A method of regulating the degradation rate of a biomagnesium alloy in the urinary system

Abstract

The application provides a method for regulating degradation rate of biomagnesium alloy in urinary system. The method comprises the following steps: S1, melting magnesium alloy raw material under protective atmosphere to obtain magnesium alloy ingot; S2, homogenizing the magnesium alloy ingot under inert atmosphere to obtain base material after cooling; S3, stirring friction processing the base material to obtain biomagnesium alloy with predetermined size, wherein the magnesium alloy raw material is composed of the following components by weight percentage: Y: 2-3 wt.%, Nd: 1-2 wt.%, Gd: 0-1 wt.%, Zn: 0-1 wt.%, Ca: 0-1 wt.%, Sr: 0-1 wt.%, and the balance is magnesium and impurity elements. The method can regulate the degradation rate of biomagnesium alloy in urinary system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical materials, in particular to a method for regulating the degradation rate of a biologic magnesium alloy in the urinary system. BACKGROUND

[0002] Magnesium alloys have low density, high specific strength, specific stiffness, and good biocompatibility, and have broad application prospects in traditional industries and biomedical fields. In recent years, magnesium alloys as degradable biomaterials have shown great application potential in orthopedics, cardiovascular system, and urinary system. However, due to the strong activity and poor corrosion resistance of magnesium alloys, the degradation rate is too fast and the degradation process is uneven during application, which greatly limits the development of magnesium alloys in the biological field. In different application environments, the ideal degradation time of the implanted material also has great differences. For example, the demand for magnesium alloy degradation rate in the urinary system, such as ureteral stents, is relatively short (2-4 weeks to complete degradation) compared to orthopedics and cardiovascular system, and the degradation rate of implanted materials also varies with the age of the patient. Therefore, the controllability of the degradation rate of biologic magnesium alloy in the urinary system is of great significance for its subsequent application. SUMMARY

[0003] The present application aims to at least partially solve one of the problems in the related art. The purpose of the present application is to provide a method for regulating the degradation rate of a biologic magnesium alloy in the urinary system.

[0004] Specifically, the present application provides the following technical solutions:

[0005] In a first aspect of the present application, a method for regulating the degradation rate of a biologic magnesium alloy in the urinary system is provided, comprising:

[0006] S1: Melting the magnesium alloy raw material under a protective atmosphere to obtain a magnesium alloy ingot;

[0007] The magnesium alloy raw material is composed of the following components by weight percentage: Y (yttrium): 2-3 wt.%, Nd (neodymium): 1-2 wt.%, Gd: 0-1 wt.%, Zn: 0-1 wt.%, Ca: 0-1 wt.%, Sr (strontium): 0-1 wt.%, and the balance being magnesium and other impurity elements;

[0008] S2: Homogenizing heat treatment of the magnesium alloy ingot under an inert atmosphere, and cooling to obtain a base material;

[0009] S3: Stir friction processing of the base material to obtain a biologic magnesium alloy of a predetermined size.

[0010] The method provided by the present application can regulate the degradation rate of the biologic magnesium alloy.

[0011] According to the embodiments of the present application, the method for regulating the degradation rate of the biodegradable magnesium alloy in the urinary system can further comprise the following technical features:

[0012] In some embodiments of the present application, the protective atmosphere in step S1 is a mixture of CO2 and SF6.

[0013] In some embodiments of the present application, the volume ratio of the CO2 and the SF6 is (95-99):(1-5). According to a preferred embodiment, the protective atmosphere in step S1 is a mixture of CO2 and SF6, and the volume ratio is 99:1.

[0014] In some embodiments of the present application, the magnesium alloy raw material comprises the following raw materials: intermediate alloy Mg-30wt.%Y, intermediate alloy Mg-30wt.%Nd, intermediate alloy Mg-30wt.%Gd, intermediate alloy Mg-20wt.%Sr, pure Mg, pure Zn and pure Ca raw material.

[0015] In some embodiments of the present application, the temperature of the melting treatment is 650-750℃, and the time of the melting treatment is 10-30 minutes.

[0016] In some embodiments of the present application, the composition homogenization heat treatment in step S2 is carried out under the protection of argon atmosphere. According to a specific embodiment, the temperature of the heat treatment is 300℃-450℃, and the time is 12-24h.

[0017] In some embodiments of the present application, in step S3, the stir head used in the friction stir processing treatment is tungsten-rhenium alloy.

