Biomedical super-corrosion-resistant magnesium alloy wire and preparation method thereof
By adding Al, Y and Ca elements to the magnesium alloy wire, and performing large deformation extraction and heat treatment, the problem of excessive corrosion rate of magnesium alloy wire is solved, and uniform corrosion and high corrosion resistance of magnesium alloy wire is achieved, and it is suitable for the biomedical field.
Patent Information
- Application Number
- CN202510940375.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-08
- Publication Date
- 2025-08-29
AI Technical Summary
The corrosion rate of existing magnesium alloy wire materials is too fast in the biomedical field, unable to meet clinical requirements, and the corrosion is uneven, resulting in loss of mechanical properties and local inflammatory response.
By adding Al, Y and Ca elements, a dense aluminum hydroxide film and stable intermetallic compounds were formed, and combined with large deformation pulling and heat treatment, a biomedical ultra-corrosion magnesium alloy wire material was prepared to improve its corrosion resistance.
The corrosion rate of the prepared magnesium alloy wire material was significantly reduced in Hanks solution at 37℃, and the corrosion behavior was uniform, forming a dense corrosion product film, which significantly improved the corrosion resistance and mechanical properties of the magnesium alloy.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of magnesium alloy preparation, and in particular to a biomedical super corrosion-resistant magnesium alloy wire and a preparation method thereof. Background Art
[0002] In the 21st century, biodegradable metal materials have attracted widespread attention in the medical field. Magnesium alloys, in particular, have attracted increasing attention in the biomedical field due to their excellent biocompatibility, biodegradability, mechanical properties, and density and elastic modulus similar to human bone, becoming a research hotspot for biodegradable metal materials.
[0003] Currently, biodegradable magnesium alloys are primarily used in the manufacture of degradable bone screws, stents, and anastomotic staples. Degradable magnesium alloy stents and staples are a new type of medical device, primarily used for creating anastomotic stomas and closing stumps or incisions during surgery. The advantage of these staples lies in their biodegradability, which avoids the potential problems associated with long-term retention of staples made of inert materials such as titanium alloys, such as impaired medical imaging and increased inflammation. Magnesium alloys possess excellent mechanical properties, meeting the mechanical requirements of anastomotic staples during surgery, such as sufficient clamping force and strength to ensure anastomotic stability and healing. However, magnesium alloys are chemically active, with a low standard electrode potential. Furthermore, staples are primarily manufactured from wire, which has a larger surface area. This leads to a very rapid corrosion rate in vivo, making it unsuitable for clinical applications. Magnesium alloy wires, due to their high specific surface area, can completely corrode before the disease is resolved, resulting in a loss of mechanical properties. Furthermore, this rapid corrosion rate generates large amounts of hydrogen, which can cause local inflammation and other allergic reactions. Furthermore, the rapid and uneven corrosion rate of magnesium alloys limits their clinical application in load-bearing areas. Although high-purity magnesium has good corrosion resistance, its mechanical properties are poor compared to magnesium alloys and cannot meet the mechanical performance requirements of biological devices. Therefore, there is an urgent need to develop magnesium alloy wires with good corrosion resistance.
[0004] Therefore, how to improve the corrosion resistance of magnesium alloys has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention
[0005] The present invention provides a biomedical super corrosion-resistant magnesium alloy wire and a preparation method thereof, which are used to solve the problem of how to improve the corrosion resistance of the magnesium alloy.
[0006] In one aspect, the present invention provides a biomedical super-corrosion-resistant magnesium alloy wire comprising the following composition by weight: 6-11 wt% Al, 0.01-1.5 wt% Y, 0.01-1.5 wt% Ca, with the balance being Mg and unavoidable impurities. The unavoidable impurities include no more than 0.02 wt% Fe, no more than 0.004 wt% Ni, no more than 0.005 wt% Cu, and no more than 0.2 wt% Si.
