A self-healing dental implant based on magnesium alloy material and its preparation method

Abstract

The present invention provides a self-healing dental implant based on a magnesium alloy material and a preparation method thereof, belonging to the technical field of alloy materials. The self-healing dental implant comprises the following raw materials by mass percentage: Zn 0.5-3%, Ca 0.01-0.1%, Mg 30 Nd 0.01-0.1%, the balance being Mg and inevitable impurities, wherein the mass ratio of Zn, Ca and Mg 30 Nd is (30-50):1:1. The self-healing dental implant prepared by the present invention not only has excellent mechanical properties, but also has good corrosion resistance, and can provide a longer service life and better oral repair effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloy materials, and particularly relates to a self-healing dental implant based on magnesium alloy materials and a preparation method thereof. Background Art

[0002] In recent years, with the progress of medical technology and the improvement of people's requirements for quality of life, dental implants have gradually become an important option in dental restoration treatment. Dental implants usually need to have excellent biocompatibility, sufficient mechanical strength, corrosion resistance, and good long-term stability. However, traditional dental implant materials such as titanium alloys and stainless steels, although having good mechanical properties and corrosion resistance, may require secondary surgery for removal due to their non-degradability and potential bioreaction problems, which brings inconvenience to patients. In addition, these metal implant materials may cause local inflammation or other complications when exposed to the complex chemical environment of the oral cavity for a long time.

[0003] Magnesium alloys, as a new type of biomaterial, have received extensive attention in the fields of dentistry and other orthopedic implants in recent years due to their good biocompatibility, moderate degradation rate, and lightweight high strength. Magnesium is one of the essential elements required by the human body and can participate in various biochemical reactions in the human body. The magnesium ions released during the degradation of magnesium alloy implants not only do not have harmful effects on the human body, but also contribute to the regeneration and repair of bone tissue. Therefore, implants based on magnesium alloys can gradually degrade in the body, avoiding problems caused by the long-term presence of traditional metal material implants, such as infection, rejection reaction, and secondary surgery for removal.

[0004] However, the main challenge in the long-term application of magnesium alloys in the oral cavity is their corrosion resistance problem. Since magnesium is prone to rapid corrosion in the human body fluid environment, it may lead to premature failure of the material and cannot meet the long-term use requirements of dental implants. To solve this problem, researchers are committed to developing magnesium alloy implants that have both good biocompatibility and sufficient corrosion resistance and self-healing ability through alloy design, surface treatment technology, and the introduction of self-healing materials.

[0005] The technology of self-healing materials provides a new idea for the development of magnesium alloy implants. By introducing self-healing microcapsules or coatings into magnesium alloy materials, the implants can automatically repair when suffering from corrosion or mechanical damage, thereby extending their service life. Self-healing microcapsules usually contain repair agents that can be released when cracks or corrosion occur. These repair agents react with the surrounding environment to form a new protective layer, preventing further corrosion and damage expansion. This technology has been preliminarily applied in fields such as aerospace and the automotive industry, but its application in the field of biomedical implants is still in the research stage.

[0006] Therefore, the development of a self-healing dental implant based on magnesium alloy materials can not only solve the problem of rapid corrosion of traditional magnesium alloy implants, but also provide a longer service life and better oral restoration effect. The introduction of this new material is expected to significantly improve the safety and stability of dental implants and provide a more comfortable treatment experience for patients. Summary of the Invention

[0007] The object of the present invention is to provide a self-healing dental implant based on magnesium alloy materials and a preparation method thereof to solve the problem of poor corrosion resistance of the above-mentioned magnesium alloy materials as self-healing dental implants. The self-healing dental implant prepared by the present invention not only has excellent mechanical properties, but also has good corrosion resistance, and can provide a longer service life and better oral restoration effect.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] In the first aspect of the present invention, a self-healing dental implant based on magnesium alloy materials is provided, which comprises the following raw materials by mass percentage: Zn 0.5-3%, Ca 0.01-0.1%, Mg 30 Nd 0.01-0.1%, the balance being Mg and inevitable impurities, wherein the mass ratio of Zn, Ca and Mg 30 Nd is (30~50):1:1.

