Magnesium-based rare earth alloy based on electrostatic field assisted aging heat treatment and preparation method of magnesium-based rare earth alloy

Abstract

The invention discloses a magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment, which is prepared by the following steps: firstly, preparing an as-cast magnesium-based rare earth alloy through smelting, then, carrying out solid solution treatment to enable a second phase of the as-cast magnesium-based rare earth alloy to be dissolved into a matrix to obtain a solid solution magnesium-based rare earth alloy, and finally, carrying out aging heat treatment at 250 DEG C to obtain the magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment. An electrostatic field is connected in the early stage of aging to assist aging treatment; and the precipitation phase proportion can be 45-50% and the hardness can be 90-95 HV by aging for 2 hours in an electrostatic field. The preparation method comprises the following steps: 1, smelting the magnesium-based rare earth alloy; 2, carrying out solution treatment on the magnesium-based rare earth alloy; and 3, carrying out electrostatic field aging treatment on the solid-solution-state magnesium-based rare earth alloy.

Description

Technical Field

[0001] This invention relates to the field of heat treatment technology for non-ferrous metal structural materials, specifically to a magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment and its preparation method. Background Technology

[0002] Magnesium and its alloys are among the lightest metallic structural materials, possessing advantages such as low density, high specific strength, and biodegradability. However, cast magnesium alloys inherently suffer from poor plasticity and relatively low absolute strength. To improve the mechanical properties of cast magnesium alloys, alloying can be employed, such as adding rare earth elements like Gd, Y, Nd, and Zr, combined with age-hardening. Among magnesium-based rare earth alloys, the alloy systems most significantly affected by age-hardening precipitation hardening include the Mg-Gd, Mg-Y, and Mg-Nd systems.

[0003] The conventional optimization method for aging heat treatment of magnesium rare earth alloys involves adjusting temperature parameters. In addition, electric fields, magnetic fields, and stress fields are currently used to assist in aging control in aluminum alloys and magnesium-aluminum alloys. Among these, introducing an electrostatic field simultaneously with temperature for composite aging precipitation can adjust the composition and morphology of the precipitated phases, achieving better precipitation strengthening effects. Furthermore, rare earth elements possess a 4f5d valence electron structure, and their coordination number variability can improve conductivity and reduce ion diffusion resistance compared to elements such as aluminum and zinc. However, current research in this area is limited, and the effects of electrostatic field-assisted aging on magnesium rare earth alloys lack mature and systematic research results.

[0004] Among existing technologies, electrostatic field-assisted aging of aluminum alloys, such as in existing literature 1 (SHOU W, YID, YIR, et al. Influence of electric field on microstructure and mechanical properties of an Al-Cu-Li alloy during aging[J]. Materials & Design, 2016, 98: 79-87.), involves connecting the Al-Cu-Li alloy to the positive electrode and the auxiliary electrode steel plate to the negative electrode, and continuously applying a 5kV voltage at 175℃ for 40 hours of aging. This technical solution achieves a 30MPa increase in strength and a 2.4% increase in elongation of the Al-Cu-Li alloy after electric field aging. Furthermore, applying the electric field in this solution also reduces the time required for the Al-Cu-Li alloy to reach its peak aging state. However, a technical problem with this solution is that the electric field aging time is 40 hours, meaning that an electric field needs to be applied throughout the entire aging process, resulting in high energy consumption.

[0005] Similarly, existing techniques that employ electrostatic field-assisted aging of magnesium-aluminum alloys, such as in existing literature 2 (Sun Ming, Liu Meijuan, Cao Sheng, et al. Method for electrostatic field-assisted aging heat treatment of magnesium-aluminum alloys [P]. Shanghai: CN201811296880.6, 2021-03-30.), utilize electrostatic field-assisted aging of magnesium-aluminum alloys. The magnesium-aluminum alloy sample is connected to the positive electrode, and the auxiliary steel plate is connected to the negative electrode. Under the condition of an electrostatic field strength of 30 kV / cm, aging is carried out at 175℃ for 64 hours, with the electric field applied throughout the process. This technique reduces the discontinuous precipitates by 18% and increases the density of continuous precipitates by applying the electrostatic field. Like existing literature 1, this technique also suffers from the problem of requiring the application of an electrostatic field throughout the entire aging process.