[0007] In some embodiments, the magnesium alloy wire includes the following components in percentage by weight: Al 6-10 wt%, Y 0.01-1 wt%, Ca 0.01-1 wt%, and the balance is Mg and inevitable impurities, wherein the inevitable impurities include: Fe with a content not exceeding 0.005 wt%, Ni with a content not exceeding 0.001 wt%, Cu with a content not exceeding 0.001 wt%, and Si with a content not exceeding 0.15 wt%.
[0008] In some embodiments, the magnesium alloy wire comprises the following components in percentage by weight: Al 7-11 wt%, Y 0.02-1.5 wt%, Ca 0.02-1.5 wt%, and the balance is Mg and unavoidable impurities.
[0009] In some embodiments, the magnesium alloy wire includes the following components in percentage by weight: Al 7.36 wt%, Y 0.16 wt%, Ca 0.12 wt%, and inevitable impurities include: Fe 0.0036 wt%, Ni 0.0002 wt%, Cu 0.0001 wt%, Si 0.06 wt%, and the balance is Mg.
[0010] In some embodiments, the magnesium alloy wire includes the following components in percentage by weight: Al 9.25 wt%, Y 0.18 wt%, Ca 0.11 wt%, and unavoidable impurities include: Fe 0.0004 wt%, Ni 0.0010 wt%, Cu 0.0005 wt%, Si 0.13 wt%, and the balance is Mg.
[0011] In some embodiments, the magnesium alloy wire contains 6 wt %, 6.5 wt %, 7 wt %, 7.5 wt %, 8 wt %, 8.5 wt %, 9 wt %, 9.5 wt %, 10 wt % Al, or a range or sub-range between any two of these values.
[0012] In some embodiments, the magnesium alloy wire contains Y in an amount of 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, 0.7 wt%, 0.75 wt%, 0.8 wt%, 0.85 wt%, 0.9 wt%, 0.95 wt%, 1.0 wt%, or a range or sub-range between any two of these values.
[0013] In some embodiments, the magnesium alloy wire contains 0.01 wt %, 0.05 wt %, 0.1 wt %, 0.15 wt %, 0.2 wt %, 0.25 wt %, 0.3 wt %, 0.35 wt %, 0.4 wt %, 0.45 wt %, 0.5 wt %, 0.55 wt %, 0.6 wt %, 0.65 wt %, 0.7 wt %, 0.75 wt %, 0.8 wt %, 0.85 wt %, 0.9 wt %, 0.95 wt %, 1.0 wt % or a range or sub-range between any two of these values of Ca.
[0014] In some embodiments, the corrosion-resistant magnesium alloy is prepared into wire, and the diameter of the wire ranges from 0.3 mm to 1 mm.
[0015] It should be noted that the Al element can be oxidized to form a dense aluminum hydroxide film. Aluminum hydroxide can be deposited quickly, promoting the densification of the magnesium hydroxide film layer, and at the same time has passivation properties. The addition of an appropriate Al content can enhance the corrosion resistance of the magnesium matrix. Excessive Al addition will cause the alloy to become brittle and difficult to deform, and will impair the corrosion resistance. Y can improve the fluidity of magnesium alloys and reduce the tendency of hot cracking, thereby improving casting performance; it can also promote the formation of a more uniform and dense oxide film, which helps to improve the corrosion resistance of magnesium alloys; Y forms stable intermetallic compounds with elements such as iron and copper in magnesium alloys, reducing the harmful effects of these elements. Ca can react with iron to form insoluble compounds, reducing the solubility of iron, and can improve the casting performance and corrosion resistance of magnesium alloys.