[0018] In some embodiments of the present application, in step S3, the forward speed of the stir head used in the friction stir processing treatment is 10-200mm / min.

[0019] In some embodiments of the present application, in step S3, the rotation speed of the stir head used in the friction stir processing is 100-1500r / min.

[0020] In some embodiments of the present application, in the artificial urine environment, the corrosion current density of the biodegradable magnesium alloy is 10-500μA / cm 2 , and the degradation rate is 0.5-40mm / y.

[0021] In the second aspect of the present application, a method for preparing a biodegradable magnesium alloy for the urinary system is provided, comprising:

[0022] S1: smelting the magnesium alloy raw material under a protective atmosphere to obtain a magnesium alloy ingot;

[0023] The magnesium alloy raw material comprises Y: 2-3 wt.%, Nd: 1-2 wt.%, Gd: 0-1 wt.%, Zn: 0-1 wt.%, Ca: 0-1 wt.%, Sr: 0-1 wt.%, and the balance of magnesium and other impurity elements;

[0024] S2: uniformly heat-treating the magnesium alloy ingot under an inert atmosphere to obtain a base material after cooling;

[0025] S3: performing friction stir processing on the base material to obtain a biological magnesium alloy with a predetermined size.

[0026] In a third aspect of the present application, a biological magnesium alloy is provided, which is prepared by the method according to any one of the first aspect or the second aspect.

[0027] In a fourth aspect of the present application, the use of the biological magnesium alloy according to the third aspect in the preparation of a biomaterial for the urinary system is provided.

[0028] The technical solution of the present application at least has the following beneficial effects:

[0029] The present application provides a preparation and processing method for adjusting the degradation rate of magnesium alloy in the urinary system by synergistic adjustment of the component, ratio and key process parameters of the processing method, rational design of alloy elements with good biocompatibility, and fine regulation and control of the microstructure of the prepared magnesium alloy by using friction stir processing technology. The specific advantages are as follows:

[0030] The element composition and content added in the magnesium alloy raw material used in the present application are in line with and fully meet the international requirements for biomedical implant materials, have good biological safety and biocompatibility, the alloy element content is controlled to be below 8 wt.%, and the rare earth element addition amount is controlled to be below 6 wt.%.

[0031] The preparation method provided by the present application includes friction stir processing technology, which can realize fine regulation and control of the microstructure of the magnesium alloy after casting, and through the regulation and modification of the grain size, element solid solubility in the matrix, precipitate size and distribution of the prepared magnesium alloy, the degradation rate of the biological magnesium alloy is realized. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is the surface SEM morphology diagram of the magnesium alloy base material prepared in Example 1 of the present application and the biological magnesium alloy sample after friction stir processing (FSP).

[0033] Figure 2are the polarization curve test results of the magnesium alloy base material and the friction stir processed biological magnesium alloy sample prepared in Example 2 of the present application in artificial urine.

[0034] Figure 3 are the hydrogen evolution test results of the magnesium alloy base material and the friction stir processed biological magnesium alloy sample prepared in Example 4 of the present application during the degradation process in artificial urine.

[0035] Figure 4 are the surface SEM morphology diagrams of the magnesium alloy base material and the friction stir processed biological magnesium alloy sample prepared in Example 5 of the present application after long-term degradation in artificial urine.

[0036] Figure 5 is a degradation rate histogram of the biological magnesium alloy sample prepared in different examples of the present application in artificial urine. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, the embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0038] The present application proposes a preparation and processing method for regulating the degradation rate of biological magnesium alloy in the urinary system, which comprises:

[0039] [Step S1] Melting of magnesium alloy

[0040] In this step, the magnesium alloy raw material is supplied to the resistance furnace for melting, wherein the magnesium alloy raw material is configured according to the following mass percentage ratio: Y: 2-3wt.%, Nd: 1-2wt.%, Gd: 0-1wt.%, Zn: 0-1wt.%, Ca: 0-1wt.%, Sr: 0-1wt.%, and the balance is magnesium and impurity elements. The inventors found that the introduction of a small amount of rare earth elements can effectively improve the mechanical strength of the magnesium alloy, and at the same time will not be toxic to the living body, and zinc and calcium elements are essential elements for the human body, and through rational design, the magnesium alloy system realizes the ideal degradation behavior and has good biocompatibility. According to the specific embodiments, the content of Zn is not 0, preferably 0.3-0.8wt%. According to the specific embodiments, the content of Ca is not 0, preferably 0.3-0.8wt%. According to the specific embodiments, the content of Gd is not 0, preferably 0.5-1wt%. According to the specific embodiments, the content of Sr is not 0, preferably 0.5-1wt%.

