A high-strength, heat-resistant aluminum-lithium alloy and its preparation method

Abstract

This invention belongs to the technical field of aluminum alloy materials and discloses a high-strength, heat-resistant aluminum-lithium alloy and its preparation process. The aluminum-lithium alloy composition and weight percentage applicable to this process are: Cu 3.6-4.4%, Li 1.1-1.5%, Mg 0.3-1.2%, Mn 0.4-0.8%, Zr 0.09-0.15%, Ti 0.02-0.05%, Sc 0.10-0.30%, Ag 0.25-0.40%, impurity elements Fe≤0.1%, Si≤0.1%, other impurities ≤0.05% individually, ≤0.15% in total, with the balance being Al. The preparation process of this alloy is: aluminum-lithium alloy melting and casting → homogenization → hot deformation → solution quenching → cold deformation → artificial aging. After the above process, the alloy provided by this invention exhibits good room temperature performance while also possessing high strength at high temperatures of 250℃ and 300℃.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy material technology, and relates to a high-strength heat-resistant aluminum-lithium alloy and its preparation method. Specifically, it relates to an Al-Cu-Li-Mg-X series high-strength heat-resistant aluminum-lithium alloy and its preparation process. The prepared aluminum-lithium alloy has high strength at room temperature, 250℃ and 300℃. Background Technology

[0002] With the rapid development of the aviation and aerospace fields, the demand for low structural weight and high performance in aircraft is becoming increasingly urgent. Using low-density materials is a crucial measure to effectively improve the carrying capacity of aircraft. Aluminum alloys possess excellent low-density properties, but their high-temperature performance is poor. Existing mature 2xxx series wrought heat-resistant aluminum alloys have a long-term permissible operating temperature of no more than 200℃. However, lightweight, high-strength, heat-resistant aluminum alloys capable of operating within a temperature range of 250℃ to 300℃ are required for fuselage skin and bulkheads near engines, high-speed UAV skins, and hypersonic skeletons.

[0003] Improving the stability of precipitates in aluminum alloys is a major direction for obtaining higher heat resistance. To improve the high-temperature performance of aluminum alloys, researchers both domestically and internationally typically employ methods such as modifying multi-element alloying to suppress precipitate growth. Patent CN110423926A discloses a heat-resistant aluminum alloy and its preparation method. Ag is added to an Al-Cu-Mg alloy, and the type of precipitates is controlled through pre-stretching after solution treatment and two-stage aging, thereby improving the alloy's heat resistance. However, the long-term service temperature of this type of alloy generally does not exceed 200℃. Patent CN115537617A discloses a high-strength heat-resistant aluminum alloy and its preparation method. Trace amounts of Sn are introduced into the Al-Cu-Mg alloy. By introducing these trace amounts of Sn, a large number of vacancies in the intergranular space are captured, forming solute atom-vacancy pairs and hindering the formation of the subsequent S phase. Simultaneously, it suppresses the coarsening of the main strengthening heat-resistant phase, the Ω phase, thereby improving the alloy's heat resistance. This alloy is mainly used for aircraft wheel hubs, and its operating temperature generally does not exceed 165℃.

[0004] At normal temperatures, grain boundaries impede slip movement, causing deformation to occur within the grains and thus increasing alloy strength. However, when aluminum alloys are exposed to high temperatures of 300°C, the grain boundary regions soften due to numerous point defects, becoming weak areas in the alloy. Therefore, improving grain boundary strength is a crucial measure to enhance the high-temperature performance of aluminum alloys at 300°C. Summary of the Invention

[0005] The purpose of this invention is to address the issue that the temperature resistance of existing mature deformable heat-resistant aluminum alloys does not meet the requirements for use in UAVs and hypersonic aircraft (above Mach 5). This invention proposes an Al-Cu-Li-X series high-strength heat-resistant aluminum-lithium alloy and its preparation method, enabling the prepared aluminum-lithium alloy to have the performance of long-term use (50 hours) at 250℃ and short-term use at 300℃.

