CN108823469B - Sub-micron crystal superplasticity kirsite, preparation method and application - Google Patents

Abstract

The invention discloses a submicron crystal superplastic zinc alloy, a preparation method and application thereof. The submicron crystalline superplastic zinc alloy comprises: 0wt%<Mn≤5wt%, 95wt%≤Zn<100wt%; and the grain size of the submicron crystalline superplastic zinc alloy is submicron. The preparation method of the submicron crystal superplastic zinc alloy includes: mixing and melting pure zinc and pure manganese to obtain as-cast zinc-manganese alloy; and subjecting the obtained as-cast zinc-manganese alloy to multi-pass hot extrusion to make the cast zinc-manganese alloy. The cumulative deformation of the as-state zinc-manganese alloy is greater than or equal to 90%, thereby obtaining a submicron grain superplastic zinc alloy. Compared with the prior art, the submicron crystal superplastic zinc alloy of the present invention has excellent plasticity and toughness, the elongation rate can reach 150-450%, and the preparation method is simple and easy to operate, and the sub-micron crystal superplastic zinc alloy can be prepared by further drawing treatment. Microcrystalline superplastic zinc alloy wire, expand the application range of zinc alloy.

Description

Submicron grain superplastic zinc alloy, its preparation method and application

technical field

The invention relates to the technical field of metal material processing, in particular to a submicron crystal superplastic zinc alloy, a preparation method and application thereof.

Background technique

Zinc metal is a diamagnetic metal with a close-packed hexagonal structure. Zinc and zinc alloys are widely used in industries such as construction, household appliances and automobiles. In recent years, zinc alloys have become a new generation of potential biomedical applications. Degradable metal. However, the crystal structure of zinc determines that pure zinc has fewer slip systems and poor plasticity. Although its strength and plasticity can be improved by adding alloying elements, if it is used as a medical degradable metal, it is necessary to exclude conventional alloying elements such as aluminum and copper that are harmful to the human body. As a common alloying element, manganese can not only improve the strength, plasticity and corrosion resistance of zinc alloys, but also is a bio-friendly element. The zinc-manganese alloy prepared by manganese as an alloying element can also be used as an option for biomedical degradable metals while being used in industry.

Existing zinc-manganese alloys are mainly composed of zinc-manganese binary elements, supplemented by trace amounts of other elements. The properties of as-cast zinc-manganese alloys are improved by rolling, heat treatment and other processing methods, but their grain size is relatively large, and the alloy's comprehensive Performance is not optimal. Zinc-manganese alloys have broad application prospects, and their properties can be further expanded by improving their properties through grain refinement. When the grains are refined to sub-micron size, the properties of the material, especially the plasticity, will be significantly improved. The preparation of submicron grain superplastic zinc alloy is of great significance for expanding the application scope of zinc alloy in the industrial field. In some applications, it is a strong competitor of aluminum alloy, magnesium alloy and copper alloy.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a submicron crystal superplastic zinc alloy, its preparation method and application, so as to overcome the deficiencies in the prior art.

In order to realize the foregoing invention purpose, the technical scheme adopted in the present invention includes:

An embodiment of the present invention provides a submicron crystalline superplastic zinc alloy, the submicron crystalline superplastic zinc alloy comprises 0wt%<Mn≤5wt% and 95wt%≤Zn<100wt%; and the submicron crystalline superplasticity The grain size of zinc alloys is sub-micron.

The embodiment of the present invention also provides a preparation method of submicron crystal superplastic zinc alloy, comprising the following steps:

(1) smelting after mixing pure zinc and pure manganese to obtain as-cast zinc-manganese alloy;

(2) The as-cast zinc-manganese alloy obtained in step (1) is subjected to multi-pass hot extrusion, so that the cumulative deformation of the as-cast zinc-manganese alloy is greater than or equal to 90%, thereby obtaining a submicron crystal superplastic zinc alloy.

The embodiment of the present invention also provides a preparation method of submicron crystal superplastic zinc alloy wire, comprising the following steps:

(1) mixing and smelting pure zinc and pure manganese to obtain as-cast zinc-manganese alloy;

(2) Multi-pass hot extrusion is performed on the as-cast zinc-manganese alloy obtained in step (1), so that the cumulative deformation of the as-cast zinc-manganese alloy is greater than or equal to 95%, thereby obtaining a submicron crystal superplastic zinc alloy rod material;

(3) Drawing the submicron grain superplastic zinc alloy rod obtained in step (2) to obtain a submicron grain superplastic zinc alloy wire.

