Rare earth aluminum alloy plate and preparation method thereof

Abstract

The invention discloses a rare earth aluminum alloy plate and a preparation method thereof, relates to an aluminum alloy plate and a preparation method thereof, and aims to solve the problem that high strength and high toughness of an existing aluminum alloy plate are difficult to consider, and the rare earth aluminum alloy plate comprises the following elements in percentage by mass: 4.2-5.0 wt% of Mg element, 5.0-10.0 wt% of Al element, 5.0-10.0 wt% of Ti element and the balance of Al element. The content of the Mn element is 0.14-0.20 wt%, the content of the Sc element is 0.12-0.20 wt%, the content of the Zr element is 0.10-0.13 wt%, the content of the Ti element is 0.05-0.15 wt%, the total content of inevitable impurities is less than or equal to 0.15 wt%, the content of a single impurity is less than or equal to 0.05 wt%, and the balance is the Al element. Wherein the Sc element and the Zr element are added, so that the strength and the toughness of the rare earth aluminum alloy plate can be improved. The method is applied to the technical field of aluminum alloy.

Description

Technical Field

[0001] The invention relates to a rare earth aluminum alloy plate and a preparation method thereof. Background Art

[0002] Aluminum alloy has the characteristics of light weight, high specific strength, low cost, easy processing, and corrosion resistance. It has long been an indispensable key structural material in the global aerospace field. In the contemporary aviation manufacturing industry, aluminum alloy has always been one of the most important materials for aircraft fuselage structure, accounting for about 40% to 70% of the weight of the fuselage structure, and is widely used in the main load-bearing frame, beams, wall panels, skins and other parts of the aircraft. With the rapid development of the aviation industry, it is urgent to develop aluminum alloys with better comprehensive properties such as strength and toughness to replace the existing alloys, so as to meet the material needs of the new generation of aviation equipment upgrades. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that it is difficult to achieve both high strength and high toughness in existing aluminum alloy plates, and to provide a rare earth aluminum alloy plate and a preparation method thereof.

[0004] The rare earth aluminum alloy plate of the present invention is composed of 4.2-5.0% Mg, 0.14-0.20% Mn, 0.12-0.20% Sc, 0.10-0.13% Zr, 0.05-0.15% Ti and the balance Al in terms of element mass percentage; and the mass ratio of Sc element to Zr element is 1.36-1.55:1.

[0005] A method for preparing a rare earth aluminum alloy plate is carried out according to the following steps:

[0006] 1. Weighing raw materials according to the proportion of element mass percentage of 4.2-5.0% Mg, 0.14-0.20% Mn, 0.12-0.20% Sc, 0.10-0.13% Zr, 0.05-0.15% Ti and the balance Al, and then casting to obtain a rare earth aluminum alloy ingot;

[0007] 2. The aluminum alloy ingot is kept at 340-360° C. for 16-18 hours for homogenization heat treatment, then heated to 440-460° C. for 10-14 hours, and then subjected to hot rough rolling and hot finish rolling in sequence to obtain a hot finish rolled coil; wherein the number of passes of the hot rough rolling is 17-19, the sum of the processing rates of each pass is 94-95.5%, and the rolling speed is 1.50-3.00 m·s -1 The number of hot finishing rolling passes is 3, the processing rate of each pass is 30-45%, and the rolling speed is 2.00-3.00 m·s -1 Then the hot-rolled coil is uncoiled, cut into pieces, and annealed to obtain rare earth aluminum alloy plates.

[0008] The addition of Mg element to the rare earth aluminum alloy plate of the present invention helps to improve the strength and rigidity of the rare earth aluminum alloy plate, while reducing the density of the rare earth aluminum alloy plate. The addition of Mn element helps to improve the strength, plasticity and corrosion resistance of the rare earth aluminum alloy plate. The addition of Sc element and Zr element helps to form fine dispersed Al ingots during the homogenization heat treatment process. 3 (Sc, Zr) second phase, thereby helping to improve the strength and toughness of the rare earth aluminum alloy sheet. The addition of Ti element helps to improve the strength, corrosion resistance and heat resistance of the rare earth aluminum alloy sheet. Preferably, the mass percentage of Mg element, Mn element, Sc element, Zr element and Ti element is controlled within the above range, which helps to improve the mutual synergy between the elements, thereby helping to further improve the comprehensive performance of the strength, corrosion resistance and toughness of the rare earth aluminum alloy sheet. The rare earth aluminum alloy sheet of the present application has important application value in the structures such as the nose, lip, leading edge, wing, straight fuselage of the aircraft, and can be used for in-situ replacement of the application parts of 2xxx series alloys such as 2024 and 2524, thereby helping to reduce the weight of the aircraft and extend the service life of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is an optical photograph of the hot-rolled coil in Example 1 of the present application;