[0006] To solve this technical problem, the technical solution of the present invention is as follows:

[0007] A high-strength, heat-resistant aluminum-lithium alloy is provided, wherein the components and their mass percentages are as follows: Cu 3.6–4.4%, Li 1.1–1.5%, Mg 0.3–1.2%, Mn 0.4–0.8%, Zr 0.09–0.15%, Ti 0.02–0.05%, Sc 0.10–0.30%, Ag 0.25–0.40%, impurity elements Fe ≤0.1%, Si ≤0.1%, other impurities individually ≤0.05%, total ≤0.15%, and the balance is Al.

[0008] Preferably, the components of the aluminum-lithium alloy and their mass percentages are: Cu 3.60%, Li 1.3%, Mg 0.8%, Mn 0.6%, Zr 0.15%, Ti 0.03%, Sc 0.10%, and Ag 0.25%.

[0009] Furthermore, the components and their mass percentages of the aluminum-lithium alloy are as follows: Cu 3.8%, Li 1.4%, Mg 1.2%, Mn 0.8%, Zr 0.15%, Ti 0.03%, Sc 0.3%, Ag 0.3%.

[0010] A method for preparing the heat-resistant aluminum-lithium alloy according to claim 1 is also provided, comprising the following steps:

[0011] Step 1: Melt and cast the alloy according to its composition to prepare a semi-continuous ingot;

[0012] Step 2: Homogenize the ingots in an air-circulating furnace using a two-stage heating process.

[0013] Step 3: After the homogenized ingot is peeled off, it undergoes initial hot deformation → high temperature holding → medium temperature secondary hot deformation.

[0014] Step 4: After forming, the sheet metal / forging undergoes solution quenching, cold deformation, and aging treatment to obtain high-strength heat-resistant aluminum-lithium alloy material.

[0015] The secondary heating process described in step 2 is as follows: the first-stage homogenization temperature is 380-440℃, and the second-stage homogenization temperature is 485-510℃.

[0016] The hot working process described in step 3 is either hot rolling or hot forging. The initial hot rolling / hot forging heating temperature is 400-440℃, and the initial hot deformation is carried out until the finished product thickness is 1.5-1.7 times. The high temperature holding temperature is 490-530℃ for 2-4 hours. After exiting the furnace, the product is air-cooled, wind-cooled, or water-cooled to 180-210℃ for medium-temperature secondary hot rolling / hot forging until the finished product thickness specification is reached.

[0017] The solution treatment in step 4 is a two-stage solution treatment. First, it is held at 470–490℃ for 0.5–3 hours, then the temperature is raised to 520℃–540℃ and held for 0.5–4 hours. Then, it is quenched in water at room temperature, and finally, 4.5%–6.5% cold deformation treatment is performed within 30 minutes.

[0018] The aging treatment in step 4 involves holding at 120–130℃ for 6–10 hours, followed by heating to 145–155℃ and holding for 12–20 hours.

[0019] The beneficial effects of this invention are:

[0020] This invention addresses the two aforementioned measures to improve the high-temperature performance of aluminum alloys. By rationally adjusting the content of Cu, Li, and Mg elements in the aluminum-lithium alloy, and simultaneously introducing trace alloying elements such as Ag, Sc, Ti, and Zr, combined with the preparation method of this invention, the stability of precipitated phases can be effectively improved, and the dispersion of high-temperature stable phases at the alloy grain boundaries can be controlled. Furthermore, by utilizing a hot deformation-high-temperature holding-medium-temperature deformation preparation process combined with subsequent graded solution treatment, the grain morphology of the aluminum-lithium alloy can be controlled, resulting in a nested blocky microstructure, thereby improving the high-temperature performance of the aluminum-lithium alloy. Specifically, the following effects are achieved:

[0021] 1. This invention, through multi-component design, multi-stage homogenization process, variable-temperature deformation, and deformation heat treatment, obtains a relatively large and nested grain boundary characteristic microstructure (such as...). Figure 1 , 2 As shown in the figure, it effectively suppresses grain boundary sliding at high temperatures, obtains macroscopic and microscopic features with good high-temperature stability, and thus improves the heat resistance of aluminum-lithium alloy;

[0022] 2. The preparation process and method adopted in this invention can be implemented on existing industrial equipment, and have strong operability and feasibility.

