Ultrahigh-strength rare earth magnesium alloy deformed material and preparation method thereof

Abstract

The invention discloses an ultrahigh-strength rare earth magnesium alloy deformed material and a preparation method thereof, and the ultrahigh-strength rare earth magnesium alloy deformed material comprises the following components in percentage by mass: 8.4%-9.5% of Gd, 2.4%-3.6% of Y, 1.5%-2.5% of Zn, 0.4%-0.55% of Zr, 0.8%-1.4% of Ho and the balance of Mg. The method for preparing the ultrahigh-strength magnesium alloy deformed material comprises the steps of alloy smelting, homogenizing treatment, multidirectional free forging and aging treatment. According to the Mg-Gd-Y-Zn-Zr alloy and the preparation method thereof, the Ho element is added into the Mg-Gd-Y-Zn-Zr alloy, the stacking fault energy is reduced through a large amount of solid solution of Ho in an Mg matrix, a large amount of stacking faults are induced to be formed, and the lt is hindered; c + egt; according to the ultrahigh-strength rare earth magnesium alloy deformation material, the alloy strength is improved through the sliding of the dislocation on the conical surface, so that the yield strength of the ultrahigh-strength rare earth magnesium alloy deformation material ranges from 449 MPa to 454 MPa, the tensile strength ranges from 490 MPa to 498 MPa, and the ductility ranges from 9.7% to 11.4%.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnesium alloys, and in particular relates to an ultra-high strength rare earth magnesium alloy deformed material and a preparation method thereof. Background Art

[0002] Magnesium alloys have attracted wide attention in the fields of transportation, aerospace, and military due to their low density, high specific strength, and high specific stiffness. With the advancement of lightweighting, high-strength and tough deformable magnesium rare earth alloy load-bearing structural parts have gradually gained attention in industrial applications to meet the needs of diverse lightweight structural parts.

[0003] In the existing ultra-high strength rare earth magnesium alloys, such as a Mg-Zn-Ce-Ca-Zr high strength rare earth magnesium alloy deformed material developed by Chinese Patent Publication No. CN115478199A, after homogenization treatment and differential temperature extrusion deformation, the rare earth magnesium alloy has a yield strength of 358MPa, a tensile strength of 389MPa, and an elongation of 13%. The alloy strength is not high and cannot fully meet the current performance requirements for magnesium alloy structural parts. Therefore, it is particularly important to develop a new type of ultra-high strength magnesium alloy. Summary of the invention

[0004] In order to improve the comprehensive mechanical properties of rare earth magnesium alloy, the present invention provides an ultra-high strength rare earth magnesium alloy deformed material and a preparation method thereof.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] An ultra-high strength rare earth magnesium alloy deformed material, comprising, by mass percentage, Gd: 8.4%-9.5%, Y: 2.4%-3.6%, Zn: 1.5%-2.5%, Zr: 0.4%-0.55%, Ho: 0.8%-1.4%, and the balance being Mg;

[0007] The high-strength and high-plasticity rare earth magnesium alloy has a yield strength of 449MPa-454MPa, a tensile strength of 490-498MPa, and an elongation of 9.7%-11.4%.

[0008] Based on the same inventive concept, the present invention also provides a method for preparing an ultra-high strength rare earth magnesium alloy deformed material, comprising the following steps:

[0009] S1: melting the raw materials and then casting to obtain a magnesium alloy ingot;

[0010] S2: homogenizing the magnesium alloy ingot obtained in step S1;

[0011] S3: After the homogenization treatment in step S2 is completed, three multi-directional free forgings are performed;

[0012] S4: After the forging process is completed, the obtained forged plate is subjected to aging treatment to finally obtain an ultra-high strength rare earth magnesium alloy deformed material.

