Magnesium alloy fine wire material having high strength and corrosion resistance and method for manufacturing the same

Abstract

The application provides a magnesium alloy fine wire material with high strength plasticity and corrosion resistance and a preparation method thereof, and belongs to the technical field of metal material preparation and plastic processing. The magnesium alloy fine wire material provided by the application comprises the following components in percentage by weight: Al 1.3%~1.8%, Mn 0.5%~0.9%, La 0.7%~1.1%, Nd 0.7%~1.1%, and the balance is Mg. The diameter of the magnesium alloy fine wire material is 1~2 mm. The wire material prepared by the application has uniform structure, high strength, high plasticity and excellent corrosion resistance. The tensile strength of the wire material can be up to 322.3 MPa, and the elongation can be up to 50% at most, which is far higher than the strength plasticity matching of conventional magnesium alloy wire materials. After being soaked in Hank's solution for 14 days, the corrosion pit depth of the deepest part of the surface of the wire material can be controlled within about 12 microns, which proves the excellent corrosion resistance of the wire material.

Description

Technical Field

[0001] This invention relates to the field of metal material preparation and plastic processing technology, and in particular to a magnesium alloy fine wire with both high strength, plasticity and corrosion resistance and its preparation method. Background Technology

[0002] Magnesium and magnesium alloys, as one of the lightest engineering structural materials, have low density, high specific strength and specific stiffness, good damping performance, as well as excellent thermal and electrical conductivity, electromagnetic shielding ability and machinability. They show broad application prospects in aerospace, automotive industry, 3C electronic products, biomedicine and energy equipment.

[0003] However, the inherent hexagonal close-packed crystal structure of magnesium alloys limits the number of slip systems that can be activated at room temperature, resulting in poor plastic forming ability, especially when fabricating complex shapes or micro-section components. Currently, magnesium alloy profiles are mainly in the form of bars, plates, and tubes, and their production processes are relatively mature. In contrast, the fabrication of fine filaments (typically less than 2 mm in diameter) faces severe challenges due to the extensive deformation required: insufficient room-temperature plasticity makes continuous filament forming difficult, and the surface is prone to oxidation; high thermal conductivity induces significant thermal stress during hot working, increasing the risk of cracking and filament breakage; improper control of forming temperature can easily lead to grain coarsening, significant texture, and internal defects, severely impairing the material's strength and plasticity and exacerbating the anisotropy of mechanical properties. Furthermore, the presence of microstructure inhomogeneity and residual stress can induce localized galvanic corrosion, further deteriorating its corrosion resistance.

[0004] To improve the overall performance of magnesium alloys, approaches are typically taken from two aspects: alloying design and process control. Regarding alloying, Al (Al) has excellent solid solution and precipitation strengthening effects in magnesium and is a commonly used alloying element. Rare earth (RE) elements such as La, Gd, Y, and Nd can enhance mechanical properties and improve surface film stability through solid solution and aging strengthening mechanisms, thereby increasing corrosion resistance. However, high alloying content not only increases costs but also easily leads to compositional segregation and the formation of a large amount of second phase, increasing deformation resistance and causing uneven microstructure, which is detrimental to the precision forming of wires.