The embodiment of the present invention also provides the use of the submicron crystalline superplastic zinc alloy or the submicron crystalline superplastic zinc alloy wire in preparing a medical metal stent material.

Compared with the prior art, the beneficial effects of the present invention include:

(1) The submicron crystalline superplastic zinc alloy provided in the embodiment of the present invention has a submicron crystalline structure, and contains the alloying element manganese (Mn), and the content of manganese is in the range of more than 0 wt % and less than or equal to 5 wt %. In the zinc alloy system, it can promote the refinement of grains, which can improve the plasticity of the zinc alloy, and can show room temperature superplasticity;

(2) The submicron grain superplastic zinc alloy provided by the embodiment of the present invention improves the shortcoming of insufficient toughness of the zinc alloy, and the elongation reaches the standard of superplasticity. The elongation of this type of zinc alloy can reach 150-450%. The application range of zinc alloy in industrial production. The prepared submicron crystalline superplastic zinc alloy or submicron crystalline superplastic zinc alloy wire has excellent performance, can be used for various zinc alloy wire applications, and can be used for vascular stents in medical metals in the future;

(3) The preparation method of the submicron crystal superplastic zinc alloy or the submicron crystal superplastic zinc alloy wire provided by the embodiment of the present invention, by controlling the preparation process, the zinc alloy grains are refined to the submicron level, and the superplasticity is achieved. performance, and the preparation method is simple and easy to operate.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the topography of the Zn-Mn alloy prepared in Example 1 of the present invention;

Fig. 2 is the grain size distribution of the Zn-Mn alloy prepared in Example 1 of the present invention;

3 is the stress-strain curve of the Zn-Mn alloy prepared in Example 1 of the present invention;

Fig. 4 is the cell morphology picture of the Zn-Mn alloy cytotoxicity experiment prepared in Example 1 of the present invention;

Fig. 5 is the grain size distribution of the Zn-Mn alloy prepared in Example 2 of the present invention;

6 is the grain size distribution of the Zn-Mn alloy prepared in Example 3 of the present invention;

FIG. 7 is a Zn-Mn alloy wire prepared in Example 4 of the present invention.

Detailed ways

In view of the deficiencies in the prior art, the inventor of the present application was able to propose the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

In the submicron crystalline superplastic zinc alloy provided by the embodiment of the present invention, the submicron crystalline superplastic zinc alloy comprises 0wt%<Mn≤5wt% and 95wt%≤Zn<100wt%; and the submicron grain superplastic zinc alloy The grain size is 0.1 μm ~ 0.95 μm, reaching the sub-micron level.

In some more specific embodiments, the submicron crystalline superplastic zinc alloy contains 0wt%<Mn≤5wt%, and the balance is Zn.

Manganese (Mn) element plays a role in promoting grain refinement in zinc alloy system and can improve the plasticity of zinc alloy. When the content of Mn is greater than 5%, the effect of Mn on promoting grain refinement will be weakened, and the addition of a large amount of Mn is not conducive to maintaining the strength of the zinc alloy. When the content of Mn is in the range of 0-5% but not including 0, the effect of promoting the grain refinement of the zinc alloy will be basically the same.

In some embodiments, the Mn content in the submicron crystalline superplastic zinc alloy is greater than 0 wt% and less than or equal to 1 wt%.

In some embodiments, the submicron crystalline superplastic zinc alloy has a grain size of 0.1 μm to 0.95 μm.

The preparation method of the submicron crystal superplastic zinc alloy provided by the embodiment of the present invention comprises the following steps:

(1) smelting after mixing pure zinc and pure manganese to obtain as-cast zinc-manganese alloy;

(2) The as-cast zinc-manganese alloy obtained in step (1) is subjected to multi-pass hot extrusion, so that the cumulative deformation of the as-cast zinc-manganese alloy is greater than or equal to 90%, thereby obtaining a submicron crystal superplastic zinc alloy.

In some embodiments, the step (1) specifically includes: mixing pure zinc and pure manganese, smelting at 650-700°C for 10-30min, pouring into a mold at 600-650°C, and cooling to room temperature The as-cast zinc-manganese alloy billet is obtained.

In some embodiments, the mass ratio of pure zinc to pure manganese is 19:1 to 9999:1, preferably 99:1 to 9999:1.

