Medical biological rare earth magnesium alloy material as well as preparation method and application thereof

Abstract

The invention provides a medical biological magnesium neodymium silver zinc dysprosium rare earth magnesium alloy material and a preparation method and application thereof. Rare earth elements neodymium and dysprosium and transition metal elements silver and zinc are added into pure magnesium, the medical biodegradable rare earth magnesium alloy material containing a gamma phase with a certain proportion, size and distribution is prepared, and a microstructure containing the specific structure is subjected to heat treatment and hot extrusion deformation, so that the alloy strength is remarkably improved; and the supporting and fixing functions of the medical implant material can be achieved. The rare earth magnesium alloy provided by the invention is excellent in plasticity and non-toxic, and can play a role of being mechanically processed into a medical implant product. The gamma-phase-containing alloy has good biocompatibility, can be degraded in human body fluid to generate hydroxyapatite, promotes repair of defective tissues, enhances hardness and fracture resistance of human bones, has stimulation or induction effects on hyperostosis and treats osteoporosis, and is a degradable medical biological light magnesium alloy material with repair and treatment functions.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical magnesium alloy materials, and relates to a medical biological rare earth magnesium alloy and a preparation method and application thereof, and in particular to a medical biological rare earth magnesium alloy material and a preparation method and application thereof. Background Art

[0002] my country is a country with abundant magnesium resources and reserves. Magnesium has many applications and development space as a metal structural material and functional material. As a medical biomaterial, magnesium is light in weight, high in specific strength and specific stiffness, and is closest to the density and elastic modulus of human bones. It does not produce stress shielding effect, is degradable and absorbable, and does not require secondary surgery to remove. This is also a huge advantage compared with other metal implant materials. Despite this, the shortcomings of medical biomagnesium alloy materials developed by existing technologies, such as insufficient mechanical properties, poor processing properties, and single biological functionality, restrict the application of medical biomagnesium alloy materials.

[0003] Therefore, how to design and develop a medical biological magnesium alloy material with better comprehensive performance, solve the above-mentioned problems of existing medical biological magnesium alloys, and be able to meet the requirements of being used as a medical biological implant material and processed into related products, and play the functions of support, fixation, repair and treatment at the implantation site in the human body has become one of the urgent problems to be solved by many researchers in the industry. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a medical biological rare earth magnesium alloy and its preparation method and application, in particular, a medical biological magnesium neodymium silver zinc dysprosium rare earth magnesium alloy material. The medical biological rare earth magnesium alloy provided by the present invention is prepared by adding binary rare earth elements neodymium and dysprosium to pure magnesium, and the composite application of silver and zinc transition metal elements, and the medical biological degradable rare earth magnesium alloy material containing a certain proportion, size and distribution of Mg, Nd, Ag and Zn elements is obtained. After heat treatment and hot extrusion deformation, the tensile strength and yield strength are significantly improved, the plasticity is excellent, non-toxic, and has good biocompatibility, bactericidal function, promotes cell growth, proliferation and repair of defective tissue, enhances human bone hardness and fracture resistance, has a stimulating or inducing effect on bone hyperplasia, and treats osteoporosis. At the same time, its preparation method is low in cost, simple in process equipment, easy to operate, and high in production efficiency, and is suitable for industrial large-scale production, promotion and application.

[0005] The present invention provides a medical biological rare earth magnesium alloy, wherein the rare earth magnesium alloy comprises a γ phase containing Mg, Nd, Ag and Zn elements;

[0006] The γ phase containing Mg, Nd, Ag and Zn elements is continuous or discontinuous in the grains and presents a spatial three-dimensional structure;

[0007] The γ phase containing Mg, Nd, Ag and Zn elements is located at the grain boundary and in the grain of the alloy.

[0008] Preferably, the γ phase containing Mg, Nd, Ag and Zn elements is specifically a precipitation phase;

[0009] The γ phase containing Mg, Nd, Ag and Zn elements accounts for 10% to 30% of the precipitated phase;

[0010] The γ phase containing Mg, Nd, Ag and Zn elements is mostly distributed in the eutectic region, and a small part is distributed in the non-eutectic region.

[0011] Preferably, the γ phase containing Mg, Nd, Ag and Zn elements is in a coherent relationship and / or a semi-coherent relationship with the matrix;

[0012] Some of the γ phases containing Mg, Nd, Ag and Zn elements span the grain boundaries, connecting the eutectic region and the non-eutectic region;

[0013] The length of the γ phase containing Mg, Nd, Ag and Zn elements is 2 to 15 μm;

[0014] The width of the γ phase containing Mg, Nd, Ag and Zn elements is 0.05 to 1 μm.

[0015] The present invention provides a medical biological rare earth magnesium alloy, which comprises, by mass percentage:

[0016] Nd: 0.5wt%~3.0wt%;

[0017] Ag: 0.1wt%~1.0wt%;

[0018] Zn: 0.05wt%~1.0wt%;

[0019] Dy: 0.1wt% to 0.5wt%;

[0020] The balance is magnesium;

[0021] Among them, the mass ratio of (Nd+Dy) / Ag is (2.5~6):1.

[0022] Preferably, the medical biological rare earth magnesium alloy also includes impurity elements;

[0023] The impurity elements include one or more of Fe, Cu, Si and Ni;

[0024] Among the impurity elements, Fe≤0.005wt%;

[0025] Cu≤0.0005wt%;

[0026] Si≤0.005wt%;

[0027] Ni≤0.0005wt%.

[0028] The present invention provides a method for preparing a medical biological rare earth magnesium alloy, comprising the following steps:

[0029] 1) placing a magnesium source and a zinc source in a smelting device for smelting to obtain an alloy liquid, and then adding a neodymium source, a silver source and a dysprosium source for further smelting to obtain a medical biological rare earth magnesium alloy ingot;

[0030] 2) The medical biological rare earth magnesium alloy ingot obtained in the above steps is subjected to solid solution treatment and hot extrusion deformation to obtain a medical biological rare earth magnesium alloy material.

[0031] Preferably, the magnesium source comprises pure magnesium;

[0032] The neodymium source includes a magnesium-neodymium master alloy;

[0033] In the magnesium-neodymium master alloy, the mass content of the rare earth element neodymium is 20% to 30%;

[0034] The silver source includes pure silver ingots;

[0035] The dysprosium source includes a magnesium-dysprosium master alloy;

[0036] In the magnesium-dysprosium master alloy, the mass content of the rare earth element dysprosium is 20% to 30%;

[0037] The zinc source includes pure zinc particles.

[0038] Preferably, the smelting is specifically carried out in a graphite silicon carbide crucible of a vacuum induction furnace;

[0039] The smelting temperature is 750-810°C;

[0040] The smelting time is 2 to 5 hours;

[0041] The temperature of the solution treatment is 310-550°C;

[0042] The solution treatment time is 3 to 5 hours.