[0010] By introducing specific contents of Zn, Ca and Mg 30 Nd into the magnesium alloy, the mechanical strength of the magnesium alloy can be improved. The present invention also finds that by setting the ratios of the added Zn, Ca and Mg 30 Nd, the corrosion resistance of the magnesium alloy can also be improved. The analysis is through the compounding of specific contents of Zn, Ca and Mg 30 Nd, which reaches an ideal balance point in the magnesium alloy, making the magnesium alloy material have good mechanical properties. Among them, Zn can form a solid solution with Mg and may also form intermetallic compounds with other elements, such as MgZn2. These strengthening phases can improve the hardness and strength of the alloy. Ca can also form hard particles, such as Mg2Ca. Such compounds usually have a high melting point and can exist as strengthening phases in the alloy. In addition, the Mg-Zn-Ca-Mg 30 Nd alloy formed by adding Zn, Ca and Mg 30 Nd in proportion can promote the formation of a denser oxide film on the surface in a corrosive environment. This oxide film can effectively prevent the direct contact between the corrosive medium and the matrix metal and slow down the corrosion rate.

[0011] Preferably, the particle diameter distribution of Zn is by mass percentage: the content of particles with a diameter of 50 - 70 μm is 0.5 - 2%, the content of particles with a diameter of 20 - 40 μm is 30 - 40%, and the content of particles with a diameter of 10 - 15 μm is 55 - 80%.

[0012] Preferably, the particle diameter distribution of Ca is by mass percentage: the content of particles with a diameter of 45 - 55 μm is 1 - 3%, the content of particles with a diameter of 15 - 30 μm is 50 - 60%, and the content of particles with a diameter of 8 - 10 μm is 30 - 45%.

[0013] Preferably, for Mg 30 Nd, the particle diameter distribution is by mass percentage: the content of particles with a diameter of 40 - 50 μm is 5 - 8%, the content of particles with a diameter of 50 - 70 μm is 30 - 45%, and the content of particles with a diameter of 50 - 70 μm is 50 - 70%.

[0014] In order to optimize the properties of the magnesium alloy material, especially to improve its corrosion resistance, the present invention sets the particle diameter distributions of Zn, Ca, and Mg 30 Nd, thereby improving the corrosion resistance of the magnesium alloy. The analysis shows that when the particle diameter distributions of Zn, Ca, and Mg 30 Nd are within a specific range, these elements can be more uniformly distributed throughout the magnesium alloy matrix, forming fine and uniformly distributed strengthening phases. Appropriate particle sizes can help form a denser oxide film or other forms of protective layers, which can effectively block the contact between the corrosive medium and the matrix metal, thereby reducing the corrosion rate. Appropriate particle sizes can reduce the pores generated during casting or solidification, making the material more dense, reducing corrosion channels, and improving corrosion resistance. Controlling the particle size in the present invention also helps to obtain a more uniform microstructure, which can reduce the risk of local corrosion caused by non-uniform composition.

[0015] The second aspect of the present invention provides a preparation method for a self - healing dental implant based on a magnesium alloy material, including the following steps:

[0016] (1) Melting

[0017] Mix 50 - 60% of the mass of Zn powder and 20 - 30% of the mass of Mg powder, and melt them at 700 - 720 °C under a protective atmosphere, then cool to room temperature to obtain alloy one;

[0018] Mix 30 - 40% of the mass of Ca powder and 10 - 15% of the mass of Mg powder, and melt them at 700 - 720 °C under a protective atmosphere, then cool to room temperature to obtain alloy two;

[0019] Mix Mg 30 Nd powder, alloy one, alloy two, and the remaining Zn powder, Ca powder, and Mg powder, and melt them at 700 - 750 °C under a protective atmosphere to obtain a molten alloy;

