7xxx-series aluminum alloy sheet for aerospace applications and method of making

Abstract

The application discloses a kind of 7xxx series aluminum alloy plate for aviation and preparation method thereof, and is sequentially carried out batching, smelting, refining, casting, homogenization, milling, hot rolling, solid solution, quenching and aging treatment, control interpass hot rolling deformation amount is 5%~10%, rolling temperature 380~450 ℃, interpass rolling insulation 5~10 minutes, then hot rolling again, until the thickness required is satisfied, control finish rolling temperature is above 320 ℃, the application can effectively solve the problem of poor plasticity at room temperature and poor corrosion resistance by the above specific hot rolling and heat treatment process, the comprehensive mechanical properties of the plate are improved by optimizing solid solution and aging treatment system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aluminum alloy processing, and particularly relates to an aviation 7xxx series aluminum alloy plate and a preparation method thereof. BACKGROUND

[0002] Aluminum alloy is widely used in aerospace, transportation, machinery and electronics and many other fields due to its lightweight, high strength, high thermal conductivity, high modulus and low expansion and other excellent performances. The 7xxx series super high strength aluminum alloy is mainly Al-Zn-Mg-Cu aluminum alloy, which successfully replaces the relatively high-cost titanium alloy and the relatively small specific strength steel in many fields, and becomes an indispensable structural material in military and civilian aircraft, and is one of the key structural materials for large transport aircraft, fighter aircraft, missile and armored vehicle, which is mainly because the 7xxx series aluminum alloy has excellent strength, toughness and welding performance and other comprehensive performances, but its heat resistance and corrosion resistance are poor.

[0003] In the actual production process, the performance and stability of the 7xxx series aluminum alloy product do not meet the standards due to the influence of deformation process and heat treatment system. Among them, the rolling deformation can change the grain orientation distribution in the alloy plate, and enhance the stress corrosion resistance, exfoliation corrosion resistance and intergranular corrosion resistance of the alloy, and the regression re-aging heat treatment system can obtain high stress corrosion resistance while maintaining high strength.

[0004] T6 peak aging treatment can obtain the highest hardness of the Al-Zn-Mg-Cu alloy, but the stress corrosion resistance is poor under this aging; the double-stage over-aging treatment can well improve the stress corrosion resistance and exfoliation corrosion resistance of the alloy, but at the cost of sacrificing certain strength; the existing preparation method of the high-strength corrosion-resistant 7xxx series aluminum alloy plate for aviation adopts double-stage aging treatment, which improves the corrosion resistance of the aluminum alloy plate, but reduces the strength of the alloy to some extent, which is not conducive to the comprehensive performance of the alloy plate. SUMMARY

[0005] The technical problem to be solved by the application is to provide an aviation 7xxx series aluminum alloy plate and a preparation method thereof, which can solve the technical problem of cracking and cracking of the plate during hot rolling, improve the stability and formability of the rolled plate by refining the grain through micro-alloying elements, optimizing the alloy plate preparation process, and improving the corrosion resistance and comprehensive mechanical properties.

[0006] The application adopts the following technical scheme:

[0007] An aviation 7xxx series aluminum alloy plate, by mass percentage, comprises the following components:

[0008] Cu: 1.9% to 2.5%, Mn: 0.1% to 0.2%, Mg: 2.0% to 2.7%, Zn: 5.9% to 6.9%, Ti: 0.05% to 0.15%, Zr: 0.05% to 0.15%, La: 0.05% to 0.15%, Ce: 0.05% to 0.10%, Y: 0.10% to 0.15%, Sc: 0.05% to 0.30%, Er: 0.05% to 0.30%, total amount of impurities: ≤0.15%, and the balance being Al.

[0009] Another technical solution of the present application is a preparation method of the 7xxx series aluminum alloy plate for aviation, comprising the following steps:

[0010] industrial pure Mg, industrial pure Zn, industrial pure Al and intermediate alloy are dosed; the dosed materials are vacuum melted to obtain an alloy liquid, and then the alloy liquid is refined; the raw materials in a molten state after refining are cast to obtain an aluminum alloy ingot, and the aluminum alloy ingot is subjected to homogenization treatment; the aluminum alloy ingot after homogenization treatment is subjected to face milling treatment, and then the aluminum alloy ingot after face milling is subjected to heating treatment; after heating and heat preservation, the aluminum alloy ingot is hot-rolled to obtain an aluminum alloy plate; the aluminum alloy plate after hot rolling is subjected to solid solution quenching treatment; the aluminum alloy plate after solid solution quenching is subjected to regression re-aging treatment and post-treatment, thereby obtaining the 7xxx series aluminum alloy plate for aviation.

[0011] Specifically, the intermediate alloy comprises AlCu50, AlMn10, AlTi5, AlZr5, AlLa20, AlCe10, AlV5, AlY10, AlSc2 and AlEr20.

[0012] Specifically, the temperature of vacuum melting is 750-780℃, the time is 1.5-2.5h, the refining is carried out by using a protective atmosphere, the temperature of refining is 30-750℃, and the time is 30-40min.

[0013] Specifically, the casting temperature is 720-740℃, and the temperature of homogenization treatment is 475-485℃, and the heat preservation time is 24-30h.

[0014] Specifically, the heating temperature is 380-450℃, and the heat preservation time is 2-3h.

[0015] Specifically, the ingot after heating and heat preservation is alternately subjected to vertical roll rolling and horizontal rolling, the vertical roll rolling is rolling along the side surface in the length direction of the ingot, the horizontal rolling is rolling along the surface in the thickness direction perpendicular to the ingot, and the last rolling is horizontal rolling, thereby obtaining a hot-rolled plate.

[0016] Specifically, the hot rolling process includes hot rough rolling and hot finish rolling; the hot rough rolling is to brush the surface of the roller with a steel brush for 2-4 minutes before rolling; the rotation direction of the steel brush roller is consistent with that of the roller, and the pressing force of the brush roller is 3600-3900 N;

[0017] The hot rough rolling process specifically includes static pressure welding, medium-speed rolling and high-speed rolling, and the reduction amount is controlled during the rolling process.

[0018] The static pressure welding specifically includes that the reduction amount of the first 1-3 passes of hot rolling is 4-6 mm, and the rolling speed is ≤10 m / min; the static pressure welding is performed by using a spraying method without spraying emulsion.

[0019] The medium-speed rolling specifically includes that the medium-speed rolling is performed according to a reduction amount of 10-20 mm per pass, and the rolling speed is 20-30 m / min.

[0020] The high-speed rolling specifically includes that the high-speed rolling is performed according to a large reduction amount of 15-25 mm per pass at a speed of 40-50 m / min, and the last 5 passes are performed for plate shape control with a reduction amount of 10-15 mm.