[0013] Preferably, the step S1 specifically includes: the raw materials of the ultra-high strength rare earth magnesium alloy deformed material are Mg ingots, Zn ingots, Mg-20Ho master alloys, Mg-30Gd master alloys, Mg-30Y master alloys, and Mg-30Zr master alloys, the raw material Mg ingot is melted, the temperature is raised to 700-720°C, and then the Mg-30Gd master alloy, Mg-30Y master alloy, and Zn ingot are added in sequence, and the temperature is kept for 5-15 minutes, and then the furnace temperature is set to 735-745°C, and the temperature is kept for 10-20 minutes, and then the Mg-30Zr master alloy and Mg-20Ho master alloy are added, and the temperature is kept for 10-20 minutes for refining and stirring. After the smelting is completed, an alloy liquid is obtained; and the alloy liquid is cast to obtain a magnesium alloy ingot.

[0014] Preferably, the homogenization treatment in step S2 is: keeping the magnesium alloy ingot at 500° C.-520° C. for 18 h-22 h; and then air cooling.

[0015] Preferably, in step S3, the magnesium alloy ingot after homogenization treatment is preheated to 455°C-460°C and then subjected to three multi-directional free forgings, wherein one multi-directional free forging is: forging along the height direction of the magnesium alloy ingot, and then alternating forging along the length and width directions of the magnesium alloy ingot.

[0016] Preferably, the number of forging passes along the height direction of the magnesium alloy ingot is 1-2 passes, and the deformation amount of a single forging pass along the height direction of the magnesium alloy ingot is 35-45%. The number of alternating forging passes along the length and width directions of the magnesium alloy billet is 2-6 passes, and the deformation amount of a single alternating forging pass is 20-25%.

[0017] Preferably, the speed of the three multi-directional free forgings is 10-25 mm / s.

[0018] Preferably, the step S4 specifically comprises: performing aging treatment on the forged plate obtained after three times of multi-directional free forging: placing the forged plate in a muffle furnace at 190-210° C. for 35-45 hours.

[0019] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0020] (1) Ho has a very large solid solubility in Mg. Its maximum solid solubility at the eutectic temperature is 28wt%, and it still has a solid solubility of 12wt% when the temperature is reduced to 200℃. When Ho is dissolved in a large amount in the Mg matrix, it will reduce the stacking fault energy and induce the formation of a large number of stacking faults. Usually, during the deformation process of magnesium alloys, basal slip, prism slip and twinning are difficult to start due to their unfavorable orientation. At this time, it is necessary to rely on<c+a> Therefore, after adding Ho to the Mg matrix alloy, the high-density basal plane stacking faults produced can<c+a> The slip of dislocations on the cone surface strongly hinders the<c+a> Dislocations can also cut basal plane stacking faults into segments, providing additional dislocation pinning points at the stacking fault segments, thereby greatly improving the strength. It should be pointed out that the stacking fault strengthening mechanism does not follow the Hall-Petch relationship, that is, the yield strength is not linearly related to the inverse of the square root of the stacking fault spacing, but is linearly related to the inverse of the stacking fault spacing. In other words, compared with the fine grain strengthening mechanism, the stacking fault strengthening mechanism has a more obvious improvement in yield strength. In addition, high-density stacking faults can accommodate dislocations, increase the degree of dislocation accumulation, and thus improve the work hardening ability, which is conducive to improving ductility.

[0021] (2) The composite addition of Ho and Zn can form a nano-sized H1 phase, which is dispersed in the matrix and can effectively hinder dislocation movement and further improve the strength.

[0022] (3) The present invention adds a multi-directional free forging process during the preparation process. Under severe plastic deformation, the grains of the magnesium alloy are refined, achieving the purpose of fine grain strengthening, and improving the strength and toughness of the magnesium alloy. At the same time, the multi-directional free forging process is adopted, making the present invention better suitable for large-size magnesium alloys with high strength and improved plasticity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a comparison chart of the mechanical properties of magnesium alloys obtained in the embodiments of the present invention and the comparative examples. DETAILED DESCRIPTION

[0024] The present invention adds Ho element to the Mg-Gd-Y-Zn-Zr alloy, and reduces the stacking fault energy by solid dissolving Ho in the Mg matrix in large quantities, thereby inducing the formation of a large number of stacking faults and preventing<c+a> The dislocations slip on the cone surface, thereby improving the strength of the alloy. At the same time, a multi-directional free forging process is adopted in the preparation process, making the magnesium alloy of the present invention more suitable for the production of large-size magnesium alloys.