[0023] 3. The Al-Cu-Li aluminum alloy of the present invention has excellent high-temperature mechanical properties. Its creep strength at 250°C can reach more than 300 MPa, its high-temperature tensile strength at 300°C can reach more than 300 MPa, and its yield strength can reach more than 270 MPa. Attached Figure Description

[0024] Figure 1 The high-magnification microstructure of the forging in Example 1 is shown in the nested blocky microstructure diagram.

[0025] Figure 2 The high-magnification microstructure of the plate material in Example 3 is shown in the image, which depicts a coarse, fully recrystallized morphology. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The features of various aspects of embodiments of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. Well-known structures and techniques are not shown in the following description to avoid unnecessarily obscuring the invention.

[0028] The high-strength heat-resistant aluminum-lithium alloy of this invention comprises the following components and their mass percentages: Cu 3.6–4.4%, Li 1.1–1.5%, Mg 0.3–1.2%, Mn 0.4–0.8%, Zr 0.09–0.15%, Ti 0.02–0.05%, Sc 0.10–0.30%, Ag 0.25–0.40%, impurity elements Fe ≤ 0.1%, Si ≤ 0.1%, other impurities ≤ 0.05% individually, ≤ 0.15% in total, with the balance being Al. The preparation method of the high-strength heat-resistant aluminum-lithium alloy of this invention involves the following steps: melting the alloy according to the alloy composition ratio to prepare an ingot; after homogenization treatment, peeling the surface of the ingot; initial hot deformation → high-temperature holding → medium-temperature secondary hot deformation to reach the predetermined dimensions; subsequently, a two-stage solution treatment + quenching + cold deformation treatment; and a two-stage aging treatment after cold deformation.

[0029] The specific steps are as follows:

[0030] Step 1: Melt and cast the alloy according to its composition to prepare a semi-continuous ingot;

[0031] Step 2: Homogenize the ingots in an air-circulating furnace using a two-stage heating process; the first-stage homogenization temperature is 380–440℃, and the second-stage homogenization temperature is 485–510℃.

[0032] Step 3: After the homogenized ingot is peeled, it undergoes initial hot deformation → high-temperature holding → medium-temperature secondary hot deformation. The hot working process can be either hot rolling or hot forging. The initial hot rolling / hot forging temperature is 400-440℃, and the initial hot deformation is carried out until the finished product thickness is 1.5-1.7 times. The high-temperature holding temperature is 490℃-530℃ for 2-4 hours. After exiting the furnace, it is air-cooled, wind-cooled, or water-cooled to 180℃-210℃ for medium-temperature secondary hot rolling / hot forging until the finished product thickness specification is reached.

[0033] Step 4: The formed sheet / forging undergoes solution quenching, cold deformation, and aging treatment to obtain a high-strength, heat-resistant aluminum-lithium alloy material. The solution treatment is a two-stage process: first, holding at 470–490℃ for 0.5–3 hours, then raising the temperature to 520℃–540℃ and holding for 0.5–4 hours, followed by room temperature water quenching, and then cold deformation treatment of 4.5%–6.5% within 30 minutes. The aging treatment involves holding at 120–130℃ for 6–10 hours, followed by furnace heating to 145–155℃ and holding for 12–20 hours.

[0034] The effects of alloy composition and process on the final alloy properties are illustrated below with reference to specific embodiments.

[0035] The heat-resistant aluminum-lithium alloy of this invention employs Ag and Sc combined microalloying to refine the grains, and combined with the preparation process, it forms coarse recrystallization, which is beneficial to improving the high-temperature strength of the alloy. To illustrate the beneficial effect of Ag and Sc combined microalloying on the heat resistance of the alloy, multiple sets of comparative experiments were conducted, as shown in Examples 1 to 4. Among them, Examples 1 and 3 are aluminum-lithium alloys with Ag and Sc combined microalloying, Example 2 is an aluminum-lithium alloy with Ag microalloying, and Example 4 is an aluminum-lithium alloy with Sc microalloying. By comparing Examples 1 and 2, and Examples 3 and 4, the effectiveness of this invention in improving the high-temperature mechanical properties of aluminum-lithium alloys is demonstrated.

[0036] Example 1:

[0037] The composition and weight percentage of the heat-resistant aluminum-lithium alloy are as follows: Cu 3.60%, Li 1.3%, Mg 1.0%, Mn 0.73%, Ag 0.28%, Sc 0.10%, Zr 0.12%, Ti 0.03%, Fe 0.08%, Si 0.06%, with the balance being Al.