[0021] During the hot finish rolling process, the emulsion nozzle is opened for 5 seconds and closed for 15 seconds to cyclically lubricate the plate at the part with a width of 100-120 mm on both sides of the ingot, the temperature of the emulsion is 60-65 ℃, the pH value is 7-8.5, and the emulsion lubrication spraying pressure is 0.5-0.7 MPa.

[0022] The hot finish rolling process adopts 3 passes: the hot finish rolling temperature is 350-400 ℃, the first pass rolling speed is 2-3.0 M / S, the second pass rolling speed is 1-2.0 M / S, and the third pass rolling speed is 0.5-1 M / S; after the hot rolling is completed, the ingot is cooled by nitrogen blowing, and the cooling is completed to room temperature within 30-40 minutes; the holding time between the hot rolling passes is 5-10 minutes.

[0023] Specifically, the solid solution quenching treatment has a solid solution temperature of 470-480 ℃ and a holding time of 90-100 minutes, and the temperature of the cooling medium during the quenching process is 20-25 ℃.

[0024] Specifically, the retrogression and re-aging treatment specifically includes:

[0025] the temperature is increased from room temperature to 120-150 ℃ at a rate of 5-10 ℃ / min, the pre-aging is completed by holding for 24-26 hours; then the temperature is increased from room temperature to 160-200 ℃ at a rate of 5-10 ℃ / min, the retrogression is completed by holding for 80-120 minutes; finally, the temperature is increased from room temperature to 120 ℃ at a rate of 5-10 ℃ / min, and the re-aging is completed by holding for 24-26 hours.

[0026] Compared with the prior art, the present application has at least the following beneficial effects:

[0027] The application discloses an aviation 7xxx series aluminum alloy plate, trace alloy elements Sc and Er can form Al3(Sc, Zr, Er) particles with Zr, which can refine the as-cast grains to 20-40 nm, prevent recrystallized grain growth, improve alloy welding performance and corrosion performance, improve the corrosion resistance and comprehensive mechanical properties of the alloy plate, and the control of impurity elements is more strict, so that the formation of impurity phases such as Al3Fe and Mg2Si can be greatly removed, the elongation of the material can be improved, the Zn / Mg ratio in the alloy is improved, the increase of Zn content can increase the MgZn2 content, and the S(Al2CuMg) phase ratio is reduced, the brittleness of the S(Al2CuMg) phase is higher than that of the theta (Al2Cu) phase, so that the strength and plasticity of the material can be improved, the single pass reduction of the alloy is 10% of the total reduction during rolling, the microstructure uniformity and the strength of the plate in the thickness direction can be improved, and the corrosion resistance and other comprehensive mechanical properties of the alloy can be optimized through an optimized heat treatment system.

[0028] The application discloses a preparation method of an aviation 7xxx series aluminum alloy plate, which comprises the following steps: ingredient preparation of industrial pure Mg, industrial pure Zn, industrial pure Al and intermediate alloy; vacuum melting of the ingredients to obtain alloy liquid, and then refining the alloy liquid; casting the raw materials in a molten state after the refining to obtain an aluminum alloy ingot, and homogenizing the aluminum alloy ingot; milling the surface of the aluminum alloy ingot after the homogenizing treatment, and then heating the aluminum alloy ingot after the milling; hot rolling the aluminum alloy ingot after the heating and keeping warm to obtain an aluminum alloy plate; solid solution quenching the aluminum alloy plate after the hot rolling; returning the aluminum alloy plate after the solid solution quenching to aging treatment and post-treatment to obtain the aviation 7xxx series aluminum alloy plate, and successfully preparing the aluminum alloy plate with optimized performance.

[0029] Further, the alloy composition has a high Zn / Mg ratio, increasing the Zn content can increase the MgZn2 content, while reducing the S (Al2CuMg) phase ratio, the brittleness of the S phase is higher than that of the θ (Al2Cu) phase, which is beneficial to simultaneously improve the strength and plasticity of the material, Sc, Er and Zr cooperate to form Al3 (Er, Zr, Sc) with the lattice of the matrix, which has better thermodynamic matching, which can refine the grain and improve the welding performance and corrosion resistance of the material. Ti is added to make the alloy have better toughness. The addition of rare earth element La can form Al11La3 phase, which has strong anti-creep performance and can strengthen the grain boundary at high temperature, reducing the thermal cracking tendency of the alloy. The addition of Ce can inhibit the formation of GP zone and θ" phase, and is easy to form θ' phase, and Ce can increase the lattice distortion of the matrix, so that the system energy rises, and θ' phase is easy to form around Ce, so that the tensile strength of the alloy is improved; appropriate Y can refine the grain, and can form FeYAl8, Fe6AlY6, Fe4YAl8, SiYAl2, Si2YAl2, MnYAl8 and other compounds with impurity elements Fe, Si, etc. The formation of these Fe, Si and other compounds can purify the matrix.

[0030] Further, the affinity between aluminum and oxygen is very large, and it is easy to oxidize, in order to prevent the violent reaction of aluminum-oxygen, the aluminum alloy smelting temperature is controlled below 760℃, the viscosity of the aluminum liquid is generally small, so the temperature should be appropriately reduced for refining, and if the temperature is too high, a large amount of AlN inclusions will be generated during nitrogen refining, which will contaminate the aluminum liquid, and if the temperature is too low, the nitrogen diffusion coefficient will be reduced, and the reaction products generated by the introduction of chlorine gas refining are gaseous and insoluble in aluminum, and the unreacted chlorine gas forms bubbles to refine, and the refining time is too long, which will cause the alloy grain to be coarse and reduce the mechanical properties.

[0031] Further, the pouring temperature is set between 720-740℃, mainly because too high a temperature can burn the Mg element in the alloy, increase the alloy absorption capacity, and easily produce pinholes and pores, reducing the alloy quality; if the temperature is too low, the flowability of the aluminum liquid is poor; the homogenization temperature is 475-485℃, mainly because too high a temperature will cause the alloy to be overburned, and too low a temperature will cause serious intragranular segregation in the matrix, resulting in uneven composition; and a large number of calculation results show that with the extension of homogenization time, the homogenization degree of Mg and Zn elements is higher, while the homogenization degree of Sc, Ti and Zr elements is lower, and when the homogenization time is 20-28h, the difference between the surface and the center of the alloy elements is smaller and smaller, and the homogenization degree of the alloy elements is higher, so the best homogenization heat treatment process of the alloy is to keep it at 475-485℃ for 24-30h.

[0032] Further, the temperature is too high, easy to appear grain coarse or intergranular low melting point phase of melting, resulting in heating ingot overheating or overburning, hot rolling cracking, can not meet the performance requirements; temperature is too low, causing metal work hardening, energy consumption increases, incomplete recrystallization, ultimately leading to uneven grain size and poor performance.

[0033] Further, the rolling piece section can be compressed simultaneously, the rolling piece deformation is more uniform, the speed difference of the rolling piece section is smaller, and the internal stress of the rolling piece is smaller.