[0043] Preferably, the temperature of the hot extrusion is 270-420°C;

[0044] The extrusion speed of the hot extrusion is 0.4 to 1.6 m / s;

[0045] The extrusion ratio of the hot extrusion is (6-11):1.

[0046] The present invention provides the use of the medical biological rare earth magnesium alloy described in any one of the above technical solutions or the medical biological rare earth magnesium alloy prepared by the preparation method described in any one of the above technical solutions in the field of medical materials and / or biomaterials.

[0047] The present invention provides a medical biological rare earth magnesium alloy, wherein the rare earth magnesium alloy includes a γ phase containing Mg, Nd, Ag and Zn elements; the γ phase containing Mg, Nd, Ag and Zn elements is continuous or discontinuous in a three-dimensional spatial structure in a grain; the γ phase containing Mg, Nd, Ag and Zn elements is located at the grain boundary and in the grain of the alloy. Compared with the prior art, the present invention believes that the use of binary rare earth elements neodymium, dysprosium, and silver and zinc transition metal elements as alloying elements can synergistically improve the tensile strength, yield strength and elongation of the medical biological rare earth magnesium alloy, and the excellent strength can ensure that the alloy can play the supporting and fixing function as a medical biological material, and the good plasticity can ensure that the alloy can play the function of being machined into a medical device product, thereby promoting the development of medical biological magnesium alloy materials. The trace rare earth neodymium and dysprosium elements released by the medical biological rare earth magnesium alloy materials and related medical device products in the body are dissolved in body fluids, and their diffusion speed is extremely slow. The concentration after dilution by body fluids is extremely low, and they have no toxic effect on the organism. At the same time, due to the high solubility of rare earth neodymium and dysprosium elements, they are easily metabolized by the organism and excreted from the body with sweat and urine. In addition, medical biological rare earth magnesium alloy materials and related medical device products have good biocompatibility, and their bactericidal ability ensures that the human body does not have inflammation during service. They can be degraded in human body fluids to generate biologically active hydroxyapatite, promote cell growth, proliferation and repair of defective tissues, enhance human bone hardness and fracture resistance, stimulate or induce bone hyperplasia, and treat osteoporosis.

[0048] Based on this, the present invention creatively designs a medical biological rare earth magnesium alloy with a specific element ratio and microstructure. The alloy structure is regulated and refined by adding different contents of rare earth neodymium and dysprosium elements to pure magnesium for synergistic effect, and then combining the solid solution and precipitation of appropriate amounts of transition metal zinc and silver elements, thereby improving the tensile strength, yield strength and elongation. At the same time, the specific ratio between the elements is controlled to obtain excellent mechanical properties and ensure biosafety and biocompatibility for human tissues, so that the alloy has both repair and treatment functions.First, rare earth neodymium and dysprosium, as well as rare earth neodymium present in a specific structural γ phase, are soluble in body fluids and have no toxic effect on the human body. Moreover, Nd and Dy have high solubility and are easily metabolized by the body along with body fluids, showing outstanding biosafety and biocompatibility. Second, the binding force between rare earth neodymium, zinc, and silver and magnesium atoms is stronger than that between rare earth neodymium, zinc, and silver, and they can synergistically form fine, dispersed, and evenly distributed micron-sized particle γ phases, which refines the grain boundaries and intracrystalline structure of the casting, thereby improving the mechanical properties. Third, rare earth neodymium and dysprosium, as well as rare earth neodymium present in a specific structural γ phase, can synergistically optimize the orientation of magnesium grains, control the slip path during plastic deformation, and make perigranular slip and dynamic slip more uniform. Deformation mechanisms such as grain boundary throughput are suppressed, thereby improving plastic deformation capacity; fourth, rare earth neodymium and dysprosium as well as rare earth neodymium present in a specific structural γ phase can synergistically stabilize the stability of oxides during heat treatment and reduce the reaction between oxides and the magnesium matrix, thereby improving the thermal stability of magnesium alloys during heat treatment; fifth, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural γ phase can synergistically affect grain boundary activity and dislocation movement behavior, reduce the interference of magnesium crystals during plastic deformation, improve the processing performance of magnesium alloys, and reduce manufacturing costs; sixth, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural γ phase are non-toxic, non-sensitizing, and have bactericidal properties. It can also promote cell growth, proliferation and bone tissue growth, shorten the patient's repair cycle and wound healing time; Seventh, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural γ phase have similar chemical properties to elemental calcium, which can not only resist calcium ions in the blood but also reduce the surface tension of the material, thereby reducing the adhesion between medical device implants and body tissues, and have special anti-coagulation properties; Eighth, silver and silver present in a specific structural γ phase have a large solid solubility in magnesium, which can reach 15.5%, which is 11% different from the atomic radius of magnesium. When Ag is dissolved in Mg, an interstitial solid solution is formed, which causes a large distortion of the lattice, and has a strong solid solution strengthening effect. Silver can form a micron-sized compound γ phase with magnesium, thereby improving the strength and formability of the material, and is easy to be processed into various medical device products with smooth and beautiful surfaces. An appropriate amount of silver and its compound γ phase have significant antibacterial and antimicrobial properties, which can destroy the cell walls of bacteria and interfere with the normal metabolic process of bacteria, thereby achieving the antibacterial purpose and improving the bactericidal ability of magnesium alloys; ninth, zinc and zinc present in a specific structural γ phase as strengthening elements can effectively improve the yield strength and tensile strength of the alloy; tenth, zinc and zinc present in a specific structural γ phase can also promote the precipitation of fine, diffusely distributed strengthening phase γ phase in magnesium alloys, further improving the mechanical properties of the alloy.The addition of zinc and zinc present in a specific structural γ phase can also reduce the grain size of the magnesium alloy, thereby improving the plasticity and toughness of the alloy. The addition of an appropriate amount of zinc can significantly improve the strength and hardness of the magnesium alloy, but too much zinc will cause the alloy to become brittle and reduce its plasticity and toughness. Therefore, the present invention determines the appropriate zinc content according to the specific application scenario and demand. Zinc and zinc present in a specific structural γ phase are the second largest essential trace elements for human nutrition after iron. They play an indispensable role in the development and metabolism of major systems such as human nerves, immunity, cardiovascular, reproduction, and musculoskeletal in the form of participating in protein and tissue composition or regulating signal pathways as signal factors. When zinc is deficient and cannot meet the normal metabolic needs of the body, a series of diseases such as cognitive dysfunction and osteoporosis may occur. When tissue is damaged, zinc and zinc present in a specific structural γ phase aggregate to participate in the whole process of tissue repair including hemostasis, inflammatory response, cell proliferation and tissue remodeling. This effect is of great significance for promoting repair and reconstruction after bone defects. Zinc ions, one of the main degradation products after implanting γ-phase Mg-Nd-Ag-Zn alloy in bone defect, can promote bone repair by regulating vascular endothelial cells, immune cells and osteocytes, etc. The medical biological Mg-Nd-Ag-Zn rare earth magnesium alloy material provided by the present invention has excellent mechanical properties and processing properties, is non-toxic to human tissue, can meet the requirements of being used as a human medical implant material and being mechanically processed into related medical device products, and has both repair and treatment functions.