[0038] Example 2

[0039] An Ag microalloyed aluminum-lithium alloy was used, with the following alloy composition and weight percentage: Cu 3.62%, Li 1.3%, Mg 0.85%, Mn 0.71%, Zr 0.12%, Ag 0.33%, Ti 0.03%, Fe 0.08%, Si 0.06%, and the balance being Al.

[0040] Using the alloy preparation method involved in this invention, forgings from Examples 1 and 2 were prepared by the following method:

[0041] The Φ440mm ingot was placed in an air-circulating furnace for two-stage homogenization: first stage: 410℃ / 10h, second stage: 505℃ / 22h.

[0042] After homogenization, the ingot is peeled off and heated at 430℃±10℃. Then it is taken out of the furnace and free forged. After two upsetting and two drawing processes, a forging with a thickness of 200mm is prepared. The forging is placed in an air circulation furnace and heated at 500℃ for 4 hours. After being taken out of the furnace and air-cooled to 210℃, it is forged into a forging with a thickness of 130mm.

[0043] The forgings were placed in a box-type quenching furnace for solution quenching. The solution quenching process was as follows: hold at 470℃ for 4 hours, then raise the temperature to 520℃ and hold for 2 hours, followed by room temperature water quenching. After quenching, the forgings were subjected to cold compression treatment with a compression deformation of 5.2%. The cold-compressed forgings were then subjected to a two-stage artificial aging treatment. The aging process was as follows: hold at 125℃ for 8 hours, then raise the temperature to 145℃ and hold for 16 hours.

[0044] The Φ440mm ingot was placed in an air-circulating furnace for two-stage homogenization: first stage: 410℃ / 10h, second stage: 505℃ / 22h.

[0045] After homogenization, the ingot is peeled off and heated at 430℃±10℃. Then it is taken out of the furnace and free forged. After two upsetting and two drawing processes, a forging with a thickness of 200mm is prepared. The forging is placed in an air circulation furnace and heated at 500℃ for 4 hours. After being taken out of the furnace and air-cooled to 210℃, it is forged into a forging with a thickness of 130mm.

[0046] The forgings were placed in a box-type quenching furnace for solution quenching. The solution quenching process was as follows: hold at 470℃ for 4 hours, then raise the temperature to 520℃ and hold for 2 hours, followed by room temperature water quenching. After quenching, the forgings were subjected to cold compression treatment with a compression deformation of 5.2%. The cold-compressed forgings were then subjected to a two-stage artificial aging treatment. The aging process was as follows: hold at 125℃ for 8 hours, then raise the temperature to 145℃ and hold for 16 hours.

[0047] Implementation results:

[0048] The creep rupture properties at 250°C and the tensile properties at 250°C and 300°C of Examples 1 and 2 were compared. The creep rupture test method was GB / T 2039-1997, and the short-time mechanical tensile test method was GB / T228.2-2015. The results are shown in Table 1. It can be found that the alloy with Ag and Sc combined microalloying has a 16% increase in creep rupture strength at 250°C and an approximately 35% increase in tensile strength at 300°C.

[0049] Table 1 Comparison of high-temperature creep resistance and tensile properties between Examples 1 and 2

[0050] alloy Test temperature / °C <![CDATA[σ 50 / MPa]]> <![CDATA[σ b / MPa]]> <![CDATA[σ 0.2 / MPa]]> <![CDATA[δ5%]]> Example 1 250 312 345 318 9.8 Example 2 250 278 320 287 10.5 Example 1 300 / 321 289 10.4 Example 2 300 / 238 204 15.8

[0051] Example 3

[0052] A microalloyed aluminum-lithium alloy with Ag and Sc is designed. The corresponding alloy composition and weight percentage are: Cu 3.73%, Li 1.48%, Mg 1.2%, Mn 0.80%, Zr 0.12%, Ag 0.28%, Sc 0.10%, Ti 0.03%, Fe 0.08%, Si 0.06%, with the balance being Al.

[0053] Example 4

[0054] A Sc microalloyed aluminum-lithium alloy is designed with the following alloy composition and weight percentages: Cu 3.8%, Li 1.46%, Mg 1.2%, Mn 0.80%, Zr 0.12%, Sc 0.30%, Ti 0.03%, Fe 0.08%, Si 0.06%, and the balance being Al.