[0034] Further, the roughness of the working roll surface of the rolling mill is high, the reduction is large, the rolling metal temperature is high, the aluminum sticking is serious, the steel wire brush has strong cleaning force, good high temperature resistance, and the cleaning surface is uniform, so the cleaning force of the heat-resistant stainless steel wire is selected. The surface roughness of the brush roll is rapidly reduced, the bite is difficult, the serious slip is increased, the surface quality is deteriorated, the emulsion is sprayed on the aluminum plate and the roll with very high temperature, the balance state is destroyed, the oil and water are rapidly separated, the water evaporation takes away a large amount of heat, and the roll and the aluminum plate are cooled. The remaining water and oil form an anti-milk film uniformly diffused on the surface of the metal, forming a lubricating film, which plays a lubricating role in rolling. The cycle lubrication of the open 5s and the closed 15s can maximize the utilization, the temperature is low, various microorganisms are easy to breed, the emulsion is deteriorated, the heat separation is poor, the lubricating performance is reduced, the temperature is too high, the additives in the emulsion are precipitated, and the stability of the emulsion is affected. Low pH value, emulsion rancidity, poor lubrication and cooling effect, high pH value, emulsion lubrication capacity decreases; in the initial rolling stage, static pressure welding can make the force acting on the surface uniformly transmitted in all directions, so that the performance of the plate is uniformly distributed, the rolling speed is appropriately increased in the middle rolling stage, and the amount of deformation heat loss is reduced. In the final stage, high-speed rolling can reduce energy consumption and obtain plate with good comprehensive performance. The surface quality of the plate is good by adopting three passes with different rolling speeds in the finishing rolling, and the surface defects are reduced or eliminated. Nitrogen blowing can make the water in the plate evaporate and separate rapidly, realize oxygen-free concentration of the sample, and keep the sample surface pure.

[0035] Further, the solid solution temperature is set to 470-480℃, the holding time is 90-100min, and then quenching, which can fully dissolve alloying elements into the matrix to obtain supersaturated solid solution for subsequent heat treatment. If the solid solution temperature is too high, the alloying elements will be overburned, which will affect the performance of the alloy. If the temperature is too low, the alloying elements will not be fully dissolved, and the performance of the alloy will not be fully utilized.

[0036] Further, the regression re-aging can make the plate have the strength of single-stage peak aging state and the corrosion resistance of two-stage aging state, that is, the alloy can obtain good stress corrosion resistance and fracture toughness after the regression re-aging.

[0037] In conclusion, the 7xxx series aluminum alloy plate for vehicles is prepared by optimizing alloy composition, casting, hot rolling, regression re-aging heat treatment and other technical means, so that the corrosion resistance and fracture toughness of the aluminum alloy are effectively improved.

[0038] The technical solutions of the present application will be further described in detail below by means of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a hot rolling process schematic diagram of the present application;

[0040] Figure 2 It is a 5 7xxx series aluminum alloy hot rolling sample actual picture of the present application;

[0041] Figure 3 It is an alloy hot rolling plate IPF diagram of example 1 of the present application;

[0042] Figure 4 It is an alloy hot rolling plate IPF diagram of example 2 of the present application;

[0043] Figure 5 It is an alloy hot rolling plate IPF diagram of example 3 of the present application;

[0044] Figure 6 It is an alloy hot rolling plate IPF diagram of example 4 of the present application;

[0045] Figure 7 It is an alloy hot rolling plate IPF diagram of example 5 of the present application. DETAILED DESCRIPTION

[0046] The technical solutions of the present application will be further described in detail below by means of the drawings and examples.

[0047] In the present application, all the embodiments and preferred implementation methods mentioned in the present application can be combined to form new technical solutions, if not specifically stated.

[0048] In the present application, all the technical features and preferred features mentioned in the present application can be combined to form new technical solutions, if not specifically stated.

[0049] In the present application, unless otherwise specified, percentage (%) or part refers to the weight percentage or weight part of the composition.

[0050] In the present application, unless otherwise specified, each component or its preferred component involved can be combined with each other to form a new technical solution.

[0051] In the present application, unless otherwise specified, the numerical range "a~b" represents a shorthand notation for any real number combination between a and b, wherein a and b are both real numbers. For example, the numerical range "6~22" represents that all real numbers between "6~22" have been listed herein, and "6~22" is only a shorthand notation for these numerical combinations.

[0052] The lower limit and upper limit of the range disclosed in the present application can be one or more lower limits and one or more upper limits, respectively.

[0053] In the present application, the term "and / or" used herein means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0054] In the present application, unless otherwise specified, each reaction or operation step can be carried out sequentially or according to the sequence. Preferably, the reaction method herein is carried out sequentially.

[0055] Unless otherwise specified, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to that described can also be applied in the present application.

[0056] The present application provides an aviation 7xxx series aluminum alloy plate and a preparation method thereof, which comprises the following steps: sequentially performing batching, smelting, refining, casting, homogenization, face milling, hot rolling, solid solution, quenching and aging treatment; controlling the interpass hot rolling deformation amount to be 5%~10%, the rolling temperature to be 370~410℃, the interpass rolling holding time to be 10 minutes, then hot rolling again until the required thickness is met, and controlling the finish rolling temperature to be above 320℃. Through the above specific hot rolling and heat treatment process, the problems of poor plasticity at room temperature and poor corrosion resistance are effectively solved, and through the optimized solid solution and aging treatment system, the comprehensive mechanical properties of the plate are improved.

[0057] Please refer to Figure 1 The present application provides an aviation 7xxx series aluminum alloy plate and a preparation method thereof, which comprises the following steps:

[0058] S1, batching

[0059] The industrial pure Mg, industrial pure Zn, industrial pure Al and intermediate alloy are batched according to the designed mass percentage.

[0060] S2, smelting

[0061] The ingredients obtained in step S1 are placed in a vacuum smelting furnace, and the smelting temperature is controlled to be 750-780℃ during the smelting process, and the smelting time is 1-2h. During the smelting process, the intermediate alloys AlCu50, AlMn10, AlTi5, AlZr5, AlLa20, AlCe10, AlV5, AlY10, AlSc2 and AlEr20 are added.

[0062] The prepared raw materials are placed in a smelting furnace to a completely molten state, and slag is removed to make the surface of the aluminum liquid free of floating slag. Then, the alloy components are detected, and the alloy components are qualified before refining.

[0063] S3, refining

[0064] The alloy liquid obtained in step S2 is refined, and the temperature is controlled to be 730-740℃ during the refining process. The refining is carried out in a protective atmosphere to obtain a molten raw material, and the refining time is 30-40min.

[0065] The protective atmosphere is obtained by removing chlorine and nitrogen.