[0016] On the other hand, the present invention also provides a method for preparing a biomedical super corrosion-resistant magnesium alloy wire, the preparation method comprising the following steps: S1: Calculate the mass of the required pure magnesium ingot, pure aluminum ingot, Mg-Y master alloy and Mg-Ca master alloy according to the mass fraction of each element in the magnesium alloy, and prepare the ingredients; S2: Under a protective gas, pure magnesium ingots, pure aluminum ingots, Mg-Y master alloys, and Mg-Ca master alloys are melted to obtain a magnesium alloy melt; S3: stirring, refining, standing and heat-insulating the magnesium alloy melt in sequence under a protective gas to obtain a purified magnesium alloy melt; S4: casting the purified magnesium alloy melt into a preheated mold under a protective gas to obtain a magnesium alloy ingot; S5: homogenizing the magnesium alloy ingot and extruding it to obtain a magnesium alloy wire with a diameter of 1 mm; S6: cold drawing the magnesium alloy wire with a diameter of 1 mm to obtain a wire with a diameter of less than 1 mm; S7: heat-treating the wire having a diameter of less than 1 mm to obtain a heat-treated super corrosion-resistant magnesium alloy wire, wherein the heat treatment includes aging treatment and / or solution treatment, and intermediate annealing treatment during drawing.
[0017] In some embodiments, the S2 includes: S21: Under the protection of SF6 and CO2 mixed gas, pure magnesium ingot is melted at 720℃, and then Mg-Ca master alloy is added at a temperature of 700-750℃ and kept warm for 20-30 minutes; S22: removing the slag on the surface of the melt obtained in step S21, adding pure aluminum ingots at 750°C, and spraying a layer of covering agent on the liquid surface. Preferably, the covering agent is RJ6; S23: After keeping the temperature for 20-30 minutes, remove the surface slag, add Mg-Y master alloy, stir for 3-5 minutes, and then keep the temperature at 750° C. for 20-30 minutes to obtain the magnesium alloy melt.
[0018] In some embodiments, in S3, the refining temperature is 720-740° C., the stirring time is 3-5 minutes, the standing temperature is 740-750° C., and the standing and heat preservation time is 30-50 minutes.
[0019] In some embodiments, in S4, the casting temperature is 690-720°C; In S5, the homogenization temperature is 350-420° C., the treatment time is 5-24 hours, the extrusion temperature is 350-420° C., the extrusion speed is 4-10 m / min, and the extrusion ratio is 600:1-1000:1.
[0020] In some embodiments, in S6, the deformation of a single pass of the cold drawing is 10%-90%; In the step S7, the aging treatment is performed at a temperature of 100-300° C. for a time of 6-74 hours; and the solution treatment is performed at a temperature of 380-445° C. for a time of 1-24 hours.
[0021] The present invention has the following beneficial effects: 1. The biomedical super corrosion-resistant magnesium alloy wire prepared in this application has a large number of fine grains formed due to large deformation drawing, and the wire has a dispersed second phase Mg 17 Al 12 During the corrosion process, it can promote the precipitation of Al on the corrosion interface and the rapid deposition of aluminum hydroxide. Aluminum hydroxide has a low solubility product Ksp=3.2×10 -34 , easier to precipitate. Ca can form stable compounds with harmful impurity elements such as Fe, Ni, and Cu in magnesium alloys, reducing the negative impact of these impurities on corrosion resistance, thereby improving the corrosion resistance of magnesium alloys. Ca reacts with Mg in Mg-Al alloys to form Mg2Ca phase. An appropriate amount of Ca can promote the refinement and uniform distribution of the second phase Mg2Ca, which is beneficial to grain refinement and microstructure homogenization, thereby improving the overall corrosion resistance of the alloy. In addition, the evenly distributed fine Mg2Ca particles can assist in the formation of a continuous and dense corrosion product film during the corrosion process, providing a barrier effect and inhibiting further corrosion. The addition of Ca not only affects the formation of the second phase, but also regulates the chemical composition of the surface natural oxide film and the corrosion product film. Ca can promote the formation of calcium-containing compounds such as CaO, Ca(OH)2, and CaCO3. These compounds interact with the oxides of Mg and Al to form a denser and more stable mixed protective film, thereby improving the ability to resist chloride ion corrosion. In addition, the Y element can act as a corrosion nucleation site to promote the nucleation of corrosion products and form a protective film; 2. The magnesium alloy wire of the present invention has the fastest weight loss corrosion rate of only 0.32 mg / cm after being immersed in Hanks solution at 37°C for 7 days. 2 / day, the corrosion rate is significantly lower than that of high-purity magnesium wire, and the corrosion behavior of the magnesium alloy wire of the present invention is ideal uniform corrosion. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 This is the SEM micrograph of the biomedical corrosion-resistant magnesium alloy wire in Example 2 of the present application; Figure 2 The cross-sectional SEM and surface scanning distribution images of the biomedical corrosion-resistant magnesium alloy wire in Example 2 of the present application after being corroded in Hanks solution at 37°C for 7 days; Figure 3 This is a cross-sectional SEM image of the corrosion product of the high-purity magnesium wire after corrosion in Comparative Example 1 of the present application; Figure 4 The weight loss and hydrogen evolution rate of the biomedical corrosion-resistant magnesium alloy wire in Example 2 of the present application when immersed in Hanks solution at 37°C; Figure 5 This is a surface morphology of the biomedical corrosion-resistant magnesium alloy wire in Example 2 of the present application after being immersed in Hanks solution at 37°C for 7 days; Figure 6 This is a surface morphology of the biomedical corrosion-resistant magnesium alloy wire in Example 2 of the present application after cleaning the corrosion products in Hanks solution at 37°C. DETAILED DESCRIPTION
[0023] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0024] Unless otherwise indicated, implied from the context, or customary in the art, all parts and percentages in this application are based on weight, and the test and characterization methods used are current as of the filing date of this application. Where applicable, the contents of any patents, patent applications, or publications referred to in this application are incorporated herein by reference in their entirety, and their equivalent patent families are also incorporated by reference. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in this application, the definition of the term provided in this application shall prevail.
[0025] Numerical ranges in this application are approximate values, so unless otherwise stated, they may include numerical values outside the range. Numerical ranges include all numerical values from the lower limit to the upper limit increased by 1 unit, provided that there is an interval of at least 2 units between any lower value and any higher value. For example, if the recorded component, physical or other properties (such as molecular weight, melt index, etc.) are 100 to 1000, it is meant that all individual numerical values are clearly enumerated, such as 100, 101, 102, etc., and all subranges, such as 100 to 166, 155 to 170, 198 to 200, etc. For a range comprising a numerical value less than 1 or comprising a fraction greater than 1 (such as 1.1, 1.5, etc.), 1 unit is appropriately considered to be 0.0001, 0.001, 0.01 or 0.1. For a range comprising a single digit less than 10 (such as 1 to 5), 1 unit is typically considered to be 0.1. These are merely specific examples of what is intended, and all possible combinations of values between the lowest and highest values recited are considered to be expressly stated in this application. It should also be noted that the terms "first," "second," etc. herein do not limit the order of precedence, but are only used to distinguish substances of different structures.
[0026] When used with respect to chemical compounds, unless expressly stated otherwise, the singular includes all isomeric forms, and vice versa. In addition, unless expressly stated otherwise, nouns using "a," "an," or "the" also include their plural forms.
[0027] The terms "comprising", "including", "having" and their derivatives do not exclude the presence of any other components, steps or processes and are irrelevant to whether these other components, steps or processes are disclosed in this application. To eliminate any doubt, all compositions using the terms "comprising", "including", or "having" in this application may include any additional additives, excipients or compounds unless expressly stated otherwise. In contrast, the term "essentially consisting of" excludes any other components, steps or processes from the scope of any description of the term below, except those necessary for operational performance. The term "consisting of" does not include any components, steps or processes that are not specifically described or listed. Unless expressly stated otherwise, the term "or" refers to the listed members alone or in any combination thereof.