[0020] (2) Refining

[0021] Add a refining agent to the molten alloy to remove impurities;

[0022] (3) Casting

[0023] Perform semi - continuous casting on the refined molten alloy under a protective atmosphere;

[0024] (4) Homogenization heat treatment

[0025] Perform homogenization treatment on the cast alloy ingot to eliminate compositional segregation inside the alloy;

[0026] (5) Solution heat treatment

[0027] Perform solution heat treatment on the homogenized magnesium alloy ingot;

[0028] (6) Plastic processing

[0029] Extrude the solution - heat - treated magnesium alloy ingot;

[0030] (7) Aging treatment

[0031] Perform aging treatment on the extruded alloy material;

[0032] (8) Machining

[0033] Machine the aged alloy material according to the shape of the dental implant to obtain a self - healing dental implant.

[0034] In the preparation process of the present invention, zinc powder and calcium powder are added step by step. After part of the zinc powder or calcium powder is first mixed with magnesium powder to form an alloy, then continue to mix with the remaining zinc powder, calcium powder, magnesium powder and neodymium powder. By precisely controlling the addition methods of Zn, Ca and Mg 30 Nd, it can promote the formation of a more uniform and dense oxide film or other protective layers, thereby improving the corrosion resistance of the magnesium alloy. By controlling the addition methods of these elements in the present invention, the microstructure of the alloy can also be optimized, improving the hardness, strength and toughness of the material, making it more suitable for dental implant applications.

[0035] Preferably, in step (3), the casting temperature is 680 - 720 °C.

[0036] Preferably, in step (4), the temperature of the homogenization heat treatment is 350 - 420 °C, and the time is 8 - 16 h.

[0037] Preferably, in step (5), the temperature of the solution heat treatment is 350 - 420 °C, the time is 8 - 16 h, and the temperature of the solution heat treatment is 20 - 30 °C higher than that of the homogenization heat treatment.

[0038] In order to optimize the preparation process of magnesium alloy and further improve the corrosion resistance of magnesium alloy, the present invention sets the temperature of solution heat treatment higher than that of homogenization heat treatment. The analysis is that the higher temperature helps to eliminate the micro-defects formed during the casting process, such as pores, cracks, etc., thereby optimizing the microstructure of the material. The dense microstructure can reduce the chance of corrosive media entering the interior of the material and improve the corrosion resistance of the material. The solution heat treatment carried out at a higher temperature in the present invention can promote the formation of a more stable solid solution, dissolve alloying elements into the magnesium matrix sufficiently, and then through cooling, the state of these elements in the solid solution can be retained. In this state, the alloying elements can participate more effectively in the formation of a protective oxide film, thereby improving the corrosion resistance. If the temperature difference between the solution heat treatment and the homogenization heat treatment is too large, it may cause the material to embrittle and the grain size to grow, resulting in a decline in the mechanical properties and corrosion resistance of the magnesium alloy.

[0039] Preferably, in step (6), the temperature of plastic working is 350 - 450 °C.

[0040] Preferably, in step (7), the temperature of aging treatment is 200 - 250 °C, and the time is 24 - 60 h.

[0041] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0042] 1. By optimizing the alloy composition ratio and particle size distribution, the present invention can significantly improve the mechanical properties of magnesium alloy. The addition of Zn and Ca can form strengthening phases, improving the hardness and strength of the material; while Mg 30 Nd helps to form more stable compounds, thereby increasing the toughness of the material.

[0043] 2. Magnesium alloy is prone to corrosion in a physiological environment. The present invention adds Zn, Ca and Mg 30 Nd elements and controls their particle size distribution, which can effectively reduce the corrosion rate. The presence of these elements can promote the formation of a denser oxide film, preventing the corrosive media from further eroding the base metal.

[0044] 3. The magnesium alloy in the present invention has good biocompatibility with human tissues, which makes it a potential biodegradable implant material. The magnesium alloy prepared by the present invention can not only improve the mechanical and corrosion properties, but also maintain or improve its biocompatibility.

