A medical biomagnesium alloy material containing trace light rare earth elements, a preparation method thereof and application thereof

Abstract

The application provides a medical biological magnesium alloy material containing trace light rare earth elements, which comprises: Nd 1.0-5.0%, Ag 0.5-1.8%, Pr 0.15-0.65%, Pm 0.15-0.65%, and the balance is Mg. The application also provides a preparation method of the medical biological rare earth magnesium alloy material and application thereof. The medical biological rare earth magnesium alloy material provided by the application has excellent mechanical properties, uniform degradation performance and processing performance by adding appropriate alloying elements Nd, Ag, Pm and Pr which meet a certain relationship formula and using a specific preparation method, and can meet the requirements of being used as a medical implant material and being processed into related medical devices; the medical biological rare earth magnesium alloy material has excellent biological safety and biocompatibility, and also has the biological functions of inhibiting and killing bacteria, resisting inflammation and resisting infection, and can also activate cells, promote tissue repair and wound healing.

Description

Technical Field

[0001] This invention relates to the field of magnesium alloy materials technology, and in particular to a medical and biological magnesium alloy material containing trace amounts of light rare earth elements, its preparation method and its application. Background Technology

[0002] Bone defect repair faces multiple challenges, including antibacterial and bactericidal action, anti-inflammatory and anti-infective measures, cell activation, damaged tissue repair, and wound healing. Traditional metal implant materials such as titanium alloys and stainless steel can provide basic support and fixation, but these materials have a high infection rate, and the surgical site is prone to inflammation. Once infection and inflammation occur, implant failure and secondary surgery are often necessary.

[0003] To address the aforementioned issues, lightweight magnesium alloys, whose elastic modulus closely resembles that of natural bone, have garnered significant attention in recent years. These alloys gradually degrade after implantation without producing a stress-shielding effect. By adding appropriate alloying elements to high-purity magnesium and / or combining this with advanced preparation methods, not only can the magnesium alloy exhibit excellent mechanical, degradation, and processing properties, meeting the requirements for use as a medical bone defect repair implant material and for manufacturing related medical devices, but this magnesium alloy also possesses excellent biocompatibility and antibacterial, anti-inflammatory, and anti-infective biological functions, while simultaneously activating cells and promoting tissue repair and wound healing.

[0004] Therefore, it is of great significance to provide a lightweight biomedical magnesium alloy material that has excellent mechanical properties, uniform degradation properties, processing properties, biocompatibility, and biosafety, while also being able to inhibit bacteria, kill bacteria, fight inflammation and infection, activate cells, and promote tissue repair and wound healing. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a medical bio-magnesium alloy material containing trace amounts of light rare earth elements. The medical bio-rare earth magnesium alloy material provided by this application has excellent mechanical properties, uniform degradation performance, processing performance, biosafety and biocompatibility, while also having antibacterial, bactericidal, anti-inflammatory and anti-infective biological functions, and at the same time activating cells, promoting tissue repair and wound healing.

[0006] In view of this, this application provides a medical bio-magnesium alloy material containing trace amounts of light rare earth elements, comprising, by mass percentage: Nd 1.0~5.0%, Ag 0.5~1.8%, Pr 0.15~0.65%, Pm 0.15~0.65%, with the balance being Mg and unavoidable impurity elements, wherein (Nd+Pr+Pm) / Ag=3.15~5.8.

[0007] In some specific embodiments, the medical-grade biomagnesium alloy material includes nano-sized bulk Nd3Ag3Mg.14 Phase, the blocky Nd3Ag3Mg 14 The phase dimensions are 300~400nm in length and 200~300nm in width.

[0008] In some specific embodiments, the Nd content is 3.1-4.8%.

[0009] In some specific embodiments, the content of Ag is 1.1~1.7%.

[0010] In some specific embodiments, the impurity element includes one or more of Fe, Cu, Si and Ni, wherein Fe ≤ 0.005%, Cu ≤ 0.0005%, Si ≤ 0.005%, and Ni ≤ 0.0005%.

[0011] This application also provides a method for preparing the aforementioned medical bio-magnesium alloy material, including the following steps:

[0012] S1. Pure magnesium raw material, pure silver raw material, magnesium-neodymium master alloy, magnesium-praseodymium master alloy and magnesium-promethium master alloy are mixed according to the component ratio, then melted and cast to obtain magnesium alloy ingots.

[0013] S2. Homogenize the magnesium alloy ingot;

[0014] S3. The magnesium alloy ingot obtained in step S2 is hot-extruded, then aged, and cooled to obtain medical bio-magnesium alloy material.

[0015] In some specific embodiments, in step S1), the smelting specifically involves:

[0016] The pure magnesium raw material and the magnesium-neodymium master alloy are mixed and preheated to 180~195℃, held at that temperature, and then heated to 800~830℃ under the action of a protective gas to obtain an initial alloy melt; the protective gas is a mixture of SF6 and CO2 with a volume ratio of 1:(170~200).

[0017] The pure silver raw material is added to the initial alloy melt and heated again to 800~830℃. Then, magnesium praseodymium master alloy and magnesium promethium master alloy are added, and the temperature is further raised to 800~830℃ and held to obtain magnesium alloy melt.

[0018] In some specific embodiments, the homogenization process is carried out in a vacuum environment. The first-stage homogenization process is carried out at a temperature of 370~390℃ for 5~8 hours, and the second-stage homogenization process is carried out at a temperature of 400~450℃ for 3~6 hours. The homogenization process is further followed by air cooling. And / or, the hot extrusion temperature is 340~360℃, and the hot extrusion speed is 0.5~1.2 m / s.

[0019] In some specific embodiments, the aging process includes a first-level aging process and a second-level aging process performed sequentially. The temperature of the first-level aging process is 180~210℃ and the holding time is 6~8h. The temperature of the second-level aging process is 200~220℃ and the holding time is 3~5h. The cooling is air cooling.

[0020] This application also provides the application of the described medical-biomagnesium alloy material or the medical-biomagnesium alloy material prepared by the described preparation method in medical materials and / or biological materials.

