Rare earth magnesium alloy medical biological material as well as preparation method and application thereof

Abstract

The invention provides a medical biological magnesium neodymium silver calcium dysprosium rare earth magnesium alloy material and a preparation method and application thereof. The rare earth elements neodymium and dysprosium, the transition metal element silver and the alkaline earth element calcium are added into pure magnesium, the degradable rare earth magnesium alloy biological material containing a beta phase with a certain proportion, size and distribution is prepared, the mechanical strength of the material is remarkably improved through heat treatment and hot extrusion deformation of the microstructure of the material, and the material has excellent mechanical supporting and fixing functions. The rare earth magnesium alloy provided by the invention is excellent in plasticity and non-toxic, and can be mechanically processed into related three types of medical equipment products. The beta-phase-containing rare earth magnesium alloy has excellent biocompatibility and biological activity, can be degraded in human body fluid to generate hydroxyapatite serving as a main component of human bones, can repair defective tissues, and can treat osteoporosis and prevent muscle spasm in combination with calcium ions gradually released by degradation; the magnesium alloy material is a degradable medical biological light magnesium alloy material with repairing, nutrition and treatment effects.

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 rare earth magnesium alloy medical biological 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, nutrition 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 calcium 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 transition metal elements and calcium alkaline earth elements, and the β-phase medical biological degradable rare earth magnesium alloy material containing a certain proportion, size and distribution of Mg, Nd, Ag and Ca 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, treats osteoporosis, and prevents muscle spasms. At the same time, its preparation method is low in cost, simple in process equipment, easy to operate, and has high production efficiency, which 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 β phase containing Mg, Nd, Ag and Ca elements;

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

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

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

[0009] The β phase containing Mg, Nd, Ag and Ca elements accounts for 15% to 35% of the precipitated phase;

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

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

[0012] Some of the β phases containing Mg, Nd, Ag and Ca elements span the grain boundary, connecting the eutectic region and the non-eutectic region;

[0013] The length of the β phase containing Mg, Nd, Ag and Ca elements is 3 to 20 μm;

[0014] The width of the β phase containing Mg, Nd, Ag and Ca elements is 0.025 to 1.5 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] Ca: 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) / Ca is (3.5~7.5):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 also provides a method for preparing a medical biological rare earth magnesium alloy, comprising the following steps:

[0029] 1) placing a magnesium source and a calcium 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 calcium source includes a magnesium-calcium master alloy;

[0038] The mass content of calcium in the magnesium-calcium master alloy is 20% to 30%.

[0039] Preferably, the smelting is specifically carried out in a graphite silicon carbide crucible of a vacuum induction furnace;

[0040] The smelting temperature is 740-820°C;

[0041] The smelting time is 2.5 to 6 hours;

[0042] The temperature of the solution treatment is 320-570°C;

[0043] The time of the solution treatment is 2 to 7 hours.

[0044] Preferably, the temperature of the hot extrusion is 250-430°C;

[0045] The extrusion speed of the hot extrusion is 0.45-1.7 m / s;

[0046] The extrusion ratio of the hot extrusion is (5-13):1.

[0047] The present invention also 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.

[0048] The present invention provides a medical biological rare earth magnesium alloy, wherein the rare earth magnesium alloy includes a β phase containing Mg, Nd, Ag and Ca elements; the β phase containing Mg, Nd, Ag and Ca elements is continuous or discontinuous in a three-dimensional spatial structure in a grain; the β phase containing Mg, Nd, Ag and Ca 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 binary rare earth elements neodymium and dysprosium, as well as silver transition metal elements and calcium alkaline earth elements are used as alloying elements to 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, treat osteoporosis, and prevent muscle spasms.