[0049] The magnesium-neodymium-silver-zinc-dysprosium rare earth magnesium alloy medical biomaterial provided by the present invention takes pure magnesium as the matrix, and rare earth elements neodymium, dysprosium and transition metal elements zinc and silver are added according to a certain formula and proportion. After smelting, solution treatment and hot extrusion deformation, the tensile strength and yield strength are improved while maintaining good elongation, and the material is non-toxic to human tissues, has good biocompatibility, and has repair and treatment functions. In order to obtain a specific metallographic microscope structure, scanning electron microscope structure, and excellent mechanical properties and processing properties, rare earth neodymium and dysprosium elements are added in the form of an intermediate alloy with a ratio of 20% to 30% to pure magnesium, zinc elements are added in the form of pure zinc particles, and silver elements are added in the form of pure silver ingots, and the smelting preparation process is accurately controlled, and then combined with a specific heat treatment and hot extrusion process for processing and processing. The invention uses the synergistic strengthening and toughening effect of rare earth neodymium and dysprosium elements, the solid solution and precipitation effect of appropriate transition metal zinc and silver elements, and the formation of a γ phase containing Mg, Nd, Ag and Zn elements at the alloy grain boundary and in the grain as a precipitation phase to simultaneously improve the strength and plasticity, so that the cast Mg-Nd-Ag-Zn-Dy rare earth magnesium alloy obtained by smelting maintains a good elongation after heat treatment and hot extrusion deformation, while the tensile strength and yield strength are significantly improved; the in vitro cytotoxicity evaluation test results prove that the alloy is non-toxic to cells and human tissues, and has Good biocompatibility can promote cell growth and proliferation; medical biological Mg-Nd-Ag-Zn-Dy rare earth magnesium alloy can be degraded to generate hydroxyapatite in simulated human body fluids, promote the repair of defective tissues, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, and treat osteoporosis; and silver has outstanding antibacterial, bactericidal, anti-inflammatory and rapid wound healing effects, and zinc is also a necessary nutrient and repair element for the human body, which makes the biodegradable Mg-Nd-Ag-Zn-Dy rare earth magnesium alloy have medical effects.

[0050] The medical biological rare earth magnesium alloy provided by the present invention adopts specific melting, solution treatment and hot extrusion process parameters, has high tensile strength and yield strength, good plasticity, excellent processing performance, is degradable, non-toxic, and the alloy is non-sensitizing. It has outstanding antibacterial and anti-inflammatory effects, can stimulate and induce bone hyperplasia, treat osteoporosis, and nourish and repair human tissues and muscles and bones. It is a lightweight magnesium alloy material that can be used as a medical biological material.

[0051] The experimental results show that the magnesium-neodymium-silver-zinc-dysprosium rare earth magnesium alloy prepared by the present invention has excellent mechanical properties and can meet the performance requirements of medical implant biomaterials. Its room temperature tensile strength, yield strength and elongation reach 93-352MPa, 82-300MPa and 4-10% respectively. Good plasticity also ensures that the medical biological rare earth magnesium alloy obtained by the present invention can be mechanically processed into Class III medical device products. The medical biological rare earth magnesium alloy is non-toxic to human tissue, safe and reliable, and has both nutritional, repair and therapeutic effects. By analyzing the cell morphology photos and relative growth rate of 100%, 50% and 10% leaching solutions of the present invention and 3T3 cells after 5 days of culture, the results show that the alloy is non-toxic to cells and human tissues, has good biocompatibility, and can promote cell growth and proliferation. The hydroxyapatite generated by immersion in simulated body fluid can promote the repair of defective tissues, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, treat osteoporosis, and enable the alloy to have repair, nutritional and therapeutic functions, and be applied in the medical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a metallographic microscope photograph of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention;

[0053] Figure 2 This is a scanning electron microscope photograph of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention;

[0054] Figure 3 This is a spectrum scanning photo of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention;

[0055] Figure 4 The morphological photographs of 3T3 cells cultured for 5 days after being immersed in 100%, 50% and 10% extracts of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention;

[0056] Figure 5 The following are scanning electron microscope photographs and energy spectrum analysis results of hydroxyapatite generated by immersing the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared by Example 1 of the present invention in simulated body fluid. DETAILED DESCRIPTION

[0057] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0058] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0059] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses medical grade materials or materials with conventional purity requirements in the field of medical magnesium alloy preparation.

[0060] The brands and abbreviations of all raw materials of the present invention are conventional brands and abbreviations in the art. Each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the brands, abbreviations and corresponding uses.

[0061] The abbreviations of the processes used in the present invention are all conventional abbreviations in the field. The specific steps and conventional parameters of each abbreviation are clear and definite in its relevant field. Those skilled in the art can implement them in a conventional manner based on the abbreviations.

[0062] The present invention provides a medical biological rare earth magnesium alloy, wherein the rare earth magnesium alloy comprises a γ phase containing Mg, Nd, Ag and Zn elements;

[0063] The γ phase containing Mg, Nd, Ag and Zn elements is continuous or discontinuous in the grains and presents a spatial three-dimensional structure;

[0064] The γ phase containing Mg, Nd, Ag and Zn elements is located at the grain boundary and in the grain of the alloy.

[0065] In the present invention, the γ phase containing Mg, Nd, Ag and Zn elements is preferably a precipitation phase.

[0066] In the present invention, the ratio of the γ phase containing Mg, Nd, Ag and Zn elements to the precipitated phase is preferably 10% to 30%, more preferably 12% to 28%, more preferably 15% to 25%, more preferably 17% to 23%.

[0067] In the present invention, the γ phase containing Mg, Nd, Ag and Zn elements is preferably mostly distributed in the eutectic region, and a small part is distributed in the non-eutectic region.

[0068] In the present invention, the γ phase containing Mg, Nd, Ag and Zn elements is preferably in a coherent relationship and / or a semi-coherent relationship with the matrix.

[0069] In the present invention, part of the γ phase containing Mg, Nd, Ag and Zn elements preferably spans the grain boundary to connect the eutectic region and the non-eutectic region.

[0070] In the present invention, the length of the γ phase containing Mg, Nd, Ag and Zn elements is preferably 2 to 15 μm, more preferably 5 to 13 μm, and even more preferably 7 to 11 μm.

