An ultra-light strong plastic synergic Mg-Li-Zn-Ca-Mn alloy and a preparation method thereof

Abstract

The application discloses a kind of ultra-light strong plastic synergic Mg-Li-Zn-Ca-Mn alloy and preparation method thereof, belong to metal material technical field. Including the following steps: take pure magnesium ingot, pure zinc ingot, magnesium-lithium intermediate alloy, magnesium-manganese intermediate alloy and pure calcium particle as raw material;Argon is under heating and melting raw material and obtains alloy melt;Pouring forming alloy ingot;After preheating at 230 DEG C, hot extrusion forming, air cooling to room temperature and extruded bar material;3-7 pass rotary swaging deformation treatment is carried out to extruded bar material at room temperature and obtains rod alloy material.The application replaces rare earth elements by Zn-Ca-Mn multielement conventional element composite strengthening, and realizes fine-grain strengthening, dispersion strengthening and grain boundary segregation strengthening synergistic effect by combining with "hot extrusion-rotary swaging" composite process regulation organization and element distribution, and the alloy density is only 1.553g / cm 3 , yield strength can reach 222MPa, tensile strength 237MPa, elongation 26.36%.

Description

Technical Field

[0001] This invention relates to the field of metallic materials technology, and in particular to an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy and its preparation method. Background Technology

[0002] Magnesium-lithium alloys are among the lightest metallic structural materials currently available, with densities typically ranging from 1.35 to 1.65 g / cm³. 3 With a strength only 2 / 3 that of aluminum alloys and 1 / 4 that of steel, magnesium-lithium alloys possess outstanding advantages such as high specific strength, excellent damping performance, good electromagnetic shielding effect, and excellent machinability, making them promising candidates for lightweight applications in aerospace, transportation, and other fields. However, traditional magnesium-lithium alloys suffer from a core problem of mutual constraint between strength and plasticity, severely limiting their application in load-bearing structural components.

[0003] Current technologies primarily enhance performance through alloying and plastic processing. In alloying, elements such as Zn, Ca, and Mn are commonly added to improve strength through solid solution strengthening, dispersion strengthening, and second-phase strengthening. For plastic processing, hot extrusion, rolling, and forging are widely used. However, single alloying or traditional processing techniques have limited ability to optimize the microstructure, making it difficult to simultaneously achieve significant grain refinement, uniform dispersion of the second phase, and element segregation in favorable positions, resulting in unsatisfactory strengthening effects or severe loss of plasticity. Furthermore, some high-performance magnesium-lithium alloys rely on rare earth elements, leading to high costs.

[0004] Therefore, it is of great significance to develop a magnesium-lithium alloy that is not dependent on rare earth elements, has controllable costs, and can simultaneously achieve ultra-lightweight, high-strength, and high-ductility properties, as well as its preparation process. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-lightweight, high-strength, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy and its preparation method. By precisely controlling the Li content to form an α-Mg+β-Li dual-phase structure, combined with Zn-Ca-Mn multi-component conventional element composite strengthening, and through a synergistic process of vacuum argon-protected melting, hot extrusion pretreatment, and multi-pass controllable rotary forging deformation, the grain size is refined and the dispersion distribution of the second phase is optimized, thus preparing a magnesium-lithium alloy rod with ultra-lightweight properties, high strength, and high ductility. This solves the problems of mismatch between strength and ductility, poor process stability, and high cost of some rare earth elements in traditional magnesium-lithium alloys.

[0006] To achieve the above objectives, the present invention provides an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy, characterized in that: The chemical composition, by mass fraction, includes: Li: 9.07 wt%, Zn: 3.29 wt%, Ca: 1.04 wt%, Mn: 0.28 wt%, with the remainder being Mg and unavoidable impurities, the total impurity content being ≤0.3 wt%. The alloy has a dual-phase structure of α-Mg+β-Li, with the second phase mainly being Mg2Ca, and Zn element is enriched at the grain boundaries and the Mg2Ca phase interface.