[0025] It should be noted that the temperature field and deformation degree of different regions of large-sized magnesium alloys are different during thermal deformation, resulting in uneven microstructure and performance during thermal deformation. Therefore, the present invention adopts multi-directional free forging, and adopts three multi-directional free forgings to make the magnesium alloy as uniform as possible in terms of deformation degree, temperature field and microstructure and performance during thermal deformation, thereby making the present invention more suitable for the preparation of large-sized magnesium alloys.

[0026] The preparation method of the ultra-high strength rare earth magnesium alloy deformed material of the present invention is as follows:

[0027] 1. Raw material selection: The raw materials include Mg ingot, Mg-30Gd master alloy, Mg-30Y master alloy, Mg-30Zr master alloy, Zn ingot and Mg-20Ho master alloy.

[0028] 2. Melt the raw material Mg ingot, heat it to 710℃, add Mg-30Gd master alloy, Mg-30Y master alloy and Zn ingot in turn, keep warm for 10min, set the furnace temperature to 740℃, keep warm for 15min, add Mg-30Zr master alloy and Mg-20Ho master alloy, keep warm for 15min for refining and stirring, and the smelting is completed to obtain alloy liquid; then cast the alloy liquid into magnesium alloy ingot.

[0029] 3. The magnesium alloy ingot is homogenized by keeping it at 500℃-520℃ for 18h-22h, followed by air cooling to complete the homogenization process.

[0030] 4. During the multi-directional free forging process, the magnesium alloy ingot after homogenization treatment is preheated to 455°C-460°C, and the deformation of a single forging pass along the height direction of the ingot is 35-45%. Then, the ingot is alternately forged along the length and width of the ingot for 2-6 passes, and the deformation of a single forging pass is 20-35%. A total of three multi-directional free forgings are performed, and the speed of the three multi-directional free forgings is 10-25 mm / s.

[0031] 5. Perform aging treatment on the forged plate. The process is as follows: place the forged plate in a muffle furnace at 200℃ for 48 hours, and then take it out and air cool it.

[0032] The following is a further detailed description of an ultra-high strength rare earth magnesium alloy deformed material and a preparation method thereof proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description.

[0033] Embodiment 1:

[0034] The technical solution of this embodiment is as follows:

[0035] (1) In terms of mass percentage, the element composition of the ultra-high strength rare earth magnesium alloy deformed material of this embodiment includes:

[0036] Gd: 8.4%, Y: 2.5%, Zn: 1.5%, Zr: 0.4%, Ho: 0.8%, and the balance is Mg.

[0037] (2) The method for preparing the ultra-high strength rare earth magnesium alloy deformed material of this embodiment includes the following steps:

[0038] 1. The total weight of each batch is 5kg. When batching, adjust the burnout ratio according to the type and content range of the alloy elements. The raw materials used are: pure Mg, Mg-30Gd, Mg-30Y, pure Zn, Mg-30Zr, Mg-20Ho master alloy. Bake the batch and mold before smelting. The initial furnace temperature is set to 710℃, pure Mg is placed in the furnace and heated with the furnace, and protective gas (N2+SF6) is passed. When the furnace temperature rises to 710℃, pure Mg begins to melt after about 10-15 minutes, and the furnace temperature is reduced to 670℃; when the melt temperature rises to 750℃ again, Mg-30Gd, Mg-30Y, and pure Zn are added, and the furnace temperature is set to 750℃ after 10 minutes of insulation, and the insulation is continued for 15 minutes, and then Mg-30Zr and Mg-20Ho intermediate alloys are added, and the insulation is continued for 15 minutes, followed by refining and stirring. The refining agent is 1.2% of the total weight of the ingredients, that is, 0.06kg. Take out a small ingot from the melt to measure the direct reading spectrum. If the composition meets the standard, the melt is left to stand for 45 minutes before casting. If the composition does not meet the standard, the material is supplemented until the final direct reading composition is close to the nominal composition.