[0071] In the present invention, the width of the γ phase containing Mg, Nd, Ag and Zn elements is preferably 0.05 to 1 μm, more preferably 0.1 to 0.9 μm, and even more preferably 0.3 to 0.7 μm.

[0072] The present invention provides a medical biological rare earth magnesium alloy, which comprises, by mass percentage:

[0073] Nd: 0.5wt%~3.0wt%;

[0074] Ag: 0.1wt%~1.0wt%;

[0075] Zn: 0.05wt%~1.0wt%;

[0076] Dy: 0.1wt% to 0.5wt%;

[0077] The balance is magnesium;

[0078] Among them, the mass ratio of (Nd+Dy) / Ag is (2.5~6):1.

[0079] In the present invention, the content of Nd is 0.5wt% to 3.0wt%, may be 1.0wt% to 2.5wt%, or may be 1.5wt% to 2.0wt%.

[0080] In the present invention, the content of Ag is 0.1wt% to 1.0wt%, may be 0.3wt% to 0.8wt%, or may be 0.5wt% to 0.6wt%.

[0081] In the present invention, the content of Zn is 0.05wt% to 1.0wt%, may be 0.1wt% to 0.9wt%, may be 0.2wt% to 0.8wt%, may be 0.3wt% to 0.7wt%, may be 0.4wt% to 0.6wt%.

[0082] In the present invention, the content of Dy is 0.1wt% to 0.5wt%, may be 0.15wt% to 0.45wt%, may be 0.2wt% to 0.4wt%, may be 0.25wt% to 0.35wt%.

[0083] In the present invention, the mass ratio of (Nd+Dy) / Ag is (2.5-6):1, may be (3-5.5):1, may be (3.5-5):1, or may be (4-4.5):1.

[0084] In the present invention, the medical biological rare earth magnesium alloy preferably further includes impurity elements.

[0085] In the present invention, the impurity elements preferably include one or more of Fe, Cu, Si and Ni, and more preferably Fe, Cu, Si or Ni.

[0086] In the present invention, in order to meet the medical safety and controllable corrosion rate, the impurity content is required to be as follows:

[0087] In the present invention, among the impurity elements, Fe is preferably ≤ 0.005 wt %, more preferably Fe is ≤ 0.004 wt %, and more preferably Fe is ≤ 0.003 wt %.

[0088] In the present invention, among the impurity elements, preferably Cu≤0.0005wt%, more preferably Cu≤0.0004wt%, and more preferably Cu≤0.0003wt%.

[0089] In the present invention, among the impurity elements, Si is preferably ≤ 0.005 wt %, more preferably Si is ≤ 0.004 wt %, and more preferably Si is ≤ 0.003 wt %.

[0090] In the present invention, among the impurity elements, preferably Ni≤0.0005wt%, more preferably Ni≤0.0004wt%, and more preferably Ni≤0.0003wt%.

[0091] The present invention provides a method for preparing a medical biological rare earth magnesium alloy, comprising the following steps:

[0092] 1) placing a magnesium source and a zinc source in a smelting device for smelting to obtain an alloy liquid, and then adding a neodymium source, a silver source and a dysprosium source for further smelting to obtain a medical biological rare earth magnesium alloy ingot;

[0093] 2) The medical biological rare earth magnesium alloy ingot obtained in the above steps is subjected to solid solution treatment and hot extrusion deformation to obtain a medical biological rare earth magnesium alloy material.

[0094] The invention first places a magnesium source and a zinc source in a smelting device for smelting to obtain an alloy liquid, then adds a neodymium source, a silver source and a dysprosium source for further smelting to obtain a medical biological rare earth magnesium alloy ingot.

[0095] In the present invention, the magnesium source preferably comprises pure magnesium.

[0096] In the present invention, the neodymium source preferably comprises a magnesium-neodymium master alloy. Specifically, the mass content of the rare earth element neodymium in the magnesium-neodymium master alloy is preferably 20% to 30%, more preferably 22% to 28%, and more preferably 24% to 26%.

[0097] In the present invention, the silver source preferably comprises pure silver ingots.

[0098] In the present invention, the zinc source preferably comprises pure zinc particles.

[0099] In the present invention, the dysprosium source preferably comprises a magnesium-dysprosium master alloy. Specifically, the mass content of the rare earth element dysprosium in the magnesium-dysprosium master alloy is preferably 20% to 30%, more preferably 22% to 28%, and more preferably 24% to 26%.

[0100] In the present invention, the smelting is preferably carried out in a graphite silicon carbide crucible of a vacuum induction furnace.

[0101] In the present invention, the smelting temperature is preferably 750-810°C, more preferably 760-800°C, more preferably 770-790°C, and more preferably 775-785°C.

[0102] In the present invention, the smelting time is preferably 2 to 5 hours, more preferably 2.5 to 4.5 hours, and more preferably 3 to 4 hours.

[0103] In the present invention, the medical biological rare earth magnesium alloy ingot obtained in the above steps is subjected to solid solution treatment and hot extrusion deformation to obtain a medical biological rare earth magnesium alloy material.

[0104] In the present invention, the temperature of the solution treatment is preferably 310 to 550°C, more preferably 350 to 500°C, and even more preferably 400 to 450°C.

[0105] In the present invention, the solution treatment time is preferably 3 to 5 hours, more preferably 3.2 to 4.8 hours, more preferably 3.5 to 4.5 hours, and more preferably 3.8 to 4.2 hours.

[0106] In the present invention, the temperature of the hot extrusion is preferably 270-420°C, more preferably 300-400°C, and more preferably 330-380°C.

[0107] In the present invention, the extrusion speed of the hot extrusion is 0.4 to 1.6 m / s, more preferably 0.6 to 1.4 m / s, and more preferably 0.8 to 1.2 m / s.

[0108] In the present invention, the extrusion ratio of the hot extrusion is (6-11):1, more preferably (7-10):1, and more preferably (8-9):1.

[0109] The present invention provides the use of the medical biological rare earth magnesium alloy described in any one of the above technical solutions or the medical biological rare earth magnesium alloy prepared by the preparation method described in any one of the above technical solutions in the field of medical materials and / or biomaterials.

[0110] The present invention is to complete and refine the overall technical solution, better ensure the proportion and microstructure morphology of the medical biological rare earth magnesium alloy, and further improve the mechanical properties and medical properties of the medical biological rare earth magnesium alloy. The above-mentioned medical biological magnesium neodymium silver zinc dysprosium rare earth magnesium alloy material and its preparation method may specifically include the following contents:

[0111] The medical biological magnesium-neodymium-silver-zinc-dysprosium rare earth magnesium alloy material provided by the present invention is a pure magnesium-based alloy to which binary rare earth elements neodymium and dysprosium, as well as transition metal elements zinc and silver are added in a certain ratio and are made through smelting, heat treatment and hot extrusion molding.