[0006] Based on the aforementioned existing literature, it is evident that the existing technology suffers from the following two technical problems:

[0007] 1. Although applying an electrostatic field can promote the formation of aged precipitates, existing electrostatic field-assisted aging techniques apply the electrostatic field throughout the entire process, which results in energy consumption issues.

[0008] 2. The existing technology simply selects an alloy as one end of the electrode. This technical feature directly leads to the alloy generating Joule heat when there is current. According to common knowledge in the field of alloys, excessive Joule heat will cause the alloy to overheat, thereby affecting the stability and mechanical properties of the alloy. Summary of the Invention

[0009] The purpose of this invention is to provide a magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment and its preparation method. The basic principle of the invention is as follows:

[0010] 1. By improving the electrostatic field auxiliary device, the power supply is connected through the auxiliary conductive plate, while the alloy sample is not connected to the power supply, so that no closed circuit is formed, that is, no current is generated, thereby improving the electrostatic assisted aging process and avoiding the generation of Joule heat.

[0011] 2. Improve the electrostatic field aging process by influencing vacancy diffusion to affect aging precipitation behavior. Specifically, control the vacancy to be mainly concentrated in the under-aging stage by applying an electrostatic field, thereby reducing electrostatic aging time and energy consumption.

[0012] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0013] A magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment is disclosed. First, a cast magnesium-based rare earth alloy is prepared by melting. Then, a solution treatment is performed to dissolve the second phase of the cast magnesium-based rare earth alloy into the matrix, resulting in a solution-treated magnesium-based rare earth alloy. Finally, an aging heat treatment is performed at 250℃ for 2 hours under electrostatic field-assisted conditions. After electrostatic field-assisted aging heat treatment, the obtained magnesium-based rare earth alloy has a precipitated phase ratio of 45-50% and a hardness of 90-95HV.

[0014] A method for preparing magnesium-based rare earth alloys based on electrostatic field-assisted aging heat treatment includes the following steps:

[0015] Step 1, smelting of Mg-Gd-Y-Zn-Zr alloy: First, with Mg, Gd, Y, Zn, and Zr meeting certain content requirements, weigh the raw materials: pure magnesium, pure zinc, and Mg-30Gd alloy, Mg-30Y alloy, and Mg-30Zr alloy. All alloys are mass fractions. Then, under certain conditions, heat and melt the raw materials for smelting. After smelting, cast the mixture and air-cool it to room temperature to obtain the Mg-Gd-Y-Zn-Zr alloy ingot. This as-cast sample is referred to as MgGdYZnZr-A.

[0016] In step 1, the Mg content is 87.3 wt.%, the Gd content is 9 wt.%, the Y content is 3 wt.%, the Zn content is 0.1 wt.%, and the Zr content is 0.6 wt.%.

[0017] In step 1, the smelting conditions are as follows: a mixture of CO2 and SF6 is used as the protective gas, and the heating temperature is 740-780℃.

[0018] In step 1, the smelting process is specifically divided into 7 steps.

[0019] Step 1.1: Prepare magnesium melt by heating at 740-760℃ for 100-120 minutes to melt pure magnesium and obtain magnesium melt.

[0020] Step 1.2: Prepare magnesium gadolinium melt by heating at 740-760℃, adding Mg-30Gd wt.% to the magnesium melt and heating for 30-40 min to obtain magnesium gadolinium melt;

[0021] Step 1.3: Prepare magnesium gadolinium yttrium melt by heating at 740-760℃, adding Mg-30Y wt.% to the magnesium gadolinium melt and heating for 30-40 min to obtain magnesium gadolinium yttrium melt;

[0022] Step 1.4: Prepare magnesium gadolinium yttrium zinc melt. The heating temperature is 740-760℃. Add pure Zn to the magnesium gadolinium yttrium melt and heat for 20-30 minutes to obtain the magnesium gadolinium yttrium zinc melt.

[0023] Step 1.5: Prepare magnesium gadolinium yttrium zinc zirconium melt. Heat the melt to 770-780℃, add Mg-30Zr wt.% to the magnesium gadolinium yttrium zinc melt and heat for 20-30 min to obtain magnesium gadolinium yttrium zinc zirconium melt;

[0024] Step 1.6: Let stand. Heat the temperature to 740-760℃ and let stand for 10-15 minutes. Then stir for 2-3 minutes. Then let stand for another 10-15 minutes.