[0045] 4. The magnesium alloy implant under the specific composition ratio of the present invention has a certain self-healing ability, which means that after being slightly damaged, the material can restore some functions through its own mechanism, extending the service life of the implant. Description of the Drawings

[0046] Figure 1 It is the external view of a magnesium alloy round bar;

[0047] Figure 2 It is the external view of a self - healing dental implant;

[0048] Figure 3 It is the SEM image of a magnesium alloy round bar. Specific embodiments

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] Embodiment 1

[0051] This embodiment provides a self - healing dental implant based on magnesium alloy materials, including the following raw materials by mass percentage: Zn 2%, Ca 0.05%, Mg 30 Nd 0.05%, and the balance is Mg and inevitable impurities, where the mass ratio of Zn, Ca, and Mg 30 Nd is 40:1:1.

[0052] The particle diameter distribution of Zn by mass percentage is as follows: the content of 50 - 70μm is 1%, the content of 20 - 40μm is 35%, and the content of 10 - 15μm is 64%.

[0053] The particle diameter distribution of Ca by mass percentage is as follows: the content of 45 - 55μm is 2%, the content of 15 - 30μm is 55%, and the content of 8 - 10μm is 43%.

[0054] Mg 30 The particle diameter distribution of Nd by mass percentage is as follows: the content of 40 - 50μm is 6%, the content of 50 - 70μm is 40%, and the content of 50 - 70μm is 54%.

[0055] A preparation method of a self - healing dental implant based on magnesium alloy materials includes the following steps,

[0056] (1) Melting

[0057] Mix 50% of the mass of Zn powder and 30% of the mass of Mg powder, and conduct melting at 700°C under a protective atmosphere, and cool to room temperature to obtain alloy one;

[0058] Mix 30% of the mass of Ca powder and 15% of the mass of Mg powder, and melt them at 715 °C under a protective atmosphere. Cool to room temperature to obtain Alloy II;

[0059] Mix Mg 30 Mix Nd powder, Alloy I, Alloy II and the remaining Zn powder, Ca powder and Mg powder, and melt them at 735 °C under a protective atmosphere to obtain a molten alloy;

[0060] (2)Refining

[0061] Add a refining agent to the molten alloy to remove impurities. The refining agent is NaF, and the addition amount of the refining agent is 10 wt%;

[0062] (3)Casting

[0063] Perform semi - continuous casting on the refined molten alloy under a protective atmosphere. The casting temperature is 700 °C;

[0064] (4)Homogenization heat treatment

[0065] Perform homogenization treatment on the cast alloy ingot to eliminate compositional segregation inside the alloy. The temperature of the homogenization heat treatment is 390 °C, and the time is 10 h;

[0066] (5)Solution heat treatment

[0067] Perform solution heat treatment on the homogenized magnesium alloy ingot. The temperature of the solution heat treatment is 420 °C, and the time is 12 h. The temperature of the solution heat treatment is 20 °C higher than that of the homogenization heat treatment;

[0068] (6)Plastic working

[0069] Extrude the solution - heat - treated magnesium alloy ingot. The temperature of the plastic working is 415 °C;

[0070] (7)Aging treatment

[0071] Perform aging treatment on the extruded alloy material. The temperature of the aging treatment is 220 °C, and the time is 45 h to obtain a magnesium alloy round bar with a diameter of 12 mm;

[0072] (8)Machining

[0073] Machine the aged magnesium alloy round bar according to the shape of the dental implant to obtain a self - reparable dental implant. The appearance of the magnesium alloy round bar and the self - reparable dental implant is shown in Figure 1 and Figure 2 . The SEM image of the magnesium alloy round bar is shown in Figure 3 .