In some specific embodiments, the raw materials of the submicron crystalline superplastic zinc alloy are mixed according to the metering ratio, and the raw materials are smelted at 650-700° C. for 10-30 minutes, and then poured into a mold at 600-650° C. , the as-cast zinc-manganese alloy is obtained after cooling to room temperature.

According to the melting point of each component in the zinc alloy, the smelting temperature of the zinc alloy is controlled between 650 and 700 °C, the melting temperature is 10 to 30 minutes, and the pouring temperature is at 600 to 650 °C, so that the components of the zinc alloy can be fully dissolved in each other, and the It can reduce the burning loss and obtain the best as-cast structure.

In some embodiments, the step (2) specifically includes: turning the as-cast zinc-manganese alloy obtained in step (1) to remove oxide scale, and then performing multiple passes of hot extrusion on the as-cast zinc-manganese alloy.

In some embodiments, in the multi-pass hot extrusion, the heating temperature of the ingot is 200-300°C, the holding time is 2-3 hours, and the heating temperature of the die is 220-240°C.

In some embodiments, the multi-pass hot extrusion is 10-30 passes.

In some embodiments, the amount of deformation per hot extrusion pass ranges from 4% to 95%.

In some embodiments, the cumulative deformation of the as-cast zinc-manganese alloy is >95% through multiple passes of hot extrusion.

Appropriate extrusion temperature is conducive to the extrusion process, and will also affect the microstructure of the material. The change of the pass deformation will significantly affect the grain size, thereby affecting the properties of the material.

In some preferred embodiments, the as-cast zinc-manganese alloy is extruded, the extrusion temperature is 230-280° C., the extrusion passes are 20-30, and the cumulative deformation of the as-cast zinc-manganese alloy is ≥ 95%.

The embodiment of the present invention provides a submicron crystalline superplastic zinc alloy prepared by the method.

The preparation method of the submicron crystal superplastic zinc alloy wire provided by the embodiment of the present invention comprises the following steps:

(1) mixing and smelting pure zinc and pure manganese to obtain as-cast zinc-manganese alloy;

(2) Multi-pass hot extrusion is performed on the as-cast zinc-manganese alloy obtained in step (1), so that the cumulative deformation of the as-cast zinc-manganese alloy is greater than or equal to 95%, thereby obtaining a submicron crystal superplastic zinc alloy bar ;

(3) Drawing the submicron grain superplastic zinc alloy rod obtained in step (2) to obtain a submicron grain superplastic zinc alloy wire.

In some embodiments, the step (1) specifically includes: mixing pure zinc and pure manganese, smelting at 650-700°C for 10-30min, pouring into a mold at 600-650°C, and cooling to room temperature The as-cast zinc-manganese alloy billet is obtained.

In some embodiments, the mass ratio of pure zinc to pure manganese is 19:1 to 9999:1, preferably 99:1 to 9999:1.

In some embodiments, the step (2) specifically includes: turning the as-cast zinc-manganese alloy obtained in step (1) to remove oxide scale, and then performing multiple passes of hot extrusion on the as-cast zinc-manganese alloy.

Further, after the oxide scale is removed, the diameter difference of the as-cast zinc-manganese alloy bar is ≤0.1 mm.

Further, after the oxide scale is removed, the surface roughness Ra of the as-cast zinc-manganese alloy is less than or equal to 1.4 μm.

In some embodiments, in the multi-pass hot extrusion, the heating temperature of the ingot is 200-300°C, the holding time is 2-3 hours, and the heating temperature of the die is 220-240°C.

In some embodiments, the multi-pass hot extrusion is 10-30 passes.

In some embodiments, the amount of deformation per hot extrusion pass ranges from 4% to 95%.

In some embodiments, the step (3) specifically includes: the deformation amount of the drawing pass is less than or equal to 5%, and the cumulative deformation amount of the drawing is greater than or equal to 20%.

In some embodiments, the resulting as-cast zinc-manganese alloy wire is straightened and/or polished.

Specifically, after the submicron grain superplastic zinc alloy rod is drawn, the accumulated deformation is ≥20% compared with the initial drawing, and then the obtained submicron grain superplastic zinc alloy wire is straightened at room temperature.

The embodiment of the present invention also provides the submicron crystalline superplastic zinc alloy wire prepared by the method.

The embodiment of the present invention also provides the use of the submicron crystalline superplastic zinc alloy or the submicron crystalline superplastic zinc alloy wire in the preparation of a medical metal stent material.