[0010] Figure 2 This is an optical photograph of the rare earth aluminum alloy plate in Example 1 of the present application;

[0011] Figure 3 This is a microstructure diagram of the rare earth aluminum alloy plate in Example 1 of the present application;

[0012] Figure 4 This is the microstructure diagram of the rare earth aluminum alloy plate in Comparative Example 4 of the present application. DETAILED DESCRIPTION

[0013] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0014] Specific implementation method 1: In this implementation method, a rare earth aluminum alloy plate is composed of 4.2-5.0% Mg, 0.14-0.20% Mn, 0.12-0.20% Sc, 0.10-0.13% Zr, 0.05-0.15% Ti and the balance Al; and the mass ratio of Sc element to Zr element is 1.36-1.55:1.

[0015] The total content of inevitable impurities in the rare earth aluminum alloy plate of this embodiment is ≤0.15wt%, and the content of a single impurity does not exceed 0.05wt%.

[0016] The addition of Mg to rare earth aluminum alloy sheets helps to improve the strength and rigidity of rare earth aluminum alloy sheets, while reducing the density of rare earth aluminum alloy sheets. The addition of Mn helps to improve the strength, plasticity and corrosion resistance of rare earth aluminum alloy sheets. The addition of Sc and Zr elements helps to form fine dispersed Al ingots during homogenization heat treatment. 3 (Sc, Zr) second phase, thereby helping to improve the strength and toughness of the rare earth aluminum alloy sheet. The addition of Ti element helps to improve the strength, corrosion resistance and heat resistance of the rare earth aluminum alloy sheet. It is preferred to control the mass percentage of Mg element, Mn element, Sc element, Zr element and Ti element within the above range, which helps to improve the mutual synergy between the elements, thereby helping to further improve the comprehensive performance of the strength, corrosion resistance and toughness of the rare earth aluminum alloy sheet. The rare earth aluminum alloy sheet of this specific embodiment has important application value in the structures such as the nose, lip, leading edge, wing, straight fuselage of the aircraft, and can be used for in-situ replacement of the application parts of 2xxx series alloys such as 2024 and 2524, thereby helping to reduce the weight of the aircraft and extend the service life of the aircraft.

[0017] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the rare earth aluminum alloy plate is composed of 4.6-4.9% Mg, 0.15-0.19% Mn, 0.15-0.18% Sc, 0.11-0.12% Zr, 0.06-0.12% Ti and the balance Al. The rest is the same as the specific embodiment 1.

[0018] In this embodiment, the mass percentage of Mg, Mn, Sc, Zr and Ti is preferably controlled within the above range, which helps to further improve the synergistic effect between the elements, thereby helping to further improve the comprehensive properties of the rare earth aluminum alloy sheet, such as strength, corrosion resistance and toughness. A too large mass ratio of Sc to Zr is not conducive to the control of coarse primary phases containing Sc compounds. Once a coarse primary phase containing Sc compounds appears in the organization, it will have an adverse effect on the comprehensive performance of the product. A too small mass ratio of Sc to Zr is not conducive to the control of Al 3 The formation and distribution of (Sc, Zr) phase. The increase of Sc element will also increase the cost of raw materials. It is preferred to control the mass ratio of Sc element to Zr element within the above range, which helps to give full play to the synergistic effect between Sc element and Zr element, so that more fine dispersed Al2O3 phases are formed in the aluminum alloy ingot during the homogenization heat treatment process. 3(Sc, Zr) second phase, which helps to further improve the strength and toughness of rare earth aluminum alloy sheets.

[0019] Specific implementation method three: In this implementation method, a method for preparing a rare earth aluminum alloy plate is carried out according to the following steps:

[0020] 1. Weighing raw materials according to the proportion of element mass percentage of 4.2-5.0% Mg, 0.14-0.20% Mn, 0.12-0.20% Sc, 0.10-0.13% Zr, 0.05-0.15% Ti and the balance Al, and then casting to obtain a rare earth aluminum alloy ingot;

[0021] 2. The aluminum alloy ingot is kept at 340-360° C. for 16-18 hours for homogenization heat treatment, then heated to 440-460° C. for 10-14 hours, and then subjected to hot rough rolling and hot finish rolling in sequence to obtain a hot finish rolled coil; wherein the number of passes of the hot rough rolling is 17-19, the sum of the processing rates of each pass is 94-95.5%, and the rolling speed is 1.50-3.00 m·s -1 The number of hot finishing rolling passes is 3, the processing rate of each pass is 30-45%, and the rolling speed is 2.00-3.00 m·s -1 Then the hot-rolled coil is uncoiled, cut into pieces, and annealed to obtain rare earth aluminum alloy plates.