[0007] This invention also provides a method for preparing the above-mentioned ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy, comprising the following steps: (1) Select pure magnesium ingots, pure zinc granules, magnesium-lithium master alloy, magnesium-manganese master alloy and pure calcium granules in proportion for batching; (2) Under an argon protective atmosphere, the raw material from step (1) is heated and melted in a vacuum furnace to obtain an alloy melt; (3) Cast the alloy melt obtained in step (2) to obtain an alloy ingot; (4) The alloy ingot obtained in step (3) is preheated, hot extruded and then air-cooled to room temperature to obtain extruded bars; (5) The extruded bar obtained in step (4) is subjected to multi-pass rotary die forging deformation at room temperature to finally obtain rod-shaped Mg-Li-Zn-Ca-Mn alloy material.

[0008] Preferably, in step (1), the purity of the pure magnesium ingot is ≥99.95%, the purity of the pure zinc granules is ≥99.98%, and the purity of the pure calcium granules is ≥99.96%.

[0009] Preferably, in step (2), the vacuum furnace is evacuated to a vacuum level of 2.5 × 10⁻⁶. -1 Pa, argon purity ≥99.99%.

[0010] Preferably, in step (2), the heating and melting process conditions are: heating to 720°C at a heating rate of 5°C / min, holding for 30 minutes, until the raw material is completely melted.

[0011] Preferably, in step (3), the specific operation of casting is as follows: after stirring and settling the alloy melt at 710°C, it is poured into a stainless steel mold, cooled with water, and then cut into an ingot by wire cutting.

[0012] Preferably, in step (4), the preheating process conditions are: preheating temperature of 230℃ and preheating time of 1-2 hours.

[0013] Preferably, in step (4), the hot extrusion molding process conditions are: extrusion temperature 230℃, extrusion ratio 28:1, and extrusion speed 0.5-1.0mm / s.

[0014] Preferably, in step (5), 3-7 passes of rotary forging deformation are performed, with a single pass radial compression of 0.2 mm.

[0015] Therefore, the ultra-lightweight, high-strength, and synergistic Mg-Li-Zn-Ca-Mn alloy and its preparation method provided by the present invention have the following beneficial effects: (1) By controlling the Li content to 9.07%, the present invention forms a continuous network dual-phase structure of α-Mg+β-Li, laying the optimal microstructure for strong-plastic balance. The conventional element combination of Zn-Ca-Mn is used to replace rare earth elements. Through solid solution and dispersion strengthening of 3.29% Zn, fine grain and pinning strengthening of 1.04% Ca, and purification and auxiliary refinement of 0.28% Mn, a multi-mechanism composite strengthening is achieved, which not only reduces the cost of raw materials, but also avoids the limitation of a single element strengthening mechanism.

[0016] (2) The present invention optimizes the microstructure and element distribution of the alloy through the "hot extrusion-rotary forging" composite process, forming a multi-mechanism synergistic strengthening effect: the coarse grains in the as-cast state are refined by extrusion and then further refined by rotary forging; the coarse blocky Mg2Ca phase in the as-cast state is broken into fine particles by extrusion-rotary forging, and at the same time, it induces Zn elements to be oriented to agglomerate at the grain boundaries and Mg2Ca phase interface - which not only improves the grain boundary bonding force and inhibits grain boundary slip cracking during deformation, but also strengthens the hindering effect of the second phase relative dislocation, realizing the synergistic effect of "fine grain strengthening + dispersion strengthening + grain boundary agglomeration strengthening", solving the defects of uneven structure and random element distribution of traditional single process, and accurately controlling the strength-plastic balance.

