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

Abstract

The invention discloses a high-strength rare earth magnesium alloy deformed material and a preparation method thereof, and the high-strength rare earth magnesium alloy deformed material comprises the following elements in percentage by mass: 8.5 wt%-10.3 wt% of Gd, 3.5 wt%-4.5 wt% of Y, 2.0 wt%-3.0 wt% of Zn, 0.45 wt%-0.60 wt% of Zr, 0.4 wt%-0.6 wt% of Nd and the balance of Mg. The method for preparing the high-strength rare earth magnesium alloy deformed material comprises the steps of alloy smelting, homogenizing treatment, upsetting and drawing type multidirectional forging and aging treatment. The microstructure of the magnesium alloy is improved by introducing the light rare earth element Nd and the heavy rare earth elements Gd and Y at the same time, crushing of a grain boundary blocky LPSO phase in the plastic deformation process is promoted, meanwhile, the high-performance magnesium alloy deformed material is obtained through the reasonable forging and pressing technology, and the application prospect of the magnesium alloy in the fields of aerospace, the military industry and the like is greatly expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of magnesium alloys, and in particular relates to a 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 recent years, domestic and foreign scholars have combined magnesium and heavy rare earth elements to develop a series of magnesium rare earth alloys with significant aging strengthening effects. Among them, the strength of Mg-Gd-Y-Zr alloy is the best, but the elongation of this alloy is low. By adding Zn elements to Mg-Gd-Y-Zr magnesium alloy, the plasticity of the material can be significantly improved without reducing the strength. However, Mg-Gd-Y-Zn-Zr alloy is prone to form an 18R-type LPSO structure during the casting process. Subsequently, during the homogenization heat treatment and cooling process, the 18R-type LPSO structure is transformed into a 14H-type LPSO structure. The transformed blocky LPSO structure is mainly distributed at the grain boundaries. Since the blocky LPSO structure at the grain boundary of Mg-Gd-Y-Zn-Zr alloy is not easy to break during the later plastic deformation process, when hot forming large-sized magnesium rare earth alloy parts under industrial conditions, the organization is greatly different, the performance of each part fluctuates greatly, and it is difficult to meet the service requirements of the parts. Summary of the invention

[0004] In order to further improve the comprehensive mechanical properties of Mg-Gd-Y-Zn-Zr rare earth magnesium alloy and improve the structural uniformity and performance consistency of the material, the present invention provides a high-strength rare earth magnesium alloy deformed material and a preparation method thereof. By adding Nd, the crushing of the grain boundary blocky LPSO phase can be promoted during the plastic deformation of the Mg-Gd-Y-Zn-Zr alloy.

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

[0006] A high-strength rare earth magnesium alloy deformed material, comprising, by mass percentage, Gd: 8.5%-10.3%, Y: 3.5%-4.5%, Zn: 2.0%-3.0%, Zr: 0.45%-0.60%, Nd: 0.4%-0.6%, and the balance is Mg;

[0007] The high-strength rare earth magnesium alloy deformed material has a yield strength of 390MPa-403MPa, a tensile strength of 465MPa-473MPa, and an elongation of 9.4%-10.1%.

[0008] Based on the same invention, a method for preparing a high-strength rare earth magnesium alloy deformed material comprises 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;

[0011] S3: After homogenization treatment is completed, upsetting multi-directional forging is performed;

[0012] S4: After the forging process is completed, an aging treatment is performed to obtain the high-strength rare earth magnesium alloy deformed material.

[0013] Preferably, the raw materials of the high-strength rare earth magnesium alloy deformed material are Mg ingots, Mg-30Gd master alloys, Mg-30Nd master alloys, Mg-30Y master alloys, Mg-30Zr master alloys, and Zn ingots;

[0014] The smelting process includes: melting the raw material Mg ingot, heating it to 700-720°C, adding Mg-30Gd master alloy, Mg-30Y master alloy and Zn ingot in sequence, keeping the temperature for 5-15 minutes, setting the furnace temperature to 730-750°C, and continuing to keep the temperature for 10-20 minutes, adding Mg-30Zr master alloy and Mg-30Nd master alloy, and continuing to keep the temperature 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.