[0074] Example 2

[0075] This embodiment provides a self-healing dental implant based on a magnesium alloy material, which comprises the following raw materials by mass percentage: 3% Zn, 0.1% Ca, Mg 30 0.1% Nd, with the balance being Mg and inevitable impurities, wherein the mass ratio of Zn, Ca, and Mg 30 to Nd is 30:1:1.

[0076] The particle diameter distribution of Zn is as follows by mass percentage: the content of 50 - 70μm is 0.5%, the content of 20 - 40μm is 38%, and the content of 10 - 15μm is 61.5%.

[0077] The particle diameter distribution of Ca is as follows by mass percentage: the content of 45 - 55μm is 1.5%, the content of 15 - 30μm is 58%, and the content of 8 - 10μm is 40.5%.

[0078] Mg 30 The particle diameter distribution of Nd is as follows by mass percentage: the content of 40 - 50μm is 7.5%, the content of 50 - 70μm is 30.5%, and the content of 50 - 70μm is 62%.

[0079] A preparation method of a self-healing dental implant based on a magnesium alloy material comprises the following steps,

[0080] (1) Melting

[0081] Mix 55% of the mass of Zn powder and 25% of the mass of Mg powder, and melt them at 715°C under a protective atmosphere, then cool to room temperature to obtain Alloy One;

[0082] Mix 35% of the mass of Ca powder and 12% of the mass of Mg powder, and melt them at 720°C under a protective atmosphere, then cool to room temperature to obtain Alloy Two;

[0083] Mix Mg 30 Nd powder, Alloy One, Alloy Two, and the remaining Zn powder, Ca powder, and Mg powder, and melt them at 710°C under a protective atmosphere to obtain a molten alloy;

[0084] (2) Refining

[0085] Add a refining agent to the molten alloy to remove impurities. The refining agent is NaF, and the addition amount of the refining agent is 10wt%;

[0086] (3) Casting

[0087] Perform semi-continuous casting on the refined molten alloy under a protective atmosphere, and the casting temperature is 700°C;

[0088] (4) Homogenization heat treatment

[0089] The cast alloy ingot is subjected to homogenization treatment to eliminate the compositional segregation inside the alloy. The temperature of the homogenization heat treatment is 380 °C and the time is 14 h;

[0090] (5)Solution heat treatment

[0091] The homogenized magnesium alloy ingot is subjected to solution heat treatment. The temperature of the solution heat treatment is 400 °C and the time is 15 h. The temperature of the solution heat treatment is 20 °C higher than that of the homogenization heat treatment;

[0092] (6)Plastic working

[0093] The solution heat-treated magnesium alloy ingot is extruded. The temperature of the plastic working is 400 °C;

[0094] (7)Aging treatment

[0095] The extruded alloy material is subjected to aging treatment. The temperature of the aging treatment is 225 °C and the time is 30 h, obtaining a magnesium alloy round bar with a diameter of 12 mm;

[0096] (8)Machining

[0097] The aged magnesium alloy round bar is machined according to the shape of the dental implant to obtain a self-repairing dental implant.

[0098] Example 3

[0099] This example provides a self-repairing dental implant based on a magnesium alloy material, including the following raw materials by mass percentage: Zn 0.5%, Ca 0.01%, Mg 30 Nd 0.01%, the balance being Mg and inevitable impurities, where the mass ratio of Zn, Ca, and Mg 30 Nd is 50:1:1.

[0100] The particle diameter distribution of Zn is by mass percentage: the content of 50 - 70 μm is 1.8%, the content of 20 - 40 μm is 32.5%, and the content of 10 - 15 μm is 65.7%.

[0101] The particle diameter distribution of Ca is by mass percentage: the content of 45 - 55 μm is 2.5%, the content of 15 - 30 μm is 54.2%, and the content of 8 - 10 μm is 43.3%.

[0102] Mg 30 The particle diameter distribution of Nd is by mass percentage: the content of 40 - 50 μm is 5.3%, the content of 50 - 70 μm is 31.5%, and the content of 50 - 70 μm is 63.2%.