[0017] (3) The Mg-Li-Zn-Ca-Mn alloy prepared by this invention has a density of only 1.553 g / cm³. 3 It belongs to the category of ultralight magnesium-lithium alloys, and the process is stable and controllable with good repeatability. After 7 passes of rotary forging, the yield strength reaches 222MPa, the tensile strength reaches 237MPa, and the elongation reaches 26.36%, achieving a simultaneous improvement in strength and plasticity, and solving the problem of mismatch between strength and plasticity in traditional magnesium-lithium alloys.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 The images show the metallographic structure and SEM images of the magnesium-lithium alloy in the initial as-cast state and the magnesium-lithium alloy produced by hot extrusion in Embodiment 1 of the present invention; wherein (a) is the metallographic structure of the magnesium-lithium alloy in the initial as-cast state; (b) is the SEM image of the magnesium-lithium alloy in the initial as-cast state; (c) is the metallographic structure of the magnesium-lithium alloy produced by hot extrusion; and (d) is the SEM image produced by hot extrusion. Figure 2The stress-strain curves of the magnesium-lithium alloy in the initial as-cast state and after hot extrusion in Embodiment 1 of the present invention are shown. Figure 3 This is a SEM image of the magnesium-lithium alloy produced by hot extrusion-rotary forging process in Embodiment 1 of the present invention; Figure 4 This is a stress-strain curve of a magnesium-lithium alloy produced by hot extrusion-rotary forging process in Embodiment 1 of the present invention. Figure 5 This is a SEM image of the magnesium-lithium alloy produced by hot extrusion-rotary forging process in Embodiment 2 of the present invention; Figure 6 This is a stress-strain curve of a magnesium-lithium alloy produced by hot extrusion-rotary forging process in Embodiment 2 of the present invention. Figure 7 This is a SEM image of the magnesium-lithium alloy produced by hot extrusion-rotary forging process in Embodiment 3 of the present invention; Figure 8 This is a stress-strain curve of a magnesium-lithium alloy produced by hot extrusion-rotary forging process in Embodiment 3 of the present invention. Figure 9 This is a stress-strain curve diagram of the magnesium-lithium alloy from the cast state to the extruded state and then to the rotary forging state in Embodiment 3 of the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. Furthermore, it should be understood that after reading the contents of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims and are all within the protection scope of the present invention.

[0021] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0022] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0023] When a quantity, concentration, or other value or parameter is described as a range, a preferred range, or a preferred upper and lower limit of a numerical value, it should be understood that all ranges formed by any combination of any pair of upper or preferred values ​​and any lower or preferred values ​​have been specifically disclosed, whether or not such ranges are explicitly stated; unless otherwise indicated, the numerical ranges listed herein include the endpoints of the range and all integers and fractions within the range.

[0024] Unless otherwise stated, all percentages, portions, ratios and other measurements mentioned herein are based on weight.

[0025] Unless otherwise specified, the reagents, instruments, and equipment used in this invention are all commonly used by those skilled in the art, and the testing standards all use national or international standards commonly used in the field, without further explanation.

[0026] The materials, preparation methods, and embodiments mentioned herein are exemplary and should not be construed as limiting the invention unless otherwise specified.

[0027] The pure magnesium ingots, pure zinc granules, magnesium-lithium master alloy, magnesium-manganese master alloy, and pure calcium granules used in this embodiment of the invention are commercially available products. The purity of the magnesium ingots is ≥99.95%, the purity of the pure zinc ingots is ≥99.98%, and the purity of the pure calcium granules is ≥99.96%. In this embodiment of the invention, the magnesium-lithium master alloy and the magnesium-manganese master alloy are collectively referred to as magnesium master alloys, and the lithium and manganese in the magnesium master alloys account for 10-20% of the total mass of the magnesium master alloys, respectively. The stretching machine used in this embodiment of the invention is a UTM4104. The metallurgical microscope used in this embodiment of the invention is an OLYMPUS PMG3. The scanning electron microscope used in this embodiment of the invention is model JSM-7800F; In this embodiment of the invention, the vacuum furnace is evacuated to a vacuum level of 2.5 × 10⁻⁶. -1 Pa, then argon gas is added as a protective gas until the entire vacuum furnace is in a protective gas atmosphere for melting.