[0005] In recent years, in the pursuit of high-performance, special-functional materials, the concept of multi-component microalloying, which synergistically modulates the properties of various trace solute components, has developed rapidly. This concept differs from the traditional high-content single-component alloying approach, instead achieving wide-range, precise control of microstructure and properties through the synergistic addition of multiple trace elements. This significantly improves material performance while effectively controlling costs. This provides new theoretical support for the compositional design of magnesium alloys that possess high strength, plasticity, corrosion resistance, and suitability for fine wire forming. Nevertheless, the preparation of magnesium alloy wires still faces a series of technological challenges: hot extrusion can exacerbate cracking due to microstructure inhomogeneity; the narrow hot working window is extremely sensitive to temperature fluctuations—too low a temperature results in insufficient plasticity, while too high a temperature leads to grain boundary embrittlement; during fine wire forming, the small cross-section and large die contact area result in significant frictional heat generation and temperature drop effects, often leading to breakage, surface cracks, and loss of dimensional accuracy. Therefore, how to achieve efficient and stable preparation of high-performance magnesium alloy fine wires through synergistic innovation in composition and process remains a key technological bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a magnesium alloy filament material with both high strength and plasticity and corrosion resistance, and a method for preparing the same.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] One of the technical solutions of this invention is a magnesium alloy fine wire with high strength, plasticity and corrosion resistance, which comprises the following components by weight percentage: Al 1.3%~1.8%, Mn 0.5%~0.9%, La 0.7%~1.1%, Nd 0.7%~1.1%, and the balance being Mg.

[0009] Preferably, the diameter of the magnesium alloy filament is 1~2 mm.

[0010] The second technical solution of the present invention is a method for preparing the above-mentioned magnesium alloy fine wire with both high strength and corrosion resistance, comprising the following steps:

[0011] S1. Prepare the ingredients, then melt the prepared ingredients to obtain a melt;

[0012] S2. Refine the melt, then let it stand to remove slag, and then let it stand until the temperature drops to the casting temperature, then cast to obtain an alloy ingot;

[0013] S3. The alloy ingot is homogenized and then processed into a billet;

[0014] S4. The billet is subjected to gradient heating to increase the temperature. After reaching the extrusion temperature, it is extruded once to obtain the magnesium alloy fine wire.

[0015] The gradient heating process is as follows: the temperature is increased from room temperature to 300 ℃ at a heating rate of 10 K / min, then increased to 300~450 ℃ at a heating rate of 5 K / min, and finally increased to 450~500 ℃ at a heating rate of 3 K / min, and held at 500 ℃ for 20 min. The temperature error range is ±5 ℃.

[0016] The present invention discloses the following technical effects:

[0017] This invention systematically solves the problem of preparing high-performance magnesium alloy fine wires through synergistic innovation in composition design and forming process: On the one hand, based on the theory of multi-element microalloying, a new alloy system with high strength, plasticity, corrosion resistance and good hot formability is constructed by adding trace amounts of elements such as Al, Mn, La and Nd; on the other hand, a single-pass hot extrusion process is innovatively adopted, and a gradient heating and precise temperature control strategy is introduced to make the processing temperature dynamically match the material microstructure evolution law, which not only broadens the narrow hot processing window of magnesium alloys, but also realizes the efficient and stable forming of fine wires with a diameter of 1~2mm, and finally obtains magnesium alloy fine wires with uniform microstructure, high surface quality, good dimensional accuracy, and high strength, high plasticity and excellent corrosion resistance.

[0018] This invention overcomes the problems of insufficient plasticity, high tendency to hot cracking, uneven microstructure leading to repeated drawing and annealing, narrow process window, easy wire breakage, and deterioration of corrosion resistance in the traditional preparation of magnesium alloy fine wires. The fine wire prepared by this invention has a uniform microstructure and good surface quality, while also possessing high strength, high plasticity, and excellent corrosion resistance. This product is suitable for aerospace, biomedical, precision electronics, and high-end equipment fields with stringent requirements for lightweight, toughness, and durability.

[0019] The magnesium alloy wire prepared by this invention has a tensile strength of up to 322.3 MPa and an elongation of up to 50%, which far exceeds the strength-plasticity matching of conventional magnesium alloy wires. After being immersed in Hank's solution, a simulated body fluid, for 14 days, the deepest corrosion pit on the surface of the wire can be controlled within about 12 μm, proving its excellent corrosion resistance. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a macroscopic morphology image of the Mg-1.5Al-0.5Mn-1La-1Nd alloy wire obtained in the embodiments of the present invention;

[0022] Figure 2 The macroscopic morphology and microstructure of the Mg-1.5Al-0.5Mn-1La-1Nd alloy wire of Example 1 of the present invention are shown in the figure.