[0015] Preferably, the homogenization treatment in step S2 comprises: keeping the magnesium alloy ingot at 500-520° C. for 18-22 hours, and then air cooling.

[0016] Preferably, after the homogenization treatment in step S3, the magnesium alloy ingot is preheated to 460-470° C., the upper and lower anvils are preheated to 390-410° C., and then upsetting multi-directional forging is performed.

[0017] Preferably, in the upsetting and drawing multi-directional forging in step S3, the pressing amount in the upsetting pass is 30-50%, the pressing amount in the drawing pass is 5-10%, and the pressing speed is 200-400 mm / min.

[0018] Preferably, in step S3, three upsetting multi-directional forgings are performed.

[0019] Preferably, the aging treatment in step S4 is: keeping at 190-210° C. for 46-50 hours, and then air cooling.

[0020] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0021] (1) Nd is a light rare earth element belonging to the lanthanide series. Its solid solubility in the Mg matrix is ​​relatively low, with a maximum solid solubility of about 3.6wt% at a eutectic temperature of 548°C and about 0.8wt% at room temperature. The solid solubility of heavy rare earth elements Gd and Y in the magnesium matrix is ​​relatively high, at 23.5wt% and 11.4wt%, respectively, and about 0wt% at room temperature. Therefore, the composite addition of light and heavy rare earths can produce obvious solid solution strengthening and aging hardening effects, significantly improving the strength of the material.

[0022] (2) Nd can improve the lattice symmetry of magnesium, thereby promoting the<c+a> Slip, while the local deformation inside the grain is uneven, and a network-distributed shear band structure appears. The shear band is conducive to relieving stress concentration, promoting plastic deformation, and promoting the crushing of the grain boundary block LPSO phase in the Mg-Gd-Y-Zn-Zr alloy while refining the grains to the greatest extent. Therefore, the high-performance magnesium alloy deformed material in the present invention, by compositely adding light and heavy rare earth elements, comprehensively improves the strength and plasticity of the magnesium alloy through the effects of grain refinement strengthening, solid solution strengthening, and precipitation strengthening.

[0023] (3) The present invention only introduces a small amount of rare earth element Nd and adopts conventional heat treatment and forging processes to significantly improve the comprehensive mechanical properties of Mg-Gd-Y rare earth alloys, expand the application range of magnesium alloys, and the manufacturing process is not complicated, which is convenient for large-scale production and use. DETAILED DESCRIPTION

[0024] The present invention improves the microstructure of the magnesium alloy by simultaneously introducing the light rare earth element Nd and the heavy rare earth elements Gd and Y, promotes the crushing of the grain boundary blocky LPSO phase during the plastic deformation process, and obtains a high-performance magnesium alloy deformed material through a reasonable forging process.

[0025] The following is a further detailed description of a high-strength rare earth magnesium alloy deformed material and a preparation method thereof proposed by the present invention in conjunction with specific embodiments. The advantages and features of the present invention will become more apparent from the following description.

[0026] Example 1

[0027] The technical solution of this embodiment is as follows:

[0028] 1. In terms of mass percentage, the element composition of the high-strength rare earth magnesium alloy deformed material of this embodiment includes:

[0029] Gd: 10.3%, Y: 4.5%, Zn: 3.0%, Zr: 0.6%, Nd: 0.4%, and the balance is Mg.

[0030] 2. The method for preparing the high-strength rare earth magnesium alloy deformed material of this embodiment includes the following steps:

[0031] The total weight of each batch is 5kg. When batching, the burnout ratio is adjusted 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-30Nd. 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-30Nd intermediate alloys, and continue to keep warm for 15 minutes. Then, refining and stirring are carried out. The refining agent is 1.2% of the total weight of the ingredients, i.e. 0.06 kg. Stirring: left and right 100 times, up and down 60 times, left and right 100 times, up and down 60 times, left and right 100 times. Take 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.

[0032] The magnesium alloy ingot was placed in a muffle furnace and kept at 500°C for 20 hours; it was then air-cooled and homogenized.