[0025] Step 1.7, refining: with a mass ratio of commercial refining agent to melt of 15:1000, under stirring conditions and heating temperature of 740-760℃, the commercial refining agent is added to the magnesium gadolinium yttrium zinc zirconium melt for refining. After the commercial refining agent is added, it is allowed to stand for 10-15 minutes. After standing, the surface scum and bottom impurities are removed to obtain the refined magnesium gadolinium yttrium zinc zirconium melt.

[0026] Step 2: Solution treatment of the Mg-Gd-Y-Zn-Zr alloy. Under certain conditions, the as-cast Mg-Gd-Y-Zn-Zr alloy obtained in Step 1 is subjected to solution treatment. After the solution treatment is completed, the Mg-Gd-Y-Zn-Zr alloy is subjected to rapid quenching treatment to allow the eutectic second phase Mg to be released. 24 When (Gd,Y)5 is completely dissolved, a solid solution Mg-Gd-Y-Zn-Zr alloy can be obtained, which is simply referred to as MgGdYZnZr-B.

[0027] In step 2, the conditions for solution treatment are: heating temperature of 490℃ and heating time of 6-8h.

[0028] Step 3: Electrostatic aging treatment of the solid solution Mg-Gd-Y-Zn-Zr alloy. Under certain conditions, the MgGdYZnZr-B obtained in Step 2 is subjected to aging strengthening. After the aging strengthening is completed, the sample is taken out and quenched to obtain the electrostatically aged Mg-Gd-Y-Zn-Zr alloy, abbreviated as MgGdYZnZr-C.

[0029] In step 3, the conditions for electrostatic aging treatment are: aging temperature of 250℃, aging time of 256h, and an electrostatic field of 5kV applied only 2h before aging.

[0030] The technical effectiveness of this invention can be seen from the following tests:

[0031] XRF testing revealed that the actual composition of the MgGdYZnZr-A alloy is Mg-9.5Gd-2.6Y-0.1Zn-0.4Zr (wt.%), indicating successful alloy preparation.

[0032] XRD and SAED tests revealed that the second phase in MgGdYZnZr-A is a eutectic compound Mg. 24 (Gd,Y)5;

[0033] SEM-BSE and XRD tests showed that the eutectic second phase of MgGdYZnZr-B disappeared and was completely dissolved into the matrix;

[0034] According to HAADF-STEM testing, after aging at 250℃ and 5kV electrostatic field for 2 hours, the proportion of precipitated phase in the Mg-Gd-Y-Zn-Zr alloy is 45-50%.

[0035] Microhardness testing showed that the aging hardness after aging in a 5kV electrostatic field for 2 hours was 90-95HV.

[0036] Therefore, the present invention has the following advantages:

[0037] 1. This invention employs electrostatic field-assisted aging magnesium rare earth alloys, utilizing the unique valence electron structure of rare earth elements to improve the number density of aging precipitated phases;

[0038] 2. This invention uses a unipolar electrostatic field device with an upper and lower auxiliary conductive plates generating a potential difference to form an electrostatic field, without generating current to pass through the sample, thus avoiding the influence of Joule heating on performance.

[0039] 3. Based on the formation mechanism of aging precipitates, this invention can significantly reduce power loss by performing electrostatic field-assisted aging only in the under-aging stage, while retaining the electrostatic field-assisted strengthening effect. Attached Figure Description

[0040] Figure 1 SEM image of the as-cast Mg-Gd-Y-Zn-Zr alloy prepared in step 1 of Example 1;

[0041] Figure 2 The image shows the XRD pattern of the as-cast Mg-Gd-Y-Zn-Zr alloy prepared in step 1 of Example 1.

[0042] Figure 3 SAED image of the as-cast Mg-Gd-Y-Zn-Zr alloy prepared in step 1 of Example 1;

[0043] Figure 4 The image shows the XRD pattern of the solid solution Mg-Gd-Y-Zn-Zr alloy prepared in step 2 of Example 1.