[0023] Figure 3 The stress-strain curve of the Mg-1.5Al-0.5Mn-1La-1Nd alloy wire of Example 1 of the present invention is shown.

[0024] Figure 4 This is a 3D corrosion morphology image of the Mg-1.5Al-0.5Mn-1La-1Nd alloy wire of Example 1 of the present invention;

[0025] Figure 5 The image shows the macroscopic morphology and microstructure of the Mg-2.5Al-1Mn-1.5La-1.5Nd alloy wire of Comparative Example 1 of this invention.

[0026] Figure 6 The stress-strain curve of the Mg-2.5Al-1Mn-1.5La-1.5Nd alloy wire of Comparative Example 1 of this invention;

[0027] Figure 7 This is a 3D corrosion morphology image of the Mg-2.5Al-1Mn-1.5La-1.5Nd alloy wire of Comparative Example 1 of the present invention;

[0028] Figure 8 The macroscopic morphology and microstructure of the Mg-0.5Al-0.1Mn-0.2La-0.2Nd alloy wire of Comparative Example 2 of this invention are shown in the figure.

[0029] Figure 9 The stress-strain curve of the Mg-0.5Al-0.1Mn-0.2La-0.2Nd alloy wire of Comparative Example 2 of this invention;

[0030] Figure 10 This is a 3D corrosion morphology image of the Mg-0.5Al-0.1Mn-0.2La-0.2Nd alloy wire of Comparative Example 2 of the present invention;

[0031] Figure 11 The macroscopic morphology and microstructure of the Mg-1.5Al-0.5Mn-1La alloy wire of Comparative Example 3 of this invention are shown in the figure.

[0032] Figure 12 The stress-strain curve of the Mg-1.5Al-0.5Mn-1La alloy wire of Comparative Example 3 of this invention;

[0033] Figure 13 This is a 3D corrosion morphology image of the Mg-1.5Al-0.5Mn-1La alloy wire of Comparative Example 3 of the present invention. Detailed Implementation

[0034] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0036] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0037] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0038] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0039] The first aspect of the present invention provides a magnesium alloy fine wire with high strength, plasticity and corrosion resistance, comprising the following components by weight percentage: Al 1.3%~1.8%, Mn 0.5%~0.9%, La 0.7%~1.1%, Nd 0.7%~1.1%, with the balance being Mg.

[0040] Based on the theory of multi-element microalloying, this invention designs a novel magnesium alloy. By adding trace amounts of elements such as Al, Mn, La, and Nd, it achieves multiple objectives: microstructure refinement, texture weakening, strength and toughness enhancement, and surface film stability improvement, significantly improving corrosion resistance while maintaining excellent thermoplasticity. Furthermore, a highly compatible single-pass hot extrusion forming process is proposed. This process employs a strategy combining gradient heating and precise temperature control to stably constrain the deformation process within the optimal plasticity range, effectively suppressing grain coarsening and hot brittleness, thereby efficiently and stably producing fine wires with diameters of 1-2 mm in a single pass. The resulting magnesium alloy fine wires possess comprehensive advantages such as uniform microstructure, high surface quality, good dimensional accuracy, high strength, high plasticity, and excellent corrosion resistance.

[0041] More preferably, the magnesium alloy filament comprises, by weight percentage: Al 1.3%, Mn 0.5%, La 0.7%, Nd 0.7%, with the balance being Mg.

[0042] More preferably, the magnesium alloy filament comprises, by weight percentage: Al 1.5%, Mn 0.5%, La 1%, Nd 1%, with the balance being Mg.

[0043] More preferably, the magnesium alloy filament comprises, by weight percentage: Al 1.8%, Mn 0.9%, La 1.1%, Nd 1.1%, with the balance being Mg.

[0044] In a preferred embodiment of the present invention, the diameter of the magnesium alloy filament is 1-2 mm.