[0112] The chemical composition of the medical biological rare earth magnesium alloy is 0.5-3.0wt.% Nd, 0.1-1.0wt.%, Ag, 0.05-1.0wt.%, Dy: 0.1-0.5wt.%, and the rest is Mg. The impurity elements Fe≤0.005wt.%, Cu≤0.0005wt.%, Si≤0.005wt.%, and Ni≤0.0005wt.%.

[0113] Specifically, in order to obtain a specific metallographic microscope and scanning electron microscope structure, the total amount of rare earth neodymium does not exceed 3.0wt.% of the total alloy, and the total amount of rare earth dysprosium does not exceed 0.5wt.% of the total alloy. Among them, Nd is 0.5-3.0wt.%, and Dy is 0.1-0.5wt.%.

[0114] Specifically, in order to obtain specific metallographic microscope structure, scanning electron microscope structure and stable and excellent mechanical properties, rare earth neodymium and dysprosium elements are added in the form of an intermediate alloy, and an appropriate smelting preparation process is adopted according to this method. The intermediate alloy used is a magnesium-neodymium intermediate alloy made of 80wt.% to 70wt.% of magnesium and 20wt.% to 30wt.% of rare earth neodymium. A magnesium-dysprosium intermediate alloy made of 80wt.% to 70wt.% of magnesium and 20wt.% to 30wt.% of rare earth dysprosium.

[0115] Specifically, the alloy uses specific melting, solution treatment and hot extrusion molding process parameters and preparation processes. The alloy is non-sensitizing, antibacterial, bactericidal and anti-inflammatory, can stimulate or induce bone hyperplasia, treat osteoporosis, and has repair, nutrition and therapeutic effects.

[0116] The above content of the present invention provides a medical biological magnesium-neodymium-silver-zinc-dysprosium rare earth magnesium alloy material and its preparation method and application. The medical biological rare earth magnesium alloy designed by the present invention has a specific element ratio and microstructure, and the alloy structure is refined by adding different contents of rare earth neodymium and dysprosium elements to pure magnesium, and then combined with the solid solution and precipitation of appropriate amounts of transition metal zinc and silver elements to improve the tensile strength, yield strength and elongation. At the same time, the specific ratio between the elements is controlled to obtain excellent mechanical properties and ensure the biosafety and biocompatibility of human tissues, so that the alloy has both repair and treatment functions.First, rare earth neodymium and dysprosium, as well as rare earth neodymium present in a specific structural γ phase, are soluble in body fluids and have no toxic effect on the human body. Moreover, Nd and Dy have high solubility and are easily metabolized by the body along with body fluids, showing outstanding biosafety and biocompatibility. Second, the binding force between rare earth neodymium, zinc, and silver and magnesium atoms is stronger than that between rare earth neodymium, zinc, and silver, and they can synergistically form fine, dispersed, and evenly distributed micron-sized particle γ phases, which refines the grain boundaries and intracrystalline structure of the casting, thereby improving the mechanical properties. Third, rare earth neodymium and dysprosium, as well as rare earth neodymium present in a specific structural γ phase, can synergistically optimize the orientation of magnesium grains, control the slip path during plastic deformation, and make perigranular slip and dynamic slip more uniform. Deformation mechanisms such as grain boundary throughput are suppressed, thereby improving plastic deformation capacity; fourth, rare earth neodymium and dysprosium as well as rare earth neodymium present in a specific structural γ phase can synergistically stabilize the stability of oxides during heat treatment and reduce the reaction between oxides and the magnesium matrix, thereby improving the thermal stability of magnesium alloys during heat treatment; fifth, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural γ phase can synergistically affect grain boundary activity and dislocation movement behavior, reduce the interference of magnesium crystals during plastic deformation, improve the processing performance of magnesium alloys, and reduce manufacturing costs; sixth, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural γ phase are non-toxic, non-sensitizing, and have bactericidal properties. It can also promote cell growth, proliferation and bone tissue growth, shorten the patient's repair cycle and wound healing time; Seventh, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural γ phase have similar chemical properties to elemental calcium, which can not only resist calcium ions in the blood but also reduce the surface tension of the material, thereby reducing the adhesion between medical device implants and body tissues, and have special anti-coagulation properties; Eighth, silver and silver present in a specific structural γ phase have a large solid solubility in magnesium, which can reach 15.5%, which is 11% different from the atomic radius of magnesium. When Ag is dissolved in Mg, an interstitial solid solution is formed, which causes a large distortion of the lattice, and has a strong solid solution strengthening effect. Silver can form a micron-sized compound γ phase with magnesium, thereby improving the strength and formability of the material, and is easy to be processed into various medical device products with smooth and beautiful surfaces. An appropriate amount of silver and its compound γ phase have significant antibacterial and antimicrobial properties, which can destroy the cell walls of bacteria and interfere with the normal metabolic process of bacteria, thereby achieving the antibacterial purpose and improving the bactericidal ability of magnesium alloys; ninth, zinc and zinc present in a specific structural γ phase as strengthening elements can effectively improve the yield strength and tensile strength of the alloy; tenth, zinc and zinc present in a specific structural γ phase can also promote the precipitation of fine, diffusely distributed strengthening phase γ phase in magnesium alloys, further improving the mechanical properties of the alloy.The addition of zinc and zinc present in a specific structural γ phase can also reduce the grain size of the magnesium alloy, thereby improving the plasticity and toughness of the alloy. The addition of an appropriate amount of zinc can significantly improve the strength and hardness of the magnesium alloy, but too much zinc will cause the alloy to become brittle and reduce its plasticity and toughness. Therefore, the present invention determines the appropriate zinc content according to the specific application scenario and demand. Zinc and zinc present in a specific structural γ phase are the second largest essential trace elements for human nutrition after iron. They play an indispensable role in the development and metabolism of major systems such as human nerves, immunity, cardiovascular, reproduction, and musculoskeletal in the form of participating in protein and tissue composition or regulating signal pathways as signal factors. When zinc is deficient and cannot meet the normal metabolic needs of the body, a series of diseases such as cognitive dysfunction and osteoporosis may occur. When tissue is damaged, zinc and zinc present in a specific structural γ phase aggregate to participate in the whole process of tissue repair including hemostasis, inflammatory response, cell proliferation and tissue remodeling. This effect is of great significance for promoting repair and reconstruction after bone defects. Zinc ions, one of the main degradation products after implanting γ-phase Mg-Nd-Ag-Zn alloy in bone defect, can promote bone repair by regulating vascular endothelial cells, immune cells and osteocytes, etc. The medical biological Mg-Nd-Ag-Zn rare earth magnesium alloy material provided by the present invention has excellent mechanical properties and processing properties, is non-toxic to human tissue, can meet the requirements of being used as a human medical implant material and being mechanically processed into related medical device products, and has both repair and treatment functions.