[0022] In this embodiment, the aluminum alloy ingot is subjected to homogenization heat treatment, and the structure of the alloy is regulated by homogenization heat treatment, so that fine dispersed Al 3 (Sc, Zr) second phase, thereby helping to improve the strength and toughness of the rare earth aluminum alloy sheet. Through hot rolling and annealing, more and more stable subgrain structures can be formed inside the rare earth aluminum alloy sheet, thereby helping to further improve the comprehensive properties of the rare earth aluminum alloy sheet, such as strength, corrosion resistance and toughness. Therefore, the rare earth aluminum alloy sheet prepared by the above method has important application value in the nose, lip, leading edge, wing, straight fuselage and other structures of the aircraft, and can replace the application parts of 2xxx series alloys such as 2024 and 2524 in situ, thereby helping to reduce the weight of the aircraft and extend the service life of the aircraft.

[0023] In this embodiment, the annealing temperature is too high, which is not conducive to controlling the nano-scale Al 3 The distribution and size of (Sc, Zr) dispersed phase, the temperature is too high Al 3The (Sc, Zr) dispersed phase will show obvious coarsening. If the annealing temperature is too low, it will not be conducive to improving the toughness of the rare earth aluminum alloy plate. It is preferred to control the annealing temperature and holding time within the above range, which will help to improve the elongation of the rare earth aluminum alloy plate while maintaining a high yield strength and tensile strength, thereby helping to improve the comprehensive performance of the rare earth aluminum alloy plate.

[0024] Too high a temperature for homogenization heat treatment is not conducive to grain refinement, while too low a temperature for homogenization heat treatment is not conducive to fully releasing the stress inside the material. It is preferred to control the temperature and holding time of homogenization heat treatment within the above range, which is helpful to improve the defects inside the alloy structure, eliminate stress, and refine Al 3 (Sc, Zr) second phase, which helps to improve the strength and toughness of rare earth aluminum alloy sheets.

[0025] The material after homogenization heat treatment is heated to improve the plasticity of the material and reduce the deformation resistance. After hot rough rolling, the material is preliminarily processed and shaped, which helps to refine the structure, eliminate the defects of the material, and make the structure more uniform. Through hot finishing rolling, the size of the material can be accurately controlled, the quality of the material surface can be improved, the uniformity of the organization distribution can be improved, and the grains can be further refined, which helps to improve the strength and toughness of the rare earth aluminum alloy plate.

[0026] It is preferred to control the temperature and holding time of the heating treatment within the above ranges, which helps to further improve the plasticity of the material and reduce the deformation resistance. It is preferred to control the number of passes, rolling speed and processing rate of the hot rough rolling treatment within the above ranges, which helps to further refine the structure, eliminate material defects and make the structure more uniform. It is preferred to control the number of passes, rolling speed and processing rate of the hot finishing rolling treatment within the above ranges, which helps to further improve the quality of the material surface, improve the uniformity of the structure distribution, and further refine the grains, thereby helping to further improve the strength and toughness of the rare earth aluminum alloy plate.

[0027] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the mass ratio of Sc element to Zr element in the raw material weighed in step 1 is 1.36-1.55:1. The rest is the same as specific embodiments 1 to 3.

[0028] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the temperature of the homogenization heat treatment in step 2 is 350° C. and the holding time is 16 hours. The rest is the same as specific embodiments 1 to 4.

[0029] Specific implementation example 6: This implementation example is different from specific implementation examples 1 to 5 in that: step 2 is heated to 450° C. and the heat preservation time is 10 hours. The rest is the same as specific implementation examples 1 to 5.

[0030] Specific embodiment 7: This embodiment is different from specific embodiments 1 to 6 in that the temperature of the annealing treatment in step 2 is 250-300° C. and the holding time of the annealing treatment is 1.5-3 hours. The rest is the same as specific embodiments 1 to 6.