[0033] The magnesium alloy ingot after homogenization treatment is subjected to upsetting and drawing type multi-step forging processing: during the forging processing, the magnesium alloy ingot after homogenization treatment is preheated to 465°C, and the upper and lower anvils are preheated to 400°C.

[0034] When the ingot is subjected to upsetting and drawing multi-directional forging, the downstroke in the upsetting pass is 45%, the downstroke in the drawing pass is 7%, and the downstroke speed is controlled at 280 mm / min.

[0035] When the ingot is subjected to upsetting multi-directional forging, the above-mentioned three upsetting treatments are performed.

[0036] After forging, aging treatment is carried out, and the process is as follows: the forged plate is kept at 200℃ for 48h, and then taken out for air cooling.

[0037] Embodiment 2:

[0038] The technical solution of this embodiment is as follows:

[0039] 1. In terms of mass percentage, the element composition of the high-strength rare earth magnesium alloy deformed material of this embodiment includes:

[0040] Gd: 8.5%, Y: 3.5%, Zn: 2.0%, Zr: 0.45%, Nd: 0.6%, and the balance is Mg.

[0041] 2. The method for preparing the high-strength rare earth magnesium alloy deformed material of this embodiment includes the following steps:

[0042] The total weight of each batch is 5kg. When batching, the burnout ratio is adjusted 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-30Nd. 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-30Nd intermediate alloys, and continue to keep warm for 15 minutes. Then, refining and stirring are carried out. The refining agent is 1.2% of the total weight of the ingredients, i.e. 0.06 kg. Stirring: left and right 100 times, up and down 60 times, left and right 100 times, up and down 60 times, left and right 100 times. Take 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.

[0043] The magnesium alloy ingot was placed in a muffle furnace and kept at 500°C for 20 hours; it was then air-cooled and homogenized.

[0044] The magnesium alloy ingot after homogenization treatment is subjected to upsetting and drawing type multi-step forging processing: during the forging processing, the magnesium alloy ingot after homogenization treatment is preheated to 465°C, and the upper and lower anvils are preheated to 400°C.

[0045] When the ingot is subjected to upsetting and drawing multi-directional forging, the downstroke in the upsetting pass is 45%, the downstroke in the drawing pass is 7%, and the downstroke speed is controlled at 280 mm / min.

[0046] When the ingot is subjected to upsetting multi-directional forging, the above-mentioned three upsetting treatments are performed.

[0047] After forging, aging treatment is carried out, and the process is as follows: the forged plate is kept at 200℃ for 48h, and then taken out for air cooling.

[0048] Comparative Example 1:

[0049] The technical scheme of this comparative example is as follows:

[0050] 1. In terms of mass percentage, the element composition of the rare earth magnesium alloy deformed material of this embodiment includes:

[0051] Gd: 10%, Y: 4%, Zn: 2.5%, Zr: 0.6%, and the balance is Mg.

[0052] 2. The preparation method of the rare earth magnesium alloy deformed material of this comparative example includes the following process:

[0053] The total weight of each batch is 5kg. When batching, the burnout ratio is adjusted according to the type and content range of the alloying elements. The raw materials used are: pure Mg, Mg-30Gd, Mg-30Y, pure Zn, and 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 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 alloying elements, and continue to keep warm for 15 minutes. Then, refining and stirring are carried out. The refining agent is 1.2% of the total weight of the ingredients, i.e. 0.06 kg. Stirring: left and right 100 times, up and down 60 times, left and right 100 times, up and down 60 times, left and right 100 times. Take 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.

[0054] The magnesium alloy ingot was placed in a muffle furnace and kept at 500°C for 20 hours; it was then air-cooled and homogenized.

[0055] The magnesium alloy ingot after homogenization treatment is subjected to upsetting and drawing type multi-step forging process: during the forging process, the magnesium alloy ingot after homogenization treatment is preheated to 465°C, and the upper and lower anvils are preheated to 400°C.

[0056] When the ingot is subjected to upsetting and drawing multi-directional forging, the downstroke in the upsetting pass is 45%, the downstroke in the drawing pass is 7%, and the downstroke speed is controlled at 280 mm / min.