[0117] The magnesium-neodymium-silver-zinc-dysprosium rare earth magnesium alloy medical biomaterial provided by the present invention takes pure magnesium as the matrix, and rare earth elements neodymium, dysprosium and transition metal elements zinc and silver are added according to a certain formula and proportion. After smelting, solution treatment and hot extrusion deformation, the tensile strength and yield strength are improved while maintaining good elongation, and the material is non-toxic to human tissues, has good biocompatibility, and has repair and treatment functions. In order to obtain a specific metallographic microscope structure, scanning electron microscope structure, and excellent mechanical properties and processing properties, rare earth neodymium and dysprosium elements are added in the form of an intermediate alloy with a ratio of 20% to 30% to pure magnesium, zinc elements are added in the form of pure zinc particles, and silver elements are added in the form of pure silver ingots, and the smelting preparation process is accurately controlled, and then combined with a specific heat treatment and hot extrusion process for processing and processing. The invention uses the synergistic strengthening and toughening effect of rare earth neodymium and dysprosium elements, the solid solution and precipitation effect of appropriate transition metal zinc and silver elements, and the formation of a γ phase containing Mg, Nd, Ag and Zn elements at the alloy grain boundary and in the grain as a precipitation phase to simultaneously improve the strength and plasticity, so that the cast Mg-Nd-Ag-Zn-Dy rare earth magnesium alloy obtained by smelting maintains a good elongation after heat treatment and hot extrusion deformation, while the tensile strength and yield strength are significantly improved; the in vitro cytotoxicity evaluation test results prove that the alloy is non-toxic to cells and human tissues, and has Good biocompatibility can promote cell growth and proliferation; medical biological Mg-Nd-Ag-Zn-Dy rare earth magnesium alloy can be degraded to generate hydroxyapatite in simulated human body fluids, promote the repair of defective tissues, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, and treat osteoporosis; and silver has outstanding antibacterial, bactericidal, anti-inflammatory and rapid wound healing effects, and zinc is also a necessary nutrient and repair element for the human body, which makes the biodegradable Mg-Nd-Ag-Zn-Dy rare earth magnesium alloy have medical effects.

[0118] The medical biological rare earth magnesium alloy provided by the present invention adopts specific melting, solution treatment and hot extrusion process parameters, has high tensile strength and yield strength, good plasticity, excellent processing performance, is degradable, non-toxic, and the alloy is non-sensitizing. It has outstanding antibacterial and anti-inflammatory effects, can stimulate and induce bone hyperplasia, treat osteoporosis, and nourish and repair human tissues and muscles and bones. It is a lightweight magnesium alloy material that can be used as a medical biological material.

[0119] The experimental results show that the magnesium-neodymium-silver-zinc-dysprosium rare earth magnesium alloy prepared by the present invention has excellent mechanical properties and can meet the performance requirements of medical implant biomaterials. Its room temperature tensile strength, yield strength and elongation reach 93-352MPa, 82-300MPa and 4-10% respectively. Good plasticity also ensures that the medical biological rare earth magnesium alloy obtained by the present invention can be mechanically processed into Class III medical device products. The medical biological rare earth magnesium alloy is non-toxic to human tissue, safe and reliable, and has both nutritional, repair and therapeutic effects. By analyzing the cell morphology photos and relative growth rate of 100%, 50% and 10% leaching solutions of the present invention and 3T3 cells after 5 days of culture, the results show that the alloy is non-toxic to cells and human tissues, has good biocompatibility, and can promote cell growth and proliferation. The hydroxyapatite generated by immersion in simulated body fluid can promote the repair of defective tissues, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, treat osteoporosis, and enable the alloy to have repair, nutritional and therapeutic functions, and be applied in the medical field.

[0120] In order to further illustrate the present invention, a medical biological rare earth magnesium alloy provided by the present invention and its preparation method and application are described in detail in combination with embodiments below. However, it should be understood that these embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. The protection scope of the present invention is not limited to the following embodiments.

[0121] Example 1

[0122] The preparation method of Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy medical biological rare earth magnesium alloy is as follows:

[0123] Equipment: 35Kg vacuum induction melting furnace

[0124] Melting process:

[0125] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 9.054 kg of high-purity magnesium ingot, 0.833 kg of magnesium-neodymium master alloy, 0.056 kg of silver ingot, 0.035 kg of zinc particles, and 0.022 kg of magnesium-dysprosium master alloy, preheat to 325°C, put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 325°C, and mix for 5 minutes;

[0126] (2) Evacuate the air and then fill it with argon as a protective gas;

[0127] (3) By controlling the power, the temperature is raised to 790°C within 35 minutes;

[0128] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 775°C, add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, stir and let stand for 19 minutes, then add zinc particles, raise the temperature to 785°C, stir, let stand and keep warm for 3.5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0129] (5) After naturally cooling in the stainless steel mold for 35 minutes, the alloy ingot is taken out;

[0130] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 410°C, keep warm for 3 hours, take out and air cool;

[0131] (7) Hot extrusion molding: The extruded material is extruded at 390°C, the die and barrel temperature is 375°C, and the extrusion speed is set to 1.5m / s.

[0132] The chemical composition (mass percentage) of the prepared alloy is: 2.5% Nd, 0.56% Ag, 0.35% Zn, 0.22% Dy, impurity elements (Fe≤0.002%; Cu≤0.0002%; Si≤0.002%; Ni≤0.0002%), and the balance is Mg.

[0133] The mechanical properties of the medical biological rare earth magnesium alloy prepared in Example 1 of the present invention were tested, and the results showed that the tensile strength was 344±5 MPa, the yield strength was 290±3 MPa, and the elongation was 5.1±0.6%.

[0134] The medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention was characterized.

[0135] See also Figure 1 , Figure 1 The metallographic microscope photos of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention are shown in Figure 1. (a) is in the cast state, (b) is in the extruded state (perpendicular to the extrusion direction), and (c) is in the extruded state (along the extrusion direction).

[0136] See also Figure 2 , Figure 2 The following are scanning electron microscope photos of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention, wherein (ab) is the cast state and (cd) is the extruded state (along the extrusion direction).

[0137] from Figure 1 and Figure 2It can be seen that fine γ phases containing Mg, Nd, Ag and Zn elements of a certain size, proportion and dispersion distribution exist at the grain boundaries and within the grains, which is one of the main reasons why the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy has excellent mechanical properties.

[0138] See also Figure 3 , Figure 3 This is a spectrum scanning photo of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention, wherein (a) is the cast state and (b) is the extruded state (along the extrusion direction).

[0139] from Figure 3 It can be seen that the fine γ phase containing Mg, Nd, Ag and Zn elements of a certain size, proportion and dispersed distribution at the grain boundary and in the grain contains Mg, Nd, Ag and Zn elements. The specific element distribution and the stable organizational structure formed by the elements in the γ phase containing Mg, Nd, Ag and Zn elements are one of the main reasons why the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy has excellent mechanical properties.