[0021] This application provides a medical bio-magnesium alloy material containing trace amounts of light rare earth elements, which, by mass percentage, comprises: Nd 1.0~5.0%, Ag 0.5~1.8%, Pr 0.15~0.65%, Pm 0.15~0.65%, with the balance being Mg and unavoidable impurity elements, wherein (Nd+Pr+Pm) / Ag=3.15~5.8. In the medical-grade magnesium alloy material provided in this application, the light rare earth elements neodymium, praseodymium, and promethium can synergistically refine the alloy grains. Simultaneously, all three have high solid solubility in magnesium, allowing their atoms to dissolve into the magnesium matrix. This synergistic effect strengthens the interatomic bonding, causing lattice distortion in the matrix, slowing atomic diffusion, hindering dislocation movement, and toughening the matrix. Furthermore, the light rare earth elements praseodymium and promethium can promote the formation of stable nano-sized bulk Nd3Ag3Mg with neodymium, silver, and magnesium during alloy solidification. 14 The reinforcing phase is dispersed at grain boundaries and within grains, and consists of nano-sized bulk Nd3Ag3Mg. 14 Pinning grain boundaries inhibits grain boundary slip and hinders dislocation movement; the light rare earth elements praseodymium and promethium can promote the formation of a dispersed strengthening phase (nano-sized bulk Nd3Ag3Mg) by light rare earth elements neodymium with silver and magnesium during long-term aging after hot extrusion of magnesium alloys. 14 This enhances the interaction between the phase meeting and dislocation. Therefore, light rare earth elements neodymium, praseodymium, and promethium, as well as nanoscale bulk Nd3Ag3Mg, are important. 14 The synergistic effect enhances the mechanical properties and uniform degradation performance of magnesium alloys, resulting in superior processing performance after hot extrusion and aging treatment. This facilitates the production of more precise and refined devices (millimeter-level dimensions). Simultaneously, the presence of light rare earth elements neodymium, praseodymium, and promethium, along with nanoscale bulk Nd3Ag3Mg, contributes to the process. 14 The neodymium in the phase is gradually released into the body as the alloy degrades. The diffusion rate is extremely slow, and the concentration is greatly reduced after being diluted by human body fluids. It has no toxic effect on the human body, thus ensuring the biosafety and biocompatibility of the magnesium alloy.

[0022] Meanwhile, the addition of silver to lightweight magnesium alloy biomedical materials can refine the grain structure of magnesium alloys, while improving their strength, plasticity, and hardness; silver, along with the light rare earth element neodymium and magnesium, forms nano-sized bulk Nd3Ag3Mg. 14 Phase that hinders dislocation movement and enhances the mechanical properties of magnesium alloys; silver element and nano-sized bulk Nd3Ag3Mg 14 The silver element in the sample can disrupt the cell wall and cell membrane of bacteria, interfering with their enzyme system and DNA replication, leading to bacterial death. This provides antibacterial, bactericidal, anti-inflammatory, and anti-infective properties for magnesium alloys and their products, greatly reducing the risk of infection in implants. Simultaneously, it activates cells, promoting tissue repair and wound healing. Furthermore, the content of the light rare earth elements Nd, Pr, and Pm, along with Ag, is limited to ensure the production of nano-sized bulk Nd3Ag3Mg. 14 At the same time, it can also improve the mechanical properties, uniform degradation properties, processing properties and biological functions of magnesium alloy biomedical materials, especially providing antibacterial, bactericidal, anti-inflammatory and anti-infective biological functions, while activating cells and promoting tissue repair and wound healing.

[0023] Furthermore, this application also provides a method for preparing medical bio-magnesium alloy materials containing trace amounts of light rare earth elements. The simultaneous addition of the light rare earth elements neodymium, praseodymium, and promethium creates a purified melt with synergistic effects of hydrogen removal, oxygen removal, sulfur removal, iron removal, inclusion removal, and degassing refining. Moreover, by controlling the silver content, solution treatment, hot extrusion deformation, and aging treatment processes, the nano-sized bulk Nd3Ag3Mg can be controlled. 14 The quantity and distribution of phases alter the composition and structure of degradation products on the magnesium alloy surface, forming a denser protective film. This improves mechanical properties while controlling the uniform degradation rate within a range that matches the bone tissue healing rate. Simultaneously, trace amounts of light rare earth elements Nd, Pr, and Pm enhance the melt flowability and optimize processing performance during magnesium alloy material preparation, working in conjunction with nanoscale bulk Nd3Ag3Mg. 14 The combined effect allows magnesium alloy materials to be easily machined after hot extrusion and aging treatment to obtain more precise medical device products with dimensions at the millimeter level, and can be customized according to patient needs, thus improving the application of magnesium alloy materials in biomaterials and medical materials. Attached Figure Description

[0024] Figure 1 Metallographic photograph of the medical-grade bio-magnesium alloy material prepared in Example 1 of this invention;

[0025] Figure 2 The nano-sized bulk Nd3Ag3Mg in the medical bio-magnesium alloy material prepared in Example 1 of this invention 14 Scanning electron microscope images of the phase;

[0026] Figure 3 Scanning electron microscope image of the surface morphology of the medical bio-magnesium alloy material prepared in Example 1 of the present invention after degradation in SBF simulated body fluid for 35 days;

[0027] Figure 4 This is a cell growth photograph of 3T3 cells cultured for 37 days after the medical-grade magnesium alloy material prepared in Example 1 of this invention was soaked in the extract. Detailed Implementation

[0028] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention.

[0029] In existing technologies, magnesium alloy materials used as medical and biomaterials need to simultaneously possess excellent mechanical properties, uniform degradation performance, processing performance, biosafety, biocompatibility, as well as antibacterial, anti-inflammatory, and anti-infective properties and functions, cell activation, and promotion of tissue repair and wound healing. However, existing magnesium alloy materials cannot simultaneously possess all of the above properties and functions. In view of this, this application provides a medical and biomaterial magnesium alloy containing trace amounts of light rare earth elements. By introducing light rare earth elements Pr and Pm and controlling their content, it can promote fine grain strengthening and also promote better combination of Mg, Ag, and Nd elements in a specific atomic ratio to generate nano-sized bulk Nd3Ag3Mg. 14 The resulting medical-grade bio-magnesium alloy material possesses excellent mechanical properties, uniform degradation performance, processing performance, biosafety, and biocompatibility, while also exhibiting antibacterial, anti-inflammatory, and anti-infective properties, cell activation, and promotion of tissue repair and wound healing. Specifically, this application provides a magnesium alloy material containing trace amounts of light rare earth elements, comprising, by mass percentage: Nd 1.0~5.0%, Ag 0.5~1.8%, Pr 0.15~0.65%, Pm 0.15~0.65%, with the balance being Mg and unavoidable impurity elements, wherein (Nd+Pr+Pm) / Ag=3.15~5.8.

[0030] In the medical-grade bio-magnesium alloy material containing trace amounts of light rare earth elements provided in this application, Nd element has solid solution strengthening and grain refinement effects, while the high solubility of Nd exhibits outstanding biocompatibility. The Nd content is 1.0~5.0%, specifically, the Nd content is 1.6~4.9%, more specifically, the Nd content is 3.1~4.8%; for example, in this application, the Nd content is 1.1%, 1.2%, 1.4%, 1.5%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, and 4.7%.

[0031] The Pr content is 0.15~0.65%, with examples of 0.2%, 0.3%, 0.4%, and 0.5%. The Pm content is 0.15~0.65%, with examples of 0.2%, 0.3%, 0.4%, and 0.5%. The addition of trace amounts of light rare earth elements Pr and Pm can promote grain refinement and also promote the better formation of nano-sized bulk Nd3Ag3Mg with specific atomic ratios of Mg, Ag, and Nd. 14 The addition of these two rare earth elements primarily generates a new second phase, namely nano-sized bulk Nd3Ag3Mg, which is beneficial for improving the mechanical properties and degradation resistance of magnesium alloys. 14 This phase, and also affects the quantity and distribution of existing organizations.