[0031] Specific embodiment 8: This embodiment differs from specific embodiments 1 to 7 in that the annealing temperature in step 2 is 300° C. and the holding time for the annealing treatment is 2 hours. The rest is the same as specific embodiments 1 to 7.

[0032] Specific embodiment 9: This embodiment is different from specific embodiments 1 to 8 in that the annealing temperature in step 2 is 250° C. and the holding time for annealing is 2 hours. The rest is the same as specific embodiments 1 to 8.

[0033] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the yield strength of the rare earth aluminum alloy plate is 260-288 MPa, the tensile strength is 352-378 MPa, the elongation is 13.3-18.8%, and the fracture toughness Kc is 143-168 MPa·m 1 / 2 . The rest is the same as the specific implementation modes 1 to 9.

[0034] The following examples are used to verify the beneficial effects of the present invention:

[0035] Example 1

[0036] A method for preparing a rare earth aluminum alloy plate is carried out according to the following steps:

[0037] In terms of mass percentage, the aluminum alloy ingot contains 4.8wt% Mg, 0.18wt% Mn, 0.17wt% Sc, 0.11wt% Zr, 0.07wt% Ti, a single impurity content of no more than 0.05wt%, and the balance is Al. The aluminum alloy ingot is subjected to homogenization heat treatment at a temperature of 350° C. for a holding time of 16 hours, and then subjected to hot rolling treatment, wherein the temperature of the heating treatment before hot rolling is 450° C. for a holding time of 10 hours, and then subjected to hot rough rolling after being taken out of the furnace, and subjected to 19 passes of hot rough rolling after being taken out of the furnace, and the rolling speed of the hot rough rolling is 2.00 m·s -1 The sum of the processing rates of each pass in the hot rough rolling is 94%, and the steel is rolled to a thickness of 24 mm, and then three passes of coil hot finishing rolling are performed. The rolling speed of the hot finishing rolling is 3.00 m·s -1 , the processing rate of each pass is 45%, and air cooling to room temperature is obtained. Figure 1The hot-rolled coil shown in the figure is unrolled and cut into pieces, each piece is 4000 mm long, and the piece is annealed at a temperature of 250° C. The annealing time is 2 h, and the following is obtained: Figure 2 Rare earth aluminum alloy sheet shown.

[0038] Example 2

[0039] The difference from Example 1 is that the number of hot rough rolling passes is 17, the sum of the processing rates of each hot rough rolling pass is 95.5%, the thickness is rolled to 24 mm, the processing rate of each coil hot finishing rolling pass is 30%, and finally a rare earth aluminum alloy sheet is obtained.

[0040] Example 3

[0041] The difference from Example 1 is that the annealing temperature is 300° C., the holding time of the annealing treatment is 2 h, and finally a rare earth aluminum alloy plate is obtained.

[0042] Example 4

[0043] The difference from Example 3 is that the number of hot rough rolling passes is 17, the sum of the processing rates of each hot rough rolling pass is 95.5%, the thickness is rolled to 24 mm, the processing rate of each coil hot finishing rolling pass is 30%, and finally a rare earth aluminum alloy sheet is obtained.

[0044] Example 5

[0045] The difference from Example 1 is that the content of Sc element is 0.15wt%, the content of Zr element is 0.11wt%, and the mass ratio of Sc element to Zr element is 1.36:1, and finally a rare earth aluminum alloy plate is obtained.

[0046] Example 6

[0047] The difference from Example 1 is that the content of Mg element is 4.6wt%, the content of Mn element is 0.19wt%, the content of Sc element is 0.15wt%, the content of Zr element is 0.12wt%, and the content of Ti element is 0.06wt%, and finally a rare earth aluminum alloy plate is obtained.

[0048] Example 7

[0049] The difference from Example 1 is that the content of Mg element is 4.9wt%, the content of Mn element is 0.15wt%, the content of Sc element is 0.18wt%, the content of Zr element is 0.11wt%, and the content of Ti element is 0.12wt%, and finally a rare earth aluminum alloy plate is obtained.

[0050] Example 8

[0051] The difference from Example 1 is that the content of Mg element is 4.2wt%, the content of Mn element is 0.20wt%, the content of Sc element is 0.12wt%, the content of Zr element is 0.13wt%, and the content of Ti element is 0.05wt%, and finally a rare earth aluminum alloy plate is obtained.

[0052] Example 9

[0053] The difference from Example 1 is that the content of Mg element is 5.0wt%, the content of Mn element is 0.14wt%, the content of Sc element is 0.20wt%, the content of Zr element is 0.10wt%, and the content of Ti element is 0.15wt%, and finally a rare earth aluminum alloy plate is obtained.