[0028] Example 1 This embodiment provides an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy with the following actual mass composition: Li 9.07%, Zn 3.29%, Ca 1.04%, Mn 0.28%, Mg 86.32%, and total impurities ≤0.3%.

[0029] The preparation method is as follows: (1) Ingredients: Pure magnesium ingots, pure zinc ingots, magnesium-lithium master alloy, magnesium-manganese master alloy, and pure calcium granules are selected as raw materials according to the mass percentage of the above alloy components.

[0030] (2) Melting: Place the raw material in a vacuum furnace crucible and evacuate to a vacuum level of 2.5 × 10⁻⁶. -1 Pa, then fill with high-purity argon gas (≥99.99%) to atmospheric pressure. Heat to 720℃ at a rate of 5℃ / min, hold for 30 minutes, and stir at 60r / min for 3 minutes every 5 minutes during this period to ensure that the alloy is fully melted and mixed evenly.

[0031] (3) Casting: Cool the alloy melt to 710℃, stir and let it stand for 5 minutes to remove the surface slag, and pour it into a stainless steel mold with a diameter of Φ90mm and a length of 300mm; after water cooling and solidification, it is processed into an ingot with a diameter of Φ80mm by wire cutting.

[0032] (4) Hot extrusion: Remove the oxide scale on the surface of the ingot, put it into a heating furnace, and preheat it at 230°C for 1 hour; then hot extrusion is carried out under the conditions of extrusion temperature of 230°C, extrusion ratio of 28:1 and extrusion speed of 0.6mm / s. After extrusion, air cool to room temperature to obtain Φ16mm extruded bar.

[0033] (5) Rotary forging deformation: The extruded bar was rotary forged at room temperature, with a radial reduction of 0.2 mm per pass, for a total of 3 passes, finally obtaining a magnesium-lithium alloy bar with a diameter of 14.60 mm, a true strain of 0.18, a deformation of 16.73%, and a density of 1.553 g / cm³. 3 .

[0034] Example 2 The alloy composition of this embodiment is the same as that of Example 1. The only difference between the preparation method and Example 1 is the number of forging passes in step (5): five forging passes are performed to finally obtain a magnesium-lithium alloy rod with a diameter of 13.84 mm, a true strain of 0.29, a deformation of 25.18%, and a density of 1.553 g / cm³. 3 .

[0035] Example 3 The alloy composition of this embodiment is the same as that of Example 1. The only difference between the preparation method and Example 1 is the number of forging passes in step (5): seven forging passes are performed to finally obtain a magnesium-lithium alloy rod with a diameter of 13.15 mm, a true strain of 0.39, a deformation of 32.45%, and a density of 1.553 g / cm³. 3 .

[0036] To comprehensively evaluate the correlation between the microstructure evolution of the Mg-Li-Zn-Ca-Mn alloy described in this invention and different forging passes, room temperature tensile tests and microstructure characterization (SEM, metallographic microscopy) were performed on the alloys in Examples 1, 2, or 3. The results of each example are described in detail below with reference to the accompanying drawings.

[0037] Depend on Figure 1 It can be seen that the Mg-Li-Zn-Ca-Mn alloy prepared in Example 1 exhibits a typical two-phase solidification structure in its initial as-cast state, mainly composed of α-Mg phase, β-Li phase, and coarse blocky Mg2Ca second phase, showing a typical dendritic solidification structure with no obvious elemental segregation. After hot extrusion, the two-phase matrix and Mg2Ca phase are elongated along the extrusion direction, the originally coarse second phase is broken into blocky pieces, and the grains are refined through dynamic recrystallization, resulting in good structural continuity and no obvious defects. Figure 2 As shown, the as-cast alloy has a yield strength of only 78 MPa and a tensile strength of 79.3 MPa, and poor plasticity. However, after hot extrusion treatment, the alloy has a yield strength of 161 MPa and a tensile strength of 214 MPa, and its performance is significantly improved.