[0032] Specifically, the light rare earth elements neodymium, praseodymium, and promethium can work together to significantly refine the grain size of the alloy. At the same time, they all have high solid solubility in magnesium, and their atoms can dissolve into the magnesium matrix. They can work together to enhance the bonding force between atoms, cause lattice distortion in the matrix, slow down the atomic diffusion rate, hinder dislocation movement, and strengthen the matrix.

[0033] The content of Ag is 0.5% to 1.8%, specifically, the content of Ag is 1.1% to 1.7%; for example, in this application, the content of Ag is 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.2%, 1.3%, 1.4%, 1.5%, and 1.6%. The addition of silver can refine the grain structure of magnesium alloys, while improving the strength, plasticity, and hardness of magnesium alloys.

[0034] Furthermore, the light rare earth elements praseodymium and promethium can promote the formation of stable nano-sized bulk Nd3Ag3Mg by light rare earth elements neodymium, silver, and magnesium during alloy solidification. 14The reinforcing phase is dispersed at grain boundaries and within grains, and consists of nano-sized bulk Nd3Ag3Mg. 14 Pinning grain boundaries inhibits grain boundary slip and hinders dislocation movement; the light rare earth elements praseodymium and promethium can promote the formation of a dispersed strengthening phase (nano-sized bulk Nd3Ag3Mg) by light rare earth elements neodymium with silver and magnesium during long-term aging after hot extrusion of magnesium alloys. 14 This enhances the interaction between the phase meeting and dislocation. Therefore, light rare earth elements neodymium, praseodymium, and promethium, as well as nanoscale bulk Nd3Ag3Mg, are important. 14 The synergistic effect enhances the mechanical properties and uniform degradation performance of magnesium alloys, resulting in superior processing performance after hot extrusion and aging treatment. This facilitates the production of more precise and refined devices (millimeter-level dimensions). Simultaneously, the presence of light rare earth elements neodymium, praseodymium, and promethium, along with nanoscale bulk Nd3Ag3Mg, contributes to the process. 14 The neodymium in the phase is gradually released into the body as the alloy degrades, with an extremely slow diffusion rate. Its concentration is significantly reduced after dilution in bodily fluids, posing no toxic effects to humans and ensuring the biosafety and biocompatibility of the magnesium alloy. Silver, along with the light rare earth elements neodymium and magnesium, forms nanoscale bulk Nd3Ag3Mg. 14 Phase that hinders dislocation movement and enhances the mechanical properties of magnesium alloys; silver element and nano-sized bulk Nd3Ag3Mg 14 The silver element in the sample can destroy the cell wall and cell membrane of bacteria, interfere with their enzyme system and DNA replication, leading to bacterial death. This provides antibacterial, bactericidal, anti-inflammatory and anti-infective protection for magnesium alloys and their products, greatly reducing the risk of infection of implants. At the same time, it activates cells and promotes tissue repair and wound healing.

[0035] Furthermore, this application specifies that (Nd+Pr+Pm) / Ag = 3.15~5.8, specifically (Nd+Pr+Pm) / Ag = 3.16~5.0, more specifically (Nd+Pr+Pm) / Ag = 3.18~4.8, more specifically (Nd+Pr+Pm) / Ag = 3.4~4.5, and more specifically (Nd+Pr+Pm) / Ag = 3.8~4.2. In this application, the content of the light rare earth elements Nd, Pr, and Pm with Ag is limited, and this relationship is limited to ensure the obtaining of nano-sized bulk Nd3Ag3Mg. 14 At the same time, it can also improve the mechanical properties, uniform degradation properties, processing properties and biological functions of magnesium alloy biomedical materials, especially providing antibacterial, bactericidal, anti-inflammatory and anti-infective biological functions, while activating cells and promoting tissue repair and wound healing.

[0036] The medical bio-magnesium alloy material applied in this application includes nano-sized Nd3Ag3Mg. 14 Phase, the Nd3Ag3Mg 14The phase dimensions are 300~400nm in length and 200~300nm in width.

[0037] The medical-grade magnesium alloy material provided in this application also includes impurity elements, specifically one or more of Fe, Cu, Si and Ni, wherein Fe ≤ 0.005%, Cu ≤ 0.0005%, Si ≤ 0.005%, and Ni ≤ 0.0005%.

[0038] Furthermore, this application also provides a method for preparing the above-mentioned medical bio-magnesium alloy material, including the following steps:

[0039] S1. Pure magnesium raw material, pure silver raw material, magnesium-neodymium master alloy, magnesium-praseodymium master alloy and magnesium-promethium master alloy are mixed according to the component ratio, then melted and cast to obtain magnesium alloy ingots.

[0040] S2. Homogenize the magnesium alloy ingot;

[0041] S3. The magnesium alloy ingot obtained in step S2 is hot-extruded, then aged, and cooled to obtain medical bio-magnesium alloy material.

[0042] In the preparation process of medical bio-magnesium alloy materials, pure magnesium raw materials, pure silver raw materials, magnesium-praseodymium master alloys, magnesium-neodymium master alloys, and magnesium-promethium master alloys are first mixed and smelted according to the component ratio to obtain a magnesium alloy melt. In the above process, the pure magnesium raw materials and pure silver raw materials are high-purity magnesium ingots and high-purity silver ingots, respectively. The praseodymium content in the magnesium-praseodymium master alloy is 20 wt%, the promethium content in the magnesium-promethium master alloy is 20 wt%, and the neodymium content in the magnesium-neodymium master alloy is 20 wt%. The above pure metal materials and master alloys are first cut and polished to remove the surface oxide scale. In this application, the smelting is specifically carried out in a low-carbon steel crucible of a silicon carbide rod resistance furnace. Before smelting the alloy, the oxide scale and other impurities in the furnace chamber must be cleaned, and the operation of the silicon carbide rod resistance furnace must be checked to ensure it is functioning properly. The slag and oxide scale in the crucible must be removed, and the crucible must be checked for damage or severe oxide scale detachment that could thin the crucible wall and affect its use.

[0043] After the above preparations are completed, the pure magnesium raw material and the magnesium-neodymium master alloy are mixed and preheated to 180-195°C. After holding at this temperature, the mixture is placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 320-340°C. The mixture is mixed for 10-20 minutes, and then a protective gas is introduced into the resistance furnace. The mixture is then heated to 800-830°C for 30-40 minutes to obtain the initial alloy melt. The protective gas is a mixture of SF6 and CO2 with a volume ratio of 1:(170-200).

[0044] The pure silver raw material is added to the initial alloy melt and stirred for 20-30 minutes. The temperature is raised again to 800-830°C, and then magnesium praseodymium master alloy and magnesium promethium master alloy are added. After stirring, the mixture is allowed to stand for 30-40 minutes and then heated to 800-830°C. The mixture is stirred, allowed to stand, and kept at this temperature for 3-5 hours to obtain a magnesium alloy melt.