[0140] See also Figure 4 , Figure 4 The following are morphological photos of 3T3 cells cultured for 5 days after being immersed in 100%, 50% and 10% extracts of the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared in Example 1 of the present invention. Among them, (a) is the 100% extract, (b) is the 50% extract and (c) is the 10% extract.

[0141] The results show that the vast majority of cells cultured in the 100%, 50% and 10% extracts of the alloy of the present invention are in a normal and healthy state (adherent to the wall in an elongated shape), and the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy is non-toxic to cells and human tissues. In addition, the number of healthy cells cultured in the 100%, 50% and 10% extracts of the alloy of the present invention is significantly greater than that of healthy cells cultured in normal culture medium, and the cell state is significantly better than that of cells cultured in normal culture medium, because the fine γ phase containing Mg, Nd, Ag and Zn elements of a certain size, proportion and diffuse distribution existing at the grain boundary and in the grain enhances the antibacterial and anti-inflammatory effects, promotes cell growth, proliferation and bone tissue growth, and shortens the patient's repair cycle and wound healing time.

[0142] See also Figure 5 , Figure 5The present invention is a scanning electron microscope photo and energy spectrum analysis result of hydroxyapatite generated by immersing the medical biological Mg-2.5Nd-0.56Ag-0.35Zn-0.22Dy rare earth magnesium alloy prepared by Example 1 of the present invention in simulated body fluid. The fine γ phase containing Mg, Nd, Ag and Zn elements of a certain size, proportion and dispersed distribution existing at the grain boundary and in the grain promotes the formation of a large amount of hydroxyapatite in the alloy during the degradation process, which can further promote the repair of defective tissues, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, and treat osteoporosis.

[0143] Example 2

[0144] The preparation method of Mg-2Nd-0.45Ag-0.3Zn-0.15Dy medical biological rare earth magnesium alloy is as follows:

[0145] Equipment: 35Kg vacuum induction melting furnace

[0146] Melting process:

[0147] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 9.208 kg of high-purity magnesium ingot, 0.667 kg of magnesium-neodymium master alloy, 0.045 kg of silver ingot, 0.03 kg of zinc particles, and 0.05 kg of magnesium-dysprosium master alloy, preheat to 335° C., put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 335° C., and mix for 10 minutes;

[0148] (2) Evacuate the air and then fill it with argon as a protective gas;

[0149] (3) By controlling the power, the temperature is raised to 800°C within 30 minutes;

[0150] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 770°C, add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, stir and let stand for 18 minutes, then add zinc particles, raise the temperature to 780°C, stir, let stand and keep warm for 5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0151] (5) After cooling naturally in the stainless steel mold for 30 minutes, the alloy ingot is taken out;

[0152] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 420°C, keep warm for 4 hours, take out and air cool;

[0153] (7) Hot extrusion molding: The extruded material is extruded at 380°C, the temperature of the mold and the barrel is 380°C, and the extrusion speed is set to 2m / s.

[0154] The chemical composition (mass percentage) of the prepared alloy is: 2% Nd, 0.45% Ag, 0.3% Zn, 0.15% Dy, impurity elements (Fe≤0.001%; ​​Cu≤0.0001%; ​​Si≤0.001%; ​​Ni≤0.0001%), and the balance is Mg.

[0155] The mechanical properties of the medical biological rare earth magnesium alloy prepared in Example 2 of the present invention were tested, and the results showed that the tensile strength was 320±2 MPa, the yield strength was 265±1 MPa, and the elongation was 4.5±0.2%.

[0156] Example 3

[0157] The preparation method of Mg-1.5Nd-0.35Ag-0.29Zn-0.14Dy medical biological rare earth magnesium alloy is as follows:

[0158] Equipment: 35Kg vacuum induction melting furnace

[0159] Melting process:

[0160] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 9.389 kg of high-purity magnesium ingot, 0.5 kg of magnesium-neodymium master alloy, 0.035 kg of silver ingot, 0.029 kg of zinc particles, and 0.047 kg of magnesium-dysprosium master alloy, preheat to 330° C., put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 330° C., and mix for 7 minutes;

[0161] (2) Evacuate the air and then fill it with argon as a protective gas;

[0162] (3) By controlling the power, the temperature was raised to 795°C within 37 minutes;

[0163] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 785°C, add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, stir and let stand for 20 minutes, then add zinc particles, raise the temperature to 775°C, stir, let stand and keep warm for 5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0164] (5) After naturally cooling in the stainless steel mold for 45 minutes, the alloy ingot is taken out;

[0165] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 415°C, keep warm for 3.5 hours, take out and air cool;

[0166] (7) Hot extrusion molding: The extruded material is extruded at 385°C, the temperature of the die and the barrel is 385°C, and the extrusion speed is set to 1.5m / s.

[0167] The chemical composition (mass percentage) of the prepared alloy is: 1.5% Nd, 0.35% Ag, 0.29% Zn, 0.14% Dy, impurity elements (Fe≤0.0025%; Cu≤0.00025%; Si≤0.0025%; Ni≤0.00025%), and the balance is Mg.

[0168] The mechanical properties of the medical biological rare earth magnesium alloy prepared in Example 3 of the present invention were tested, and the results showed that the tensile strength was 285±6MPa, the yield strength was 255±2MPa, and the elongation was 3.5±0.5%.

[0169] The room temperature mechanical property data results in Examples 1 to 3 of the present invention show that the medical biological rare earth magnesium alloy of the present invention has excellent mechanical properties, meets the requirements of being used as a medical implant material and being machined into Class III medical device products, and has optimal tensile strength, yield strength and elongation when the rare earth element Nd content is 2.5wt%, the transition metal element Ag content is 0.56wt%, the transition metal element Zn content is 0.35% and the rare earth element Dy content is 0.22wt%.

[0170] Comparative Example 1

[0171] The preparation method of Mg-3Nd-0.15Ag-0.15Zn-0.1Dy medical biological rare earth magnesium alloy is as follows:

[0172] Equipment: 35Kg vacuum induction melting furnace

[0173] Melting process:

[0174] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 8.937 kg of high-purity magnesium ingot, 1 kg of magnesium-neodymium master alloy, 0.015 kg of silver ingot, 0.015 kg of zinc particles, and 0.033 kg of magnesium-dysprosium master alloy, preheat to 325°C, put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 325°C, and mix for 5 minutes;

[0175] (2) Evacuate the air and then fill it with argon as a protective gas;

[0176] (3) By controlling the power, the temperature is raised to 790°C within 35 minutes;

[0177] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 775°C, add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, stir and let stand for 19 minutes, then add zinc particles, raise the temperature to 785°C, stir, let stand and keep warm for 3.5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0178] (5) After naturally cooling in the stainless steel mold for 35 minutes, the alloy ingot is taken out;

[0179] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 410°C, keep warm for 3 hours, take out and air cool;

[0180] (7) Hot extrusion molding: The extruded material is extruded at 390°C, the die and barrel temperature is 375°C, and the extrusion speed is set to 1.5m / s.

