A medical absorbable zinc alloy and a preparation method thereof

Abstract

The application discloses a preparation method of a medical absorbable zinc alloy, and comprises the following steps: step one, polishing the original material of magnesium, aluminum, lithium, silver and zinc to remove the oxide layer; step two, filling the electric resistance furnace with protective gas, and putting the zinc into the electric resistance furnace to heat to 520±5 DEG C, then sequentially adding the silver, lithium, aluminum and magnesium after melting; step three, smelting the metal to the molten state and keeping the temperature in the semi-solid temperature interval to obtain the zinc alloy melt in the semi-solid temperature interval; step four, putting the aerosol in the quantitative closed container, and introducing the heated aerosol into the zinc alloy melt in the semi-solid temperature interval through the diffuser at the flow rate of 150-400 ml / min to make the aerosol and the zinc alloy melt fully contact; step five, stopping the introduction of the aerosol, and standing for 10-20 minutes to obtain the zinc alloy semi-solid slurry, and then casting the ingot to obtain the solid zinc alloy; the prepared zinc alloy is degradable, high in strength, good in plasticity and antibacterial.

Description

Technical Field

[0001] This invention relates to the field of medical metal materials technology, specifically to a medical absorbable zinc alloy and its preparation method. Background Technology

[0002] Metallic materials have become widely used implant materials in clinical practice due to their good mechanical and processing properties. They mainly include pure metals, stainless steel, titanium alloys, cobalt-based alloys, shape memory alloys, and precious metals. These materials have good corrosion resistance and can remain stable for a long time after being implanted in the human body. However, they also bring some problems, such as the need for a second surgery to remove them and the potential harm to the human body caused by the release of alloying elements.

[0003] Biodegradable biomedical metallic materials have been widely researched and applied because they can avoid the risk of secondary surgery for medical implants. However, currently used magnesium-based alloys degrade too quickly in the human body, affecting the mechanical integrity of implants, while iron-based alloys are also limited in application due to the harmful effects of their degradation products on the human body. Zinc is one of the essential trace elements for the human body, and its degradation rate is between that of magnesium and iron, but the mechanical properties of pure zinc do not meet the requirements for implant materials. Summary of the Invention

[0004] To address the problems of existing medical metal materials requiring secondary surgery for removal and the release of alloying elements that can harm the human body, this invention provides a medical absorbable zinc alloy and its preparation method.

[0005] The technical solution adopted by the present invention to achieve the above objectives is: a method for preparing a medical absorbable zinc alloy, comprising the following steps:

[0006] Step 1: Using magnesium, aluminum, lithium, silver, and zinc as raw materials, polish them in sequence to remove the oxide layer;

[0007] Step 2: Fill the resistance furnace 7 with protective gas 5, and put the zinc metal into the resistance furnace 7 and heat it to 520±5℃. After the zinc metal melts, add the silver metal, lithium metal, aluminum metal and magnesium metal in sequence.

[0008] Step 3: After all the metal has melted, smelt the metal to a molten state and hold it at a semi-solid temperature range to obtain a zinc alloy melt in the semi-solid temperature range;

[0009] Step 4: Place aerosol 8 in a quantitative sealed container 3, and introduce the heated aerosol 8 into the zinc alloy melt in the semi-solid temperature range through diffuser 4 at a flow rate of 150-400 ml / min, so that the aerosol 8 and the zinc alloy melt can be in full contact.

[0010] Step 5: After the aerosol 8 and the zinc alloy melt have come into full contact, stop introducing the aerosol 8 and let it stand for 10-20 minutes to obtain the zinc alloy semi-solid slurry 6. Then cast the ingot to obtain the solid zinc alloy.

[0011] Preferably, in step two, the protective gas 5 is nitrogen and argon.

[0012] Preferably, in step three, the semi-solid temperature range is 600℃-650℃.

[0013] Preferably, the aerosol 8 in step four includes an aerosol solvent 1 and an aerosol solute 2. The aerosol solute 2 is a composite alloy powder, and the aerosol solvent 1 is composed of an inert gas or a protective gas used in zinc smelting, with a gas purity of chemical purity or higher.

[0014] Preferably, the aerosol solute 2 specifically includes the following components and their mass percentages: Er: 0.1-0.5%, Zr: 0.1-0.5%, Ce: 0.1-0.15%, impurities ≤0.2%, and the balance being Zn.