[0045] In the above smelting process, the preheating temperature is specifically 185~190℃, the mixture is specifically heated to 810~820℃, the volume ratio of SF6 to CO2 is specifically 1:(170~180), the reheating temperature is specifically 810~820℃, and the further heating temperature is 810~822℃.

[0046] This application then cools the aforementioned magnesium alloy molten metal to 700-740°C, pours the alloy solution into a water-cooled mold under gas protection, and allows it to cool naturally for 30-40 minutes to obtain a magnesium alloy ingot. Before casting, it is necessary to remove oxide slag from the surface of the alloy melt to prevent slag from entering the mold with the alloy during casting, ensuring the fluidity of the melt and the quality of the alloy. While ensuring good alloy fluidity, the lowest possible casting temperature should be used to reduce oxidation of the alloy melt. Gas protection must be used during casting. A slag-blocking tool should be placed at the gate during casting to prevent slag from entering the mold and to ensure a stable flow rate of the alloy melt. During casting, the crucible spout should be as close to the gate as possible, with gentle pressure to ensure a smooth liquid flow, preventing splashing, flow interruption, and turbulence, and ensuring no gas entrapment.

[0047] According to the present invention, after obtaining the magnesium alloy ingot, it is subjected to homogenization treatment to improve the deformability of the magnesium alloy material, eliminate compositional segregation (microscopic segregation), and ensure that some reinforcing phases are dissolved in the matrix. The homogenization treatment is carried out in a vacuum heat treatment furnace and includes a primary homogenization treatment and a secondary homogenization treatment performed sequentially. The temperature of the primary homogenization treatment is 370~390℃, and the holding time is 5~8h. The temperature of the secondary homogenization treatment is 400~450℃, and the holding time is 3~6h. Specifically, the temperature of the primary homogenization treatment is 375~385℃, and the holding time is 5.5~7.5h. The temperature of the secondary homogenization treatment is 405~440℃, and the holding time is 3.5~5h. More specifically, the temperature of the primary homogenization treatment is 370~380℃, and the holding time is 6.0~7.0h. The temperature of the secondary homogenization treatment is 410~430℃, and the holding time is 4~4.5h. After the above homogenization process, air cooling was performed.

[0048] After homogenization, the magnesium alloy ingot needs to be machined before hot extrusion to ensure that the surface of the extruded billet is free of protrusions, inclusions, and depressions.

[0049] This application then performs hot extrusion on the homogenized magnesium alloy ingot. Before the hot extrusion, the process includes: placing the extrusion billet in a blast furnace, adjusting the furnace temperature to an extrusion temperature of 340-360°C, and holding the temperature for 8-11 hours; placing the extrusion die in a small box furnace, adjusting the furnace temperature to 370-390°C, and holding the temperature for later use; setting the extrusion temperature of the extruder to 400-410°C, and the temperature of the ingot holder to 350-390°C. The hot extrusion temperature is 340-360°C, and the hot extrusion speed is 0.5-1.2 m / s; specifically, the hot extrusion temperature is 342-357°C, and the hot extrusion speed is 0.65-0.70 m / s; the hot extrusion is performed at the above temperatures to give the magnesium alloy material excellent strength, plasticity, and hardness.

[0050] Finally, the hot-extruded billet undergoes aging treatment and then cooling to obtain a magnesium alloy material. In this process, the aging treatment includes a first-stage aging treatment and a second-stage aging treatment performed sequentially. The first-stage aging treatment is performed at a temperature of 180-210℃ for 6-8 hours, and the second-stage aging treatment is performed at a temperature of 200-220℃ for 3-5 hours. Specifically, the first-stage aging treatment is performed at a temperature of 190-200℃ for 7-7.5 hours, and the second-stage aging treatment is performed at a temperature of 205-210℃ for 3.5-4 hours. The cooling is air cooling.

[0051] In the above preparation method, the simultaneous addition of light rare earth elements neodymium, praseodymium, and promethium has a synergistic effect on purifying the melt and refining it by removing hydrogen, oxygen, sulfur, iron, and inclusions. Furthermore, by controlling the silver content, solution treatment, hot extrusion deformation, and aging treatment, the nano-sized bulk Nd3Ag3Mg can be controlled. 14 The quantity and distribution of phases alter the composition and structure of degradation products on the magnesium alloy surface, forming a denser protective film. This improves mechanical properties while controlling the uniform degradation rate within a range that matches the bone tissue healing rate. Simultaneously, trace amounts of light rare earth elements Nd, Pr, and Pm enhance the melt flowability and optimize processing performance during magnesium alloy material preparation, working in conjunction with nanoscale bulk Nd3Ag3Mg. 14 The combined effect allows magnesium alloy materials to be easily machined after hot extrusion and aging treatment to obtain more precise medical device products with dimensions at the millimeter level, and can be customized according to patient needs, thus improving the application of magnesium alloy materials in biomaterials and medical materials.

[0052] This application also provides the application of the above-mentioned medical and biological magnesium alloy materials in medical materials and / or biological materials.

[0053] To further understand the present invention, the following detailed description of the medical-grade bio-magnesium alloy material containing trace amounts of light rare earth elements and its preparation method is provided in conjunction with embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0054] Example 1

[0055] The preparation method of Mg-3.52Nd-1.21Ag-0.31Pr-0.24Pm magnesium alloy material is as follows:

[0056] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.52Nd-1.21Ag-0.31Pr-0.24Pm (burn-off amount 10%), which includes 8.6284 kg of high-purity magnesium ingots, 1.936 kg of magnesium-neodymium master alloy, 0.1331 kg of high-purity silver ingots, 0.1705 kg of magnesium-praseodymium master alloy, and 0.132 kg of magnesium-promethium master alloy.

[0057] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 195°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 325°C.

[0058] (2) After mixing the above raw materials for 10 minutes, a mixture of SF6 and CO2 (volume ratio of 1:170) is introduced as a protective gas to raise the melt temperature to 805°C within 40 minutes.

[0059] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 25 minutes. When the melt temperature rises to 805°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 35 minutes. Continue to heat up to 810°C. After it is completely melted, stir, let stand and keep warm for 4 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 35 minutes, take out the magnesium alloy ingot.

[0060] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 375°C, hold for 7 hours, then heat to 405°C, hold for 3.5 hours, and then air cool.

[0061] (5) The billet obtained in step (4) is extruded at 345°C. The temperature of the mold and the cylinder is 345°C, and the extrusion speed is set to 0.7 m / s.

[0062] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 210℃ and the holding time is 7.5h. The temperature of the second aging treatment is 205℃ and the holding time is 3.5h. After removal, it is air-cooled to obtain magnesium alloy material.

[0063] According to the test results, the chemical composition (mass percentage) of the medical bio-magnesium alloy material prepared in this embodiment is as follows: 3.52% Nd, 1.21% Ag, 0.31% Pr, 0.24% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), and the balance is Mg.

[0064] The mechanical properties of the magnesium alloy material prepared in this embodiment were tested, and the results showed that the tensile strength was 356±2MPa, the yield strength was 301±2MPa, and the elongation was 8±0.3%.