[0054] Example 10

[0055] The difference from Example 1 is that the annealing temperature is 400° C., the annealing holding time is 1 hour, and finally a rare earth aluminum alloy plate is obtained.

[0056] Embodiment 11

[0057] The difference from Example 1 is that the temperature of the homogenization heat treatment is 360° C., the holding time of the homogenization heat treatment is 16 h, the temperature of the heating treatment is 460° C., the holding time of the heating treatment is 10 h, and finally a rare earth aluminum alloy plate is obtained.

[0058] Example 12

[0059] The difference from Example 1 is that the temperature of the homogenization heat treatment is 340°C, the holding time of the homogenization heat treatment is 18 hours, the temperature of the heating treatment is 440°C, the holding time of the heating treatment is 14 hours, and finally a rare earth aluminum alloy plate is obtained.

[0060] Embodiment 13

[0061] The difference from Example 1 is that the temperature of the homogenization heat treatment is 370°C, the holding time of the homogenization heat treatment is 15 hours, the temperature of the heating treatment is 470°C, the holding time of the heating treatment is 9 hours, and finally a rare earth aluminum alloy plate is obtained.

[0062] Embodiment 14

[0063] The difference from Example 1 is that the rolling speed of the hot rough rolling process is 1.50 m·s -1 ; The rolling speed of hot finishing rolling is 3.00m·s -1 , and finally obtain rare earth aluminum alloy sheet.

[0064] Embodiment 15

[0065] The difference from Example 1 is that the rolling speed of the hot rough rolling process is 3.00 m·s -1 ; The rolling speed of hot finishing rolling is 2.00m·s -1 , and finally obtain rare earth aluminum alloy sheet.

[0066] Comparative Example 1

[0067] The difference from Example 1 is that no annealing treatment is performed, and a rare earth aluminum alloy plate is finally obtained.

[0068] Comparative Example 2

[0069] The difference from Example 2 is that no annealing treatment is performed, and a rare earth aluminum alloy plate is finally obtained.

[0070] Comparative Example 3

[0071] The difference from Example 1 is that the content of Mg element is 4.0wt%, the content of Mn element is 0.30wt%, the content of Sc element is 0.30wt%, the content of Zr element is 0.05wt%, and the content of Ti element is 0.2wt%, and finally a rare earth aluminum alloy plate is obtained.

[0072] Comparative Example 4

[0073] The difference from Example 1 is that no Sc element and no Zr element are added, and a rare earth aluminum alloy plate is finally obtained.

[0074] The rare earth aluminum alloy plates prepared in the above embodiments and comparative examples were tested for yield strength, tensile strength, elongation and fracture toughness Kc, wherein the yield strength, tensile strength and elongation were sampled and tensile properties were tested in accordance with GB / T228 metal material room temperature tensile test method, and the fracture toughness Kc was tested in accordance with HB5261. The test results are shown in Table 1.

[0075] Table 1

[0076]

[0077]

[0078] It can be seen from Table 1 that with the increase of hot rough rolling processing rate, the hot finishing rolling processing rate decreases, the yield strength and tensile strength of the alloy decrease, and the elongation increases slightly. With the increase of the annealing temperature of the plate, the yield strength and tensile strength of the alloy decrease, the elongation increases slightly, and the overall change is not obvious. Annealing at 250℃ and 300℃ for 2h respectively can obtain a good combination of strength and toughness. The yield strength of the rare earth aluminum alloy plate is 260~288MPa, the tensile strength is 352~378MPa, the elongation is 13.3~18.8%, and the fracture toughness Kc is 143~168MPa·m1 / 2 .

[0079] Figure 3 This is the microstructure diagram of the rare earth aluminum alloy plate in Example 1 of the present application, from Figure 3 It can be seen that no recrystallization occurs in the rare earth aluminum alloy plate; Figure 4 This is the microstructure diagram of the rare earth aluminum alloy plate in Comparative Example 4 of the present application. Figure 4 It can be seen that the rare earth aluminum alloy sheet without adding Sc and Zr elements has a certain degree of recrystallization. It can be seen that adding appropriate amounts of Sc and Zr elements to the rare earth aluminum alloy sheet forms dispersed nano-scale Al 3 (Sc, Zr) contribute to suppressing recrystallization.