[0049] 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 silver elements and alkaline earth calcium 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 in a specific structural β phase, are soluble in body fluids and have no toxic effects on the human body. In addition, Nd and Dy have high solubility and are easily metabolized by organisms with body fluids, showing outstanding biosafety and biocompatibility. Second, the binding force between rare earth neodymium, calcium, and silver and magnesium atoms is stronger than that between rare earth neodymium, calcium, and silver, and they can synergistically form fine, dispersed, and evenly distributed micron-sized particle β phases, refine the alloy's organization, and thus improve its mechanical properties. Third, rare earth neodymium and dysprosium, as well as rare earth neodymium in a specific structural β phase, can synergistically optimize the selection of magnesium grains. Fourth, the rare earth neodymium and dysprosium elements as well as the rare earth neodymium elements present in the specific structure β phase can synergistically stabilize the stability of the oxide during heat treatment and reduce the reaction between the oxide and the magnesium matrix, thereby improving the thermal stability of the magnesium alloy during heat treatment; Fifth, the rare earth neodymium elements, dysprosium elements and the rare earth neodymium elements present in the specific structure β phase can synergistically affect the grain boundary activity and dislocation movement behavior, reduce the interference of magnesium crystals during plastic deformation, improve the processing performance of the magnesium alloy, and reduce Low manufacturing cost; Sixth, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural β phase are non-toxic, non-sensitizing, have bactericidal function, and can also promote cell growth, proliferation and bone tissue growth, shorten the patient's repair cycle and wound healing time; Seventh, silver and silver present in a specific structural β phase have a large solid solubility in magnesium, and the atomic radius is very different from that 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. At the same time, silver can form a micron-sized compound β phase with magnesium, thereby improving the material strength and formability. It is easy to be processed into various medical device products with smooth and beautiful surfaces. The appropriate amount of silver and its compound β phase has 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 enhancing the bactericidal ability of magnesium alloys; Eighth, alkaline earth calcium elements and calcium elements present in the specific structure β phase as strengthening elements can effectively improve the yield strength and tensile strength of the alloy; Ninth, alkaline earth calcium elements and calcium elements present in the specific structure β phase can also promote the precipitation of fine and dispersed strengthening phase β phase in magnesium alloys, further improving the mechanical properties of the alloy.The addition of alkaline earth calcium and calcium present in a specific structure β 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 calcium can significantly improve the strength and hardness of the magnesium alloy, but too much calcium will cause the alloy to become brittle and reduce its plasticity and toughness. Therefore, the present invention determines the appropriate calcium content according to the specific application scenario and requirements. The addition of alkaline earth calcium and calcium present in a specific structure β phase forms a protective film on the surface of the magnesium alloy to improve its corrosion resistance. This protective film can effectively isolate the direct contact between the external environment and the magnesium alloy and extend its service life. Calcium and calcium present in a specific structure β phase can form a skeleton in the human body, play a supporting role, play a role in protecting the internal organs, and prevent osteoporosis. Calcium and calcium present in a specific structure β phase can balance the concentration of calcium ions in the blood, and at the same time regulate the excitability of the nervous system, avoiding the increase of nerve excitability due to lack of calcium, the difficulty of muscle contraction, and cramps when cold or joint movement. Calcium and calcium present in a specific structure β phase can maintain the balance of water and calcium that are essential to the human body. The β-phase Mg-Nd-Ag-Ca-Dy alloy is used to provide support and stability in fractures, joint diseases or other bone problems. One of its main degradation products, calcium ions, can form a skeleton in the human body to play a supporting role, protect the internal organs, and prevent osteoporosis. The medical biological β-phase Mg-Nd-Ag-Ca-Dy 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 machined into related medical device products, and has both repair, nutrition and treatment functions.

[0050] The magnesium-neodymium-silver-calcium-dysprosium rare earth magnesium alloy medical biomaterial provided by the present invention is based on pure magnesium, and rare earth elements neodymium, dysprosium, transition metal silver and alkaline earth calcium 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, nutrition 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, calcium elements are added in the form of an intermediate alloy with a ratio of 20% to 30% to pure magnesium, 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 silver elements and alkaline earth calcium elements, and the formation of β phases containing Mg, Nd, Ag and Ca elements at the alloy grain boundaries and in the grains as precipitation phases to simultaneously improve the strength and plasticity of the cast Mg-Nd-Ag-Ca-Dy rare earth magnesium alloy obtained by smelting, while maintaining good elongation after heat treatment and hot extrusion deformation, while significantly improving the tensile strength and yield strength; the results of in vitro cytotoxicity evaluation experiments prove that the alloy is non-toxic to cells and human tissues, and has good Good biocompatibility can promote cell growth and proliferation; medical biological Mg-Nd-Ag-Ca-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 calcium is also an essential supporting, nutritional and repairing element for the human body, which makes the biodegradable Mg-Nd-Ag-Ca-Dy rare earth magnesium alloy have medical effects.

[0051] 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, prevent muscle spasms, 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.