[0044] Figure 5 The image shows a SEM image of the solid solution Mg-Gd-Y-Zn-Zr alloy obtained in step 2 of Example 1.

[0045] Figure 6This is a schematic diagram of the electrostatic field application in the aging treatment of magnesium rare earth alloys according to the present invention. In the figure, the labels are as follows: 1 is the aging furnace, 2 is the conductive stainless steel plate, 3 is the sample chamber, 4 is mica, and 5 is the high voltage power supply.

[0046] Figure 7 The figures show the electrostatic field aging curves of the Mg-Gd-Y-Zn-Zr alloys obtained in Example 1 and Comparative Example 2.

[0047] Figure 8 The image shows the HAADF-STEM image of the electrostatically aged Mg-Gd-Y-Zn-Zr alloy obtained in step 3 of Example 1.

[0048] Figure 9 The image shows the HAADF-STEM image of the electrostatically unaffected aged Mg-Gd-Y-Zn-Zr alloy in Comparative Example 1. Detailed Implementation

[0049] The present invention will be further described in detail through embodiments and with reference to the accompanying drawings, but this is not intended to limit the scope of the invention.

[0050] Example 1

[0051] A method for preparing Mg-Gd-Y-Zn-Zr alloy based on electrostatic field-assisted aging heat treatment includes the following steps:

[0052] Step 1, smelting of the Mg-Gd-Y-Zn-Zr alloy: First, weigh the raw materials, pure magnesium, pure zinc, and Mg-30Gd alloy, Mg-30Y alloy, and Mg-30Zr alloy, with a Mg content of 87.3 wt.%, Gd content of 9 wt.%, Y content of 3 wt.%, Zn content of 0.1 wt.%, and Zr content of 0.6 wt.%, respectively. Then, using a mixture of CO2 and SF6 as a protective gas, heat the raw materials to 760℃ to melt them. After smelting, cast the mixture and air-cool it to room temperature to obtain the Mg-Gd-Y-Zn-Zr alloy ingot. This as-cast sample is referred to as MgGdYZnZr-A.

[0053] In step 1, the smelting process is as follows:

[0054] Step 1.1: Heat to 760℃ for 120 minutes to melt pure magnesium and obtain magnesium melt;

[0055] Step 1.2: The heating temperature is 760℃. Mg-30Gd wt.% is added to the magnesium melt and heated for 40 min to obtain magnesium gadolinium melt;

[0056] Step 1.3: The heating temperature is 760℃. Mg-30Y wt.% is added to the magnesium gadolinium melt and heated for 30 min to obtain magnesium gadolinium yttrium melt;

[0057] Step 1.4: The heating temperature is 760℃. Pure Zn is added to the magnesium gadolinium yttrium melt and heated for 20 minutes to obtain magnesium gadolinium yttrium zinc melt.

[0058] Step 1.5: Heat the temperature to 780℃, add Mg-30Zr wt.% to the magnesium-gadolinium-yttrium-zirconium melt and heat for 20 minutes to obtain magnesium-gadolinium-yttrium-zirconium melt;

[0059] Step 1.6: Heat to 760℃, let stand for 10 minutes, then stir for 2 minutes, and then let stand for another 10 minutes.

[0060] Step 1.7: With a mass ratio of commercial refining agent to melt of 15:1000, under stirring conditions and a heating temperature of 760°C, the commercial refining agent is added to the magnesium gadolinium yttrium zinc zirconium melt for refining. After the commercial refining agent is added, the melt is allowed to stand for 15 minutes. After standing, the surface scum and bottom impurities are removed to obtain the refined magnesium gadolinium yttrium zinc zirconium melt.

[0061] To verify the composition of the MgGdYZnZr-A alloy obtained in step 1, i.e., its successful preparation, XRF testing was performed. The test results are shown in Table 1. The actual alloy composition is Mg-9.5Gd-2.6Y-0.1Zn-0.4Zr (wt.%). The test results indicate that MgGdYZnZr-A was successfully prepared.

[0062] Table 1 Actual composition of Mg-Gd-Y-Zn-Zr alloy

[0063] Nominal composition (wt.%) Actual composition (wt.%) Mg-9Gd-3Y-0.1Zn-0.6Zr Mg-9.5Gd-2.6Y-0.1Zn-0.4Zr

[0064] To verify the microstructure of the MgGdYZnZr-A obtained in step 1, SEM-BSE testing was performed. The test results are as follows: Figure 1 As shown, a bright white network-like second phase exists on the matrix. Test results indicate that MgGdYZnZr-A consists of a matrix and a network-like second phase.