In some specific embodiments, the submicron crystalline superplastic zinc alloy wire can be used for various zinc alloy wire applications, and can be used for vascular stents in medical metals in the future.

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the technical solutions of the present invention are further described in detail below through embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only intended to illustrate the present invention and not to limit the scope of the present invention.

The percentages used in the following examples are mass percentages unless otherwise specified, and the raw materials are pure zinc (99.99wt.%) and pure manganese (99.99wt.%).

Example 1:

In this example, pure zinc and pure manganese are used as raw materials, and pure zinc and pure manganese are mixed according to a mass ratio of 99.9:0.1, and the mixed raw materials are smelted at 650°C for 20 minutes, poured into a mold at 620°C, and cooled after cooling. After reaching room temperature, a zinc-manganese alloy ingot with a diameter of 60 mm is obtained, and both ends and the outer skin of the zinc-based alloy ingot are excised to obtain a zinc-manganese alloy ingot with a diameter of 50 mm. The heating temperature of the ingot is 220°C, the temperature is kept for 2 hours, the heating temperature of the die is 230°C, and 20 passes are used for extrusion. When the diameter reaches 4 mm (the cumulative deformation is 99%), a submicron crystalline superplastic zinc-manganese alloy with a diameter of 4 mm is finally obtained.

EBSD was used to observe the microscopic morphology of the rod-shaped zinc-manganese alloy, and Figure 1 was obtained. The grain size of the zinc-manganese alloy in Figure 1 is very small. Figure 2 shows the grain size distribution measured by EBSD. The average grain size is 0.38 μm, reaching the sub-micron level.

According to the ASTM-E8-04 tensile test standard, the rod-shaped zinc-manganese alloy was prepared into tensile specimens. After polishing the tensile samples, ultrasonically cleaned them in acetone, anhydrous ethanol and deionized water for 5 min respectively. Then, a tensile test was carried out at room temperature using a universal material mechanical testing machine at a tensile speed of 1 mm/min. The obtained stress The strain curve is shown in Fig. 3, the tensile strength reaches 122MPa and the elongation reaches 275%.

The present embodiment also tests the biocompatibility of the rod-shaped zinc-manganese alloy, specifically:

The leaching solution was prepared according to ISO 10993-5:2009 standard, and the leaching medium was cell culture medium (incomplete DMEM medium (containing double antibody) containing 12.5% serum). The leaching ratio is the ratio of the surface area of the sample to the volume of the leaching solution, which is 2:3. The leaching conditions were leaching in a 37°C 5% _CO2 constant temperature incubator for 24 hours.

The preparation method of the leaching solution: the submicron crystal superplastic zinc-manganese alloy with a diameter of 4mm was first ultrasonically cleaned with deionized water, dried and then moved into a biological safety cabinet, soaked in 75% alcohol for 24 hours, and then the zinc The manganese alloy was placed on filter paper for UV sterilization for 2 hours. After sterilization, put the zinc-manganese alloy into a centrifuge tube, add a quantitative cell culture medium, seal the mouth of the centrifuge tube, and place it in a 37°C 5% _CO2 incubator for 24 hours.

After resuscitation and passage of L-929 cells (Cell Bank of Type Culture Collection, Chinese Academy of Sciences), the cells were detached from the culture flask with 0.5% trypsin, and the detached cells were prepared into 10 ⁴ cells/mL with DMEM cell culture medium. cell suspension. Take a 96-well culture plate, add 100 μL of cell suspension to each well, and place it in a 5% CO ₂ constant temperature incubator for 24 hours (37±2°C). After the cells adhered, the original culture medium was removed by suction, and 100 μL of the extraction solution was added to each well. After culturing for 72 hours in a 5% _CO2 constant temperature incubator, the cell morphology was acquired using a high-content imager (as shown in Figure 4). The results show that the cell morphology is a healthy and extended spindle-shaped convergent growth, indicating that the submicron crystalline superplastic Zn-Mn alloy has excellent cytocompatibility.

Example 2

In this example, pure zinc and pure manganese are used as raw materials, and pure zinc and pure manganese are mixed in a mass ratio of 98.5:1.5, and the mixed raw materials are smelted at 660° C. for 30 minutes, poured into a mold at 620° C., and cooled after cooling. After reaching room temperature, a zinc-manganese alloy ingot with a diameter of 60 mm was obtained, the surface of the as-cast zinc-manganese alloy billet was turned to a diameter of 50 mm, the oxide scale was completely removed, and the zinc alloy was extruded. hours, the heating temperature of the mold is 220 °C, 25 passes are used for extrusion, the deformation of the first pass is 85%, the deformation of the remaining passes is 5% to 20%, and the extrusion is to a diameter of 4.5mm (the cumulative deformation is 99%) to obtain a zinc-manganese alloy with an average grain size of 0.42 μm, whose grain size distribution is shown in Figure 5.