[0028] Examples 1-7 The seven embodiments of the biomedical corrosion-resistant magnesium alloy wire of the present invention, the composition contents of the magnesium alloy wire of embodiments 1-7 are shown in Table 1: Table 1 Composition and content of magnesium alloy wires of Examples 1-7
[0029] Example 1 A method for preparing a biomedical super corrosion-resistant magnesium alloy wire comprises the following steps: S1: Taking 20kg alloy as an example, calculate the required mass of various raw materials according to the composition ratio of magnesium alloy and make batching; S2: Under the protection of SF6 and CO2 mixed gas, first melt the pure magnesium ingot at 720℃, heat it to 750℃ and add the prepared Mg-Ca master alloy, then keep it warm for 20-30 minutes, remove the slag on the surface of the melt, add the pure aluminum ingot, and sprinkle a layer of covering agent, keep it warm for 20-30 minutes, remove the surface slag, add the Mg-Y master alloy, stir it for 3-5 minutes, and keep it warm at 750℃ for 20-30 minutes to obtain a magnesium alloy melt; S3: Under protective gas, refining is carried out at 730°C with vigorous stirring for 3-5 minutes, and then the furnace temperature is raised to 750°C and kept at this temperature for 30-50 minutes to obtain a magnesium alloy melt; S4: Under protective gas, the furnace temperature is lowered to 710°C, the slag on the surface of the melt is scraped off, and the magnesium alloy melt is cast into a preheated mold to obtain a magnesium alloy ingot; S5: placing the obtained magnesium alloy ingot in an air furnace and homogenizing it at 380° C. for 10 hours, then hot-extruding the magnesium alloy ingot at 380° C. at an extrusion ratio of 610:1, and flowing out a profile at an extrusion rate of 4 m / min to obtain a magnesium alloy wire with a diameter of 1 mm; S6: performing heat treatment on the obtained magnesium alloy wire, wherein the heat treatment adopts aging treatment, the aging treatment temperature is 250° C., and the aging treatment time is 24 hours.
[0030] Example 2 A method for preparing a biomedical super corrosion-resistant magnesium alloy wire comprises the following steps: Steps S1-S5 are the same as those in Example 1.
[0031] S6: The obtained extruded magnesium alloy wire is cold drawn and intermediate annealed. The deformation of the cold drawing process is 30% per single pass. The heat treatment temperature is 380°C and the temperature is kept at 10 minutes. Finally, an ultra-corrosion-resistant magnesium alloy wire with a diameter of 0.3 mm is obtained. The wire is then subjected to secondary heat treatment. The secondary heat treatment process is solution treatment plus aging treatment: the solution treatment temperature is 420°C and the solution treatment time is 6 hours; the aging treatment temperature is 250°C and the time is 24 hours.
[0032] Example 3 A method for preparing a biomedical super corrosion-resistant magnesium alloy wire comprises the following steps: Steps S1-S5 are the same as those in Example 1.
[0033] S6: The obtained extruded magnesium alloy wire is subjected to cold drawing and intermediate annealing treatment, the cold drawing single-pass deformation is 25%, the heat treatment temperature is 380°C, and the insulation is 10 minutes, and finally a super corrosion-resistant magnesium alloy wire with a diameter of 0.5 mm is obtained; the obtained super corrosion-resistant magnesium alloy wire is subjected to secondary heat treatment, the secondary heat treatment process is aging treatment, the aging treatment temperature is 180°C, and the aging treatment time is 48 hours, and finally a super corrosion-resistant magnesium alloy wire is obtained.
[0034] Example 4 A method for preparing a biomedical super corrosion-resistant magnesium alloy wire comprises the following steps: Steps S1-S5 are the same as those in Example 1.
[0035] The difference from embodiment 1 is that there is no step S6.
[0036] The preparation methods of the biomedical super corrosion-resistant magnesium alloy wires of Examples 5-7 are the same as the preparation method of Example 2.
[0037] Comparative Example 1 Pure magnesium wire was purchased directly from the market and contained the following composition by weight: 99.99 wt % Mg, with the remainder being inevitable impurity elements.
[0038] Effect Example 1 The magnesium alloy wires of Examples 1-4 and the pure magnesium wire of Comparative Example 1 were subjected to corrosion performance tests.
[0039] The specific test method is as follows: the test solution is a neutral Hanks solution (Biyuntian C0218), the test temperature is 37°C, three parallel samples are tested, the weight loss size is Φ0.3mm×L10cm, and the test time is 7 days. The weight loss rate test results of Examples 1-4 and Comparative Example 1 are shown in Table 2.