[0065] Figure 1 The image shows a metallographic photograph of the biomedical magnesium alloy material prepared in this embodiment. As can be seen from the image, the grain size of the magnesium alloy biomedical material prepared in this embodiment can be refined to 14.5±0.2µm and is uniformly distributed. This is also the main reason why the magnesium alloy biomedical material has excellent mechanical properties, uniform degradation properties and processing properties.

[0066] Figure 2 The metallographic structure of the medical-grade magnesium alloy material prepared in this embodiment contains Nd3Ag3Mg. 14 The scanning electron microscope image shows the bulk Nd3Ag3Mg phase. 14 The second phase is nanoscale, consisting of bulk Nd3Ag3Mg at nanoscale. 14 The phase is the main reason why magnesium alloy biomedical materials have excellent mechanical properties, uniform degradation properties and processing properties.

[0067] Figure 3 The image shows a scanning electron microscope (SEM) image of the surface morphology of the medical bio-magnesium alloy material prepared in this embodiment after 35 days of degradation in SBF simulated body fluid. As can be seen from the image, specific components and structures alter the composition and structure of the degradation products on the surface of the magnesium alloy bio-medical material, forming a denser protective film. This slows down the degradation rate of the lightweight magnesium alloy bio-medical material in the physiological environment and improves the uniform degradation performance.

[0068] Figure 4The image shows the cell growth of 3T3 cells cultured for 37 days after using the 100% extract of the lightweight magnesium alloy biomedical material prepared in this embodiment. As can be seen from the image, the vast majority of cells cultured in the 100% extract were in a normal and healthy state (elongated and adherent to the culture wall), and the number of cells increased significantly with the increase of culture time. This indicates that the magnesium alloy biomedical material prepared in this embodiment is non-toxic to human tissues. The healthy and activated cells that continuously proliferate and maintain good adhesion with the culture time are due to the strong and long-lasting antibacterial, bactericidal, anti-inflammatory and anti-infective effects of the magnesium alloy biomedical material, as well as its biological functions of activating cells, promoting tissue repair and wound healing.

[0069] Example 2

[0070] The preparation method of Mg-3.72Nd-1.35Ag-0.33Pr-0.22Pm magnesium alloy material is as follows:

[0071] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.72Nd-1.35Ag-0.33Pr-0.22Pm (burn-off amount 10%), which includes 8.503 kg of high-purity magnesium ingots, 2.046 kg of magnesium-neodymium master alloy, 0.1485 kg of high-purity silver ingots, 0.1815 kg of magnesium-praseodymium master alloy, and 0.121 kg of magnesium-promethium master alloy.

[0072] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 194°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 328°C.

[0073] (2) After mixing the above raw materials for 15 minutes, a mixture of SF6 and CO2 (volume ratio of 1:175) is introduced as a protective gas to raise the melt temperature to 802°C within 35 minutes.

[0074] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 27 minutes. When the temperature of the melt rises to 802°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 37 minutes. Continue to heat up to 812°C. After it is completely melted, stir, let stand and keep warm for 4.5 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 36 minutes, take out the magnesium alloy ingot.

[0075] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 372°C, hold for 7 hours, then heat to 412°C, hold for 4 hours, and then air cool.

[0076] (5) The billet obtained in step (4) is extruded at 347°C, the temperature of the die and the cylinder is 343°C, and the extrusion speed is set to 0.68m / s;

[0077] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 210℃ and the holding time is 6h. The temperature of the second aging treatment is 202℃ and the holding time is 4h. After removal, it is air-cooled to obtain magnesium alloy material.

[0078] According to the test results, the chemical composition (mass percentage) of the medical-grade magnesium alloy material prepared in this embodiment is as follows: 3.72% Nd, 1.35% Ag, 0.33% Pr, 0.22% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), and the balance is Mg.

[0079] The mechanical properties of the magnesium alloy material prepared in this embodiment were tested. The results showed that the tensile strength was 358±2MPa, the yield strength was 303±1MPa, and the elongation was 8.7±0.2%.

[0080] Example 3

[0081] The preparation method of Mg-3.8Nd-1.38Ag-0.35Pr-0.25Pm magnesium alloy material is as follows:

[0082] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.8Nd-1.38Ag-0.35Pr-0.25Pm (burn-off amount 10%), which includes 8.4282 kg of high-purity magnesium ingots, 2.09 kg of magnesium-neodymium master alloy, 0.1518 kg of high-purity silver ingots, 0.1925 kg of magnesium-praseodymium master alloy, and 0.1375 kg of magnesium-promethium master alloy.

[0083] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 195°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 327°C.

[0084] (2) After mixing the above raw materials for 18 minutes, a mixture of SF6 and CO2 (volume ratio of 1:178) is introduced as a protective gas to raise the melt temperature to 800°C within 38 minutes.

[0085] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 27 minutes. When the temperature of the melt rises to 800°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 37 minutes. Continue to heat up to 811°C. After it is completely melted, stir, let stand and keep warm for 4.5 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 37 minutes, take out the magnesium alloy ingot.

[0086] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 374°C, hold for 5.2 hours, then heat to 408°C and hold for 3.4 hours, then remove and air cool.

[0087] (5) The billet obtained in step (4) is extruded at 342°C, the temperature of the die and the cylinder is 340°C, and the extrusion speed is set to 0.65m / s;

[0088] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 210℃ and the holding time is 7h. The temperature of the second aging treatment is 202℃ and the holding time is 3h. After removal, it is air-cooled to obtain magnesium alloy material.

[0089] According to the test results, the chemical composition (mass percentage) of the medical bio-magnesium alloy material prepared in this embodiment is as follows: 3.8% Nd, 1.38% Ag, 0.35% Pr, 0.25% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), and the balance is Mg.

[0090] The mechanical properties of the magnesium alloy material prepared in this embodiment were tested. The results showed that the tensile strength was 359±3MPa, the yield strength was 308±1MPa, and the elongation was 8.8±0.2%.

[0091] Example 4

[0092] The preparation method of Mg-3.9Nd-1.4Ag-0.3Pr-0.26Pm magnesium alloy material is as follows:

[0093] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.9Nd-1.4Ag-0.3Pr-0.26Pm (burn-off amount 10%), which includes 8.393 kg of high-purity magnesium ingots, 2.145 kg of magnesium-neodymium master alloy, 0.154 kg of high-purity silver ingots, 0.165 kg of magnesium-praseodymium master alloy, and 0.143 kg of magnesium-promethium master alloy.

[0094] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 194°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 326°C.

[0095] (2) After mixing the above raw materials for 19 minutes, a mixture of SF6 and CO2 (volume ratio of 1:175) is introduced as a protective gas to raise the melt temperature to 801℃ within 36 minutes.

[0096] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 28 minutes. When the melt temperature rises to 801°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 38 minutes. Continue to heat up to 812°C. After it is completely melted, stir, let stand and keep warm for 3.8 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 32 minutes, take out the magnesium alloy ingot.

[0097] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 380°C, hold for 5.5 hours, then heat to 437°C and hold for 3 hours, then remove and air cool.