[0039] 2. The magnesium alloy ingot is placed in a muffle furnace at 500°C for 20 hours; then air-cooled to complete the homogenization process.

[0040] 3. The magnesium alloy ingot after homogenization treatment is subjected to multi-directional free forging treatment. The magnesium alloy ingot after homogenization treatment is preheated to 460°C. The deformation amount of a single forging pass along the height direction of the ingot is 40%. The number of forging passes along the width and length directions is 5, and the deformation amount of a single forging pass is 30%. The above-mentioned multi-directional free forging is carried out three times in total, and the speed of the three multi-directional free forgings is 20 mm / s.

[0041] 4. The forged plate after multi-directional free forging is subjected to aging treatment, and the process is as follows: the forged plate is placed in a muffle furnace at 200°C for 40 hours.

[0042] Embodiment 2:

[0043] The technical solution of this embodiment is as follows:

[0044] (1) In terms of mass percentage, the element composition of the ultra-high strength rare earth magnesium alloy deformed material of this embodiment includes:

[0045] Gd: 9.5%, Y: 3.6%, Zn: 2.5%, Zr: 0.55%, Ho: 1.4%, and the balance is Mg.

[0046] (2) The method for preparing the ultra-high strength rare earth magnesium alloy deformed material of this embodiment includes the following steps:

[0047] 1. The total weight of each batch is 5kg. When batching, adjust the burnout ratio according to the type and content range of the alloying elements. The raw materials used are: pure Mg, Mg-30Gd, Mg-30Y, pure Zn, Mg-30Zr, Mg-20Ho. Bake the batch and mold before smelting. Set the initial furnace temperature to 710℃, put pure Mg into the furnace and heat it up with the furnace, and pass the protective gas (N2+SF6). When the furnace temperature rises to 710℃, pure Mg begins to melt after about 10-15 minutes, and the furnace temperature drops to 670℃. When the melt temperature rises to 750℃ again, add Mg-30Gd, Mg-30Y, and pure Zn. After keeping warm for 10 minutes, set the furnace temperature to 750℃, continue to keep warm for 15 minutes, then put Mg-30Zr and Mg-20Ho, and continue to keep warm for 15 minutes. Then, the refining and stirring are carried out, and the refining agent is 1.2% of the total weight of the ingredients, that is, 0.06kg. A small ingot is taken out from the melt to measure the direct reading spectrum. If the composition meets the standard, the melt is left to stand for 45 minutes before casting. If the composition does not meet the standard, the material is supplemented until the final direct reading composition is close to the nominal composition.

[0048] 2. The magnesium alloy ingot is placed in a muffle furnace at 500°C for 20 hours; then air-cooled to complete the homogenization process.

[0049] 3. The magnesium alloy ingot after homogenization treatment is subjected to multi-directional free forging treatment. The magnesium alloy ingot after homogenization treatment is preheated to 460°C. The deformation amount of a single forging pass along the height direction of the ingot is 40%. The number of forging passes along the width and length directions is 5, and the deformation amount of a single forging pass is 30%. The above-mentioned multi-directional free forging is carried out three times in total, and the speed of the three multi-directional free forgings is 20 mm / s.

[0050] 4. The forged plate after multi-directional free forging is subjected to aging treatment, and the process is as follows: the forged plate is placed in a muffle furnace at 200°C for 48 hours.

[0051] Comparative Example 1:

[0052] The technical scheme of this comparative example is as follows:

[0053] (1) In terms of mass percentage, the element composition of the rare earth magnesium alloy deformed material of this embodiment includes:

[0054] Gd: 9.0%, Y: 3.0%, Zn: 2.0%, Zr: 0.5%, and the balance is Mg.