[0055] Using the alloy preparation method involved in this invention, the plates of Examples 3 and 4 were prepared by the following method:

[0056] The 330mm thick flat ingots were placed in an air-circulating furnace for two-stage homogenization: first stage: 420℃ / 8h, second stage: 500℃ / 28h. The homogenized ingots were peeled, heated at 420℃±10℃, and then hot-rolled to 100mm. The plates were then placed in an air-circulating furnace and heated to 510℃ for 2h. After being air-cooled to 200℃, they were hot-rolled again to 60mm and then air-cooled to room temperature.

[0057] The rolled plate was placed in a box-type quenching furnace for solution quenching. The solution quenching process was as follows: hold at 485℃ for 3 hours, then raise the temperature to 535℃ and hold for 1.5 hours, followed by room temperature water quenching. After quenching, the plate was pre-stretched with a deformation of 4.5%. The pre-stretched plate underwent a two-stage artificial aging treatment. The aging process was as follows: hold at 125℃ for 8 hours, then raise the temperature to 150℃ and hold for 16 hours.

[0058] The 330mm thick flat ingots were placed in an air-circulating furnace for two-stage homogenization: first stage: 420℃ / 8h, second stage: 500℃ / 28h. The homogenized ingots were peeled, heated at 420℃±10℃, and then hot-rolled to 100mm. The plates were then placed in an air-circulating furnace and heated to 510℃ for 2h. After being air-cooled to 200℃, they were hot-rolled again to 60mm and then air-cooled to room temperature.

[0059] The rolled plate was placed in a box-type quenching furnace for solution quenching. The solution quenching process was as follows: hold at 485℃ for 3 hours, then raise the temperature to 535℃ and hold for 1.5 hours, followed by room temperature water quenching. After quenching, the plate was pre-stretched with a deformation of 4.5%. The pre-stretched plate underwent a two-stage artificial aging treatment. The aging process was as follows: hold at 125℃ for 8 hours, then raise the temperature to 150℃ and hold for 16 hours.

[0060] Implementation results:

[0061] The high-temperature tensile properties of Examples 3 and 4 at 250℃ and 300℃ were compared, and the results are shown in Table 2. It can be found that the alloy sheet with Ag and Sc combined microalloying has an increased creep strength of about 27% at 250℃ and an increased tensile strength of about 40% at 300℃.

[0062] Table 2 Comparison of high-temperature tensile properties of Examples 3 and 4

[0063] alloy Test temperature / °C <![CDATA[σ 50 / MPa]]> <![CDATA[R m / MPa]]> <![CDATA[R 0.2 / MPa]]> A％ Example 3 250 308 331 294 7.8 Example 4 250 243 280 258 9.6 Example 3 300 / 305 272 10.5 Example 4 300 / 217 178 16.3

[0064] Implementation results:

[0065] The high-temperature performance of the alloy of this invention is compared with that of the new generation of aerospace heat-resistant aluminum alloy 2024. As shown in Table 3, the heat-resistant aluminum-lithium alloy of this invention has superior tensile strength at 250°C, and the tensile strength can be increased by 10% to 17%.

[0066] Table 3 Comparison of high-temperature tensile properties between the alloy of this patent and alloy 2024

[0067] alloy Test temperature / °C <![CDATA[R m / MPa]]> <![CDATA[R 0.2 / MPa]]> Implementation Example 1 250 345 318 Implementation Example 3 250 331 294 2024 alloy 250 296 278

[0068] Finally, to illustrate the effects of the initial hot rolling heating temperature and the high-temperature holding temperature in step 3 on the alloy properties, Examples 5 to 8 were conducted. Examples 5 and 6 were comparison groups of different hot rolling temperatures, and Examples 7 and 8 were comparison groups of different holding temperatures, to demonstrate the effectiveness of the preparation method of this invention in improving the high-temperature mechanical properties of aluminum-lithium alloys. Specific experimental parameters are shown in Tables 4 and 6.

[0069] Table 4 compares the alloy composition and preparation process of Examples 5-6 (hot rolling temperature - single deformation amount).