[0098] (5) The billet obtained in step (4) is extruded at 340°C, the temperature of the die and the cylinder is 338°C, and the extrusion speed is set to 0.67m / s;

[0099] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 207℃ and the holding time is 7h. The temperature of the second aging treatment is 212℃ and the holding time is 3h. After removal, it is air-cooled to obtain magnesium alloy material.

[0100] According to the test results, the chemical composition (mass percentage) of the medical bio-magnesium alloy material prepared in this embodiment is as follows: 3.9% Nd, 1.4% Ag, 0.3% Pr, 0.26% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), and the balance is Mg.

[0101] The mechanical properties of the magnesium alloy material prepared in this embodiment were tested. The results showed that the tensile strength was 360±1MPa, the yield strength was 310±3MPa, and the elongation was 8.7±0.2%.

[0102] Example 5

[0103] The preparation method of Mg-3.3Nd-1.21Ag-0.31Pr-0.24Pm magnesium alloy material is as follows:

[0104] (1) Smelting was carried out in a silicon carbide rod resistance furnace equipped with a low carbon steel crucible, with 10 kg prepared per furnace; high-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy were prepared according to the alloy ratio of Mg-3.3Nd-1.21Ag-0.31Pr-0.24Pm (burn-off amount 10%), which included 8.7494 kg of high-purity magnesium ingots, 1.815 kg of magnesium-neodymium master alloy, 0.1331 kg of high-purity silver ingots, 0.1705 kg of magnesium-praseodymium master alloy, and 0.132 kg of magnesium-promethium master alloy;

[0105] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 195°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 325°C.

[0106] (2) After mixing the above raw materials for 10 minutes, a mixture of SF6 and CO2 (volume ratio of 1:170) is introduced as a protective gas to raise the melt temperature to 805°C within 40 minutes.

[0107] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 25 minutes. When the melt temperature rises to 805°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 35 minutes. Continue to heat up to 810°C. After it is completely melted, stir, let stand and keep warm for 4 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 35 minutes, take out the magnesium alloy ingot.

[0108] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 375°C, hold for 7 hours, then heat to 405°C, hold for 3.5 hours, and then air cool.

[0109] (5) The billet obtained in step (4) is extruded at 345°C. The temperature of the mold and the cylinder is 345°C, and the extrusion speed is set to 0.7 m / s.

[0110] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 210℃ and the holding time is 7.5h. The temperature of the second aging treatment is 205℃ and the holding time is 3.5h. After removal, it is air-cooled to obtain magnesium alloy material.

[0111] According to the test results, the chemical composition (mass percentage) of the medical bio-magnesium alloy material prepared in this embodiment is as follows: 3.3% Nd, 1.21% Ag, 0.31% Pr, 0.24% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), and the balance is Mg.

[0112] The mechanical properties of the magnesium alloy material prepared in this embodiment were tested, and the results showed that the tensile strength was 330±1MPa, the yield strength was 290±3MPa, and the elongation was 7.5±0.3%.

[0113] Example 6

[0114] The preparation method of Mg-3.52Nd-0.9Ag-0.31Pr-0.24Pm magnesium alloy material is as follows:

[0115] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.52Nd-0.9Ag-0.31Pr-0.24Pm (burn-off amount 10%), which includes 8.6625 kg of high-purity magnesium ingots, 1.936 kg of magnesium-neodymium master alloy, 0.099 kg of high-purity silver ingots, 0.1705 kg of magnesium-praseodymium master alloy, and 0.132 kg of magnesium-promethium master alloy.

[0116] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 195°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 325°C.

[0117] (2) After mixing the above raw materials for 10 minutes, a mixture of SF6 and CO2 (volume ratio of 1:170) is introduced as a protective gas to raise the melt temperature to 805°C within 40 minutes.

[0118] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 25 minutes. When the melt temperature rises to 805°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 35 minutes. Continue to heat up to 810°C. After it is completely melted, stir, let stand and keep warm for 4 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 35 minutes, take out the magnesium alloy ingot.

[0119] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 375°C, hold for 7 hours, then heat to 405°C, hold for 3.5 hours, and then air cool.

[0120] (5) The billet obtained in step (4) is extruded at 345°C. The temperature of the mold and the cylinder is 345°C, and the extrusion speed is set to 0.7 m / s.

[0121] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 210℃ and the holding time is 7.5h. The temperature of the second aging treatment is 205℃ and the holding time is 3.5h. After removal, it is air-cooled to obtain magnesium alloy material.

[0122] According to the test results, the chemical composition (mass percentage) of the medical bio-magnesium alloy material prepared in this embodiment is as follows: 3.52% Nd, 0.9% Ag, 0.31% Pr, 0.24% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), and the balance is Mg.

[0123] The mechanical properties of the magnesium alloy material prepared in this embodiment were tested. The results showed that the tensile strength was 341±2MPa, the yield strength was 297±2MPa, and the elongation was 7.5±0.3%.

[0124] Comparative Example 1

[0125] The preparation method of Mg-3.6Nd-1.25Ag-0.26Sc magnesium alloy material is as follows:

[0126] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy and magnesium-scandium master alloy are prepared according to the alloy ratio of Mg-3.6Nd-1.25Ag-0.26Sc (burn-off amount 10%), which includes 8.7395 kg of high-purity magnesium ingots, 1.98 kg of magnesium-neodymium master alloy, 0.1375 kg of high-purity silver ingots and 0.143 kg of magnesium-scandium master alloy.

[0127] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 194°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 320°C.

[0128] (2) After mixing the above raw materials for 15 minutes, a mixture of SF6 and CO2 (volume ratio of 1:172) is introduced as a protective gas to raise the melt temperature to 805°C within 25 minutes.

[0129] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 24 minutes. When the temperature of the melt rises to 805°C again, add the magnesium scandium intermediate alloy, stir and let stand for 30 minutes. Continue to heat up to 810°C. After it is completely melted, stir, let stand and keep warm for 3.5 hours. Then pour it into a water-cooled mold under a protective gas. After cooling naturally for 30 minutes, take out the magnesium alloy ingot.

[0130] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 378°C, hold for 7 hours, then heat to 407°C, hold for 3 hours, and then remove and air cool.

[0131] (5) The billet obtained in step (4) is extruded at 340°C, the temperature of the die and the cylinder is 337°C, and the extrusion speed is set to 0.65m / s;

[0132] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 208℃ and the holding time is 7.2h. The temperature of the second aging treatment is 200℃ and the holding time is 3.2h. After removal, it is air-cooled to obtain magnesium alloy material.

[0133] The chemical composition (mass percentage) of the medical-grade magnesium alloy material prepared in this comparative example is as follows: 3.6% Nd, 1.25% Ag, 0.26% Sc, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), with the balance being Mg.

[0134] The mechanical properties of the magnesium alloy material prepared in this comparative example were tested. The results showed that the tensile strength was 296±1MPa, the yield strength was 229±2MPa, and the elongation was 7.2±0.1%.