[0181] The chemical composition (mass percentage) of the prepared alloy is: 3% Nd, 0.15% Ag, 0.15% Zn, 0.1% Dy, impurity elements (Fe≤0.0025%; Cu≤0.00025%; Si≤0.0025%; Ni≤0.00025%), and the balance is Mg.

[0182] The mechanical properties of the medical biological rare earth magnesium alloy prepared in Comparative Example 1 of the present invention were tested, and the results showed that the tensile strength was 180±2MPa, the yield strength was 140±3MPa, and the elongation was 2.1±0.6%.

[0183] Comparative Example 2

[0184] The preparation method of Mg-3.5Nd-0.1Ag-0.1Zn-0.5Dy medical biological rare earth magnesium alloy is as follows:

[0185] Equipment: 35Kg vacuum induction melting furnace

[0186] Melting process:

[0187] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 8.646 kg of high-purity magnesium ingot, 1.167 kg of magnesium-neodymium master alloy, 0.01 kg of silver ingot, 0.01 kg of zinc particles, and 0.167 kg of magnesium-dysprosium master alloy, preheat to 325°C, put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 325°C, and mix for 5 minutes;

[0188] (2) Evacuate the air and then fill it with argon as a protective gas;

[0189] (3) By controlling the power, the temperature is raised to 790°C within 35 minutes;

[0190] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 775°C, add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, stir and let stand for 19 minutes, then add zinc particles, raise the temperature to 785°C, stir, let stand and keep warm for 3.5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0191] (5) After naturally cooling in the stainless steel mold for 35 minutes, the alloy ingot is taken out;

[0192] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 410°C, keep warm for 3 hours, take out and air cool;

[0193] (7) Hot extrusion molding: The extruded material is extruded at 390°C, the die and barrel temperature is 375°C, and the extrusion speed is set to 1.5m / s.

[0194] The chemical composition (mass percentage) of the prepared alloy is: 3.5% Nd, 0.1% Ag, 0.1% Zn, 0.5% Dy, impurity elements (Fe≤0.002%; Cu≤0.0002%; Si≤0.002%; Ni≤0.0002%), and the balance is Mg.

[0195] The mechanical properties of the medical biological rare earth magnesium alloy prepared in Comparative Example 2 of the present invention were tested, and the results showed that the tensile strength was 170±5MPa, the yield strength was 150±3MPa, and the elongation was 2.2±0.3%.

[0196] The above is a detailed introduction to a medical biological magnesium-neodymium-silver-zinc-dysprosium rare earth magnesium alloy material provided by the present invention, and its preparation method and application. In this article, specific examples are used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A medical biological rare earth magnesium alloy, characterized in that: The rare earth magnesium alloy includes a γ phase containing Mg, Nd, Ag and Zn elements; The γ phase containing Mg, Nd, Ag and Zn elements is continuous or discontinuous in the grains and presents a spatial three-dimensional structure; The γ phase containing Mg, Nd, Ag and Zn elements is located at the grain boundary and in the grain of the alloy.

2. The medical biological rare earth magnesium alloy according to claim 1, characterized in that: The γ phase containing Mg, Nd, Ag and Zn elements is specifically a precipitation phase; The γ phase containing Mg, Nd, Ag and Zn elements accounts for 10% to 30% of the precipitated phase; The γ phase containing Mg, Nd, Ag and Zn elements is mostly distributed in the eutectic region, and a small part is distributed in the non-eutectic region.

3. The medical biological rare earth magnesium alloy according to claim 1, characterized in that: The γ phase containing Mg, Nd, Ag and Zn elements is in a coherent relationship and / or a semi-coherent relationship with the matrix; Some of the γ phases containing Mg, Nd, Ag and Zn elements span the grain boundaries, connecting the eutectic region and the non-eutectic region; The length of the γ phase containing Mg, Nd, Ag and Zn elements is 2 to 15 μm; The width of the γ phase containing Mg, Nd, Ag and Zn elements is 0.05 to 1 μm.

4. A medical biological rare earth magnesium alloy, characterized in that: Included by mass percentage: Nd: 0.5wt%~3.0wt%; Ag: 0.1wt%~1.0wt%; Zn: 0.05wt%~1.0wt%; Dy: 0.1wt% to 0.5wt%; The balance is magnesium; Among them, the mass ratio of (Nd+Dy) / Ag is (2.5~6):

1.

5. The medical biological rare earth magnesium alloy according to claim 4, characterized in that: The medical biological rare earth magnesium alloy also includes impurity elements; The impurity elements include one or more of Fe, Cu, Si and Ni; Among the impurity elements, Fe≤0.005wt%; Cu≤0.0005wt%; Si≤0.005wt%; Ni≤0.0005wt%.

6. A method for preparing a medical biological rare earth magnesium alloy, characterized in that: The following steps are involved: 1) placing a magnesium source and a zinc source in a smelting device for smelting to obtain an alloy liquid, and then adding a neodymium source, a silver source and a dysprosium source for further smelting to obtain a medical biological rare earth magnesium alloy ingot; 2) The medical biological rare earth magnesium alloy ingot obtained in the above steps is subjected to solid solution treatment and hot extrusion deformation to obtain a medical biological rare earth magnesium alloy material.

7. The preparation method according to claim 6, characterized in that: The magnesium source includes pure magnesium; The neodymium source includes a magnesium-neodymium master alloy; In the magnesium-neodymium master alloy, the mass content of the rare earth element neodymium is 20% to 30%; The silver source includes pure silver ingots; The dysprosium source includes a magnesium-dysprosium master alloy; In the magnesium-dysprosium master alloy, the mass content of the rare earth element dysprosium is 20% to 30%; The zinc source includes pure zinc particles.

8. The preparation method according to claim 6, characterized in that: The smelting is specifically carried out in a graphite silicon carbide crucible of a vacuum induction furnace; The smelting temperature is 750-810°C; The smelting time is 2 to 5 hours; The temperature of the solution treatment is 310-550°C; The solution treatment time is 3 to 5 hours.

9. The preparation method according to claim 6, characterized in that: The temperature of the hot extrusion is 270-420°C; The extrusion speed of the hot extrusion is 0.4 to 1.6 m / s; The extrusion ratio of the hot extrusion is (6-11):

1.

10. Use of the medical biological rare earth magnesium alloy according to any one of claims 1 to 5 or the medical biological rare earth magnesium alloy prepared by the preparation method according to any one of claims 4 to 9 in the field of medical materials and / or biomaterials.

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