[0041] The "impurity elements" mentioned refer to other chemical elements inevitably present in the biological magnesium alloy. They include but are not limited to iron (Fe), nickel (Ni), aluminum (Al), manganese (Mn), copper (Cu), etc. The presence of impurity elements usually affects the corrosion ability and mechanical properties of the biological magnesium alloy. The content of impurity elements should be controlled at a very small amount, for example, the total content of impurity elements should be controlled at less than 0.1%. According to specific embodiments, the content of impurity elements of the biological magnesium alloy should meet the standards and specifications in the field. For example, the content of impurity elements of the biological magnesium alloy for medical use usually needs to meet specific standards and specifications, such as iron should not exceed 45 ppm, nickel should not exceed 280 ppm, etc. In addition, for impurity elements for which no limit value is specified, if the content is greater than 0.010%, it should be included in the total impurities, etc.

[0042] Specifically, Y, Nd, Gd, and Sr can be added in the form of intermediate alloy, and Zn and Ca are added in the form of single element. According to specific embodiments, the intermediate alloys Mg-30wt.% Y, Mg-30wt.% Nd, Mg-30wt.% Gd, Mg-20wt.% Sr, pure Mg, pure Zn, and pure Ca raw materials are proportioned and placed in an alumina crucible, and are placed in a resistance furnace, heated to 650-750℃ under a protective atmosphere, and the holding time is 10-30min, to obtain a magnesium alloy ingot sample. In this paper, pure in pure Mg, pure Z, and pure Ca refers to a content of more than 99.9%; according to preferred embodiments, the content of pure Mg is more than 99.99%, the content of pure Zn is more than 99.9%, and the content of pure Ca is more than 99.9%.

[0043] According to specific embodiments, the temperature range of the resistance furnace is 650-750℃, and the holding time is 10-30min.

[0044] According to specific embodiments, the protective atmosphere in step S1 is a mixed gas of CO2 and SF6, and the volume fraction ratio is 99:1.

[0045] [Step S2] homogenization treatment

[0046] In this step, the magnesium alloy ingot obtained in S1 is subjected to homogenization heat treatment under an argon protective atmosphere to improve the microstructure and properties of the cast alloy.

[0047] According to specific embodiments, the heat treatment temperature in step S2 is 300℃-450℃, and the time is 12-24h.

[0048] After homogenization heat treatment, the substrate material is cooled to room temperature.

[0049] [Step S3] friction stir processing

[0050] The obtained base material is subjected to friction stir processing treatment, and the microstructure of the base material is finely modified. Through modification of the grain size, the solid solubility of elements in the base material, the size and distribution of precipitated phases in the prepared magnesium alloy, the degradation rate of the biological magnesium alloy is adjusted.

[0051] In this step, the surface of the magnesium-rare earth alloy is polished to remove the oxide scale on the surface, and then the magnesium alloy is processed. The material of the stirring head in the processing process is tungsten-rhenium alloy, and the size of the stirring head is: shoulder diameter 15 mm, stirring needle diameter 6 mm, and stirring needle length 2.4 mm.

[0052] In some embodiments, the rotation speed of the stirring head used in the friction stir processing in step S3 is 100-1500 r / min, and the forward speed is 10-200 mm / min.

[0053] According to the embodiments of the present application, through the design of the components of the biological magnesium alloy and the subsequent processing, the degradation rate can be widely adjusted. Therefore, the corrosion current density of the prepared alloy in the artificial urine environment is 10-500 μA / cm 2 , and the degradation rate is 0.5-40 mm / y, which can meet the different needs of the ureteral stent implantation materials in the urinary system and achieve reasonable adjustment.

[0054] The technical solutions of the present application will be described below through specific embodiments. It should be noted that these embodiments are only used to facilitate the understanding of those skilled in the art, and should not be regarded as a limitation on the protection scope of the present application. Unless otherwise specified, the reagents or raw materials used in the embodiments can be obtained by commercial purchase.