[0052] The experimental results show that the magnesium-neodymium-silver-calcium-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 80-355MPa, 56-305MPa and 3-10% 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 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 15 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 fluids can promote the repair of defective tissues, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, treat osteoporosis, prevent muscle spasms, and enable the alloy to have repair, nutrition and treatment functions, and be used in the medical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a metallographic microscope photograph of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention;

[0054] Figure 2 This is a scanning electron microscope photograph of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention;

[0055] Figure 3 This is a spectrum scanning photo of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention;

[0056] Figure 4 The morphological photographs of 3T3 cells cultured for 15 days after being soaked in 100%, 50% and 10% extracts of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention, compared with the negative control group;

[0057] Figure 5 The scanning electron microscope photograph and energy spectrum analysis result of hydroxyapatite generated by immersing the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared by Example 1 of the present invention in simulated body fluid. DETAILED DESCRIPTION

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] The present invention provides a medical biological rare earth magnesium alloy, wherein the rare earth magnesium alloy comprises a β phase containing Mg, Nd, Ag and Ca elements;

[0064] The β phase containing Mg, Nd, Ag and Ca elements is continuous or discontinuous in the grains and presents a three-dimensional spatial structure;

[0065] The β phase containing Mg, Nd, Ag and Ca elements is located at the grain boundary and in the grain of the alloy.

[0066] In the present invention, the β phase containing Mg, Nd, Ag and Ca elements is preferably a precipitation phase.

[0067] In the present invention, the proportion of the β phase containing Mg, Nd, Ag and Ca elements in the precipitated phase is preferably 15% to 35%, more preferably 17% to 33%, more preferably 20% to 30%, more preferably 22% to 28%.

[0068] In the present invention, the β phase containing Mg, Nd, Ag and Ca elements is preferably mostly distributed in the eutectic region, and a small part is distributed in the non-eutectic region.

[0069] In the present invention, the β phase containing Mg, Nd, Ag and Ca elements is preferably in a coherent relationship and / or a semi-coherent relationship with the matrix.

[0070] In the present invention, part of the β phase containing Mg, Nd, Ag and Ca elements preferably spans across the grain boundary to connect the eutectic region and the non-eutectic region.

[0071] In the present invention, the length of the β phase containing Mg, Nd, Ag and Ca elements is preferably 3 to 20 μm, more preferably 5 to 17 μm, and even more preferably 7 to 13 μm.

[0072] In the present invention, the width of the β phase containing Mg, Nd, Ag and Ca elements is preferably 0.025 to 1.5 μm, more preferably 0.05 to 1.3 μm, more preferably 0.1 to 1.0 μm, and more preferably 0.4 to 0.7 μm.

[0073] The present invention provides a medical biological rare earth magnesium alloy, which comprises, by mass percentage:

[0074] Nd: 0.5wt%~3.0wt%;

[0075] Ag: 0.1wt%~1.0wt%;

[0076] Ca: 0.05wt%~1.0wt%;

[0077] Dy: 0.1wt% to 0.5wt%;

[0078] The balance is magnesium;

[0079] Among them, the mass ratio of (Nd+Dy) / Ca is (3.5~7.5):1.

[0080] 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%.

[0081] 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%.

[0082] In the present invention, the content of Ca 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%.

[0083] 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%.

[0084] In the present invention, the mass ratio of (Nd+Dy) / Ca is (3.5-7.5):1, may be (4.0-7):1, may be (4.5-6.5):1, or may be (5-6):1.

[0085] In the present invention, the medical biological rare earth magnesium alloy preferably further includes impurity elements.

[0086] 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.

[0087] In the present invention, in order to meet the medical safety and controllable corrosion rate, the impurity content is required to be as follows:

[0088] 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 %.

[0089] In the present invention, among the impurity elements, preferably Cu≤0.0005wt%, more preferably Cu≤0.0004wt%, and more preferably Cu≤0.0003wt%.

[0090] 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 %.

[0091] In the present invention, among the impurity elements, preferably Ni≤0.0005wt%, more preferably Ni≤0.0004wt%, and more preferably Ni≤0.0003wt%.

[0092] The present invention provides a method for preparing a medical biological rare earth magnesium alloy, comprising the following steps:

[0093] 1) placing a magnesium source and a calcium 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;

[0094] 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.

[0095] The invention first places a magnesium source and a calcium 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.

[0096] In the present invention, the magnesium source preferably comprises pure magnesium.

[0097] 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%.