[0055] (2) The preparation method of the rare earth magnesium alloy deformed material of this comparative example includes the following steps:

[0056] 1. The total weight of each batch is 5kg. When batching, adjust the burnout ratio according to the type and content range of the alloying elements. The raw materials used are: pure Mg, Mg-30Gd, Mg-30Y, pure Zn, Mg-30Zr. Bake the batch and mold before smelting. Set the initial furnace temperature to 710℃, put pure Mg into the furnace and heat it up with the furnace, and pass the protective gas (N2+SF6). When the furnace temperature rises to 710℃, pure Mg begins to melt after about 10min-15min, and the furnace temperature drops to 670℃. When the melt temperature rises to 750℃ again, add Mg-30Gd, Mg-30Y, and pure Zn. After keeping warm for 10min, set the furnace temperature to 750℃, continue to keep warm for 15min, then add Mg-30Zr alloying elements, and continue to keep warm for 15min. Then refine and stir, and the refining agent takes 1.2% of the total batch weight, that is, 0.06kg. Take a small ingot from the melt and measure the direct reading spectrum. If the composition meets the standard, let the melt stand for 45 minutes before casting. If the composition does not meet the standard, add material until the final direct reading composition is close to the nominal composition.

[0057] 2. The magnesium alloy ingot is placed in a muffle furnace at 500°C for 20 hours; then air-cooled to complete the homogenization process.

[0058] 3. The magnesium alloy ingot after homogenization treatment is subjected to multi-directional free forging treatment. The magnesium alloy ingot after homogenization treatment is preheated to 460°C, and the deformation amount of a single forging pass along the height direction of the ingot is 40%. Then, the number of passes of alternating forging along the width and length directions is 5, and the deformation amount of a single alternating forging pass is 30%. The multi-directional free forging is carried out three times in total, and the speed of the three multi-directional free forgings is 20 mm / s.

[0059] 4. The forged plate after multi-directional free forging is subjected to aging treatment, and the process is as follows: the forged plate is placed in a muffle furnace at 200°C for 40 hours.

[0060] Comparative Example 2:

[0061] The technical scheme of this comparative example is as follows:

[0062] (1) In terms of mass percentage, the element composition of the ultra-high strength rare earth magnesium alloy deformed material of this embodiment includes:

[0063] Gd: 9.0%, Y: 3.0%, Zn: 2.0%, Zr: 0.5%, Ho: 1.8%, and the balance is Mg.

[0064] (2) The preparation method of the ultra-high strength rare earth magnesium alloy deformed material of this comparative example includes the following steps:

[0065] 1. The total weight of each batch is 5kg. When batching, adjust the burnout ratio according to the type and content range of the alloying elements. The raw materials used are: pure Mg, Mg-30Gd, Mg-30Y, pure Zn, Mg-30Zr, and Mg-20Ho master alloy. Bake the batch and mold before smelting. Set the initial furnace temperature to 710℃, put pure Mg into the furnace and heat it up with the furnace, and pass the protective gas (N2+SF6). When the furnace temperature rises to 710℃, pure Mg begins to melt after about 10min-15min, and the furnace temperature drops to 670℃. When the melt temperature rises to 750℃ again, add Mg-30Gd, Mg-30Y, and pure Zn. After keeping warm for 10min, set the furnace temperature to 750℃, continue to keep warm for 15min, then put Mg-30Zr and Mg-10Ho master alloy, and continue to keep warm for 15min. Then, the refining and stirring are carried out, and the refining agent is 1.2% of the total weight of the ingredients, that is, 0.06kg. A small ingot is taken out from the melt to measure the direct reading spectrum. If the composition meets the standard, the melt is left to stand for 45 minutes before casting. If the composition does not meet the standard, the material is supplemented until the final direct reading composition is close to the nominal composition.

[0066] 2. The magnesium alloy ingot is placed in a muffle furnace at 500°C for 20 hours; then air-cooled to complete the homogenization process.