[0066] S4, casting

[0067] The alloy liquid obtained after standing in step S3 is cast, and the pouring temperature is controlled to be 720-740℃ during the casting process.

[0068] S5, homogenization treatment

[0069] The cast ingot obtained in step S4 is subjected to homogenization treatment at a temperature of 475-485℃ for 24-30h.

[0070] S6, heating

[0071] The milled aluminum alloy ingot is placed in a heating furnace for heating, and the heating furnace temperature is 380-450℃, and the holding time is 2-3h.

[0072] S7, hot rolling

[0073] The cast ingot after heating and holding is taken out of the furnace and subjected to hot rolling process. The cast ingot is alternately subjected to vertical rolling and horizontal rolling, and the last rolling is the horizontal rolling. First, hot rough rolling is carried out, and the roller surface is cleaned with a steel wire brush for 2-4min, and the pressing force of the brush roller is 3600-3900N. Then, the plate is hot finished, and the emulsion nozzle is opened for 5s and closed for 15s to circulate the lubricating plate. The final rolling temperature is 350±10℃, and the aluminum alloy plate is obtained. Finally, the hot-rolled plate is placed horizontally on the ground, and nitrogen is blown to cool to room temperature.

[0074] The hot rough rolling static pressure welding is specifically: the reduction of the first to third passes of the hot rolling is 4-6 mm, and the rolling speed is ≤10 m / min; the medium speed rolling is specifically: the medium speed rolling is performed according to the pass reduction of 10-20 mm, and the rolling speed is 20-30 m / min; the high speed rolling is specifically: the high speed rolling is performed according to the pass reduction of 15-25 mm at the speed of 40-50 m / min, and the last five passes are performed for the shape control with the reduction of 10-15 mm.

[0075] The hot finishing rolling temperature is 350-400℃, the first pass rolling speed is 2-3.0 M / S; the second pass rolling speed is 1-2.0 M / S; and the third pass rolling speed is 0.5-1 M / S. After the hot rolling, the hot-rolled plate is cooled to room temperature by nitrogen blowing within 30-40 min; and the hot-rolled plate is kept for 5-10 min between passes.

[0076] The lubricating medium used in the hot rolling process is an emulsion with the PH value of 7-8.5, the emulsion lubrication injection pressure is 0.5-0.7 Mpa, and the emulsion temperature during use is 60-65℃.

[0077] In the case of following the same rolling process, the measurement frequency is increased, the difference between the roll gap value and the actual thickness and the difference between the head and the tail of the plate are found out, so as to accurately set the roll gap value and accurately control the thickness.

[0078] S8, solution quenching

[0079] The hot-rolled aluminum alloy plate is subjected to solution quenching treatment, the solution temperature is 470-480℃, the holding time is 90-100 min, after the solution treatment, the aluminum alloy plate is transferred to the cooling medium within 5 s for quenching, and the temperature of the cooling medium during the quenching process is 20-25℃.

[0080] S9, aging

[0081] The aluminum alloy plate after the solution quenching is subjected to return aging treatment.

[0082] The specific steps are as follows:

[0083] S901, pre-aging

[0084] The temperature is increased from room temperature to 120-150℃ at the rate of 5-10℃ / min, and the holding time is 24-26 h.

[0085] S902, return treatment

[0086] The temperature is increased from room temperature to 160-200℃ at the rate of 5-10℃ / min, and the holding time is 80-120 min.

[0087] S903, re-aging

[0088] Rise from room temperature to 120-150 DEG C, the temperature rising rate is 5-10 DEG C / min, and the temperature is kept for 24-26 hours.

[0089] S10、Post-processing

[0090] The aluminum alloy plate after the regression re-aging heat treatment is sawed into finished product specifications.

[0091] The application discloses an aviation 7xxx series aluminum alloy plate, which comprises the following components in percentage by mass:

[0092] Cu accounts for 1.9-2.5%, Fe accounts for 0.05-0.10%, Si accounts for 0.05-0.10%, Mn accounts for 0.1-0.2%, Mg accounts for 2.0-2.7%, Zn accounts for 5.9-6.9%, Ti accounts for 0.05-0.15%, Zr accounts for 0.05-0.15%, La accounts for 0.05-0.15%, Ce accounts for 0.05-0.10%, Y accounts for 0.10-0.15%, Sc accounts for 0.05-0.30%, Er accounts for 0.05-0.30%, the total amount of impurities is less than or equal to 0.15%, and the balance is Al.

[0093] Please refer to Figure 2 The schematic diagram of the sample after rolling is shown, and the strength reaches 700-860 Mpa, the elongation reaches 9-12%, and the stress corrosion sensitivity is E loss The regression re-aging treatment can make the alloy obtain higher strength and better stress corrosion resistance.

[0094] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application will be clearly and completely described below in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are some embodiments of the application, rather than all the embodiments of the application. The components of the embodiments of the application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the application.

[0095] Embodiment 1

[0096] The application discloses a preparation method of an aviation 7xxx series aluminum alloy plate.

[0097] Cu: 1.9%, Mn: 0.1%, Mg: 2.0%, Zn: 5.9%, Ti: 0.05%, Zr: 0.05%, La: 0.05%, Ce: 0.05%, Y: 0.10%, Sc: 0.05%, Er: 0.05%, total impurities ≤ 0.15%, and the balance being Al, based on 100% of the total mass of the alloy.

[0098] The alloy of Example 1 was co-cast in 70 kg, and the detailed preparation steps are as follows:

[0099] First step: various alloy ingredients were prepared according to the designed proportions, wherein 2.66 kg of AlCu50, 0.7 kg of AlMn10, 1.4 kg of pure Mg, 4.13 kg of pure Zn, 0.7 kg of AlTi5, 0.7 kg of AlZr5, 0.175 kg of AlLa20, 0.35 kg of AlCe10, 0.7 kg of AlY10, 1.75 kg of AlSc2, 0.175 kg of AlEr20, and 56.585 kg of pure Al were added.

[0100] Second step: the ingredients obtained in step one were placed in a vacuum melting furnace for melting, the melting temperature was 750°C, and the melting time was 1.5 h.

[0101] Refining: the alloy liquid obtained in step two was refined, the temperature control during the refining process was 730°C, the refining was carried out in a protective atmosphere, and the molten raw material was obtained, the refining time was 30 min, and argon and nitrogen and chlorine were introduced for composite refining.

[0102] Casting: the molten raw material was placed for 30 min, and then cast into a mold, the casting temperature was 720°C, and an aluminum alloy ingot was obtained.

[0103] Homogenization treatment: the cast ingot was subjected to homogenization treatment at a temperature of 475°C for 24 h.

[0104] Heating: the milled aluminum alloy ingot was placed in a heating furnace, the heating furnace temperature was 380±10°C, and the holding time was 2 h.