[0045] A second aspect of the present invention provides a method for preparing the above-mentioned magnesium alloy fine wire with both high strength and plasticity and corrosion resistance, comprising the following steps:

[0046] S1. Prepare the ingredients, then melt the prepared ingredients to obtain a melt;

[0047] S2. Refine the melt, then let it stand to remove slag, and then let it stand until the temperature drops to the casting temperature, then cast to obtain an alloy ingot;

[0048] S3. The alloy ingot is homogenized and then processed into a billet;

[0049] S4. The billet is subjected to gradient heating to increase the temperature. After reaching the extrusion temperature, it is extruded once to obtain the magnesium alloy fine wire.

[0050] The gradient heating process is as follows: the temperature is increased from room temperature to 300 ℃ at a heating rate of 10 K / min, then increased to 300~450 ℃ at a heating rate of 5 K / min, and finally increased to 450~500 ℃ at a heating rate of 3 K / min, and held at 500 ℃ for 20 min. The temperature error range is ±5 ℃.

[0051] In a preferred embodiment of the present invention, the ingredients are pure Mg ingots, pure Al ingots, Mg-Mn master alloy, Mg-La master alloy and Mg-Nd master alloy weighed according to the designed alloy composition.

[0052] In a preferred embodiment of the present invention, melting the prepared raw materials specifically involves: first melting Mg ingots, then adding preheated Al ingots at 720~730 ℃ and stirring evenly; then raising the temperature to 730~740 ℃ and adding preheated Mg-La master alloy and Mg-Nd master alloy, stirring evenly; then raising the temperature to 690~700 ℃ and adding Mg-Mn master alloy, stirring evenly.

[0053] In a preferred embodiment of the present invention, the refining temperature is 730~740 ℃ and the time is 8~10 min.

[0054] In a preferred embodiment of the present invention, the casting temperature is 700~710 ℃.

[0055] In a preferred embodiment of the present invention, the homogenization treatment is carried out at a temperature of 300~320 ℃ for 12 h.

[0056] In a preferred embodiment of the present invention, the parameters for the extrusion in one pass are set as follows: extrusion speed is 0.1-0.3 mm / s, and extrusion ratio is 300:1 to 1200:1.

[0057] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0058] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0059] Example 1

[0060] Preparation of Mg-1.5Al-0.5Mn-1La-1Nd alloy fine wire:

[0061] (1) Batching: Weigh pure Mg ingots, Al ingots, Mg-Mn master alloy, Mg-La master alloy and Mg-Nd master alloy according to the proportions of Al 1.5wt.%, Mn 0.5wt.%, La 1wt.%, Nd 1wt.%, and the balance being Mg; then melt the preheated Mg ingots, add Al ingots at 720 ℃ and stir mechanically for 8 minutes; then raise the temperature to 730 ℃, add the preheated Mg-La master alloy and Mg-Nd master alloy and stir for 8 minutes; let stand until the temperature drops to 690 ℃, add Mg-Mn master alloy and stir for 5 minutes to obtain the melt;

[0062] (2) Refining: The melt is refined at 730 ℃. After mechanical stirring for 10 minutes, it is allowed to stand and remove slag. Then, it is allowed to stand until the temperature drops to 710 ℃ before pouring the alloy liquid into a preheated mold to obtain an alloy ingot.

[0063] (3) Homogenization treatment: The obtained alloy ingot was homogenized at 320 °C for 12 hours and then processed into a cylindrical sample.

[0064] (4) Preparation of fine wire: The sample was heated from room temperature to 300 ℃ at a heating rate of 10 K / min, then heated to 450 ℃ at a heating rate of 5 K / min, and finally heated to 500 ℃ at a heating rate of 3 K / min, and held at 500 ℃ for 20 min. The temperature error range was ±5 ℃. Then, one extrusion was performed with an extrusion ratio of 600:1 and an extrusion speed of 0.2 mm / s to obtain alloy fine wire with a diameter of 1~2 mm.