[0067] 3. The magnesium alloy ingot after homogenization treatment is subjected to multi-directional free forging treatment. The magnesium alloy ingot after homogenization treatment is preheated to 460°C. The deformation amount of a single forging pass along the height direction of the ingot is 40%. The number of alternating forging passes along the width and length directions is 5 passes, and the deformation amount of a single alternating forging pass is 30%. A total of three multi-directional free forgings are performed, and the speed of the three multi-directional free forgings is 20 mm / s.

[0068] 4. The forged plate after multi-directional free forging is subjected to aging treatment, and the process is as follows: the forged plate is placed in a muffle furnace at 200°C for 48 hours.

[0069] Comparative Example 3

[0070] (1) In terms of mass percentage, the element composition of the ultra-high strength rare earth magnesium alloy deformed material of this embodiment includes:

[0071] Gd: 9%, Y: 3%, Zn: 2%, Zr: 0.5%, Ho: 0.7%, and the balance is Mg.

[0072] (2) The preparation method of the ultra-high strength rare earth magnesium alloy deformed material of this comparative example includes the following steps:

[0073] 1. The total weight of each batch is 5kg. When batching, adjust the burnout ratio according to the type and content range of the alloying elements. The raw materials used are: pure Mg, Mg-30Gd, Mg-30Y, pure Zn, Mg-30Zr, and Mg-20Ho master alloy. Bake the batch and mold before smelting. Set the initial furnace temperature to 710℃, put pure Mg into the furnace and heat it up with the furnace, and pass the protective gas (N2+SF6). When the furnace temperature rises to 710℃, pure Mg begins to melt after about 10min-15min, and the furnace temperature drops to 670℃. When the melt temperature rises to 750℃ again, add Mg-30Gd, Mg-30Y, and pure Zn. After keeping warm for 10min, set the furnace temperature to 750℃, continue to keep warm for 15min, then put Mg-30Zr and Mg-10Ho master alloy, and continue to keep warm for 15min. Then, the refining and stirring are carried out, and the refining agent is 1.2% of the total weight of the ingredients, that is, 0.06kg. A small ingot is taken out from the melt to measure the direct reading spectrum. If the composition meets the standard, the melt is left to stand for 45 minutes before casting. If the composition does not meet the standard, the material is supplemented until the final direct reading composition is close to the nominal composition.

[0074] 2. The magnesium alloy ingot is placed in a muffle furnace at 500°C for 20 hours; then air-cooled to complete the homogenization process.

[0075] 3. The magnesium alloy ingot after homogenization treatment is subjected to multi-directional free forging treatment. The magnesium alloy ingot after homogenization treatment is preheated to 460°C. The deformation amount of a single forging pass along the height direction of the ingot is 40%. The number of alternating forging passes along the width and length directions is 5 passes, and the deformation amount of a single alternating forging pass is 30%. A total of three multi-directional free forgings are performed, and the speed of the three multi-directional free forgings is 20 mm / s.

[0076] 4. The forged plate after multi-directional free forging is subjected to aging treatment, and the process is as follows: the forged plate is placed in a muffle furnace at 200°C for 48 hours.

[0077] The elemental compositions of the magnesium alloy deformed materials of Examples 1-2 and Comparative Examples 1-3 are shown in Table 1:

[0078] G Y Zn Zr Ho Example 1 8.4 2.5 1.5 0.4 0.8 Example 2 9.5 3.6 2.5 0.55 1.4 Comparative Example 1 9 3 2.0 0.5 - Comparative Example 2 9 3 2.0 0.5 1.8 Comparative Example 3 9 3 2.0 0.5 0.7

[0079] The tensile mechanical properties of the magnesium alloy deformed materials of Examples 1-2 and Comparative Examples 1-3 are shown in Table 2:

[0080]

[0081]

[0082] The components of Example 1 and Example 2 are controlled within the composition range designed by the present invention. Comparative Example 1 does not add Ho element, Comparative Example 2 adds excessive Ho element, and Comparative Example 3 adds a small amount of Ho element. Figure 1 It can be seen that the final measured comprehensive mechanical properties of the embodiment are significantly better than those of the two comparative examples, which shows that the element addition and composition range designed by the present invention have a very beneficial effect on improving the mechanical properties of the Mg-Gd-Y-Zn rare earth magnesium alloy.