[0065] To further verify the MgGdYZnZr-A phase obtained in step 1, XRD tests were performed; simultaneously, SAED tests were performed on the second phase.

[0066] XRD test results are as follows Figure 2 As shown, MgGdYZnZr-A exhibits characteristic peaks of Mg and the eutectic compound Mg. 24The characteristic peaks of (Gd,Y)5, combined with SEM test results, preliminarily determine that the white reticulated second phase is Mg. 24 (Gd,Y)5;

[0067] SAED test results are as follows Figure 3 As shown, the electron diffraction pattern of the second phase is a body-centered cubic

[011] zone axis, that is, the crystal structure of the second phase is a BCC structure.

[0068] XRD and SAED tests indicate that the second phase in MgGdYZnZr-A is a eutectic compound Mg. 24 (Gd,Y)5.

[0069] Step 2: Solution treatment of the Mg-Gd-Y-Zn-Zr alloy. The as-cast Mg-Gd-Y-Zn-Zr alloy obtained in Step 1 is solution treated at a heating temperature of 490℃ for 6 hours. After solution treatment, the Mg-Gd-Y-Zn-Zr alloy is subjected to rapid quenching to allow the eutectic second phase Mg to be released. 24 When (Gd,Y)5 is completely dissolved, a solid solution Mg-Gd-Y-Zn-Zr alloy can be obtained, which is simply referred to as MgGdYZnZr-B.

[0070] To demonstrate the phase and microstructure changes of the MgGdYZnZr-B obtained in step 2, i.e. the solid solution effect, XRD and SEM-BSE tests were performed.

[0071] XRD test results are as follows Figure 4 As shown, MgGdYZnZr-B only exhibits characteristic peaks of Mg, while Mg... 24 The characteristic peaks of (Gd,Y)5 disappear. Test results indicate that the eutectic compound Mg... 24 (Gd,Y)5 dissolves into the matrix after solution treatment;

[0072] SEM-BSE test results are as follows: Figure 5 As shown, the bright white network-like second phase on the MgGdYZnZr-B matrix almost completely disappears, thus supporting the aforementioned results regarding the eutectic compound Mg. 24 (Gd,Y)5 dissolves into the matrix after solution treatment;

[0073] XRD and SAED test results show that step 2 successfully achieved solution treatment, and the effect was good.

[0074] Step 3: Electrostatic field-assisted aging treatment of the solution-treated Mg-Gd-Y-Zn-Zr alloy. First, the MgGdYZnZr-B obtained in Step 2 is placed in an aging treatment device. Then, under the conditions of electrostatic field-assisted aging treatment, the MgGdYZnZr-B is aged at an aging temperature of 250℃ for 256 hours. After the aging treatment is completed, the sample is taken out and quenched to obtain the electrostatic field-aged Mg-Gd-Y-Zn-Zr alloy, namely the Mg-Gd-Y-Zn-Zr alloy based on electrostatic field-assisted aging heat treatment, abbreviated as MgGdYZnZr-C.

[0075] In step 3, the specific condition for electrostatic field-assisted aging treatment is that the sample to be strengthened does not need to be connected to the electrode, i.e. Figure 6 As shown, the sample to be strengthened can be placed directly in the sample chamber of the electrostatic field device 3. Furthermore, the electrostatic field-assisted aging treatment is performed for the first 2 hours of the entire aging strengthening process, and the voltage of the electrostatic field-assisted aging treatment is 5kV.

[0076] To demonstrate the effectiveness of the electrostatic aging treatment in step 3, microhardness testing was performed. The test results are as follows: Figure 7 As shown by the solid line, the peak aged hardness of MgGdYZnZr-C is 117HV.

[0077] To further demonstrate the effectiveness of the electrostatic field aging treatment in step 3, when the aging strengthening time was 2 hours, i.e., when the electrostatic field assisted aging treatment was completed and the aging strengthening process ended, MgGdYZnZr-C was directly subjected to subsequent quenching operations, and HAADF-STEM and hardness tests were performed.