Example 3

In this example, pure zinc and pure manganese are used as raw materials, and pure zinc and pure manganese are mixed according to the mass ratio of 95:5, and the mixed raw materials are smelted at 690°C for 30 minutes, poured into a mold at 640°C, and cooled after cooling. After reaching room temperature, a zinc-manganese alloy ingot with a diameter of 60 mm was obtained, the surface of the as-cast zinc-manganese alloy billet was turned to a diameter of 50 mm, the oxide scale was completely removed, and the zinc alloy was extruded. hour, the mold heating temperature is 225 ℃, 13 passes are used for extrusion, the deformation of the first pass is 85%, the deformation of the remaining passes is 4% to 20%, and the extrusion is to a diameter of 6.4mm (the cumulative deformation is 98%) to obtain a zinc-manganese alloy with a grain size of 0.92 μm, whose grain size distribution is shown in Figure 6.

Example 4

In this example, pure zinc and pure manganese are used as raw materials, and pure zinc and pure manganese are mixed according to the mass ratio of 99.55:0.45, and the mixed raw materials are smelted at 680° C. for 25 minutes, poured into a mold at 630° C., and cooled after cooling. After reaching room temperature, a zinc-manganese alloy ingot with a diameter of 60 mm was obtained, the surface of the as-cast zinc-manganese alloy billet was turned to a diameter of 50 mm, the oxide scale was completely removed, and the zinc alloy was extruded. hour, the mold heating temperature is 220 ℃, 25 passes are used for extrusion, the deformation of the first pass is 80%, the deformation of the remaining passes is 4% to 20%, and the extrusion is to a diameter of 5mm (the cumulative deformation is 99%). %), and then the bar was drawn to a zinc alloy wire with a diameter of 3.7 mm. The obtained circular wire is straightened and polished to obtain a submicron crystalline superplastic zinc alloy wire, as shown in FIG. 7 .

In addition, the inventors of the present application also conducted corresponding experiments by using other process conditions listed above to replace the corresponding process conditions in Examples 1-4, and the content to be verified is close to the products of Examples 1-4. Therefore, the verification contents of each embodiment will not be described one by one here, and only embodiments 1 to 4 will be used as a representative to describe the advantages of the application of the present invention.

It should be understood that the above descriptions are only some embodiments of the present invention, and it should be pointed out that for those of ordinary skill in the art, other modifications and improvements can also be made without departing from the inventive concept of the present invention. These all belong to the protection scope of the present invention.

Claims (27)