[0080] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0081] The addition of Mg element to the rare earth aluminum alloy plate of the present application helps to improve the strength and rigidity of the rare earth aluminum alloy plate, while reducing the density of the rare earth aluminum alloy plate. The addition of Mn element helps to improve the strength, plasticity and corrosion resistance of the rare earth aluminum alloy plate. The addition of Sc element and Zr element helps to form fine dispersed Al ingots during the homogenization heat treatment process. 3 (Sc, Zr) second phase, thereby helping to improve the strength and toughness of the rare earth aluminum alloy sheet. The addition of Ti element helps to improve the strength, corrosion resistance and heat resistance of the rare earth aluminum alloy sheet. Preferably, the mass percentage of Mg element, Mn element, Sc element, Zr element and Ti element is controlled within the above range, which helps to improve the mutual synergy between the elements, thereby helping to further improve the comprehensive performance of the strength, corrosion resistance and toughness of the rare earth aluminum alloy sheet. The rare earth aluminum alloy sheet of the present application has important application value in the structures such as the nose, lip, leading edge, wing, straight fuselage of the aircraft, and can be used for in-situ replacement of the application parts of 2xxx series alloys such as 2024 and 2524, thereby helping to reduce the weight of the aircraft and extend the service life of the aircraft.

Claims

1. A rare earth aluminum alloy plate, characterized in that The rare earth aluminum alloy plate is composed of 4.2-5.0% Mg, 0.14-0.20% Mn, 0.12-0.20% Sc, 0.10-0.13% Zr, 0.05-0.15% Ti and the balance Al in terms of element mass percentage; and the mass ratio of Sc element to Zr element is 1.36-1.55:

1.

2. The rare earth aluminum alloy sheet according to claim 1, characterized in that The rare earth aluminum alloy plate is composed of 4.6-4.9% Mg, 0.15-0.19% Mn, 0.15-0.18% Sc, 0.11-0.12% Zr, 0.06-0.12% Ti and the balance Al in percentage by element weight.

3. The method for preparing a rare earth aluminum alloy sheet according to claim 1, characterized in that The preparation method is carried out according to the following steps:

1. Weighing raw materials according to the proportion of element mass percentage of 4.2-5.0% Mg, 0.14-0.20% Mn, 0.12-0.20% Sc, 0.10-0.13% Zr, 0.05-0.15% Ti and the balance Al, and then casting to obtain a rare earth aluminum alloy ingot; 2. The aluminum alloy ingot is kept at 340-360° C. for 16-18 hours for homogenization heat treatment, then heated to 440-460° C. for 10-14 hours, and then subjected to hot rough rolling and hot finish rolling in sequence to obtain a hot finish rolled coil; wherein the number of passes of the hot rough rolling is 17-19, the sum of the processing rates of each pass is 94-95.5%, and the rolling speed is 1.50-3.00 m·s -1 The number of hot finishing rolling passes is 3, the processing rate of each pass is 30-45%, and the rolling speed is 2.00-3.00 m·s -1 Then the hot-rolled coil is unrolled, cut into pieces, and annealed to obtain rare earth aluminum alloy plates.

4. The method for preparing a rare earth aluminum alloy plate according to claim 3, characterized in that The mass ratio of Sc element to Zr element in the raw material weighed in step 1 is 1.36-1.55:

1.

5. The method for preparing a rare earth aluminum alloy plate according to claim 3, characterized in that The temperature of the homogenization heat treatment in step 2 is 350° C. and the holding time is 16 h.

6. The method for preparing a rare earth aluminum alloy plate according to claim 3, characterized in that Step 2: Heat to 450°C and keep warm for 10 hours.

7. The method for preparing a rare earth aluminum alloy plate according to claim 3, characterized in that The temperature of the annealing treatment in step 2 is 250-300° C., and the holding time of the annealing treatment is 1.5-3 hours.

8. The method for preparing a rare earth aluminum alloy plate according to claim 3, characterized in that The annealing temperature in step 2 is 300° C., and the holding time for the annealing treatment is 2 h.

9. The method for preparing a rare earth aluminum alloy plate according to claim 3, characterized in that The annealing temperature in step 2 is 250° C., and the holding time for the annealing treatment is 2 h.

10. The method for preparing a rare earth aluminum alloy plate according to claim 3, characterized in that The yield strength of the rare earth aluminum alloy plate is 260-288 MPa, the tensile strength is 352-378 MPa, the elongation is 13.3-18.8%, and the fracture toughness Kc is 143-168 MPa·m 1 / 2 .

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