[0098] In the present invention, the silver source preferably comprises pure silver ingots.

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

[0100] 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%.

[0101] In the present invention, the smelting is preferably carried out in a graphite silicon carbide crucible of a vacuum induction furnace.

[0102] In the present invention, the smelting temperature is preferably 740-820°C, more preferably 750-810°C, more preferably 760-800°C, and more preferably 770-790°C.

[0103] In the present invention, the smelting time is preferably 2.5 to 6 hours, more preferably 3 to 5.5 hours, more preferably 3.5 to 5 hours, and more preferably 4 to 4.5 hours.

[0104] 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.

[0105] In the present invention, the temperature of the solution treatment is preferably 320 to 570°C, more preferably 370 to 520°C, and even more preferably 420 to 470°C.

[0106] In the present invention, the solution treatment time is preferably 2 to 7 hours, more preferably 3 to 6 hours, and more preferably 4 to 5 hours.

[0107] In the present invention, the temperature of the hot extrusion is preferably 250-430°C, more preferably 280-400°C, more preferably 300-380°C, more preferably 320-360°C.

[0108] In the present invention, the extrusion speed of the hot extrusion is 0.45 to 1.7 m / s, more preferably 0.7 to 1.5 m / s, and more preferably 0.9 to 1.3 m / s.

[0109] In the present invention, the extrusion ratio of the hot extrusion is (5-13):1, more preferably (6-12):1, more preferably (7-11):1, and more preferably (8-10):1.

[0110] 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.

[0111] 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 calcium dysprosium rare earth magnesium alloy material and its preparation method may specifically include the following contents:

[0112] The medical biological magnesium-neodymium-silver-calcium-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 element silver and alkaline earth element calcium are added in a certain ratio and are made through smelting, heat treatment and hot extrusion molding.

[0113] The chemical composition of the medical biological rare earth magnesium alloy is 0.5-3.0wt.% Nd, 0.1-1.0wt.%, Ca, 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.%.

[0114] 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.%.

[0115] 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.

[0116] Specifically, the alloy uses specific melting, solution treatment and hot extrusion molding process parameters and preparation processes. The alloy is non-allergenic, antibacterial, bactericidal and anti-inflammatory, can stimulate or induce bone hyperplasia, treat osteoporosis, prevent muscle spasms, and has repair, nutrition and therapeutic effects.