1. A submicron crystalline superplastic zinc alloy, characterized in that: the submicron crystalline superplastic zinc alloy comprises 0wt%<Mn≤5wt% and 95wt%≤Zn<100wt%; and the submicron crystalline superplasticity The grain size of zinc alloys is sub-micron. 2 . The submicron grain superplastic zinc alloy according to claim 1 , wherein the submicron grain superplastic zinc alloy contains 0wt%<Mn≤1wt%. 3 . 3 . The submicron crystalline superplastic zinc alloy according to claim 1 , wherein the grain size of the submicron crystalline superplastic zinc alloy is 0.1 μm˜0.95 μm. 4 . 4. a preparation method of submicron crystal superplastic zinc alloy, is characterized in that, comprises the following steps: (1) Mix pure zinc and pure manganese and then smelt to obtain as-cast zinc-manganese alloy; (2) The as-cast zinc-manganese alloy obtained in step (1) is subjected to multi-pass hot extrusion, so that the cumulative deformation of the as-cast zinc-manganese alloy is greater than or equal to 90%, thereby obtaining a submicron crystal superplastic zinc alloy. 5 . The preparation method according to claim 4 , wherein the step (1) specifically comprises: mixing pure zinc and pure manganese, smelting at 650-700° C. for 10-30 minutes, and heating at 600-650° C. It is poured into a mold and cooled to room temperature to obtain a cast zinc-manganese alloy billet. 6 . The preparation method according to claim 4 , wherein in step (1), the mass ratio of the pure zinc to pure manganese is 19:1 to 9999:1. 7 . 7 . The preparation method according to claim 6 , wherein in step (1), the mass ratio of the pure zinc to pure manganese is 99:1 to 9999:1. 8 . 8 . The preparation method according to claim 4 , wherein in step (2), the heating temperature of the ingot in the multi-pass hot extrusion is 200-300° C., the holding time is 2-3 hours, and the mold is 2-3 hours. 9 . The heating temperature is 220~240℃. 9 . The preparation method according to claim 4 , wherein in step (2), the multi-pass hot extrusion is 10-30 passes. 10 . 10 . The preparation method according to claim 4 , wherein in step (2), the deformation amount of each pass of hot extrusion is 4% to 95%. 11 . 11 . The preparation method according to claim 4 , wherein in step (2), the cumulative deformation of the as-cast zinc-manganese alloy is greater than 95% through multiple passes of hot extrusion. 12 . 12 . The preparation method according to claim 4 , wherein the step (2) specifically comprises: turning the as-cast zinc-manganese alloy obtained in step (1) to remove oxide scale, and then applying the as-cast zinc-manganese alloy to the as-cast zinc-manganese alloy. 13 . The alloy is subjected to multiple passes of hot extrusion. 13. A submicron crystalline superplastic zinc alloy prepared by the method of any one of claims 4-12. 14. a preparation method of submicron crystal superplastic zinc alloy wire, is characterized in that, comprises the following steps: (1) Mix and smelt pure zinc and pure manganese to obtain as-cast zinc-manganese alloy; (2) The as-cast zinc-manganese alloy obtained in step (1) is subjected to multi-pass hot extrusion, so that the cumulative deformation of the as-cast zinc-manganese alloy is greater than or equal to 95%, thereby obtaining a submicron grain superplastic zinc alloy bar ; (3) Drawing the submicron grain superplastic zinc alloy rod obtained in step (2) to obtain a submicron grain superplastic zinc alloy wire. 15 . The preparation method according to claim 14 , wherein the step (1) specifically comprises: mixing pure zinc and pure manganese, smelting at 650-700° C. for 10-30 minutes, and heating at 600-650° C. It is poured into a mold and cooled to room temperature to obtain a cast zinc-manganese alloy billet. 16. The preparation method according to claim 14, characterized in that: in step (1), the mass ratio of the pure zinc to pure manganese is 19:1 to 9999:1. 17 . The preparation method according to claim 16 , wherein in step (1), the mass ratio of the pure zinc to pure manganese is 99:1 to 9999:1. 18 . 18 . The preparation method according to claim 14 , wherein the step (2) specifically comprises: turning the as-cast zinc-manganese alloy obtained in step (1) to remove oxide scale, and then performing a process on the as-cast zinc-manganese alloy. 19 . The alloy is subjected to multiple passes of hot extrusion. 19 . The preparation method according to claim 18 , wherein the step (2) specifically comprises: after the oxide scale is removed, the diameter difference of the bars of the as-cast zinc-manganese alloy is ≤0.1 mm. 20 . 20 . The preparation method according to claim 18 , wherein the step (2) specifically comprises: after removing the oxide scale, the surface roughness Ra of the as-cast zinc-manganese alloy is less than or equal to 1.4 μm. 21 . 21 . The preparation method according to claim 14 , wherein in the step (2), the heating temperature of the ingot in the multi-pass hot extrusion is 200-300° C., and the holding time is 2-3 hours. 21 . , the mold heating temperature is 220~240℃. 22 . The preparation method according to claim 14 , wherein in the step (2), the multi-pass hot extrusion is 10-30 passes. 23 . 23 . The preparation method according to claim 14 , wherein in the step (2), the deformation amount of each pass of hot extrusion is 4% to 95%. 24 . 24 . The preparation method according to claim 14 , wherein the step (3) specifically comprises: the deformation amount of the drawing pass is less than or equal to 5%, and the cumulative deformation amount of the drawing is greater than or equal to 20%. 25 . 25. The preparation method according to claim 14, further comprising: performing straightening and/or polishing treatment on the obtained as-cast zinc-manganese alloy wire. 26. A submicron crystalline superplastic zinc alloy wire prepared by the method of any one of claims 14-25. 27. Use of the submicron crystalline superplastic zinc alloy described in any one of claims 1, 2, 3, and 13 or the submicron crystalline superplastic zinc alloy wire of claim 26 in the preparation of medical metal stent materials .