[0105] Hot rolling: the cast ingot after heating and holding was alternately subjected to vertical roll rolling and horizontal rolling, the vertical roll rolling was rolling along the side surface in the length direction of the ingot, the horizontal rolling was rolling along the surface perpendicular to the thickness direction of the ingot, and the last group of rolling was the horizontal rolling, and a hot-rolled plate was obtained.

[0106] Hot rough rolling is to clean the surface of the roller with a wire brush for 2 minutes before rolling. The wire brush roller is consistent with the direction of the roller, and the pressing force of the brush roller is 3600N. During hot finish rolling, the emulsion nozzle is opened for 5 seconds and closed for 15 seconds in a cycle to lubricate the plate on both sides of the ingot with a width of 100mm, the temperature of the emulsion during use is 60℃, the pH value is controlled at 7, and the emulsion lubrication injection pressure is 0.5Mpa.

[0107] The hot rough rolling process is as follows: static pressure welding, medium speed rolling and high speed rolling, and the reduction amount is controlled during rolling. The static pressure welding is as follows: the reduction amount of the first three passes of hot rolling is 4mm, and the rolling speed is ≤10m / min; the static pressure welding is carried out by spraying without spraying emulsion; the medium speed rolling is as follows: the medium speed rolling is carried out according to the reduction amount of 10mm pass, and the rolling speed is 20m / min; the high speed rolling is as follows: the high speed rolling is carried out according to the reduction amount of 15mm pass at a speed of 40m / min, and the last 5 passes are carried out for shape control with a reduction amount of 10mm. The hot finish rolling process adopts 3 passes of rolling: the hot finish rolling temperature is 350℃, the first pass rolling speed is 2M / S; the second pass rolling speed is 1M / S; and the third pass rolling speed is 0.5M / S. After hot rolling, the plate is cooled by nitrogen blowing, and cooled to room temperature within 30 minutes. The holding time between hot rolling passes is 5 minutes.

[0108] Solution quenching: the solution quenching treatment is carried out on the plate of the aluminum alloy after hot rolling, the solution temperature is 470±10℃, the holding time is 90 minutes, and then quenching;

[0109] Aging: the plate after solution quenching is subjected to a return and re-aging treatment, and the steps are as follows:

[0110] Pre-aging: from room temperature to 120℃, the heating rate is 5℃ / min, and the holding time is 24 hours;

[0111] Return treatment: from room temperature to 160℃, the heating rate is 5℃ / min, and the holding time is 60 minutes;

[0112] Re-aging: from room temperature to 120℃, the heating rate is 5℃ / min, and the holding time is 24 hours;

[0113] Post-processing: the aluminum alloy plate after the return and re-aging heat treatment is sawn into finished product specifications.

[0114] Please refer to Figure 3 , the plate has good performance, high strength plasticity and toughness, and good corrosion resistance (strength: 700MPa, elongation: 8.45%, E loss : 0.08).

[0115] Example 2

[0116] The application discloses a preparation method of a 7xxx aluminum alloy plate for aviation.

[0117] The alloy is calculated based on 100% of the total mass of the alloy: Cu: 2.5%, Mn: 0.2%, Mg: 2.7%, Zn: 6.9%, Ti: 0.15%, Zr: 0.15%, La: 0.15%, Ce: 0.10%, Y: 0.15%, Sc: 0.3%, Er: 0.3%, total impurities: ≤0.15%, and the balance is Al.

[0118] The co-casting alloy is 70 kg, and the detailed preparation steps are as follows:

[0119] Step 1: various alloy ingredients are proportioned according to the design proportion, and 3.5 kg of AlCu50, 1.4 kg of AlMn10, 1.89 kg of pure Mg, 4.83 kg of pure Zn, 2.1 kg of AlTi5, 2.1 kg of AlZr5, 0.525 kg of AlLa20, 0.7 kg of AlCe10, 1.05 kg of AlY10, 10.5 kg of AlSc2, 1.05 kg of AlEr20 and 40.355 kg of pure Al are added;

[0120] Step 2: the ingredients obtained in step 1 are placed into a vacuum melting furnace for melting, the melting temperature is 780 DEG C, and the melting time is 2.5 h;

[0121] Refining: the alloy liquid obtained in step 2 is refined, the temperature control during the refining process is 750 DEG C, the refining is carried out in a protective atmosphere, a molten raw material is obtained, the refining time is 40 min, and nitrogen and chlorine are introduced for solvent complex refining;

[0122] Casting: the molten raw material is placed for 30 min, and then is cast into a mold, the casting temperature is 740 DEG C, and an aluminum alloy ingot is obtained;

[0123] Homogenization treatment: the cast ingot is subjected to homogenization treatment at a temperature of 485 DEG C for 30 h;

[0124] Heating: the aluminum alloy ingot after milling is placed in a heating furnace, the heating furnace temperature is 450 DEG C ± 10 DEG C, and the holding time is 1 h;

[0125] Hot rolling: the cast ingot after heating and holding is alternately subjected to vertical roll rolling and horizontal rolling, the vertical roll rolling is rolling along the side surface in the length direction of the cast ingot, the horizontal rolling is rolling along the surface in the thickness direction perpendicular to the cast ingot, and the last rolling is the horizontal rolling, so that a hot-rolled plate is obtained.

[0126] Hot rough rolling is to clean the surface of the roller with a wire brush for 4 minutes before rolling. The wire brush roller is consistent with the direction of the roller, and the pressing force of the brush roller is 3900N. During hot finish rolling, the emulsion nozzle is opened for 5 seconds and closed for 15 seconds in a cycle to lubricate the plate on both sides of the ingot with a width of 120mm, the temperature of the emulsion during use is 65℃, the pH value is controlled at 8.5, and the emulsion lubrication injection pressure is 0.7Mpa.

[0127] The hot rough rolling process is as follows: static pressure welding, medium speed rolling and high speed rolling, and the reduction amount is controlled during rolling. The static pressure welding is as follows: the reduction amount of the first three passes of hot rolling is 6mm, and the rolling speed is ≤10m / min; the static pressure welding is carried out by spraying without spraying emulsion; the medium speed rolling is as follows: the medium speed rolling is carried out according to the pass reduction amount of 20mm, and the rolling speed is 30m / min; the high speed rolling is as follows: the high speed rolling is carried out according to the pass reduction amount of 25mm at a speed of 50m / min, and the last 5 passes are carried out for plate shape control with a reduction amount of 15mm. The hot finish rolling process adopts 3 passes of rolling: the hot finish rolling temperature is 400℃, the first pass rolling speed is 3M / S; the second pass rolling speed is 2M / S; and the third pass rolling speed is 1M / S. After hot rolling, the plate is cooled by nitrogen blowing, and cooled to room temperature within 40 minutes. The holding time between hot rolling passes is 10 minutes.