[0040] Table 2 Weight loss rate of Examples 1-4 and Comparative Example 1
[0041] As can be seen from Table 1, the weight loss rate of the corrosion-resistant magnesium alloy wire of the present application after being tested in Hanks solution at 37°C for 7 days is as low as 0.25 mg / cm 2 / day, the corrosion rate can be characterized by the weight loss rate. The weight loss rates of Examples 1-3 are all lower than the weight loss rate of the high-purity magnesium wire in Comparative Example 1. It can be seen that the corrosion resistance of the magnesium alloy wire of the present application is significantly better than that of the high-purity magnesium wire in Comparative Example 1.
[0042] Figure 1 This is the SEM microstructure of the corrosion-resistant magnesium alloy wire in Example 2. It can be seen that after drawing, the finely dispersed β-Mg 17 Al 12 The second phase is evenly distributed throughout the magnesium matrix, rather than along the drawing direction, and β-Mg 17 Al 12 The second phase acts as a corrosion barrier, hindering the corrosion of the magnesium alloy matrix and improving the corrosion resistance of the magnesium alloy.
[0043] Figure 2 The cross-sectional SEM morphology and surface scanning element distribution map of the corrosion-resistant magnesium alloy wire in Example 2 after being tested in Hanks solution at 37°C for 7 days. It can be seen that the corrosion product film of the corrosion-resistant magnesium alloy is uniform in thickness, indicating that the corrosion behavior is uniform corrosion. From the surface scanning element distribution map, it can be seen that the corrosion product film of the super-corrosion-resistant magnesium alloy wire is mainly composed of Mg, Al, and O elements, which indicates that in addition to the basic Mg(OH)2 and MgO, the corrosion product film also contains a large amount of Al elements, including Al(OH)3 and Al2O3. Therefore, the corrosion product film composed of Al(OH)3, Al2O3, Mg(OH)2 and MgO makes the corrosion-resistant magnesium alloy wire have a denser corrosion product film, thereby exhibiting excellent corrosion resistance.
[0044] Figure 3 This is a cross-sectional SEM image of the corrosion product of the high-purity magnesium alloy wire in Comparative Example 1 after being tested in Hanks solution at 37°C for 7 days. It can be seen that the corrosion product formed by the high-purity magnesium alloy wire in Comparative Example 1 is very loose and cracked, and the corrosion product film is very uneven.
[0045] Figure 4 The weight loss and hydrogen evolution rate of the corrosion-resistant magnesium alloy wire in Example 2 of the present application after being immersed in Hanks solution at 37°C for 7 days. It can be seen that the corrosion weight loss rate of the super corrosion-resistant magnesium alloy wire of the present application after being immersed for 7 days is 0.30 mg / cm 2 / day, with good corrosion resistance.
[0046] Figure 5 This is the surface corrosion morphology of the super corrosion-resistant magnesium alloy wire in Example 2 after being tested in Hanks solution at 37°C for 7 days. It can be seen that the corrosion product film is very uniform and dense.
[0047] Figure 6 This is the surface of the magnesium substrate after the corrosion product film was cleaned after the super-corrosion-resistant magnesium alloy wire was corroded in Hanks solution at 37°C for 7 days in Example 2. It can be seen that the magnesium substrate surface is very flat, without pitting, and has a uniform corrosion morphology.
[0048] In summary, the super corrosion-resistant magnesium alloy wire of the present application has excellent corrosion resistance.
[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.
Claims
1. A biomedical super corrosion-resistant magnesium alloy wire, characterized in that: The magnesium alloy wire comprises the following components in percentage by mass: Al 6-11 wt%, Y 0.01-1.5 wt%, Ca 0.01-1.5 wt%, and the balance is Mg and inevitable impurities.
2. The biomedical super corrosion-resistant magnesium alloy wire according to claim 1, characterized in that: The magnesium alloy wire comprises the following components in percentage by mass: Al 6-10 wt%, Y 0.01-1 wt%, Ca 0.01-1 wt%, and the balance is Mg and inevitable impurities.