[0065] The macroscopic morphology and microstructure of the fine filament are as follows: Figure 2 As shown; Figure 3 The stress-strain curve of the alloy wire was obtained, and its tensile strength (UTS) was measured to be 322.3 MPa, with an elongation (E1) as high as 50%. Figure 4 The image shows the three-dimensional white light interference morphology of the alloy wire after immersion in Hank's solution for 14 days, with the deepest corrosion pit reaching a depth of 11.8 μm.

[0066] Comparative Example 1

[0067] Preparation of Mg-2.5Al-1Mn-1.5La-1.5Nd alloy fine wire:

[0068] (1) Batching: Weigh pure Mg ingots, Al ingots, Mg-Mn master alloy, Mg-La master alloy and Mg-Nd master alloy according to the proportions of Al 2.5wt.%, Mn 1wt.%, La 1.5wt.%, Nd 1.5wt.% and the balance being Mg; then melt the preheated Mg ingots, add Al ingots at 720 ℃ and stir mechanically for 8 minutes; then raise the temperature to 730 ℃, add the preheated Mg-La master alloy and Mg-Nd master alloy and stir for 8 minutes; let stand until the temperature drops to 690 ℃, add Mg-Mn master alloy and stir for 5 minutes to obtain the melt;

[0069] (2) Refining: The melt is refined at 730 ℃. After mechanical stirring for 10 minutes, it is allowed to stand and remove slag. Then, it is allowed to stand until the temperature drops to 710 ℃ before pouring the alloy liquid into a preheated mold to obtain an alloy ingot.

[0070] (3) Homogenization treatment: The obtained alloy ingot was homogenized at 320 °C for 12 hours and then processed into a cylindrical sample.

[0071] (4) Preparation of fine wire: The sample was heated from room temperature to 300 ℃ at a heating rate of 10 K / min, then to 450 ℃ at a heating rate of 5 K / min, and finally to 500 ℃ at a heating rate of 3 K / min. The sample was then held at 500 ℃ for 20 min, with a temperature error range of ±5 ℃. After that, a single extrusion was performed with an extrusion ratio of 1200:1 and an extrusion speed of 0.1 mm / s to obtain alloy fine wire with a diameter of 1~2 mm.

[0072] The macroscopic morphology and microstructure of the fine filament are as follows: Figure 5 As shown; Figure 6 The stress-strain curve of the alloy wire was obtained, and its tensile strength (UTS) was measured to be 281.6 MPa, and its elongation (E1) was 15%. Figure 7 The image shows the three-dimensional morphology of the alloy wire after immersion in Hank's solution for 14 days using white light interference. The deepest corrosion pit is 26.8 μm.

[0073] Comparative Example 2

[0074] Preparation of Mg-0.5Al-0.1Mn-0.2La-0.2Nd alloy fine wire:

[0075] (1) Batching: Weigh pure Mg ingots, Al ingots, Mg-Mn master alloy, Mg-La master alloy and Mg-Nd master alloy according to the proportions of Al 0.5wt.%, Mn 0.1wt.%, La 0.2wt.%, Nd 1.2wt.% and the balance being Mg; then melt the preheated Mg ingots, add Al ingots at 720 ℃ and stir mechanically for 8 minutes; then raise the temperature to 730 ℃, add the preheated Mg-La master alloy and Mg-Nd master alloy and stir for 8 minutes; let stand until the temperature drops to 690 ℃, add Mg-Mn master alloy and stir for 5 minutes to obtain the melt;

[0076] (2) Refining: The melt is refined at 730 ℃. After mechanical stirring for 10 minutes, it is allowed to stand and remove slag. Then, it is allowed to stand until the temperature drops to 710 ℃ before pouring the alloy liquid into a preheated mold to obtain an alloy ingot.

[0077] (3) Homogenization treatment: The obtained alloy ingot was homogenized at 320 °C for 12 hours and then processed into a cylindrical sample.