[0038] Figure 3 , Figure 5 , Figure 7 SEM images of magnesium-lithium alloys after hot extrusion-rotary forging processes in Examples 1, 2, and 3, respectively; Figure 4 , Figure 6 , Figure 8 The corresponding stress-strain curves are shown below.

[0039] Depend on Figure 3 , Figure 5 and Figure 7 It can be seen that with the increase of the number of rotary forging passes, the alloy microstructure exhibits a continuous optimization evolution. In the 3rd pass rotary forging (deformation amount 16.73%), the α-Mg phase is refined into slender strips, the β-Li phase is distributed in a continuous matrix, and the Mg2Ca phase begins to disperse at grain boundaries and phase boundaries. SEM-EDS analysis shows that Zn element is enriched in the Mg2Ca phase, forming an initial phase boundary strengthening effect. In the 5th pass rotary forging, the Mg2Ca phase is further broken into chain-like particles, the grains are further refined, the synergy between the α-Mg phase and the β-Li phase is enhanced, and solid solution strengthening and dispersion strengthening form a composite effect. In the 7th pass rotary forging, the Mg2Ca phase is uniformly dispersed in a dotted pattern, achieving multi-mechanism synergistic regulation.

[0040] Depend on Figure 4 , Figure 6 and Figure 8It can be seen that when the alloy undergoes 3 passes of rotary forging (deformation amount 16.73%), the yield strength is 201 MPa, the tensile strength is 220 MPa, and the elongation is 21.60%. The stress-strain curve exhibits typical work hardening characteristics, with the stress rising steadily with strain after yielding without a significant yield plateau. When the alloy undergoes 5 passes of rotary forging (deformation amount 25.18%), the yield strength increases to 215 MPa, the tensile strength increases to 233 MPa, and the elongation increases to 24.48%. The curve shows a more sustained work hardening stage, and the stress continues to rise under high strain, indicating that the effects of second-phase dispersion strengthening and grain boundary segregation strengthening are significantly enhanced. When the alloy undergoes 7 passes of rotary forging (deformation amount 32.45%), the yield strength further increases to 222 MPa, the tensile strength increases to 237 MPa, and the elongation increases to 26.36%. The curve exhibits both high yield strength and high work hardening rate, and necking fracture only occurs at approximately 26% strain, achieving synergistic optimization of strength and plasticity. The above results indicate that appropriately increasing the number of rotary forging passes can effectively promote the synergistic effect of fine grain strengthening, dispersion strengthening and grain boundary segregation strengthening, thereby comprehensively improving the overall mechanical properties of the alloy. Among them, 7-pass rotary forging is the optimal process parameter.

[0041] Example 3 compares the stress-strain curves of the alloy under three different processing conditions: as-cast, extruded, and 7-pass rotary forging. Figure 9 As shown, by Figure 9 This clearly reveals the progressively improving effect of the "hot extrusion-rotary forging" composite process on the mechanical properties of the alloy. The as-cast curve exhibits typical brittle fracture characteristics, with a yield strength of only 78 MPa, a tensile strength of 79 MPa, and a fracture elongation of approximately 6%, indicating that the alloy fractures under extremely low strain. After hot extrusion, the yield strength of the extruded curve significantly increases to 161 MPa, the tensile strength to approximately 214 MPa, and the fracture elongation to approximately 23%. Furthermore, the curve shows continuous work hardening characteristics with no yield plateau, indicating that hot extrusion significantly improves the alloy's strength and plasticity through grain refinement and second-phase fragmentation. After further seven passes of rotary forging, the yield strength of the rotary-forged curve further increases to 222 MPa, the tensile strength remains at a high level of 237 MPa, and the fracture elongation increases to approximately 26%. This curve combines high yield strength with high work hardening rate, maintaining a stable stress increase even over a large strain range, achieving synergistic optimization of strength and plasticity.