3. The biomedical super corrosion-resistant magnesium alloy wire according to claim 1, characterized in that: The magnesium alloy wire comprises the following components in percentage by weight: Al 7-11 wt%, Y 0.02-1.5 wt%, Ca 0.02-1.5 wt%, and the balance is Mg and inevitable impurities.
4. The biomedical super corrosion-resistant magnesium alloy wire according to claim 1, characterized in that: The magnesium alloy wire comprises the following components in percentage by mass: Al 7.36 wt%, Y 0.16 wt%, Ca 0.12 wt%, and inevitable impurities include: Fe 0.0036 wt%, Ni 0.0002 wt%, Cu 0.0001 wt%, Si 0.06 wt%, and the balance is Mg.
5. The biomedical super corrosion-resistant magnesium alloy wire according to claim 1, characterized in that: The magnesium alloy wire comprises the following components in percentage by mass: Al 9.25 wt%, Y 0.18 wt%, Ca 0.11 wt%, and inevitable impurities include: Fe 0.0004 wt%, Ni 0.0010 wt%, Cu 0.0005 wt%, Si 0.13 wt%, and the balance is Mg.
6. A method for preparing the biomedical super corrosion-resistant magnesium alloy wire according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: S1: Calculate the mass of the required pure magnesium ingot, pure aluminum ingot, Mg-Y master alloy and Mg-Ca master alloy according to the mass fraction of each element in the magnesium alloy, and prepare the ingredients; S2: Under a protective gas, pure magnesium ingots, pure aluminum ingots, Mg-Y master alloys, and Mg-Ca master alloys are melted to obtain a magnesium alloy melt; S3: stirring, refining, standing and heat-insulating the magnesium alloy melt in sequence under a protective gas to obtain a purified magnesium alloy melt; S4: casting the purified magnesium alloy melt into a preheated mold under a protective gas to obtain a magnesium alloy ingot; S5: homogenizing the magnesium alloy ingot and extruding it to obtain a magnesium alloy wire with a diameter of 1 mm; S6: cold drawing the magnesium alloy wire with a diameter of 1 mm to obtain a wire with a diameter of less than 1 mm; S7: heat-treating the wire having a diameter of less than 1 mm to obtain a heat-treated super corrosion-resistant magnesium alloy wire, wherein the heat treatment includes aging treatment and / or solution treatment, and intermediate annealing treatment during drawing.
7. The method for preparing biomedical super corrosion-resistant magnesium alloy wire according to claim 6, characterized in that: The S2 includes: S21: Under the protection of SF6 and CO2 mixed gas, pure magnesium ingot is melted at 720℃, and then Mg-Ca master alloy is added at a temperature of 700-750℃ and kept warm for 20-30 minutes; S22: removing the slag on the surface of the melt obtained in step S21, adding pure aluminum ingots at 750°C, and spraying a layer of covering agent on the liquid surface; S23: After keeping the temperature for 20-30 minutes, remove the surface slag, add Mg-Y master alloy, stir for 3-5 minutes, and then keep the temperature at 750° C. for 20-30 minutes to obtain the magnesium alloy melt.
8. The method for preparing a biomedical super corrosion-resistant magnesium alloy according to claim 6, wherein: In S3, the refining temperature is 720-740° C., the stirring time is 3-5 minutes, the standing temperature is 740-750° C., and the standing and heat preservation time is 30-50 minutes.
9. The method for preparing a biomedical super corrosion-resistant magnesium alloy according to claim 6, wherein: In said S4, the casting temperature is 690-720°C; In S5, the homogenization temperature is 350-420° C., the treatment time is 5-24 hours, the extrusion temperature is 350-420° C., the extrusion speed is 4-10 m / min, and the extrusion ratio is 600:1-1000:
1.
10. The method for preparing a biomedical super corrosion-resistant magnesium alloy according to claim 6, characterized in that: In S6, the deformation of a single pass of the cold drawing is 10%-90%; In the step S7, the aging treatment is performed at a temperature of 100-300° C. for a time of 6-74 hours; and the solution treatment is performed at a temperature of 380-445° C. for a time of 1-24 hours.