[0117] The above content of the present invention provides a magnesium-neodymium-silver-calcium-dysprosium rare earth magnesium alloy medical biomaterial and its preparation method and application. The medical biological rare earth magnesium alloy specially designed by the present invention has a specific element ratio and microstructure. 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 silver elements and alkaline earth calcium elements to control and refine the alloy structure, improve the tensile strength, yield strength and elongation, and control the specific ratio between the elements at the same time, so as 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 in a specific structural β phase, are soluble in body fluids and have no toxic effects on the human body. In addition, Nd and Dy have high solubility and are easily metabolized by organisms with body fluids, showing outstanding biosafety and biocompatibility. Second, the binding force between rare earth neodymium, calcium, and silver and magnesium atoms is stronger than that between rare earth neodymium, calcium, and silver, and they can synergistically form fine, dispersed, and evenly distributed micron-sized particle β phases, refine the alloy's organization, and thus improve its mechanical properties. Third, rare earth neodymium and dysprosium, as well as rare earth neodymium in a specific structural β phase, can synergistically optimize the selection of magnesium grains. Fourth, the rare earth neodymium and dysprosium elements as well as the rare earth neodymium elements present in the specific structure β phase can synergistically stabilize the stability of the oxide during heat treatment and reduce the reaction between the oxide and the magnesium matrix, thereby improving the thermal stability of the magnesium alloy during heat treatment; Fifth, the rare earth neodymium elements, dysprosium elements and the rare earth neodymium elements present in the specific structure β phase can synergistically affect the grain boundary activity and dislocation movement behavior, reduce the interference of magnesium crystals during plastic deformation, improve the processing performance of the magnesium alloy, and reduce Low manufacturing cost; Sixth, rare earth neodymium, dysprosium and rare earth neodymium present in a specific structural β phase are non-toxic, non-sensitizing, have bactericidal function, and can also promote cell growth, proliferation and bone tissue growth, shorten the patient's repair cycle and wound healing time; Seventh, silver and silver present in a specific structural β phase have a large solid solubility in magnesium, and the atomic radius is very different from that 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. At the same time, silver can form a micron-sized compound β phase with magnesium, thereby improving the material strength and formability. It is easy to process into various medical device products with smooth and beautiful surfaces. The appropriate amount of silver and its compound β phase has significant antibacterial and antimicrobial properties, which can destroy the cell wall of bacteria and interfere with the normal metabolic process of bacteria, thereby achieving the purpose of antibacterial and improving the bactericidal ability of magnesium alloys; Eighth, alkaline earth calcium elements and calcium elements present in the specific structure β phase as strengthening elements can effectively improve the yield strength and tensile strength of the alloy; Ninth, alkaline earth calcium elements and calcium elements present in the specific structure β phase can also promote the precipitation of fine and dispersed strengthening phase β phase in magnesium alloys, further improving the mechanical properties of the alloy. The addition of alkaline earth calcium elements and calcium elements present in the specific structure β phase can also reduce the grain size of magnesium alloys, thereby improving the plasticity and toughness of the alloy. The appropriate amount of calcium addition can significantly improve the strength and hardness of magnesium alloys, but too much calcium will cause the alloy to become brittle and reduce its plasticity and toughness. Therefore, the present invention determines the appropriate calcium content according to specific application scenarios and requirements.The addition of alkaline earth calcium and calcium in a specific structural β phase forms a protective film on the surface of the magnesium alloy, improving its corrosion resistance. This protective film can effectively isolate the external environment from direct contact with the magnesium alloy and extend its service life. Calcium and calcium in a specific structural β phase can form a skeleton in the human body, play a supporting role, protect the internal organs, and prevent osteoporosis. Calcium and calcium in a specific structural β phase can balance the concentration of calcium ions in the blood, and at the same time regulate the excitability of the nervous system to avoid increased nerve excitability due to lack of calcium, muscle difficulty in contraction, and cramps when cold or joint movement. Calcium and calcium in a specific structural β phase can maintain the balance of water and calcium that are essential to the human body. Mg-Nd-Ag-Ca-Dy alloy containing β phase is used to provide support and stability in fractures, joint diseases or other bone problems. One of its main degradation products, calcium ions, can form a skeleton in the human body to play a supporting role, protect the internal organs, and prevent osteoporosis. The medical biological β-phase Mg-Nd-Ag-Ca-Dy 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 at the same time has repair, nutrition and treatment functions.

[0118] The magnesium-neodymium-silver-calcium-dysprosium rare earth magnesium alloy medical biomaterial provided by the present invention is based on pure magnesium, and rare earth elements neodymium, dysprosium, transition metal silver and alkaline earth calcium 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, and has good biocompatibility, as well as repair, nutrition 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, alkaline earth calcium elements are added in the form of an intermediate alloy with a ratio of 20% to 30% to pure magnesium, 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 silver elements and alkaline earth calcium elements, and the formation of β phases containing Mg, Nd, Ag and Ca elements at the alloy grain boundaries and in the grains as precipitation phases to simultaneously improve the strength and plasticity of the cast Mg-Nd-Ag-Ca-Dy rare earth magnesium alloy obtained by smelting, while maintaining good elongation after heat treatment and hot extrusion deformation, while significantly improving the tensile strength and yield strength; the results of in vitro cytotoxicity evaluation experiments prove that the alloy is non-toxic to cells and human tissues, and has good Good biocompatibility can promote cell growth and proliferation; medical biological Mg-Nd-Ag-Ca-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 calcium is also an essential supporting, nutritional and repairing element for the human body, which makes the biodegradable Mg-Nd-Ag-Ca-Dy rare earth magnesium alloy have medical effects.

[0119] 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, prevent muscle spasms, 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.

[0120] The experimental results show that the magnesium-neodymium-silver-calcium-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 80-355MPa, 56-305MPa and 3-10% 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 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 15 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 fluids can promote the repair of defective tissues, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, treat osteoporosis, prevent muscle spasms, and enable the alloy to have repair, nutrition and treatment functions, and be used in the medical field.

[0121] 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.