[0128] Solution quenching: the solution quenching treatment is carried out on the plate of the aluminum alloy after hot rolling, the solution temperature is 480±10℃, the holding time is 100 minutes, and then quenching;

[0129] Aging: the plate after solution quenching is subjected to a return and re-aging treatment, and the steps are as follows:

[0130] Pre-aging: from room temperature to 150℃, the heating rate is 10℃ / min, and the holding time is 26h;

[0131] Return treatment: from room temperature to 200℃, the heating rate is 10℃ / min, and the holding time is 120min;

[0132] Re-aging: from room temperature to 150℃, the heating rate is 10℃ / min, and the holding time is 26h;

[0133] Post-processing: the aluminum alloy plate after the return and re-aging heat treatment is sawn into finished product specifications.

[0134] Please refer to Figure 4 , the plate has good performance, high strength plasticity and toughness, and good corrosion resistance (strength: 800MPa, elongation: 9.2%, E loss : 0.10).

[0135] Example 3

[0136] The application discloses a preparation method of a 7xxx series aluminum alloy plate for aviation.

[0137] The alloy is calculated based on the total mass of 100%: Cu: 1.9%, Mn: 0.1%, Mg: 2%, Zn: 5.9%, Ti: 0.10%, Zr: 0.10%, La: 0.10%, Ce: 0.05%, Y: 0.10%, Sc: 0.15%, Er: 0.15%, total impurities: ≤0.15%, and the balance is Al.

[0138] The co-casting alloy is 70 kg, and the detailed preparation steps are as follows:

[0139] First step: various alloy ingredients are proportioned according to the designed proportion, wherein 2.66 kg of AlCu50, 0.7 kg of AlMn10, 1.4 kg of pure Mg, 4.13 kg of pure Zn, 1.4 kg of AlTi5, 1.4 kg of AlZr5, 0.35 kg of AlLa20, 0.35 kg of AlCe10, 0.7 kg of AlY10, 5.25 kg of AlSc2, 0.525 kg of AlEr20 and 51.14 kg of pure Al are added;

[0140] Second step: the ingredients obtained in the first step are placed into a vacuum melting furnace for melting, the melting temperature is 760 DEG C, and the melting time is 2 h;

[0141] Refining: the alloy liquid obtained in the second step is refined, the temperature control during the refining process is 740 DEG C, the refining is carried out in a protective atmosphere, a molten raw material is obtained, the refining time is 20 min, and nitrogen and chlorine are introduced for solvent composite refining;

[0142] Casting: the molten raw material is placed for 30 min, and then is cast into a mold, the casting temperature is 730 DEG C, and an aluminum alloy ingot is obtained;

[0143] Homogenization treatment: the cast ingot is subjected to homogenization treatment at a temperature of 480 DEG C for 25 h;

[0144] Heating: the aluminum alloy ingot after milling is placed in a heating furnace, the heating furnace temperature is 390 DEG C ± 10 DEG C, and the holding time is 2.5 h;

[0145] Hot rolling: the cast ingot after heating and holding is alternately subjected to vertical roll rolling and horizontal rolling, the vertical roll rolling is rolling along the side surface in the length direction of the cast ingot, the horizontal rolling is rolling along the surface in the thickness direction of the cast ingot, and the last rolling is the horizontal rolling, and a hot-rolled plate is obtained.

[0146] Hot rough rolling is to clean the surface of the roller with a wire brush for 3 minutes before rolling. The direction of the wire brush roller is consistent with that of the roller, and the pressing force of the brush roller is 3800N. During hot finish rolling, the emulsion nozzle is opened for 5 seconds and closed for 15 seconds in a cycle to lubricate the plate on both sides of the ingot with a width of 110mm, the temperature of the emulsion during use is 64 DEG C, the pH value is controlled to be 8, and the emulsion lubrication injection pressure is 0.65Mpa.

[0147] The hot rough rolling process is as follows: static pressure welding, medium speed rolling and high speed rolling, and the reduction amount is controlled during rolling. The static pressure welding is as follows: the reduction amount of the first three passes of hot rolling is 5mm, and the rolling speed is less than or equal to 10m / min; the static pressure welding is carried out by spraying without spraying emulsion; the medium speed rolling is as follows: the medium speed rolling is carried out according to a reduction amount of 15mm, and the rolling speed is 25m / min; the high speed rolling is as follows: the high speed rolling is carried out according to a reduction amount of 20mm at a speed of 45m / min, and the last five passes are carried out for shape control with a reduction amount of 12mm. The hot finish rolling process adopts three passes: the hot finish rolling temperature is 380 DEG C, the first pass rolling speed is 2.5M / S, the second pass rolling speed is 1.5M / S, and the third pass rolling speed is 0.75M / S. After hot rolling, the plate is cooled by nitrogen blowing, and cooled to room temperature within 35 minutes. The holding time between hot rolling passes is 8 minutes.

[0148] Aging: the solution-quenched plate is subjected to a return re-aging treatment, and the steps are as follows:

[0149] Pre-aging: from room temperature to 130 DEG C at a rate of 8 DEG C / min, and holding for 25h;

[0150] Return treatment: from room temperature to 160 DEG C at a rate of 8 DEG C / min, and holding for 100min;

[0151] Re-aging: from room temperature to 130 DEG C at a rate of 8 DEG C / min, and holding for 25h;

[0152] Post-treatment: the aluminum alloy plate after the return re-aging heat treatment is sawn into finished product specifications.

[0153] Please refer to Figure 5 , the plate has good performance, high strength plasticity and toughness, and good corrosion resistance (strength: 850MPa, elongation: 10.2%, E loss : 0.09).

[0154] Example 4

[0155] The application discloses a preparation method of a 7xxx aluminum alloy plate for aviation, and comprises the following steps:

[0156] Cu: 2.5%, Mn: 0.2%, Mg: 2.7%, Zn: 6.9%, Ti: 0.15%, Zr: 0.15%, La: 0.15%, Ce: 0.10%, Y: 0.15%, Sc: 0.30%, Er: 0.30%, total impurities ≤ 0.15%, and the balance being Al, based on the total mass of the alloy being 100%.

