Al-Y, and Al-Ti-B master alloys and stir for 15-20 minutes; High-purity argon gas (purity ≥ 99.99%) is introduced into the melt at a flow rate of 0.3~0.5 m³ / h. 3 / h, spray refining for 25~30min, while adding refining agent, let stand for 15~20min, remove slag to obtain pure melt; S3, Semi-continuous casting: The melt temperature was adjusted to 690~710℃, and semi-continuous casting was used to obtain aluminum alloy ingots. S4. Homogenization process: A two-stage homogenization process is adopted, and after homogenization, water mist cooling is performed to room temperature. S5. Isothermal forging pretreatment: The homogenized ingot is heated to 380~420℃ and held for 1~2 hours. It is then forged using isothermal forging. After forging, it is immediately water-quenched to room temperature to freeze the dislocations. S6. Hot extrusion forming: The forging billet is heated to 450~470℃, held for 1~3 hours, hot extruded using an extruder, and then air-cooled after extrusion. S7, Two-level timeliness processing: Perform a two-stage aging process, and then air-cool to room temperature after aging is complete.

4. The preparation method according to claim 3, characterized in that, The components and corresponding weight percentages of the refining agent mentioned in step S2 are: KCl 40~50%, MgCl2 20~30%, KF 5~10%, with the balance being NaCl, and the amount added is 0.1~0.2% of the melt mass.

5. The preparation method according to claim 3, characterized in that, In step S3, during semi-continuous casting, the casting speed is controlled at 80~120 mm / min, the cooling water temperature at 20~30℃, and the cooling intensity at 15~20℃ / min.

6. The preparation method according to claim 3, characterized in that, The two-stage homogenization process described in step S4 is as follows: the first stage is held at 400~420℃ for 4~6 hours, and the second stage is held at 480~500℃ for 8~10 hours.

7. The preparation method according to claim 3, characterized in that, The water mist cooling rate described in step S4 is 35~45℃ / min.

8. The preparation method according to claim 3, characterized in that, During isothermal forging as described in step S5, the deformation rate is controlled at 10~20%, and the deformation speed is 2~5 mm / s.

9. The preparation method according to claim 3, characterized in that, In step S6, the extrusion ratio is controlled at (20~30):1, the extrusion speed is 5~10mm / s, and the die temperature is 400~420℃ during hot extrusion.

10. The preparation method according to claim 3, characterized in that, The two-stage aging process described in step S7 is as follows: the first stage of aging is maintained at 100~110℃ for 4~6 hours, and the second stage of aging is maintained at 160~170℃ for 8~12 hours.

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