[0070]

[0071] Implementation results: Comparison revealed that an initial hot rolling temperature of around 420℃ is more suitable. 400℃ is too low as the initial hot rolling temperature, which not only makes cracking more likely during the hot rolling process, but also reduces the alloy properties.

[0072] Table 5 Comparison of high-temperature tensile properties of alloys at different hot rolling temperatures

[0073] alloy Test temperature / °C <![CDATA[R m / MPa]]> <![CDATA[R 0.2 / MPa]]> A％ Example 5 300 310 276 10.6 Example 6 300 278 253 11.8

[0074] Table 6 Comparison of alloy composition and preparation process in Examples 7-8 (holding temperature - single deformation amount)

[0075]

[0076]

[0077] Implementation results: Comparison revealed that the optimal high-temperature holding temperature after the initial hot rolling is around 510℃. 480℃ is too low a holding temperature, which reduces the coarsening degree of the recrystallized grains in the alloy and is detrimental to the high-temperature tensile properties of the alloy.

[0078] Table 7 Comparison of high-temperature tensile properties of alloys at different hot rolling temperatures

[0079] alloy Test temperature / °C <![CDATA[R m / MPa]]> <![CDATA[R 0.2 / MPa]]> A％ Example 7 300 310 276 10.6 Example 8 300 253 225 13.9

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A high-strength, heat-resistant aluminum-lithium alloy, characterized in that: The components and their mass percentages of the aluminum-lithium alloy are as follows: Cu 3.6–4.4%, Li 1.1–1.5%, Mg 0.3–1.2%, Mn 0.4–0.8%, Zr 0.09–0.15%, Ti 0.02–0.05%, Sc 0.10–0.30%, Ag 0.25–0.40%, impurity elements Fe ≤0.1%, Si ≤0.1%, other impurities individually ≤0.05%, total ≤0.15%, with the balance being Al; the preparation method is as follows: Step 1: Melt and cast the alloy according to its composition to prepare a semi-continuous ingot; Step 2: Homogenize the ingots in an air-circulating furnace using a two-stage heating process; specifically: the first-stage homogenization temperature is 380–440℃, and the second-stage homogenization temperature is 485–510℃. Step 3: After the homogenized ingot is peeled off, it undergoes initial hot deformation → high temperature holding → medium temperature secondary hot deformation. The initial hot rolling / hot forging temperature is 400~440℃, and the initial hot deformation is carried out until the finished product thickness is 1.5~1.7 times. High temperature insulation: 490℃~530℃, insulation time 2~4 hours; Medium-temperature secondary hot rolling / hot forging is carried out at 180℃~210℃ until the finished thickness specification is achieved; Step 4: The formed sheet / forging undergoes solution quenching, cold deformation, and aging treatment to obtain a high-strength, heat-resistant aluminum-lithium alloy material. The solution treatment adopted is a two-stage solution treatment. First, the temperature is held at 470~490℃ for 0.5~3h, then the temperature is raised to 520℃~540℃; held at 0.5~4h, quenched in water at room temperature, and then subjected to 4.5%~6.5% cold deformation treatment within 30min. The aging treatment is carried out at 120~130℃ for 6~10 hours, followed by heating to 145~155℃ and holding for 12~20 hours. The prepared aluminum-lithium alloy exhibits a creep strength of over 300 MPa at 250℃, a high-temperature tensile strength of over 300 MPa at 300℃, and a yield strength of over 270 MPa.

2. The high-strength, heat-resistant aluminum-lithium alloy according to claim 1, characterized in that: The components and their mass percentages of the aluminum-lithium alloy are as follows: Cu 3.60%, Li 1.3%, Mg 0.8%, Mn 0.6%, Zr 0.15%, Ti 0.03%, Sc 0.10%, Ag 0.25%.

3. The high-strength, heat-resistant aluminum-lithium alloy according to claim 1, characterized in that: The components and their mass percentages of the aluminum-lithium alloy are as follows: Cu 3.8%, Li 1.4%, Mg 1.2%, Mn 0.8%, Zr 0.15%, Ti 0.03%, Sc 0.3%, Ag 0.3%.

4. The high-strength, heat-resistant aluminum-lithium alloy according to claim 1, characterized in that: In step 3, after high-temperature heat preservation, the product is removed from the furnace and cooled by air, wind, or water.

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