[0103] A preparation method of a self-healing dental implant based on magnesium alloy materials, comprising the following steps:

[0104] (1) Melting

[0105] Mix 60% of the mass of Zn powder and 20% of the mass of Mg powder, and melt them at 718 °C under a protective atmosphere, and cool to room temperature to obtain Alloy 1;

[0106] Mix 30% of the mass of Ca powder and 10% of the mass of Mg powder, and melt them at 700 °C under a protective atmosphere, and cool to room temperature to obtain Alloy 2;

[0107] Mix Mg 30 Nd powder, Alloy 1, Alloy 2 and the remaining Zn powder, Ca powder and Mg powder, and melt them at 725 °C under a protective atmosphere to obtain a molten alloy;

[0108] (2) Refining

[0109] Add a refining agent to the molten alloy to remove impurities. The refining agent is NaF, and the addition amount of the refining agent is 10 wt%;

[0110] (3) Casting

[0111] Perform semi-continuous casting on the refined molten alloy under a protective atmosphere, and the casting temperature is 705 °C;

[0112] (4) Homogenization heat treatment

[0113] Perform homogenization treatment on the cast alloy ingot to eliminate compositional segregation inside the alloy. The temperature of the homogenization heat treatment is 395 °C, and the time is 14 h;

[0114] (5) Solution heat treatment

[0115] Perform solution heat treatment on the homogenized magnesium alloy ingot. The temperature of the solution heat treatment is 415 °C, and the time is 12 h. The temperature of the solution heat treatment is 20 °C higher than the temperature of the homogenization heat treatment;

[0116] (6) Plastic processing

[0117] Extrude the solution heat-treated magnesium alloy ingot, and the temperature of the plastic processing is 395 °C;

[0118] (7) Aging treatment

[0119] Perform aging treatment on the extruded alloy material. The temperature of the aging treatment is 242 °C, and the time is 42 h to obtain a magnesium alloy round bar with a diameter of 12 mm;

[0120] (8) Machining

[0121] The aged magnesium alloy round bar is machined according to the shape of the dental implant to obtain a self-healing dental implant.

[0122] Comparative Example 1

[0123] The difference between this comparative example and Example 1 is that the composition of the self-healing dental implant is different. The self-healing dental implant in this comparative example includes the following raw materials by mass percentage: Zn 3%, Ca 0.05%, Mg 30 Nd 0.05%, with the balance being Mg and unavoidable impurities, where the mass ratio of Zn, Ca, and Mg 30 Nd is 60:1:1.

[0124] Comparative Example 2

[0125] The difference between this comparative example and Example 1 is that the composition of the self-healing dental implant is different. The self-healing dental implant in this comparative example includes the following raw materials by mass percentage: Zn 2%, Ca 0.05%, Mg 30 Nd 0.1%, with the balance being Mg and unavoidable impurities, where the mass ratio of Zn, Ca, and Mg 30 Nd is 40:1:2.

[0126] Comparative Example 3

[0127] The difference between this comparative example and Example 1 is that the composition of the self-healing dental implant is different. The self-healing dental implant in this comparative example includes the following raw materials by mass percentage: Zn 5%, Ca 0.2%, Mg 30 Nd 0.2%, with the balance being Mg and unavoidable impurities, where the mass ratio of Zn, Ca, and Mg 30 Nd is 25:1:1.

[0128] Comparative Example 4

[0129] The difference between this comparative example and Example 1 is that the particle diameter distribution of Zn by mass percentage is: the content of 50 - 70 μm is 40%, the content of 20 - 40 μm is 15%, and the content of 10 - 15 μm is 45%.

[0130] Comparative Example 5

[0131] The difference between this comparative example and Example 1 is that the particle diameter distribution of Ca by mass percentage is: the content of 45 - 55 μm is 60%, the content of 15 - 30 μm is 20%, and the content of 8 - 10 μm is 20%.