[0122] Example 1

[0123] The preparation method of Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy medical biological rare earth magnesium alloy is as follows:

[0124] Equipment: 35Kg vacuum induction melting furnace

[0125] Melting process:

[0126] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 8.94 kg of high-purity magnesium ingot, 0.8 kg of magnesium-neodymium master alloy, 0.054 kg of silver ingot, 0.123 kg of magnesium-calcium master alloy, and 0.083 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;

[0127] (2) Evacuate the air and then fill it with argon as a protective gas;

[0128] (3) By controlling the power, the temperature is raised to 795°C within 40 minutes;

[0129] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 770°C, add magnesium-calcium master alloy, stir and let it stand for 20 minutes, then add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, heat it up to 780°C, stir, let it stand and keep it warm for 4 hours after it is completely melted, and then pour it into a stainless steel mold;

[0130] (5) After cooling naturally in the stainless steel mold for 30 minutes, the alloy ingot is taken out;

[0131] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 415°C, keep warm for 4 hours, take out and air cool;

[0132] (7) Hot extrusion molding: The extruded material is extruded at 395°C, the die and barrel temperature is 370°C, and the extrusion speed is set to 1.45m / s.

[0133] The chemical composition (mass percentage) of the prepared alloy is: 2.4% Nd, 0.54% Ag, 0.37% Ca, 0.25% Dy, impurity elements (Fe≤0.003%; Cu≤0.0003%; Si≤0.003%; Ni≤0.0003%), and the balance is Mg.

[0134] 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 350±2MPa, the yield strength was 295±2MPa, and the elongation was 7.1±0.5%.

[0135] The medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention was characterized.

[0136] See also Figure 1 , Figure 1 The metallographic microscope photos of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention are shown in Figure 1. (a) is the cast state, (b) is the extruded state (perpendicular to the extrusion direction), and (c) is the extruded state (along the extrusion direction).

[0137] See also Figure 2 , Figure 2 The scanning electron microscope photographs of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention are shown in Figure 1. (ab) are cast and (cd) are extruded (along the extrusion direction).

[0138] from Figure 1 and Figure 2It can be seen that fine β phases containing Mg, Nd, Ag and Ca elements of a certain size, proportion and dispersion distribution exist at the grain boundaries and in the grains, which is one of the main reasons why the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy has excellent mechanical properties.

[0139] See also Figure 3 , Figure 3 This is a spectrum scanning photo of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy 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).

[0140] from Figure 3 It can be seen that the fine β phase containing Mg, Nd, Ag and Ca elements of a certain size, proportion and dispersed distribution at the grain boundary and in the grain contains Mg, Nd, Ag and Ca elements. The specific element distribution and the stable organizational structure formed by the elements in the β phase containing Mg, Nd, Ag and Ca elements are one of the main reasons why the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy has excellent mechanical properties.

[0141] See also Figure 4 , Figure 4 The following are morphological photographs of 3T3 cells cultured for 15 days in 100%, 50% and 10% immersion extracts of the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared in Example 1 of the present invention, compared with the negative control group. Among them, (a) is the 100% leaching solution, (b) is the 50% leaching solution, (c) is the 10% leaching solution and (d) is the negative control group.

[0142] The results show that compared with the negative control group, 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-2.4Nd-0.54Ag-0.37Ca-0.25Dy 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 the number of healthy cells cultured in the negative normal culture medium, and the cell state is significantly better than the cell state cultured in the negative normal culture medium, because the fine β phase containing Mg, Nd, Ag and Ca 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.

[0143] See also Figure 5, Figure 5 The scanning electron microscope photo and energy spectrum analysis result of hydroxyapatite generated by immersing the medical biological Mg-2.4Nd-0.54Ag-0.37Ca-0.25Dy rare earth magnesium alloy prepared by Example 1 of the present invention in simulated body fluid. The fine β phase containing Mg, Nd, Ag and Ca elements of a certain size, proportion and dispersion distribution existing at the grain boundary and in the grain promotes the formation of a large amount of hydroxyapatite during the degradation process, which can further promote the repair of defective tissue, enhance the hardness and fracture resistance of human bones, stimulate or induce bone hyperplasia, treat osteoporosis, and prevent muscle spasms.