[0078] HAADF-STEM test results are as follows Figure 8 As shown, an aging precipitate appears on the MgGdYZnZr-C matrix, and the area occupied by the precipitate, referred to as the precipitate percentage, is 48%.

[0079] The hardness test result after electrostatic aging treatment for 2 hours was 91.7 HV.

[0080] To demonstrate the effect of electrostatic field on the precipitated phase, i.e., aging treatment, Comparative Example 1 is provided, in which aging treatment is performed without applying an electrostatic field.

[0081] Comparative Example 1

[0082] An aging heat treatment without the application of an electrostatic field, i.e., a conventional Mg-Gd-Y-Zn-Zr alloy preparation method, the steps unless otherwise specified are the same as those in Example 1, the difference being that in step 3, no electrostatic field is applied, and conventional aging heat treatment is performed directly, the resulting alloy is referred to as MgGdYZnZr-D.

[0083] The HAADF-STEM test results of MgGdYZnZr-D are as follows: Figure 9 As shown, although aging precipitates appear on the MgGdYZnZr-D matrix, the proportion of precipitates is only 16%. Compared with Example 1, it can be seen that applying an electrostatic field for aging treatment can significantly increase the proportion of precipitates, with an increase of up to 300%.

[0084] The hardness test result after aging treatment for 2 hours was 77.7 HV. Compared with Example 1, it can be seen that applying an electrostatic field for aging treatment can significantly improve the hardness, with an increase of 18.2%.

[0085] By comparing Example 1 and Comparative Example 1, it can be seen that applying an electrostatic field can significantly increase the density of the aged precipitate, thereby significantly increasing the hardness.

[0086] To demonstrate the influence of electrostatic field-assisted aging treatment conditions on the aging strengthening effect, Comparative Example 2 is provided, which describes a method for aging heat treatment in which an electrostatic field is applied throughout the entire aging process.

[0087] Comparative Example 2

[0088] A method for aging heat treatment with electrostatic field assisted aging throughout the process. The steps not specifically described are the same as in Example 1. The difference is that in step 3, the specific condition for electrostatic field assisted aging treatment is that the electrostatic field assisted aging treatment is the entire aging strengthening process, that is, the time of electrostatic field assisted aging treatment is the same as the aging time, which is 256h. The resulting alloy is simply referred to as MgGdYZnZr-E.

[0089] The aging hardness test results of MgGdYZnZr-E are as follows: Figure 7 As shown by the dashed line, the peak aging hardness is 110 HV. Compared with Example 1, the difference in peak aging is negligible, and the aging strengthening curve shows no substantial difference. The test results indicate that the effect of electrostatic field-assisted aging treatment mainly plays a role in the early stage of aging precipitation.

[0090] By comparing Example 1 with Comparative Example 2, it can be seen that applying electrostatic field-assisted aging treatment in the early stage of aging precipitation can achieve a similar or even better strengthening effect than applying electrostatic field-assisted aging throughout the process. At the same time, it also proves that Example 1 achieves the same or better technical effect by reducing the necessary technical feature - the time of electrostatic field-assisted aging treatment - on the basis of the prior art. Moreover, due to the significant reduction in the time of electrostatic field-assisted aging treatment, a significant reduction in energy consumption is also achieved.

Claims

1. A magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment, characterized in that: First, a cast magnesium-based rare earth alloy is prepared by melting. Then, the second phase of the cast magnesium-based rare earth alloy is dissolved into the matrix through solution treatment to obtain a solution-treated magnesium-based rare earth alloy. Finally, an electrostatic field is used to assist in the aging heat treatment.

2. The magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment according to claim 1, characterized in that: After electrostatic field-assisted aging heat treatment for only 2 hours, the obtained magnesium-based rare earth alloy can achieve a precipitated phase area fraction of 45-50% and a hardness of 90-95HV.