[0135] Comparative Example 2

[0136] The preparation method of Mg-3.9Nd-1.39Ag-0.21Pr-0.22Pm magnesium alloy material is as follows:

[0137] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.9Nd-1.39Ag-0.21Pr-0.22Pm (burn-off amount 10%), which includes 8.4656 kg of high-purity magnesium ingots, 2.145 kg of magnesium-neodymium master alloy, 0.1529 kg of high-purity silver ingots, 0.1155 kg of magnesium-praseodymium master alloy, and 0.121 kg of magnesium-promethium master alloy.

[0138] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 197°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 329°C.

[0139] (2) After mixing the above raw materials for 18 minutes, a mixture of SF6 and CO2 (volume ratio of 1:178) is introduced as a protective gas, and the melt temperature is raised to 807°C within 42 minutes.

[0140] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 30 minutes. When the melt temperature rises to 807°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 38 minutes. Continue to heat up to 813°C. After it is completely melted, stir, let stand and keep warm for 4.5 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 40 minutes, take out the magnesium alloy ingot.

[0141] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 375°C, hold for 7 hours, then heat to 410°C, hold for 3 hours, and then air cool.

[0142] (5) The billet obtained in step (4) is extruded at 346°C, the temperature of the mold and the cylinder is 343°C, and the extrusion speed is set to 0.69m / s;

[0143] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 196℃ and the holding time is 7.6h. The temperature of the second aging treatment is 207℃ and the holding time is 3.7h. After removal, it is air-cooled to obtain magnesium alloy material.

[0144] The chemical composition (mass percentage) of the medical-grade magnesium alloy material prepared in this comparative example is as follows: 3.9% Nd, 1.39% Ag, 0.21% Pr, 0.22% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), with the balance being Mg.

[0145] The mechanical properties of the magnesium alloy material prepared in this comparative example were tested. The results showed that the tensile strength was 297±1MPa, the yield strength was 221±2MPa, and the elongation was 7.1±0.2%.

[0146] Comparative Example 3

[0147] The preparation method of Mg-5.3Nd-1.85Ag-0.41Pr-0.45Pm magnesium alloy material is as follows:

[0148] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-5.3Nd-1.85Ag-0.41Pr-0.45Pm (burn-off amount 10%), which includes 7.4085 kg of high-purity magnesium ingots, 2.915 kg of magnesium-neodymium master alloy, 0.2035 kg of high-purity silver ingots, 0.2255 kg of magnesium-praseodymium master alloy, and 0.2475 kg of magnesium-promethium master alloy.

[0149] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 196°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 328°C.

[0150] (2) After mixing the above raw materials for 15 minutes, a mixture of SF6 and CO2 (volume ratio of 1:177) is introduced as a protective gas, and the melt temperature is raised to 807°C within 40 minutes.

[0151] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 28 minutes. When the melt temperature rises to 807°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 38 minutes. Continue to heat up to 816°C. After it is completely melted, stir, let stand and keep warm for 4.5 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 37 minutes, take out the magnesium alloy ingot.

[0152] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 375°C, hold for 5.5 h, then heat to 416°C, hold for 3.5 h, and then air cool.

[0153] (5) The billet obtained in step (4) is extruded at 346°C, the temperature of the mold and the cylinder is 344°C, and the extrusion speed is set to 0.68m / s;

[0154] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 200℃ and the holding time is 7.8h. The temperature of the second aging treatment is 209℃ and the holding time is 3.8h. After removal, it is air-cooled to obtain magnesium alloy material.

[0155] The chemical composition (mass percentage) of the medical-grade magnesium alloy material prepared in this comparative example is as follows: 5.3% Nd, 1.85% Ag, 0.41% Pr, 0.45% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), with the balance being Mg.

[0156] The mechanical properties of the magnesium alloy material prepared in this comparative example were tested. The results showed that the tensile strength was 252±1MPa, the yield strength was 189±3MPa, and the elongation was 6.9±0.2%.

[0157] Comparative Example 4

[0158] The preparation method of Mg-3.7Nd-0.48Ag-0.35Pr-0.32Pm magnesium alloy material is as follows:

[0159] (1) Smelting was carried out in a silicon carbide rod resistance furnace equipped with a low carbon steel crucible, with 10 kg prepared per furnace; high-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy were prepared according to the alloy ratio of Mg-3.7Nd-0.48Ag-0.35Pr-0.32Pm (burn-off amount 10%), which included 8.5437 kg of high-purity magnesium ingots, 2.035 kg of magnesium-neodymium master alloy, 0.0528 kg of high-purity silver ingots, 0.1925 kg of magnesium-praseodymium master alloy, and 0.176 kg of magnesium-promethium master alloy;

[0160] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 197°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 322°C.

[0161] (2) After mixing the above raw materials for 17 minutes, a mixture of SF6 and CO2 (volume ratio of 1:174) is introduced as a protective gas, and the melt temperature is raised to 804℃ within 38 minutes.

[0162] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 29 minutes. When the melt temperature rises to 804°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 36 minutes. Continue to heat up to 813°C. After it is completely melted, stir, let stand and keep warm for 4.2 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 36 minutes, take out the magnesium alloy ingot.

[0163] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 370°C, hold for 7 hours, then heat to 420°C, hold for 3.2 hours, and then air cool.

[0164] (5) The billet obtained in step (4) is extruded at 346°C, the temperature of the mold and the cylinder is 345°C, and the extrusion speed is set to 0.67m / s;

[0165] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 210℃ and the holding time is 8h. The temperature of the second aging treatment is 207℃ and the holding time is 4h. After being taken out, it is air-cooled to obtain magnesium alloy material.

[0166] The alloy chemical composition (mass percentage) of the medical-grade magnesium alloy material prepared in this comparative example is as follows: 3.7% Nd, 0.48% Ag, 0.35% Pr, 0.32% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), with the balance being Mg.

[0167] The mechanical properties of the magnesium alloy material prepared in this comparative example were tested. The results showed that the tensile strength was 247±3MPa, the yield strength was 186±1MPa, and the elongation was 6.7±0.2%.

[0168] Comparative Example 5

[0169] The preparation method of Mg-3.52Nd-1.21Ag-0.31Pr-0.24Pm magnesium alloy material is as follows:

[0170] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.52Nd-1.21Ag-0.31Pr-0.24Pm (burn-off amount 10%), which includes 8.6284 kg of high-purity magnesium ingots, 1.936 kg of magnesium-neodymium master alloy, 0.1331 kg of high-purity silver ingots, 0.1705 kg of magnesium-praseodymium master alloy, and 0.132 kg of magnesium-promethium master alloy.

[0171] High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy and magnesium-promethium master alloy are mixed and preheated to 195°C, kept at the temperature and placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 325°C.

[0172] (2) After mixing the above raw materials for 10 minutes, a mixture of SF6 and CO2 (volume ratio of 1:170) is introduced as a protective gas to raise the melt temperature to 805°C within 40 minutes.

[0173] (3) After it is completely melted, stir for 25 minutes, continue to heat up to 805℃, and after it is completely melted, stir, stand and keep warm for 4 hours. Then pour it into a water-cooled mold under protective gas, and after cooling naturally for 35 minutes, take out the magnesium alloy ingot.