[0055] Example 1

[0056] Example 1 provides a method for adjusting the degradation rate of a biological magnesium alloy in the urinary system, which specifically comprises the following steps:

[0057] S1, melting of the magnesium alloy: the magnesium alloy raw material is supplied to the resistance furnace for melting, wherein the magnesium alloy raw material is configured according to the following mass percentage: Y: 3wt.%, Nd: 1wt.%, Gd: 1wt.%, Zn: 0.5wt.%, Ca: 0.5wt.%, and the balance is Mg and other impurity elements. The raw material is placed in a ceramic crucible, and the temperature of the resistance furnace is raised to 680℃ under the protection of a mixed gas atmosphere of 99% CO2-1% SF6. After holding for 30 min, the magnesium alloy ingot is taken out after furnace cooling.

[0058] S2, homogenization treatment: the magnesium alloy ingot is subjected to composition homogenization heat treatment under the protection of an argon atmosphere, the heat treatment temperature is 450 DEG C, the time is 12h, the treated ingot is cooled to room temperature in the furnace, and a base material is obtained.

[0059] S3, processing procedure: the homogenized base material is first cut into a plate with a size of 200mmx65mmx4mm using a wire cutting, then the magnesium-rare earth alloy plate is polished to remove the oxide skin on the surface of the magnesium alloy, then the magnesium alloy plate is subjected to friction stir processing treatment, the material of the stirring head is tungsten-rhenium alloy, the size of the stirring head is: shoulder diameter 15mm, stirring needle diameter 6mm, stirring needle length 2.4mm. The stirring head rotation speed is 100rpm, the forward speed is 50mm / min, and then a magnesium alloy sample after friction stir processing is obtained.

[0060] Example 2

[0061] Example 2 provides a method for regulating the degradation rate of a biological magnesium alloy in the urinary system, specifically comprising the following steps:

[0062] S1, melting of the magnesium alloy: the magnesium alloy raw material is fed into a resistance furnace for melting, wherein the magnesium alloy raw material is configured according to the following mass percentage: Y: 3wt.%, Nd: 1wt.%, Gd: 1wt.%, Sr: 1wt.%, and the balance is Mg and other impurity elements. The raw material is placed in a ceramic crucible, the temperature of the resistance furnace is raised to 660 DEG C under the protection of a mixed gas atmosphere of 99% CO2-1% SF6, and the temperature is maintained for 30min. The magnesium alloy ingot is taken out after the furnace is cooled.

[0063] S2, homogenization treatment: the magnesium alloy ingot is subjected to composition homogenization heat treatment under the protection of an argon atmosphere, the heat treatment temperature is 400 DEG C, the time is 12h, the treated ingot is cooled to room temperature in the furnace, and a base material is obtained.

[0064] S3, processing procedure: the homogenized base material is first cut into a plate with a size of 200mmx65mmx4mm using a wire cutting, then the magnesium-rare earth alloy plate is polished to remove the oxide skin on the surface of the magnesium alloy, then the magnesium alloy plate is subjected to friction stir processing treatment, the material of the stirring head is tungsten-rhenium alloy, the size of the stirring head is: shoulder diameter 15mm, stirring needle diameter 6mm, stirring needle length 2.4mm. The stirring head rotation speed is 500rpm, the forward speed is 50mm / min, and then a magnesium alloy sample after friction stir processing is obtained.

[0065] Example 3

[0066] Example 3 provides a method for regulating the degradation rate of a biological magnesium alloy in the urinary system, specifically comprising the following steps:

[0067] S1, Smelting of magnesium alloy: magnesium alloy raw materials are supplied to a resistance furnace for smelting, wherein the magnesium alloy raw materials are configured according to the following mass percentage ratio: Y: 3wt.%, Nd: 1wt.%, Gd: 1wt.%, Zn: 1wt.%, Ca: 1wt.%, Sr: 0.5wt.%, and the balance of Mg and other impurity elements. The raw materials are placed in a ceramic crucible, and the temperature of the resistance furnace is raised to 750°C under the protection of a mixed gas atmosphere of 99% CO2-1% SF6, and the temperature is maintained for 10 min. After the furnace is cooled down, the magnesium alloy ingot is taken out.

[0068] S2, Homogenization treatment: the magnesium alloy ingot is subjected to composition homogenization heat treatment under the protection of an argon atmosphere, the heat treatment temperature is 420°C, and the time is 24 h. The treated ingot is cooled to room temperature in the furnace to obtain a base material.