3. A method for preparing magnesium-based rare earth alloys based on electrostatic field-assisted aging heat treatment, characterized in that... Includes the following steps: Step 1, smelting of Mg-Gd-Y-Zn-Zr alloy: First, with Mg, Gd, Y, Zn, and Zr meeting certain content requirements, weigh the raw materials: pure magnesium, pure zinc, and Mg-30Gd alloy, Mg-30Y alloy, and Mg-30Zr alloy. All alloys are mass fractions. Then, under certain conditions, heat and melt the raw materials for smelting. After smelting, cast the mixture and air-cool it to room temperature to obtain the Mg-Gd-Y-Zn-Zr alloy ingot. This as-cast sample is referred to as MgGdYZnZr-A. Step 2: Solution treatment of the Mg-Gd-Y-Zn-Zr alloy. Under certain conditions, the as-cast Mg-Gd-Y-Zn-Zr alloy obtained in Step 1 is subjected to solution treatment. After the solution treatment is completed, the Mg-Gd-Y-Zn-Zr alloy is subjected to rapid quenching treatment to allow the eutectic second phase Mg to be released. 24 When (Gd,Y)5 is completely dissolved, a solid solution Mg-Gd-Y-Zn-Zr alloy can be obtained, which is simply referred to as MgGdYZnZr-B. Step 3: Electrostatic aging treatment of the solid solution Mg-Gd-Y-Zn-Zr alloy. Under certain conditions, the MgGdYZnZr-B obtained in Step 2 is aged. After the aging treatment is completed, the sample is taken out and quenched to obtain the electrostatically aged Mg-Gd-Y-Zn-Zr alloy, abbreviated as MgGdYZnZr-C.

4. The preparation method according to claim 3, characterized in that: In step 1, the Mg content is 87.3 wt.%, the Gd content is 9 wt.%, the Y content is 3 wt.%, the Zn content is 0.1 wt.%, and the Zr content is 0.6 wt.%. In step 1, the smelting conditions are as follows: a mixture of CO2 and SF6 is used as the protective gas, and the heating temperature is 740-780℃.

5. The preparation method according to claim 3, characterized in that: In step 1, the smelting process is specifically divided into 7 steps. Step 1.1, prepare magnesium melt; Step 1.2: Prepare magnesium gadolinium melt; Step 1.3: Prepare magnesium gadolinium yttrium melt; Step 1.4: Prepare magnesium-gadolinium-yttrium-zinc melt; Step 1.5: Prepare magnesium-gadolinium-yttrium-zirconium melt; Step 1.6, let it stand; Step 1.7, Refining.

6. The preparation method according to claim 5, characterized in that: Step 1.1 involves heating at a temperature of 740-760℃ for 100-120 minutes to melt pure magnesium and obtain magnesium melt. Step 1.2 involves heating the magnesium melt at a temperature of 740-760℃, adding Mg-30Gd wt.% to the magnesium melt and heating for 30-40 minutes to obtain a magnesium-gadolinium melt. Step 1.3 involves heating the material at a temperature of 740-760℃, adding Mg-30Y wt.% to the magnesium gadolinium melt and heating for 30-40 minutes to obtain the magnesium gadolinium yttrium melt. Step 1.4 involves heating pure Zn to a magnesium gadolinium yttrium melt at a temperature of 740-760℃ for 20-30 minutes to obtain a magnesium gadolinium yttrium zinc melt. Step 1.5 involves raising the temperature to 770-780℃, adding Mg-30Zr wt.% to the magnesium-gadolinium-yttrium-zirconium melt, and heating for 20-30 minutes to obtain magnesium-gadolinium-yttrium-zirconium melt. Step 1.6 involves heating at 740-760℃, letting it stand for 10-15 minutes, stirring for 2-3 minutes, and then letting it stand for another 10-15 minutes. Step 1.7 involves adding the commercial refining agent to the magnesium gadolinium yttrium zinc zirconium melt at a mass ratio of 15:1000, under stirring conditions and a heating temperature of 740-760℃. After the commercial refining agent is added, the melt is allowed to stand for 10-15 minutes. After standing, the surface scum and bottom impurities are removed to obtain the refined magnesium gadolinium yttrium zinc zirconium melt.

7. The preparation method according to claim 3, characterized in that: In step 2, the conditions for solution treatment are: heating temperature of 490℃ and heating time of 6-8h.

8. The preparation method according to claim 3, characterized in that: In step 3, the conditions for electrostatic aging treatment are: aging temperature of 250℃, electrostatic voltage of 5kV, and aging time of 2-4h.

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