[0144] Example 2

[0145] The preparation method of Mg-2.1Nd-0.4Ag-0.35Ca-0.17Dy medical biological rare earth magnesium alloy is as follows:

[0146] Equipment: 35Kg vacuum induction melting furnace

[0147] Melting process:

[0148] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 9.086 kg of high-purity magnesium ingot, 0.7 kg of magnesium-neodymium master alloy, 0.04 kg of silver ingot, 0.117 kg of magnesium-calcium master alloy, and 0.057 kg of magnesium-dysprosium master alloy, preheat to 337° C., put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 337° C., and mix for 9 minutes;

[0149] (2) Evacuate the air and then fill it with argon as a protective gas;

[0150] (3) By controlling the power, the temperature is raised to 795°C within 35 minutes;

[0151] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 775°C, add magnesium-calcium master alloy, stir and let it stand for 19 minutes, then add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, heat it up to 785°C, stir, let it stand and keep it warm for 4.5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0152] (5) After cooling naturally in the stainless steel mold for 35 minutes, the alloy ingot was taken out;

[0153] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 425°C, keep warm for 5 hours, take out and air cool;

[0154] (7) Hot extrusion molding: The extruded material is extruded at 385°C, the die and barrel temperatures are 385°C, and the extrusion speed is set at 1.6 m / s.

[0155] The chemical composition (mass percentage) of the prepared alloy is: 2.1% Nd, 0.4% Ag, 0.35% Ca, 0.17% Dy, impurity elements (Fe≤0.002%; Cu≤0.0002%; Si≤0.002%; Ni≤0.0002%), and the balance is Mg.

[0156] 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 333±3 MPa, the yield strength was 275±2 MPa, and the elongation was 5.5±0.5%.

[0157] Example 3

[0158] The preparation method of Mg-1.6Nd-0.36Ag-0.27Ca-0.13Dy medical biological rare earth magnesium alloy is as follows:

[0159] Equipment: 35Kg vacuum induction melting furnace

[0160] Melting process:

[0161] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 9.298 kg of high-purity magnesium ingot, 0.533 kg of magnesium-neodymium master alloy, 0.036 kg of silver ingot, 0.09 kg of magnesium-calcium master alloy, and 0.043 kg of magnesium-dysprosium master alloy, preheat to 333° C., put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 333° C., and mix for 8.5 minutes;

[0162] (2) Evacuate the air and then fill it with argon as a protective gas;

[0163] (3) By controlling the power, the temperature was raised to 792°C within 40 minutes;

[0164] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 782°C, add magnesium-calcium master alloy, stir and let it stand for 25 minutes, then add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, heat it up to 778°C, stir, let it stand and keep it warm for 5.5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0165] (5) After naturally cooling in the stainless steel mold for 38 minutes, the alloy ingot was taken out;

[0166] (6) Solution treatment: Place in a vacuum heat treatment furnace, evacuate and heat to 413°C, keep warm for 3.8 hours, take out and air cool;

[0167] (7) Hot extrusion molding: The extruded material is extruded at 382°C, the die and barrel temperatures are 380°C, and the extrusion speed is set at 1.4 m / s.

[0168] The chemical composition (mass percentage) of the prepared alloy is: 1.6% Nd, 0.36% Ag, 0.27% Ca, 0.13% Dy, impurity elements (Fe≤0.0025%; Cu≤0.00025%; Si≤0.0025%; Ni≤0.00025%), and the balance is Mg.

[0169] 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 282±2MPa, the yield strength was 260±4MPa, and the elongation was 4.3±0.3%.

[0170] 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 2.4wt%, the transition metal element Ag content is 0.54wt%, the alkaline earth element Ca content is 0.37% and the rare earth element Dy content is 0.25wt%.

[0171] Comparative Example 1

[0172] The preparation method of Mg-3Nd-0.16Ag-0.14Ca-0.12Dy medical biological rare earth magnesium alloy is as follows:

[0173] Equipment: 35Kg vacuum induction melting furnace

[0174] Melting process:

[0175] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 8.897 kg of high-purity magnesium ingot, 1 kg of magnesium-neodymium master alloy, 0.016 kg of silver ingot, 0.047 kg of magnesium-calcium master alloy, and 0.04 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;

[0176] (2) Evacuate the air and then fill it with argon as a protective gas;

[0177] (3) By controlling the power, the temperature is raised to 790°C within 35 minutes;

[0178] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 775°C, add magnesium-calcium master alloy, stir and let it stand for 19 minutes, then add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, heat it up to 785°C, stir, let it stand and keep it warm for 3.5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0179] (5) After cooling naturally in the stainless steel mold for 35 minutes, the alloy ingot was taken out;

[0180] (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;

[0181] (7) Hot extrusion molding: The extruded material is extruded at 390°C, the die and barrel temperatures are 375°C, and the extrusion speed is set to 1.4 m / s.