[0015] Preferably, the composite alloy powder is prepared by volumetric method. Chemically pure Er, Zr, Ce and Zn are ground into composite alloy powder according to the ratio, which is the aerosol solute 2. The powder is placed into a quantitative sealed container 3 with a pressure of -50 to 50 kPa and filled with one or more mixed aerosol solvents 1 to complete the preparation of aerosol 8.

[0016] Preferably, the aerosol 8 is heated to 550℃-590℃ using a resistance heating furnace, the equivalent diameter of the aerosol solute 2 is ≤400nm, and the quantitative sealed container 3 is a high-pressure steel cylinder.

[0017] Preferably, the diffuser 4 is a porous graphite diffuser.

[0018] Preferably, the main components and their mass percentages are as follows: magnesium: 5-10%, Al: 1-10%, Li: 1-5%, Ag: 0.1-3%, impurities ≤0.2%, and the remainder is Zn.

[0019] Preferably, the impurities include impurities such as pig iron and scrap steel in the raw materials, impurities in gases such as air and water vapor, and impurities generated during the smelting process.

[0020] The present invention discloses a medical absorbable zinc alloy and its preparation method. By selecting a metal element that is harmless to the human body and melting it with metallic zinc, a zinc alloy melt in a semi-solid temperature range is obtained. Then, an aerosol is introduced to fully contact the zinc alloy melt in the semi-solid temperature range to obtain a semi-solid zinc alloy slurry. After casting into an ingot, a solid zinc alloy is produced. The obtained zinc alloy is degradable, has high strength, and has good plasticity and antibacterial properties. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the preparation method of the medical absorbable zinc alloy of the present invention.

[0022] Figure 2 This is a bar chart comparing the strength of zinc alloys with different compositions in Examples 1-7 of this invention.

[0023] Figure 3 This is a distribution diagram of the proportion of different grain sizes in Embodiment 1 of the present invention.

[0024] In the diagram: 1. Aerosol solvent; 2. Aerosol solute; 3. Quantitative sealed container; 4. Diffuser; 5. Protective gas; 6. Zinc alloy semi-solid slurry; 7. Resistance furnace; 8. Aerosol. Detailed Implementation

[0025] The present invention discloses a method for preparing a medical absorbable zinc alloy, comprising: Figure 1 As shown, it includes the following steps:

[0026] Step 1: Using magnesium, aluminum, lithium, silver, and zinc as raw materials, polish them in sequence to remove the oxide layer;

[0027] Step 2: Fill the resistance furnace 7 with protective gas 5, and put metallic zinc into the resistance furnace 7 and heat it to 520±5℃. After the metallic zinc melts, add metallic silver, metallic lithium, metallic aluminum and metallic magnesium in sequence. The protective gas 5 is nitrogen and argon.

[0028] Step 3: After all the metal has melted, smelt the metal to a molten state and hold it at a semi-solid temperature range to obtain a zinc alloy melt in the semi-solid temperature range;

[0029] Step 4: Place aerosol 8 in a quantitative sealed container 3, heat the aerosol 8 using a resistance heating furnace to a temperature of 550℃-590℃, and then introduce the heated aerosol 8 into the zinc alloy melt in the semi-solid temperature range through a diffuser 4 at a flow rate of 150-400ml / min, so that the aerosol 8 and the zinc alloy melt are in full contact. The specific amount of aerosol 8 added is related to the pressure of the container where the zinc alloy melt is located. The standard for judging whether the contact is sufficient is mainly based on the fact that after the aerosol 8 is stopped, there is no visible bubbling in the zinc alloy melt.

[0030] Step 5: After the aerosol 8 and the zinc alloy melt have come into full contact, stop introducing the aerosol 8 and let it stand for 10-20 minutes to obtain the zinc alloy semi-solid slurry 6. Then cast the ingot to obtain the solid zinc alloy.

[0031] The aerosol 8 in step four includes aerosol solvent 1 and aerosol solute 2. Aerosol solute 2 is a composite alloy powder. The aerosol solvent 1 is composed of an inert gas or a protective gas commonly used in zinc smelting, such as nitrogen and argon, with a gas purity of chemical purity or higher.