[0157] Example 4 The co-casting alloy was 70 kg, and the detailed preparation steps were as follows:

[0158] First step: various alloy ingredients were prepared according to the designed proportions, wherein 3.5 kg of AlCu50, 1.4 kg of AlMn10, 3.78 kg of pure Mg, 4.83 kg of pure Zn, 2.1 kg of AlTi5, 2.1 kg of AlZr5, 0.525 kg of AlLa20, 0.7 kg of AlCe10, 1.05 kg of AlY10, 10.5 kg of AlSc2, 1.05 kg of AlEr20, and 38.02 kg of pure Al were added;

[0159] Second step: the ingredients obtained in step one were placed into a vacuum melting furnace for melting, the melting temperature was 770°C, and the melting time was 2.3 h;

[0160] Refining: the alloy liquid obtained in step two was refined, the temperature control during the refining process was 740°C, the refining was performed in a protective atmosphere, a molten raw material was obtained, the refining time was 35 min, and nitrogen and chlorine were introduced for solvent complex refining;

[0161] Casting: the molten raw material was left to stand for 30 min, and then was cast into a mold, the casting temperature was 725°C, and an aluminum alloy ingot was obtained;

[0162] Homogenization treatment: the cast ingot after casting was subjected to homogenization treatment, the temperature was 485°C, and the holding time was 28 h;

[0163] Heating: the aluminum alloy ingot after milling was placed in a heating furnace for heating, the heating furnace temperature was 410±10°C, and the holding time was 2 h;

[0164] Hot rolling: the ingot after heating and holding was alternately subjected to vertical roll rolling and horizontal rolling, the vertical roll rolling was rolling along the side surface in the length direction of the ingot, the horizontal rolling was rolling along the surface in the thickness direction perpendicular to the ingot, and the last group of rolling was the horizontal rolling, and a hot-rolled plate was obtained.

[0165] Hot rough rolling is to clean the surface of the roller with a wire brush for 4 minutes before rolling. The direction of the wire brush roller is consistent with that of the roller, and the pressing force of the brush roller is 3700N. During hot finish rolling, the emulsion nozzle is opened for 5 seconds and closed for 15 seconds in a cycle to lubricate the plate on both sides of the ingot with a width of 115mm, the temperature of the emulsion during use is 63 DEG C, the pH value is controlled to be 7.5, and the emulsion lubrication injection pressure is 0.55Mpa.

[0166] The hot rough rolling process is as follows: static pressure welding, medium speed rolling and high speed rolling, and the reduction amount is controlled during rolling. The static pressure welding is as follows: the reduction amount of the first three passes of hot rolling is 6mm, and the rolling speed is less than or equal to 10m / min; the static pressure welding is carried out by spraying without spraying emulsion; the medium speed rolling is as follows: the medium speed rolling is carried out according to the reduction amount of 18mm pass, and the rolling speed is 28m / min; the high speed rolling is as follows: the high speed rolling is carried out according to the reduction amount of 23mm pass with a speed of 42m / min, and the last five passes are carried out for shape control with a reduction amount of 14mm. The hot finish rolling process adopts three passes: the hot finish rolling temperature is 360 DEG C, the first pass rolling speed is 2.2M / S; the second pass rolling speed is 1.3M / S; and the third pass rolling speed is 0.70M / S. After hot rolling, the plate is cooled by nitrogen blowing, and cooled to room temperature within 40 minutes. The holding time between hot rolling passes is 8 minutes.

[0167] aging: the solution-quenched plate is subjected to a return aging treatment, and the steps are as follows:

[0168] pre-aging: from room temperature to 140 DEG C, the heating rate is 6 DEG C / min, and the holding time is 27h;

[0169] return treatment: from room temperature to 190 DEG C, the heating rate is 6 DEG C / min, and the holding time is 110min;

[0170] re-aging: from room temperature to 140 DEG C, the heating rate is 6 DEG C / min, and the holding time is 27h;

[0171] post-treatment: the aluminum alloy plate after the return aging heat treatment is sawn into finished product specifications.

[0172] Please refer to Figure 6 , the plate has good performance, high strength plasticity and toughness, and good corrosion resistance (strength: 830MPa, elongation: 11.2%, E loss :0.10).

[0173] Example 5

[0174] The application discloses a preparation method of a 7xxx series aluminum alloy plate for aviation, and comprises the following steps:

[0175] Cu: 1.9%, Mn: 0.15%, Mg: 2.5%, Zn: 6.5%, Ti: 0.10%, Zr: 0.10%, La: 0.10%, Ce: 0.10%, Y: 0.10%, Sc: 0.15%, Er: 0.15%, total impurities ≤ 0.15%, and the balance being Al, based on 100% of the total mass of the alloy.

[0176] Example 5 The co-casting alloy was 70 kg, and the detailed preparation steps were as follows:

[0177] First step: various alloy ingredients were prepared according to the designed proportions, wherein 2.66 kg of AlCu50, 1.05 kg of AlMn10, 1.75 kg of pure Mg, 4.55 kg of pure Zn, 1.4 kg of AlTi5, 1.4 kg of AlZr5, 0.35 kg of AlLa20, 0.7 kg of AlCe10, 0.7 kg of AlY10, 5.25 kg of AlSc2, 0.525 kg of AlEr20, and 49.67 kg of pure Al were added;

[0178] Second step: the ingredients obtained in step one were placed in a vacuum melting furnace for melting, the melting temperature was 750°C, and the melting time was 2.5 h;

[0179] Refining: the alloy liquid obtained in step two was refined, the temperature control during the refining process was 730°C, the refining was performed in a protective atmosphere, a molten raw material was obtained, the refining time was 40 min, and nitrogen and chlorine were introduced for complex refining with the solvent;

[0180] Casting: the molten raw material was left to stand for 30 min, and then was cast into a mold, the casting temperature was 720°C, and an aluminum alloy ingot was obtained;

[0181] Homogenization treatment: the cast ingot after casting was subjected to homogenization treatment at a temperature of 485°C for 24 h;

[0182] Heating: the aluminum alloy ingot after milling was placed in a heating furnace, the heating furnace temperature was 380±10°C, and the holding time was 1 h;

[0183] Hot rolling: the ingot after heating and holding was alternately subjected to vertical roll rolling and horizontal rolling, the vertical roll rolling was rolling along the side surface in the length direction of the ingot, the horizontal rolling was rolling along the surface in the thickness direction perpendicular to the ingot, and the last group of rolling was the horizontal rolling, and a hot-rolled plate was obtained.

[0184] Hot rough rolling is to brush the surface of the roller with a wire brush for 4 minutes before rolling. The wire brush roller is consistent with the direction of the roller, and the pressing force of the brush roller is 3900N. During hot finish rolling, the emulsion nozzle is opened for 5 seconds and closed for 15 seconds in a cycle to lubricate the plate on both sides of the ingot with a width of 120mm. The temperature of the emulsion during use is 60℃, the pH value is controlled at 8.5, and the emulsion lubrication injection pressure is 0.5Mpa.

[0185] The hot rough rolling process is as follows: static pressure welding, medium speed rolling and medium-high speed rolling, and controlling the reduction during rolling. The static pressure welding is as follows: the reduction of the first three passes of hot rolling is 4mm, and the rolling speed is ≤10m / min; the static pressure welding is carried out by spraying without spraying emulsion; the medium speed rolling is as follows: medium speed rolling with a pass reduction of 20mm, and the rolling speed is 20m / min; the high speed rolling is as follows: rolling with a pass reduction of 25mm at a speed of 40m / min, and the last 5 passes are controlled by a reduction of 10mm for plate shape. The hot finish rolling process adopts 3 passes of rolling: the hot finish rolling temperature is 400℃, the first pass rolling speed is 1M / S; the second pass rolling speed is 1M / S; the third pass rolling speed is 1M / S. After hot rolling, the plate is cooled by nitrogen blowing, and cooled to room temperature within 40 minutes. The holding time between hot rolling passes is 5 minutes.