[0182] The chemical composition (mass percentage) of the prepared alloy is: 3% Nd, 0.16% Ag, 0.14% Ca, 0.12% Dy, impurity elements (Fe≤0.0025%; Cu≤0.00025%; Si≤0.0025%; Ni≤0.00025%), and the balance is Mg.

[0183] 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 176±3 MPa, the yield strength was 145±4 MPa, and the elongation was 1.9±0.3%.

[0184] Comparative Example 2

[0185] The preparation method of Mg-3.4Nd-0.12Ag-0.11Ca-0.52Dy medical biological rare earth magnesium alloy is as follows:

[0186] Equipment: 35Kg vacuum induction melting furnace

[0187] Melting process:

[0188] (1) Prepare 10 kg of raw materials per furnace according to the designed alloy ratio, including 8.645 kg of high-purity magnesium ingot, 1.133 kg of magnesium-neodymium master alloy, 0.012 kg of silver ingot, 0.037 kg of magnesium-calcium master alloy, and 0.173 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;

[0189] (2) Evacuate the air and then fill it with argon as a protective gas;

[0190] (3) By controlling the power, the temperature is raised to 790°C within 35 minutes;

[0191] (4) Observe the vacuum furnace, after the high-purity magnesium ingot is completely melted, cool it down to 775°C, add magnesium-calcium master alloy, stir and let it stand for 19 minutes, then add magnesium-neodymium master alloy, magnesium-dysprosium master alloy and silver ingot, heat it up to 785°C, stir, let it stand and keep it warm for 3.5 hours after it is completely melted, and then pour it into a stainless steel mold;

[0192] (5) After cooling naturally in the stainless steel mold for 35 minutes, the alloy ingot was taken out;

[0193] (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;

[0194] (7) Hot extrusion molding: The extruded material is extruded at 390°C, the die and barrel temperatures are 375°C, and the extrusion speed is set to 1.4 m / s.

[0195] The chemical composition (mass percentage) of the prepared alloy is: 3.4% Nd, 0.12% Ag, 0.11% Ca, 0.52% Dy, impurity elements (Fe≤0.002%; Cu≤0.0002%; Si≤0.002%; Ni≤0.0002%), and the balance is Mg.

[0196] 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 166±3MPa, the yield strength was 146±2MPa, and the elongation was 1.8±0.4%.

[0197] The above is a detailed introduction to a rare earth magnesium alloy medical biomaterial provided by the present invention, its preparation method and application. The principle and implementation method of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and its core idea 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 principle of the present invention, the present invention can also be improved and modified in several 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 textual expression of the claims, or if they include equivalent structural elements that are not substantially different from the textual expression 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 β phase containing Mg, Nd, Ag and Ca elements; The β phase containing Mg, Nd, Ag and Ca elements is continuous or discontinuous in the grains and presents a three-dimensional spatial structure; The β phase containing Mg, Nd, Ag and Ca 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 β phase containing Mg, Nd, Ag and Ca elements is specifically a precipitation phase; The β phase containing Mg, Nd, Ag and Ca elements accounts for 15% to 35% of the precipitated phase; The β phase containing Mg, Nd, Ag and Ca 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 β phase containing Mg, Nd, Ag and Ca elements is in a coherent relationship and / or a semi-coherent relationship with the matrix; Some of the β phases containing Mg, Nd, Ag and Ca elements span the grain boundary, connecting the eutectic region and the non-eutectic region; The length of the β phase containing Mg, Nd, Ag and Ca elements is 3 to 20 μm; The width of the β phase containing Mg, Nd, Ag and Ca elements is 0.025 to 1.5 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%; Ca: 0.05wt%~1.0wt%; Dy: 0.1wt% to 0.5wt%; The balance is magnesium; Among them, the mass ratio of (Nd+Dy) / Ca is (3.5~7.5):

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 calcium 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 calcium source includes a magnesium-calcium master alloy; The mass content of calcium in the magnesium-calcium master alloy is 20% to 30%.

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 740-820°C; The smelting time is 2.5 to 6 hours; The temperature of the solution treatment is 320-570°C; The time of the solution treatment is 2 to 7 hours.

9. The preparation method according to claim 6, characterized in that: The temperature of the hot extrusion is 250-430°C; The extrusion speed of the hot extrusion is 0.45-1.7 m / s; The extrusion ratio of the hot extrusion is (5-13):

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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