[0078] (4) Preparation of fine wire: The sample was heated from room temperature to 300 ℃ at a heating rate of 10 K / min, then heated to 450 ℃ at a heating rate of 5 K / min, and finally heated to 500 ℃ at a heating rate of 3 K / min, and held at 500 ℃ for 20 min. The temperature error range was ±5 ℃. Then, one extrusion was performed with an extrusion ratio of 300:1 and an extrusion speed of 0.3 mm / s to obtain alloy fine wire with a diameter of 1~2 mm.

[0079] The macroscopic morphology and microstructure of the fine filament are as follows: Figure 8 As shown; Figure 9 The stress-strain curve of the alloy wire was obtained, and its tensile strength (UTS) was measured to be 283.6 MPa, and its elongation (E1) was 5%. Figure 10 The image shows the three-dimensional morphology of the alloy wire after immersion in Hank's solution for 14 days using white light interference. The deepest corrosion pit is 12.7 μm deep.

[0080] Comparative Example 3

[0081] Preparation of Mg-1.5Al-0.5Mn-1La alloy fine wire:

[0082] (1) Batching: Weigh pure Mg ingots, Al ingots, Mg-Mn master alloy, Mg-La master alloy and Mg-Nd master alloy according to the proportions of Al 0.5wt.%, Mn 0.1wt.%, La 0.2wt.%, Nd 1.2wt.% and the balance being Mg; then melt the preheated Mg ingots, add Al ingots at 720 ℃ and stir mechanically for 8 minutes; then raise the temperature to 730 ℃, add the preheated Mg-La master alloy and Mg-Nd master alloy and stir for 8 minutes; let stand until the temperature drops to 690 ℃, add Mg-Mn master alloy and stir for 5 minutes to obtain the melt;

[0083] (2) Refining: The melt is refined at 730 ℃. After mechanical stirring for 10 minutes, it is allowed to stand and remove slag. Then, it is allowed to stand until the temperature drops to 710 ℃ before pouring the alloy liquid into a preheated mold to obtain an alloy ingot.

[0084] (3) Homogenization treatment: The obtained alloy ingot was homogenized at 300 °C for 12 hours and then processed into a cylindrical sample.

[0085] (4) Preparation of fine wire: The sample was heated from room temperature to 300 ℃ at a heating rate of 10 K / min, then heated to 450 ℃ at a heating rate of 5 K / min, and finally heated to 500 ℃ at a heating rate of 3 K / min, and held at 500 ℃ for 20 min. The temperature error range was ±5 ℃. Then, one extrusion was performed with an extrusion ratio of 600:1 and an extrusion speed of 0.2 mm / s to obtain alloy fine wire with a diameter of 1~2 mm.

[0086] The macroscopic morphology and microstructure of the fine filament are as follows: Figure 11 As shown; Figure 12 The stress-strain curve of the alloy wire was obtained, and its tensile strength (UTS) was measured to be 280.9 MPa, and its elongation (E1) was 9.2%. Figure 13 The image shows the three-dimensional morphology of the alloy wire after immersion in Hank's solution for 14 days using white light interference. The deepest corrosion pit is 28.3 μm deep.

[0087] In summary:

[0088] (1) The alloy of the present invention is based on Mg and is strengthened by adding trace amounts of Al, Mn, La and Nd elements in a synergistic manner, rather than by relying on high content and high cost of single rare earth elements. This design utilizes the synergistic effect of multiple components to refine the microstructure, weaken the texture, improve the strength and toughness and enhance the stability of the surface film. While significantly optimizing the overall performance of the material, it achieves good cost control and provides an ideal material basis for subsequent large deformation forming.

[0089] (2) To address the challenges of narrow hot working windows in magnesium alloys and the tendency for fine wires to break during traditional drawing, this invention abandons the multi-pass drawing process requiring frequent annealing. Instead, it employs a gradient heating strategy precisely matched to the alloy properties, directly forming the wires through single-pass hot extrusion with a large extrusion ratio (300:1~1200:1). This process significantly shortens the process time and improves efficiency. Furthermore, through precise control of parameters such as temperature and speed (e.g., reducing the extrusion speed as the alloy element content increases), it ensures the stability and surface quality of the forming process for fine wires with a diameter of 1~2mm.