[0042] In summary, the magnesium-lithium alloy prepared by this invention possesses excellent comprehensive mechanical properties at room temperature. The Li element in the alloy alters the c / a ratio of the α-Mg matrix, promoting the initiation of non-basal slip systems and significantly enhancing the material's coordination ability during deformation, laying the foundation for improved plasticity. Reasonable forging passes (3-7 passes) and a radial reduction of 0.2 mm per pass ensure continuous grain refinement after multiple passes of small plastic deformation. The coarse, blocky Mg2Ca phase in the as-cast state is broken into fine, dispersed particles. Simultaneously, it induces the directional segregation of Zn elements at grain boundaries and between Mg2Ca, while Mn elements purify the melt and assist in grain refinement, forming a synergistic effect of "fine grain strengthening + dispersion strengthening + grain boundary segregation strengthening." This plays a crucial role in the simultaneous improvement of the alloy's strength and plasticity, thus enabling the magnesium-lithium alloy rod of this invention to possess both ultra-lightweight characteristics and excellent strength-plasticity synergistic performance.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A lightweight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy, characterized in that: The chemical composition, by mass fraction, includes: Li: 9.07 wt%, Zn: 3.29 wt%, Ca: 1.04 wt%, Mn: 0.28 wt%, with the remainder being Mg and unavoidable impurities, the total impurity content being ≤0.3 wt%. The alloy has a dual-phase structure of α-Mg+β-Li, with the second phase mainly being Mg2Ca, and Zn element is enriched at the grain boundaries and the Mg2Ca phase interface.

2. The preparation method of an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy as described in claim 1, characterized in that, Includes the following steps: (1) Select pure magnesium ingots, pure zinc granules, magnesium-lithium master alloy, magnesium-manganese master alloy and pure calcium granules in proportion for batching; (2) Under an argon protective atmosphere, the raw material from step (1) is heated and melted in a vacuum furnace to obtain an alloy melt; (3) Cast the alloy melt obtained in step (2) to obtain an alloy ingot; (4) The alloy ingot obtained in step (3) is preheated, hot extruded and then air-cooled to room temperature to obtain extruded bars; (5) The extruded bar obtained in step (4) is subjected to multi-pass rotary forging deformation at room temperature to finally obtain a rod-shaped Mg-Li-Zn-Ca-Mn alloy material.

3. The method for preparing an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy according to claim 2, characterized in that, In step (1), the purity of pure magnesium ingots is ≥99.95%, the purity of pure zinc granules is ≥99.98%, and the purity of pure calcium granules is ≥99.96%.

4. The preparation method of an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy according to claim 2, characterized in that, In step (2), the vacuum furnace is evacuated to a vacuum level of 2.5 × 10⁻⁶. -1 Pa, argon purity ≥99.99%.

5. The method for preparing an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy according to claim 2, characterized in that, In step (2), the heating and melting process conditions are as follows: the temperature is raised to 720°C at a heating rate of 5°C / min, and held for 30 minutes until the raw material is completely melted.

6. The method for preparing an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy according to claim 2, characterized in that, In step (3), the specific operation of casting is as follows: after stirring and settling the alloy melt at 710°C, it is poured into a stainless steel mold, cooled with water, and then cut into an ingot by wire cutting.

7. The method for preparing an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy according to claim 2, characterized in that, In step (4), the preheating process conditions are: preheating temperature is 230℃ and preheating time is 1-2 hours.

8. The method for preparing an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy according to claim 2, characterized in that, In step (4), the process conditions for hot extrusion molding are: extrusion temperature 230℃, extrusion ratio 28:1, and extrusion speed 0.5-1.0mm / s.

9. The method for preparing an ultralight, strong, and ductile synergistic Mg-Li-Zn-Ca-Mn alloy according to claim 2, characterized in that, In step (5), 3-7 passes of rotary forging deformation are performed, with a single pass radial compression of 0.2 mm.

Images