[0032] Aerosol solute 2 specifically includes the following components and their mass percentages: Er: 0.1-0.5%, Zr: 0.1-0.5%, Ce: 0.1-0.15%, impurities ≤0.2%, and the balance is Zn. Aerosol solute 2 is prepared by volumetric method, also known as titration analysis. Chemically pure Er, Zr, Ce, and Zn are ground into composite gold alloy powder according to the ratio, placed in a quantitative sealed container 3 with a pressure of -50 to 50 kPa, and filled with one or more mixed aerosol solvents 1, thus completing the preparation of aerosol 8.

[0033] The equivalent diameter of aerosol solute 2 is ≤400nm, and the quantitative sealed container 3 is a high-pressure steel cylinder. The diffuser 4 is a porous graphite diffuser, which can promote the full diffusion of aerosol solute 2 inside the zinc alloy melt and improve the pulping efficiency.

[0034] A medical absorbable zinc alloy, prepared by the above-mentioned method for preparing medical absorbable zinc alloy, mainly includes the following components and their mass percentages: magnesium: 5-10%, Al: 1-10%, Li: 1-5%, Ag: 0.1-3%, impurities ≤0.2%, and the remainder being Zn.

[0035] Impurities in composite alloy powders and zinc alloys mainly include impurities such as pig iron and scrap steel in raw materials, impurities in gases such as air and water vapor, and impurities generated during the smelting process.

[0036] Example

[0037] The zinc used in this invention has a purity of 99.995%, the magnesium has a purity of ≥99.99%, the aluminum has a purity of ≥99.99%, the lithium has a purity of ≥99.99%, and the silver has a purity of ≥99.99%.

[0038] Unless otherwise specified, all percentages used are by weight.

[0039] The tensile test was conducted according to the national standard GB / T228-2002 "Metallic materials, tensile test method at room temperature", and the equipment was the KNWN-W50KN electronic universal testing machine manufactured by Jinan Kain Testing Machine Manufacturing Co., Ltd.

[0040] Under protective gas 5, pure zinc metal is heated to 520±5℃ in resistance furnace 7. After the zinc metal melts, silver metal, lithium metal, aluminum metal and magnesium metal of corresponding weight percentages are added in sequence according to the 7 different embodiments shown in Table 1. After all the metals are melted, they are smelted to a molten state and held at a temperature in the semi-solid temperature range to obtain a zinc alloy melt in the semi-solid temperature range.

[0041] Table 1. Chemical composition of the high-strength medical absorbable zinc alloy and its aerosol, and preparation process parameters of the present invention.

[0042]

[0043] Then, according to the mass percentages of Er, Zr, and Ce corresponding to Examples 1-6 in Table 1, the composite alloy powder of aerosol solute 2 was prepared. The composite alloy powder was loaded into a quantitative sealed container 3 with a pressure corresponding to Table 1, and then filled with one or more mixed aerosol solvents 1 to complete the preparation of aerosol 8.

[0044] In Examples 1-6, a resistance heating furnace is used to heat the aerosol 8, and it is introduced into the zinc alloy melt in the semi-solid temperature range at the corresponding flow rate in Table 1, so that the aerosol 8 and the zinc alloy melt can be in full contact. After the introduction of aerosol 8 is stopped, the tundish melt is allowed to stand for the corresponding standing time in Table 1 to complete the zinc alloy melt slurry process, and the zinc alloy semi-solid slurry 6 is then cast into ingots.

[0045] In Example 7 of Table 1, no aerosol was added, serving as a control group experiment.

[0046] Depend on Figure 2 As shown, the zinc alloys in Examples 1-6 with added aerosol 8 have higher strength than those in Example 7 without added aerosol 8. There are slight differences in strength between Examples 1-6 due to the different ratios of zinc alloy to aerosol.

[0047] Zinc alloy samples were obtained according to the alloy composition and aerosol composition ratios of Example 1 in Table 1. The grain size distribution of the samples was measured as follows: Figure 3 As shown, further calculations revealed an average grain size of 1.76 μm, indicating that the grain size was refined and the strength of the zinc alloy was further improved.