[0090] (3) The results of the examples show that, through the synergistic optimization of the above-mentioned components and processes, the obtained wire has a uniform structure and few defects. Its tensile strength can reach up to 322.3 MPa, and its elongation can reach up to 50%, which far exceeds the strength-plasticity matching of conventional magnesium alloy wires and can meet the application scenarios with high requirements for load-bearing and deformation capacity.

[0091] (4) The addition of multiple trace elements effectively stabilized and strengthened the alloy surface film. Corrosion test results showed that after immersion in Hank's solution (simulating body fluid) for 14 days, the deepest corrosion pit on the surface of the wire could be controlled within approximately 12 μm, demonstrating its excellent corrosion resistance. This makes the wire a promising candidate for applications in fields with stringent requirements for corrosion resistance, such as biomedicine and marine environments.

[0092] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A magnesium alloy fine wire material possessing both high strength, ductility, and corrosion resistance, characterized in that, By weight percentage, it comprises the following components: Al 1.3%~1.8%, Mn 0.5%~0.9%, La 0.7%~1.1%, Nd 0.7%~1.1%, with the balance being Mg; The diameter of the magnesium alloy filament is 1~2 mm; The method for preparing the magnesium alloy fine wire with high strength, plasticity, and corrosion resistance includes the following steps: S1. Prepare the ingredients, then melt the prepared ingredients to obtain a melt; S2. Refine the melt, then let it stand to remove slag, and then let it stand until the temperature drops to the casting temperature, then cast to obtain an alloy ingot; S3. The alloy ingot is homogenized and then processed into a billet; S4. The billet is subjected to gradient heating to increase the temperature. After reaching the extrusion temperature, it is extruded once to obtain the magnesium alloy fine wire. The gradient heating process is as follows: the temperature is increased from room temperature to 300 ℃ at a heating rate of 10 K / min, then increased to 300~450 ℃ at a heating rate of 5 K / min, and finally increased to 450~500 ℃ at a heating rate of 3 K / min, and held at 500 ℃ for 20 min. The temperature error range is ±5 ℃. The parameters for the first extrusion are set as follows: extrusion speed is 0.1-0.3 mm / s, and extrusion ratio is 300:1~1200:

1.

2. A method for preparing the magnesium alloy fine wire with high strength, plasticity, and corrosion resistance as described in claim 1, characterized in that, Includes the following steps: S1. Prepare the ingredients, then melt the prepared ingredients to obtain a melt; S2. Refine the melt, then let it stand to remove slag, and then let it stand until the temperature drops to the casting temperature, then cast to obtain an alloy ingot; S3. The alloy ingot is homogenized and then processed into a billet; S4. The billet is subjected to gradient heating to increase the temperature. After reaching the extrusion temperature, it is extruded once to obtain the magnesium alloy fine wire. The gradient heating process is as follows: the temperature is increased from room temperature to 300 ℃ at a heating rate of 10 K / min, then increased to 300~450 ℃ at a heating rate of 5 K / min, and finally increased to 450~500 ℃ at a heating rate of 3 K / min, and held at 500 ℃ for 20 min. The temperature error range is ±5 ℃.

3. The preparation method according to claim 2, characterized in that, The refining temperature is 730~740 ℃, and the time is 8~10 min.

4. The preparation method according to claim 2, characterized in that, The casting temperature is 700~710 ℃.

5. The preparation method according to claim 2, characterized in that, The homogenization process is carried out at a temperature of 300-320°C for 12 hours.

6. The preparation method according to claim 2, characterized in that, The parameters for the first extrusion are set as follows: extrusion speed is 0.1-0.3 mm / s, and extrusion ratio is 300:1~1200:1.

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