[0174] (4) Place the alloy ingot obtained in step (3) in a vacuum heat treatment furnace, evacuate and heat to 365°C, hold for 7.5h, then heat to 455°C, hold for 3.5h, and then air cool.

[0175] (5) The billet obtained in step (4) is extruded at 344°C. The temperature of the mold and the cylinder is 344°C, and the extrusion speed is set to 0.7 m / s.

[0176] (6) The extruded billet is subjected to aging treatment. The temperature of the first aging treatment is 215℃ and the holding time is 7h. The temperature of the second aging treatment is 195℃ and the holding time is 3h. After removal, it is air-cooled to obtain magnesium alloy material.

[0177] The chemical composition (mass percentage) of the medical-grade magnesium alloy material prepared in this comparative example is as follows: 3.52% Nd, 1.21% Ag, 0.31% Pr, 0.24% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), with the balance being Mg.

[0178] The mechanical properties of the magnesium alloy material prepared in this comparative example were tested. The results showed that the tensile strength was 245±3MPa, the yield strength was 188±2MPa, and the elongation was 6.5±0.2%.

[0179] Comparative Example 6

[0180] The preparation method of Mg-3.52Nd-1.21Ag-0.31Pr-0.24Pm magnesium alloy material is as follows:

[0181] (1) A silicon carbide rod resistance furnace equipped with a low-carbon steel crucible is used for smelting, and 10 kg is prepared per furnace. High-purity magnesium ingots, high-purity silver ingots, magnesium-neodymium master alloy, magnesium-praseodymium master alloy, and magnesium-promethium master alloy are prepared according to the alloy ratio of Mg-3.52Nd-1.21Ag-0.31Pr-0.24Pm (burn-off amount 10%), which includes 8.6284 kg of high-purity magnesium ingots, 1.936 kg of magnesium-neodymium master alloy, 0.1331 kg of high-purity silver ingots, 0.1705 kg of magnesium-praseodymium master alloy, and 0.132 kg of magnesium-promethium master alloy.

[0182] High-purity magnesium ingots and magnesium-neodymium master alloys are mixed and preheated to 195°C, held at that temperature, and then placed in a low-carbon steel crucible in a silicon carbide rod resistance furnace preheated to 325°C.

[0183] (2) After mixing the above raw materials for 10 minutes, a mixture of SF6 and CO2 (volume ratio of 1:170) is introduced as a protective gas to raise the melt temperature to 805°C within 40 minutes.

[0184] (3) The high-purity silver ingot is suspended in the above alloy liquid until it is completely melted. Stir for 20 minutes. When the temperature of the melt rises to 805°C again, add magnesium praseodymium master alloy and magnesium promethium master alloy. Stir and let stand for 35 minutes. Continue to heat up to 810°C. After it is completely melted, stir, let stand and keep warm for 4 hours. Then pour it into a water-cooled mold under protective gas. After cooling naturally for 35 minutes, take out the magnesium alloy ingot.

[0185] (4) The billet obtained in step (3) is extruded at 345°C. The temperature of the mold and the cylinder is 345°C. The extrusion speed is set to 0.7m / s. After being taken out, it is air-cooled to obtain magnesium alloy material.

[0186] The chemical composition (mass percentage) of the medical-grade magnesium alloy material prepared in this comparative example is as follows: 3.52% Nd, 1.21% Ag, 0.31% Pr, 0.24% Pm, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), with the balance being Mg.

[0187] The mechanical properties of the magnesium alloy material prepared in Comparative Example 6 of this invention were tested. The results showed that the tensile strength was 247±1MPa, the yield strength was 190±3MPa, and the elongation was 6.2±0.2%.

[0188] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0189] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A medical-grade bio-magnesium alloy material containing trace amounts of light rare earth elements, comprising, by mass percentage: Nd 1.0~5.0%, Ag 0.5~1.8%, Pr 0.15~0.65%, Pm 0.15~0.65%, with the balance being Mg and unavoidable impurity elements, wherein (Nd+Pr+Pm) / Ag=3.15~5.

8.

2. The medical-grade bio-magnesium alloy material according to claim 1, characterized in that, The medical-grade biomagnesium alloy material includes nano-sized bulk Nd3Ag3Mg. 14 Phase, the blocky Nd3Ag3Mg 14 The phase dimensions are 300~400nm in length and 200~300nm in width.

3. The medical-grade bio-magnesium alloy material according to claim 1, characterized in that, The Nd content is 3.1-4.8%.

4. The medical-grade bio-magnesium alloy material according to claim 1, characterized in that, The content of Ag is 1.1~1.7%.

5. The medical-grade bio-magnesium alloy material according to any one of claims 1 to 4, characterized in that, The impurity elements include one or more of Fe, Cu, Si and Ni, wherein Fe ≤ 0.005%, Cu ≤ 0.0005%, Si ≤ 0.005%, and Ni ≤ 0.0005%.

6. The preparation method of the medical bio-magnesium alloy material according to claim 1, comprising the following steps: S1. Pure magnesium raw material, pure silver raw material, magnesium-neodymium master alloy, magnesium-praseodymium master alloy and magnesium-promethium master alloy are mixed according to the component ratio, then melted and cast to obtain magnesium alloy ingots. S2. Homogenize the magnesium alloy ingot; S3. The magnesium alloy ingot obtained in step S2 is hot-extruded, then aged, and cooled to obtain medical bio-magnesium alloy material.

7. The preparation method according to claim 6, characterized in that, In step S1), the smelting specifically involves: The pure magnesium raw material and the magnesium-neodymium master alloy are mixed and preheated to 180~195℃, held at that temperature, and then heated to 800~830℃ under the action of a protective gas to obtain an initial alloy melt; the protective gas is a mixture of SF6 and CO2 with a volume ratio of 1:(170~200). The pure silver raw material is added to the initial alloy melt and heated again to 800~830℃. Then, magnesium praseodymium master alloy and magnesium promethium master alloy are added, and the temperature is further raised to 800~830℃ and held to obtain magnesium alloy melt.

8. The preparation method according to claim 6 or 7, characterized in that, The homogenization process is carried out in a vacuum environment. The first-stage homogenization process is carried out at a temperature of 370~390℃ for 5~8 hours, and the second-stage homogenization process is carried out at a temperature of 400~450℃ for 3~6 hours. The homogenization process is followed by air cooling. And / or, the hot extrusion temperature is 340~360℃ and the hot extrusion speed is 0.5~1.2 m / s.

9. The preparation method according to claim 8, characterized in that, The aging process includes a first-level aging process and a second-level aging process performed sequentially. The temperature of the first-level aging process is 180~210℃ and the holding time is 6~8h. The temperature of the second-level aging process is 200~220℃ and the holding time is 3~5h. The cooling process is air cooling.

10. The application of the medical bio-magnesium alloy material according to any one of claims 1 to 5 or the medical bio-magnesium alloy material prepared by the preparation method according to any one of claims 6 to 9 in medical materials and / or biological materials.

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