[0132] Comparative Example 6

[0133] The difference between this comparative example and Example 1 is that Mg 30The particle size distribution of Nd by mass percentage is as follows: the content of 40 - 50 μm is 65%, the content of 50 - 70 μm is 15%, and the content of 50 - 70 μm is 20%.

[0134] Comparative Example 7

[0135] The difference between this comparative example and Example 1 is: the melting process is different. The specific melting steps of this comparative example are as follows:

[0136] Mix Mg 30 Nd powder, Zn powder, Ca powder and Mg powder in proportion, and melt them at 735 °C under a protective atmosphere to obtain a molten alloy.

[0137] Comparative Example 8

[0138] The difference between this comparative example and Example 1 is: the temperature of homogenization heat treatment is 350 °C, the temperature of solution heat treatment is 420 °C, and the temperature of solution heat treatment is 70 °C higher than that of homogenization heat treatment.

[0139] Performance Test

[0140] Test the ultimate compressive strength and tensile strength of the magnesium alloy round bars prepared in the examples and comparative examples according to GB / T228.1 - 2010 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature". Then, after soaking the magnesium alloy round bars prepared in the examples and comparative examples in Hanks solution (purchased from Shanghai Chenwei Microbial Technology Co., Ltd.) for 30 days, test their ultimate compressive strength and tensile strength again. The test results are shown in Table 1.

[0141] Table 1 Performance Test Results

[0142]

[0143] From the above performance test results, it can be seen that the magnesium alloys prepared in Examples 1 - 3 have excellent mechanical properties and good corrosion resistance. In particular, the ultimate compressive strength of Example 2 is the most prominent. This is mainly because by optimizing the alloy composition ratio and particle size distribution in the present invention, the mechanical properties of the magnesium alloy can be significantly improved and the corrosion resistance of the magnesium alloy can be enhanced.