[0069] S3, Processing: the homogenized base material is first cut into a size of 200mm x 65mm x 4mm plate using a wire cutting, and then the magnesium-rare earth alloy plate is polished to remove the oxide skin on the surface of the magnesium alloy. The magnesium alloy plate is then subjected to friction stir processing treatment, the stir head is made of tungsten-rhenium alloy, the stir head size is: shoulder diameter 15mm, stir pin diameter 6mm, and stir pin length 2.4mm. The stir head speed is 300rpm, and the forward speed is 100mm / min. Then the magnesium alloy sample after friction stir processing is obtained.

[0070] Example 4

[0071] Example 4 provides a method for regulating the degradation rate of a biological magnesium alloy in the urinary system, specifically comprising the following steps:

[0072] S1, Smelting of magnesium alloy: magnesium alloy raw materials are supplied to a resistance furnace for smelting, wherein the magnesium alloy raw materials are configured according to the following mass percentage ratio: Y: 3wt.%, Nd: 1wt.%, Gd: 1wt.%, Ca: 1wt.%, and the balance of Mg and other impurity elements. The raw materials are placed in a ceramic crucible, and the temperature of the resistance furnace is raised to 720°C under the protection of a mixed gas atmosphere of 99% CO2-1% SF6, and the temperature is maintained for 30 min. After the furnace is cooled down, the magnesium alloy ingot is taken out.

[0073] S2, Homogenization treatment: the magnesium alloy is subjected to composition homogenization heat treatment under the protection of an argon atmosphere, the heat treatment temperature is 450°C, and the time is 12 h. The treated ingot is cooled to room temperature in the furnace to obtain a base material.

[0074] S3, Processing Procedure: First, the homogenized matrix material is cut into 200mm×65mm×4mm plates using wire EDM. Then, the magnesium-rare earth alloy plates are surface-polished to remove the oxide scale. Next, the magnesium alloy plates undergo friction stir processing. The stirring head is made of tungsten-rhenium alloy, and its dimensions are: shoulder diameter 15mm, stirring pin diameter 6mm, and stirring pin length 2.4mm. The stirring head rotates at 800rpm, and the forward speed is 50mm / min. The resulting magnesium alloy sample is then obtained after friction stir processing.

[0075] Example 5

[0076] Example 5 provides a method for regulating the degradation rate of bio-magnesium alloys in the urinary system, specifically including the following steps:

[0077] S1, Smelting of Magnesium Alloy: The smelting raw materials are fed into an electric resistance furnace for smelting. The raw materials are prepared according to the following mass percentage ratio: Y: 3 wt.%, Nd: 1 wt.%, Gd: 1 wt.%, Zn: 1 wt.%, Ca: 0.5 wt.%, with the balance being Mg and other impurity elements. The raw materials are placed in a ceramic crucible, and under the protection of a mixed gas atmosphere of 99% CO2-1% SF6, the temperature of the electric resistance furnace is raised to 700℃ and held for 30 minutes. After cooling with the furnace, the magnesium alloy ingot is removed.

[0078] S2, Homogenization treatment: The magnesium alloy is subjected to composition homogenization heat treatment under argon atmosphere protection. The heat treatment temperature is 400℃ and the time is 12h. The treated ingot is cooled to room temperature in the furnace to obtain the matrix material.

[0079] S3, Processing Procedure: First, the homogenized matrix material is cut into 200mm×65mm×4mm plates using wire EDM. Then, the magnesium-rare earth alloy plates are surface-polished to remove the oxide scale. Next, the magnesium alloy plates undergo friction stir processing. The stirring head is made of tungsten-rhenium alloy, and its dimensions are: shoulder diameter 15mm, stirring pin diameter 6mm, and stirring pin length 2.4mm. The stirring head rotates at 1200rpm, and the forward speed is 50mm / min. The resulting magnesium alloy sample is then obtained after friction stir processing.

[0080] Figure 1 It is the magnesium alloy matrix material prepared in Example 1 ( Figure 1 In the middle 'a', referring to cast magnesium alloy) and the material after friction stir processing ( Figure 1 The surface SEM microstructure of b) is shown in Figure 1. Figure 1 In Figure a, it can be observed that a large number of coarse precipitates are distributed on the surface of the magnesium alloy matrix material, and after friction stirring treatment ( Figure 1(b) The precipitated phase is fine and uniformly distributed.

[0081] Figure 2 The results show the polarization curves of the magnesium alloy matrix material prepared in Example 2 and the bio-magnesium alloy sample after stir-friction processing in artificial urine. By fitting the polarization curves to Tafel, the corrosion current density of the cast magnesium-rare earth alloy is 2.5 × 10⁻⁶. -4 A / cm 2 After friction stir processing, the corrosion current density of magnesium-rare earth alloy materials was significantly reduced to 1.2 × 10⁻⁶. -4 A / cm 2 .