[0048] This invention discloses a medical absorbable zinc alloy and its preparation method. The zinc alloy contains zinc, magnesium, aluminum, and lithium, all elements naturally present in the human body. Trace amounts of silver are harmless to the human body. The high content of magnesium and aluminum provides the alloy with high strength, while lithium increases its plasticity. Silver ions generated during degradation have a bactericidal effect, reducing the likelihood of implant-induced inflammation and infection. Furthermore, an aerosol-induced semi-solid processing technology is employed. The aerosol composition consists of a composite alloy powder containing Er (0.1-0.5%), Zr (0.1-0.5%), Ce (0.1-0.15%), impurities ≤0.2%, and the balance Zn by mass percentage. This promotes heterogeneous nucleation of the alloy, resulting in grain refinement and strengthening, thus obtaining a medical absorbable zinc alloy with high strength, good plasticity, and antibacterial properties.

[0049] The medical absorbable zinc alloy rods, wires, plates, and profiles of the present invention have a wide range of size variations and can be used to prepare different implantable devices, such as bone nails, bone plates, cardiovascular stents, bone tissue engineering scaffolds, sutures, and composite material devices made with other materials. They can also be used to prepare various biodegradable devices to meet different clinical use requirements.

[0050] This invention has been described through embodiments. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this invention.

Claims

1. A method for preparing a medical absorbable zinc alloy, characterized in that, Includes the following steps: Step 1: Using magnesium, aluminum, lithium, silver and zinc as raw materials, polish them in sequence to remove the oxide layer; Step 2: Fill the resistance furnace (7) with protective gas (5), and put the zinc metal into the resistance furnace (7) and heat it to 520±5℃. After the zinc metal melts, add the silver metal, lithium metal, aluminum metal and magnesium metal in sequence. Step 3: After all the metal has melted, smelt the metal to a molten state and hold it at a semi-solid temperature range to obtain a zinc alloy melt in the semi-solid temperature range; Step 4: Place aerosol (8) in a quantitative sealed container (3), and introduce the heated aerosol (8) into the zinc alloy melt in the semi-solid temperature range through a diffuser (4) at a flow rate of 150-400 ml / min, so that the aerosol (8) and the zinc alloy melt can be in full contact. The aerosol (8) includes an aerosol solvent (1) and an aerosol solute (2), wherein the aerosol solute (2) is a composite alloy powder, and the aerosol solvent (1) consists of nitrogen and argon, and the gas purity is chemically pure or higher. The aerosol solute (2) specifically includes the following components and their mass percentages: Er: 0.1-0.5%, Zr: 0.1-0.5%, Ce: 0.1-0.15%, impurities ≤0.2%, and the balance is Zn; Step 5: After the aerosol (8) and the zinc alloy melt have come into full contact, stop introducing the aerosol (8) and let it stand for 10-20 minutes to obtain a semi-solid zinc alloy slurry (6), and then cast the ingot to obtain a solid zinc alloy; The composition and mass percentage of the zinc alloy are as follows: Mg: 5-10%, Al: 1-10%, Li: 1-5%, Ag: 0.1-3%, impurities ≤0.2%, and the remainder is Zn.

2. The method for preparing a medical absorbable zinc alloy according to claim 1, characterized in that, In step two, the protective gas (5) is nitrogen and argon.

3. The method for preparing a medical absorbable zinc alloy according to claim 1, characterized in that, In step three, the semi-solid temperature range is 600℃-650℃.

4. The method for preparing a medical absorbable zinc alloy according to claim 1, characterized in that, Composite alloy powder was prepared by volumetric method. Chemically pure Er, Zr, Ce and Zn were ground into composite alloy powder according to the ratio, which is the aerosol solute (2). The powder was put into a quantitative sealed container (3) with a pressure of -50Kpa to 50Kpa and filled with aerosol solvent (1) to complete the preparation of aerosol (8).

5. The method for preparing a medical absorbable zinc alloy according to claim 1, characterized in that, The aerosol (8) is heated to 550℃-590℃ using a resistance heating furnace. The equivalent diameter of the aerosol solute (2) is ≤400nm. The quantitative sealed container (3) is a high-pressure steel cylinder.

6. The method for preparing a medical absorbable zinc alloy according to claim 1, characterized in that, The diffuser (4) is a porous graphite diffuser.

7. A medical absorbable zinc alloy, manufactured using any one of the preparation methods for medical absorbable zinc alloys according to claims 1-6, characterized in that, The composition and mass percentage of the zinc alloy are as follows: Mg: 5-10%, Al: 1-10%, Li: 1-5%, Ag: 0.1-3%, impurities ≤0.2%, and the remainder is Zn.

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