[0057] When the ingot is subjected to upsetting multi-directional forging, the above-mentioned three upsetting treatments are performed.

[0058] After forging, aging treatment is carried out, and the process is as follows: the forged plate is kept at 200℃ for 48h, and then taken out for air cooling.

[0059] Comparative Example 2:

[0060] The technical scheme of this comparative example is as follows:

[0061] 1. In terms of mass percentage, the element composition of the rare earth magnesium alloy deformed material of this embodiment includes:

[0062] Gd: 10%, Y: 4%, Zn: 2.5%, Zr: 0.6%, Nd: 0.2%, and the balance is Mg.

[0063] 2. The preparation method of the rare earth magnesium alloy deformed material of this comparative example includes the following steps:

[0064] The total weight of each batch is 5kg. When batching, the burnout ratio is adjusted 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-30Nd. 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-30Nd intermediate alloys, and continue to keep warm for 15 minutes. Then, refining and stirring are carried out. The refining agent is 1.2% of the total weight of the ingredients, i.e. 0.06 kg. Stirring: left and right 100 times, up and down 60 times, left and right 100 times, up and down 60 times, left and right 100 times. Take 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.

[0065] The magnesium alloy ingot was placed in a muffle furnace and kept at 500°C for 20 hours; it was then air-cooled and homogenized.

[0066] The magnesium alloy ingot after homogenization treatment is subjected to upsetting and drawing type multi-step forging processing: during the forging processing, the magnesium alloy ingot after homogenization treatment is preheated to 465°C, and the upper and lower anvils are preheated to 400°C.

[0067] When the ingot is subjected to upsetting and drawing multi-directional forging, the downstroke in the upsetting pass is 45%, the downstroke in the drawing pass is 7%, and the downstroke speed is controlled at 280 mm / min.

[0068] When the ingot is subjected to upsetting multi-directional forging, the above-mentioned three upsetting treatments are performed.

[0069] After forging, aging treatment is carried out, and the process is as follows: the forged plate is kept at 200℃ for 48h, and then taken out for air cooling.

[0070] Comparative Example 3:

[0071] The technical scheme of this comparative example is as follows:

[0072] 1. In terms of mass percentage, the element composition of the rare earth magnesium alloy deformed material of this embodiment includes:

[0073] Gd: 10%, Y: 2%, Zn: 3.0%, Zr: 0.6%, Nd: 0.7%, and the balance is Mg.

[0074] 2. The preparation method of the rare earth magnesium alloy deformed material of this comparative example includes the following process:

[0075] The total weight of each batch is 5kg. When batching, the burnout ratio is adjusted 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-30Nd. 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-30Nd intermediate alloys, and continue to keep warm for 15 minutes. Then, refining and stirring are carried out. The refining agent is 1.2% of the total weight of the ingredients, i.e. 0.06 kg. Stirring: left and right 100 times, up and down 60 times, left and right 100 times, up and down 60 times, left and right 100 times. Take 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.

[0076] The magnesium alloy ingot was placed in a muffle furnace and kept at 500°C for 20 hours; it was then air-cooled and homogenized.

[0077] The magnesium alloy ingot after homogenization treatment is subjected to upsetting and drawing type multi-step forging process: during the forging process, the magnesium alloy ingot after homogenization treatment is preheated to 465°C, and the upper and lower anvils are preheated to 400°C.

[0078] When the ingot is subjected to upsetting and drawing multi-directional forging, the downstroke in the upsetting pass is 45%, the downstroke in the drawing pass is 7%, and the downstroke speed is controlled at 280 mm / min.

[0079] When the ingot is subjected to upsetting multi-directional forging, the above-mentioned three upsetting treatments are performed.

[0080] After forging, aging treatment is carried out, and the process is as follows: the forged plate is kept at 200℃ for 48h, and then taken out for air cooling.