[0083] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. An ultra-high strength rare earth magnesium alloy deformed material, characterized in that: In terms of mass percentage, it includes Gd: 8.4%-9.5%, Y: 2.4%-3.6%, Zn: 1.5%-2.5%, Zr: 0.4%-0.55%, Ho: 0.8%-1.4%, and the balance is Mg; The high-strength and high-plasticity rare earth magnesium alloy has a yield strength of 449MPa-454MPa, a tensile strength of 490-498MPa, and an elongation of 9.7%-11.4%.

2. A method for preparing the ultra-high strength rare earth magnesium alloy deformed material according to claim 1, characterized in that: The following steps are involved: S1: melting the raw materials and then casting to obtain a magnesium alloy ingot; S2: homogenizing the magnesium alloy ingot obtained in step S1; S3: After the homogenization treatment in step S2 is completed, three multi-directional free forgings are performed; S4: After the forging process is completed, the obtained forged plate is subjected to aging treatment to finally obtain an ultra-high strength rare earth magnesium alloy deformed material.

3. The method for preparing the ultra-high strength rare earth magnesium alloy deformed material according to claim 2, characterized in that: The step S1 specifically includes: the raw materials of the ultra-high strength rare earth magnesium alloy deformed material are Mg ingots, Zn ingots, Mg-20Ho master alloys, Mg-30Gd master alloys, Mg-30Y master alloys, and Mg-30Zr master alloys, the raw material Mg ingots are melted, the temperature is raised to 700-720°C, and then the Mg-30Gd master alloy, Mg-30Y master alloy, and Zn ingots are added in sequence, and the temperature is kept for 5-15 minutes, and then the furnace temperature is set to 735-745°C, and the temperature is kept for 10-20 minutes, and then the Mg-30Zr master alloy and Mg-20Ho master alloy are added, and the temperature is kept for 10-20 minutes for refining and stirring, and the smelting is completed to obtain a molten alloy; the molten alloy is cast to obtain a magnesium alloy ingot.

4. The method for preparing the ultra-high strength rare earth magnesium alloy deformed material according to claim 2, characterized in that: The homogenization treatment in step S2 is as follows: keeping the magnesium alloy ingot at 500° C.-520° C. for 18 h-22 h; and then air cooling.

5. The method for preparing the ultra-high strength rare earth magnesium alloy deformed material according to claim 2, characterized in that: In step S3, the magnesium alloy ingot after homogenization treatment is preheated to 455°C-460°C and then subjected to three multi-directional free forgings, wherein one multi-directional free forging is: forging along the height direction of the magnesium alloy ingot, and then alternating forging along the length and width directions of the magnesium alloy ingot.

6. The method for preparing the ultra-high strength rare earth magnesium alloy deformed material according to claim 5, characterized in that: The number of forging passes along the height direction of the magnesium alloy ingot is 1-2 passes, and the deformation of a single forging pass along the height direction of the magnesium alloy ingot is 35-45%. The number of alternating forging passes along the length and width directions of the magnesium alloy billet is 2-6 passes, and the deformation of a single alternating forging pass is 20-25%.

7. The method for preparing the ultra-high strength rare earth magnesium alloy deformed material according to claim 5, characterized in that: The speed of three multi-directional free forgings is 10-25 mm / s.

8. The method for preparing an ultra-high strength rare earth magnesium alloy deformed material according to claim 5, characterized in that: The step S4 is specifically as follows: the forged plate obtained after three times of multi-directional free forging is subjected to aging treatment: the forged plate is placed in a muffle furnace at 190-210° C. for 35-45 hours.

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