[0144] In the comparative examples, because the necessary technical solutions were not adopted, their performance in the corresponding performance tests was significantly worse than that of the examples. In Comparative Example 1, the addition amount of Zn was changed. Although its mass percentage was still within the range defined in the present invention, the mass ratio of Zn, Ca and Mg 30 to Nd changed, and the addition amount of Zn increased compared with the addition amounts of Ca and Mg 30 to Nd. It can be seen that the mechanical properties and corrosion resistance of the prepared magnesium alloy both decreased significantly, proving that the mass ratio of Zn, Ca and Mg 30The mass ratio of Nd has an important influence on the comprehensive properties of magnesium alloys. In Comparative Example 2, the addition amount of Mg 30 Nd was changed, resulting in a change in the mass ratio of Zn, Ca, and Mg 30 to Nd. The addition amount of Mg 30 Nd increased compared to the addition amount of Ca. From the results, it can be seen that the mechanical properties and corrosion resistance of the prepared magnesium alloy both decreased significantly, which also proves that the mass ratio of Zn, Ca, and Mg 30 to Nd has an important influence on the comprehensive properties of magnesium alloys. When Zn, Ca, and Mg 30 Nd are added to the magnesium alloy in a specific ratio, there is an ideal balance point, which comprehensively improves the mechanical properties and corrosion resistance of the magnesium alloy. In Comparative Example 3, the ratio of Zn, Ca, and Mg 30 to Nd was changed, and their addition amounts all exceeded the range defined in the present invention, and the ratio of the three also did not fall within the range defined in the present invention. From the results, it can be seen that the mechanical properties and corrosion resistance of the prepared magnesium alloy further decreased, indicating the importance of limiting the mass percentages of various raw materials added and the mass ratio of Zn, Ca, and Mg 30 to Nd in the present invention, which will directly affect the comprehensive properties of magnesium alloys. In Comparative Examples 4 to 6, the particle diameter distributions of Zn, Ca, and Mg 30 to Nd were changed respectively. From the results, it can be seen that the mechanical properties and corrosion resistance of the prepared magnesium alloy decreased significantly, indicating that the particle size of the raw materials will affect the comprehensive properties of magnesium alloys. If the particle diameter is too large, it may cause the strengthening phase to be too thick, affecting the toughness and plasticity of the material. At the same time, large particles may become the starting points of corrosion, leading to aggravated local corrosion. In Comparative Example 7, during the preparation of the magnesium alloy, all raw materials were directly mixed according to the added mass percentages, and then melted and refined. From the results, it can be seen that the mechanical properties and corrosion resistance of the magnesium alloy decreased to varying degrees, indicating that the addition steps of various raw materials will affect the properties of magnesium alloys. In Comparative Example 8, the temperature of homogenization heat treatment was changed, increasing the gap between the temperature of solution heat treatment and the temperature of homogenization heat treatment. From the results, it can be seen that the mechanical properties and corrosion resistance of the prepared magnesium alloy decreased significantly, indicating that setting specific temperatures for solution heat treatment and homogenization heat treatment can improve the comprehensive properties of magnesium alloys. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0145] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a self-healing dental implant based on a magnesium alloy material, characterized in that, It comprises the following raw materials by mass percentage: 0.5 - 3% of Zn, 0.01 - 0.1% of Ca, Mg 30 0.01 - 0.1% of Nd, and the balance is Mg and inevitable impurities, wherein the mass ratio of Zn, Ca and Mg 30 to Nd is (30 - 50):1:1; The preparation method comprises the following steps: (1) Melting Mix 50 - 60% of the mass of Zn powder and 20 - 30% of the mass of Mg powder, and conduct melting at 700 - 720 °C under a protective atmosphere, then cool to room temperature to obtain Alloy 1; Mix 30 - 40% of the mass of Ca powder and 10 - 15% of the mass of Mg powder, and conduct melting at 700 - 720 °C under a protective atmosphere, then cool to room temperature to obtain Alloy 2; Mix Mg30Nd powder, Alloy 1, Alloy 2, and the remaining Zn powder, Ca powder, and Mg powder, and conduct melting at 700 - 750 °C under a protective atmosphere to obtain a molten alloy; (2) Refining Add a refining agent to the molten alloy to remove impurities; (3) Casting Conduct semi - continuous casting on the refined molten alloy under a protective atmosphere; (4) Homogenization heat treatment Conduct homogenization treatment on the cast alloy ingot to eliminate compositional segregation inside the alloy; the temperature of the homogenization heat treatment is 350 - 420 °C, and the time is 8 - 16 h; (5) Solution heat treatment Conduct solution heat treatment on the homogenized magnesium alloy ingot; (6) Plastic processing Extrude the solution - heat - treated magnesium alloy ingot; (7) Aging treatment Conduct aging treatment on the extruded alloy material; (8) Machining Machine the aged alloy material according to the shape of the dental implant to obtain a self - reparable dental implant; The particle diameter distribution of Zn by mass percentage is: the content of 50 - 70 μm is 0.5 - 2%, the content of 20 - 40 μm is 30 - 40%, and the content of 10 - 15 μm is 55 - 80%; The particle diameter distribution of Ca by mass percentage is: the content of 45 - 55 μm is 1 - 3%, the content of 15 - 30 μm is 50 - 60%, and the content of 8 - 10 μm is 30 - 45%; Mg 30 The particle diameter distribution of Nd is by mass percentage: the content of 40 - 50 μm is 5 - 8%, the content of 50 - 70 μm is 30 - 45%, and the content of 50 - 70 μm is 50 - 70%; In step (3), the casting temperature is 680 - 720 °C; In step (5), the temperature of the solution heat treatment is 350 - 420 °C, the time is 8 - 16 h, and the temperature of the solution heat treatment is 20 - 30 °C higher than the temperature of the homogenization heat treatment; In step (6), the temperature of the plastic processing is 350 - 450 °C; In step (7), the temperature of the aging treatment is 200 - 250 °C, and the time is 24 - 60 h.

2. A self-healing dental implant based on magnesium alloy material, characterized in that, Prepared by the method according to claim 1.

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