[0081] The compositions of the rare earth magnesium alloy deformed materials of the embodiments and comparative examples are summarized in the following table:

[0082] G Y Zn Zr Nd Example 1 10.3 4.5 3.0 0.6 0.4 Example 2 8.5 3.5 2.0 0.45 0.6 Comparative Example 1 10 4 2.5 0.6 - Comparative Example 2 10 4 2.5 0.6 0.2 Comparative Example 3 10 2 3.0 0.6 0.7

[0083] The magnesium alloy deformed materials obtained in the examples and comparative examples were subjected to tensile tests, and the results of the mechanical properties obtained are shown in the following table:

[0084] Yield strength (MPa) Tensile strength(MPa) Elongation(%) Example 1 395 457 8.9 Example 2 389 455 9.2 Comparative Example 1 336 414 8.4 Comparative Example 2 350 435 6.7 Comparative Example 3 339 427 8.3

[0085] Compared with Example 1, Example 1 and Example 2, Example 1 does not contain Nd in terms of composition, and the subsequent heat treatment and forging process are exactly the same. However, it can be seen from Table 1 that the tensile strength and elongation of Example 1 are lower than those of the embodiment when the mechanical properties are tested. Compared with Examples 2 and 3, when less Nd element is added in Example 2 and more Nd element is added in Example 3, the comprehensive mechanical properties of Example 1 and Example 2 are far less than the comprehensive mechanical properties of the rare earth magnesium alloy with the composition content designed in the present invention. Therefore, it can be concluded that the introduction of 0.4wt%-0.6wt% rare earth element Nd in the present invention enhances the mechanical properties of the Mg-Gd-Y-Zn series rare earth deformable magnesium alloy.

[0086] The above detailed description of the embodiments of the present invention is provided, 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. A high-strength rare earth magnesium alloy deformed material, characterized in that: In terms of mass percentage, it includes: Gd: 8.5%-10.3%, Y: 3.5%-4.5%, Zn: 2.0%-3.0%, Zr: 0.45%-0.60%, Nd: 0.4%-0.6%, and the balance is Mg; The high-strength rare earth magnesium alloy deformed material has a yield strength of 390MPa-403MPa, a tensile strength of 465MPa-473MPa, and an elongation of 9.4%-10.1%.

2. A method for preparing a high-strength rare earth magnesium alloy deformed material as claimed in 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; S3: After homogenization treatment is completed, upsetting multi-directional forging is performed; S4: After the forging process is completed, an aging treatment is performed to obtain the high-strength rare earth magnesium alloy deformed material.

3. The method for preparing a high-strength rare earth magnesium alloy deformed material according to claim 2, characterized in that: The raw materials of the high-strength rare earth magnesium alloy deformation material are Mg ingot, Mg-30Gd master alloy, Mg-30Nd master alloy, Mg-30Y master alloy, Mg-30Zr master alloy and Zn ingot; The smelting process includes: melting the raw material Mg ingot, heating it to 700-720°C, adding Mg-30Gd master alloy, Mg-30Y master alloy and Zn ingot in sequence, keeping the temperature for 5-15 minutes, setting the furnace temperature to 730-750°C, and continuing to keep the temperature for 10-20 minutes, adding Mg-30Zr master alloy and Mg-30Nd master alloy, and continuing to keep the temperature 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.

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

5. The method for preparing a high-strength rare earth magnesium alloy deformed material according to claim 2, characterized in that: After the homogenization treatment in step S3, the magnesium alloy ingot is preheated to 460-470° C., the upper and lower anvils are preheated to 390-410° C., and then upsetting multi-directional forging is performed.

6. The method for preparing a high-strength rare earth magnesium alloy deformed material according to claim 2 or 5, characterized in that: In the upsetting and drawing multi-directional forging in step S3, the pressing amount in the upsetting pass is 30-50%, the pressing amount in the drawing pass is 5-10%, and the pressing speed is 200-400 mm / min.

7. The method for preparing a high-strength rare earth magnesium alloy deformed material according to claim 6, characterized in that: In step S3, three times of upsetting multi-directional forging are performed.

8. The method for preparing a high-strength rare earth magnesium alloy deformed material according to claim 2, characterized in that: The aging treatment in step S4 is: keeping at 190-210° C. for 46-50 hours, and then air cooling.