[0186] Aging: the solution-quenched plate is subjected to a return aging treatment, and the steps are as follows:

[0187] Pre-aging: from room temperature to 120℃, the heating rate is 5℃ / min, and the holding time is 24h;

[0188] Return treatment: from room temperature to 200℃, the heating rate is 10℃ / min, and the holding time is 120min;

[0189] Re-aging: from room temperature to 120℃, the heating rate is 5℃ / min, and the holding time is 24h;

[0190] Post-treatment: the aluminum alloy plate after the return aging heat treatment is sawn into finished product specifications.

[0191] Please refer to Figure 7 , the plate has good performance, high strength plasticity and toughness, and good corrosion resistance (strength: 860MPa, elongation: 9.5%, E loss : 0.08).

[0192] To sum up, the 7xxx series aluminum alloy plate for aviation and the preparation method thereof are more strictly controlled in impurity elements, can greatly remove the formation of impurity phases such as Al3Fe and Mg2Si, are beneficial to improve the elongation of the material, and improve the corrosion resistance and comprehensive mechanical properties of the alloy plate; trace alloy elements Sc and Er can form Al3(Sc, Zr, Er) particles with Zr, the as-cast grains are refined to 20-40 nm, can prevent recrystallized grain growth, and improve the welding performance and corrosion performance of the alloy.

[0193] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for producing an aluminum alloy plate of 7xxx series for aerospace, characterized by, The industrial pure Mg, the industrial pure Zn, the industrial pure Al and the intermediate alloy are dosed; the dosed materials are vacuum melted to obtain alloy liquid, the temperature of vacuum melting is 750-780 DEG C, the time is 1.5-2.5 h, the alloy liquid is refined by adopting protective atmosphere, the temperature of refining is 30-750 DEG C, the time is 30-40 min, and then the alloy liquid is refined; the raw materials in molten state after refining are cast to obtain aluminum alloy ingot, and the aluminum alloy ingot is subjected to homogenization treatment; the aluminum alloy ingot after homogenization treatment is subjected to face milling treatment, and then the aluminum alloy ingot after face milling is subjected to heating treatment; the ingot after heating and heat preservation is alternately subjected to vertical rolling and horizontal rolling, the vertical rolling is rolling along the side surface in the length direction of the ingot, the horizontal rolling is rolling along the surface in the thickness direction perpendicular to the ingot, and the last rolling is horizontal rolling, to obtain hot-rolled plate; the aluminum alloy plate after hot rolling is subjected to solid solution quenching treatment; The aluminum alloy plate after solid solution quenching is subjected to regression re-aging treatment and post-treatment to obtain 7xxx series aluminum alloy plate for aviation, which comprises the following components in percentage by mass: Cu accounts for 1.9-2.5%, Mn accounts for 0.1-0.2%, Mg accounts for 2.0-2.7%, Zn accounts for 5.9-6.9%, Ti accounts for 0.05-0.15%, Zr accounts for 0.05-0.15%, La accounts for 0.05-0.15%, Ce accounts for 0.05-0.10%, Y accounts for 0.10-0.15%, Sc accounts for 0.05-0.30%, Er accounts for 0.05-0.30%, the total amount of impurities is ≤0.15%, and the balance is Al.

2. The method of making an aerospace 7xxx-series aluminum alloy sheet according to claim 1, wherein The intermediate alloy comprises AlCu50, AlMn10, AlTi5, AlZr5, AlLa20, AlCe10, AlV5, AlY10, AlSc2 and AlEr20.

3. The method of making an aerospace 7xxx-series aluminum alloy sheet according to claim 1, wherein The casting temperature is 720-740 DEG C, and the homogenization treatment temperature is 475-485 DEG C, and the heat preservation time is 24-30 h.

4. The method of making an aerospace 7xxx-series aluminum alloy sheet according to claim 1, wherein The heating temperature is 380-450 DEG C, and the heat preservation time is 2-3 h.

5. The method of making an aerospace 7xxx-series aluminum alloy sheet according to claim 1, wherein The hot rolling process comprises hot rough rolling and hot finish rolling; before rolling, the surface of the roll is brushed with a steel wire brush for 2-4 min; the rotation direction of the steel wire brush roll and the roll is consistent, and the pressing force of the brush roll is 3600-3900 N; The hot rough rolling process specifically comprises static pressure welding, medium-speed rolling and high-speed rolling, and the reduction amount is controlled during rolling; The static pressure welding specifically comprises that the reduction amount of the first 1-3 passes of hot rolling is 4-6 mm, and the rolling speed is ≤10 m / min; the static pressure welding is performed by adopting a spraying method without spraying emulsion; The medium-speed rolling specifically comprises that the medium-speed rolling is performed according to a reduction amount of 10-20 mm, and the rolling speed is 20-30 m / min; The high-speed rolling specifically comprises that the high-speed rolling is performed according to a large reduction amount of 15-25 mm at a speed of 40-50 m / min, and the last 5 passes are performed to control the plate shape with a reduction amount of 10-15 mm; The hot finish rolling is performed by using emulsion nozzles to spray the plate for 5s and stop for 15s in the process of rolling, and the width of the ingot on both sides is 100-120mm, the temperature of the emulsion is 60-65℃, the pH value is 7-8.5, and the spraying pressure of the emulsion is 0.5-0.7MPa; The hot finish rolling process adopts 3 passes: the hot finish rolling temperature is 350-400℃, the rolling speed of the first pass is 2-3.0m / s, the rolling speed of the second pass is 1-2.0m / s, and the rolling speed of the third pass is 0.5-1m / s, and after the hot rolling, the workpiece is cooled by nitrogen, and is cooled to room temperature within 30-40min, and the holding time between the hot rolling passes is 5-10min.

6. The method of making a 7xxx-series aluminum alloy sheet for aerospace applications of claim 1, wherein, The solution temperature of the solution quenching treatment is 470-480℃, the holding time is 90-100min, and the temperature of the cooling medium during the quenching process is 20-25℃.

7. The method of making a 7xxx-series aluminum alloy sheet for aerospace applications of claim 1, wherein, The retrogression and re-aging treatment is specifically as follows: from room temperature to 120-150℃, the heating rate is 5-10℃ / min, the holding time is 24-26h, and the pre-aging is completed; then from room temperature to 160-200℃, the heating rate is 5-10℃ / min, the holding time is 80-120min, and the retrogression is completed; finally from room temperature to 120℃, the heating rate is 5-10℃ / min, and the holding time is 24-26h, and the re-aging is completed.

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