[0082] Figure 3 The results of hydrogen evolution tests in artificial urine are shown for the magnesium alloy matrix material prepared in Example 4 and the bio-magnesium alloy sample after friction stirring. The average daily hydrogen evolution of the cast alloy reached 35 ml / cm³. 2 / day, the hydrogen evolution rate of the bio-magnesium alloy sample prepared in this example is approximately 3 ml / cm. 2 / day.

[0083] Figure 4 The magnesium alloy matrix material prepared in Example 5 ( Figure 4 (a, representing cast magnesium alloy) and bio-magnesium alloy samples after friction stir processing ( Figure 4 (b) Surface SEM images after long-term immersion in artificial urine (5 days and 15 days of degradation). The results show that after the design and processing of the magnesium alloy material, a uniform degradation process can be achieved in the artificial urine environment.

[0084] Figure 5 Materials and matrix materials in different embodiments (in) Figure 5 Based on the preparation and processing method proposed in this technology, bio-magnesium alloys with different degradation rates in the urinary system can be prepared according to the differences in degradation rate of the substrate in the artificial urine environment. The degradation rate can be controlled within a range of approximately (0.5–6 mm / y).

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," and "detailed implementation" refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that variations, modifications, substitutions and changes can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A method of modulating the degradation rate of a bio-magnesium alloy in the urinary system, characterized by, Comprising: S1: melting magnesium alloy raw material under protective atmosphere to obtain magnesium alloy ingot; The magnesium alloy raw material is composed of the following components in percentage by weight: Y: 2-3wt.%, Nd: 1-2 wt.%, Gd: 0-1wt.%, Zn: 0-1wt.%, Ca: 0-1wt.%, Sr: 0-1wt.%, and the balance of magnesium and impurity elements; S2: homogenizing heat treatment of the magnesium alloy ingot under inert atmosphere, cooling to obtain base material; S3: friction stir processing of the base material to obtain biological magnesium alloy of predetermined size. The biological magnesium alloy is used for preparing biomaterials for urinary system.

2. The method of claim 1, wherein, The protective atmosphere in step S1 is a mixed gas of CO2 and SF6; Optionally, the volume fraction ratio of the CO2 and the SF6 is 99: 1~5.

3. The method of claim 1, wherein, The magnesium alloy raw material includes the following raw materials: intermediate alloy Mg-30wt.%Y, intermediate alloy Mg-30wt.%Nd, intermediate alloy Mg-30wt.%Gd, intermediate alloy Mg-20wt.%Sr, pure Mg, pure Zn and pure Ca raw material.

4. The method of claim 1, wherein, The temperature of the melting treatment is 650-750℃, and the time of the melting treatment is 10-30 minutes.

5. The method of claim 1, wherein, The homogenizing heat treatment in step S2 is carried out under argon atmosphere protection; Optionally, the heat treatment temperature is 300℃-450℃, and the time is 12-24h.

6. The method of claim 1, wherein, In step S3, the stir head used in the friction stir processing is tungsten-rhenium alloy; Optionally, in step S3, the forward speed of the stir head used in the friction stir processing is 10-200 mm / min; Optionally, in step S3, the rotation speed of the stir head used in the friction stir processing is 100-1500 rpm.

7. The method of claim 1, wherein, In the artificial urine environment, the corrosion current density of the biological magnesium alloy is 10-500 μA / cm 2 , and the degradation rate is 0.5-40 mm / y.

8. A method of producing a biomagnesium alloy for use in the urinary system, characterized by, Comprising: S1: melting magnesium alloy raw material under protective atmosphere to obtain magnesium alloy ingot; The magnesium alloy raw material includes Y: 2-3wt.%, Nd: 1-2 wt.%, Gd: 0-1wt.%, Zn: 0-1wt.%, Ca: 0-1wt.%, Sr: 0-1wt.%, and the balance of magnesium and impurity elements; S2: homogenizing heat treatment of the magnesium alloy ingot under inert atmosphere, cooling to obtain base material; S3: friction stir processing of the base material to obtain biological magnesium alloy of predetermined size.

9. A biomagnesium alloy, characterized by, Prepared according to the method of any one of claims 1~8.

10. Use of the biological magnesium alloy of claim 9 in the preparation of biomaterials for urinary system.

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