Medical biological magnesium neodymium silver scandium rare earth magnesium alloy material and preparation method and application thereof

Abstract

The invention provides a medical biological magnesium neodymium silver scandium rare earth magnesium alloy material and a preparation method and application thereof. Pure magnesium serves as base alloy, rare earth neodymium, scandium and silver elements are added according to a certain matching relation, and the biomedical rare earth magnesium alloy material which has a specific structure and a microstructure and contains a dynamic recrystallization eutectic phase hexagonal gamma phase Nd2Ag3Mg14 and an orthogonal structure phase NdAgMg11 is prepared. The biomedical rare earth magnesium alloy provided by the invention is excellent in strength and ductility, excellent in processability, degradable and good in biological safety and biocompatibility. The dynamic recrystallization eutectic phase improves the antibacterial ability, avoids inflammatory response of organisms, promotes cell growth and proliferation at the same time, further stimulates bone growth, shortens the recovery time of patients, can meet the requirements of being used as a medical implant material and processed into related devices, and is a degradable biomedical light magnesium alloy material.

Description

Technical Field

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

[0002] Nowadays, magnesium alloys are widely used in aerospace, automobiles, rail vehicles, 3C electronics and other fields due to their abundant reserves in the earth's crust, inherent low density and high strength-to-weight ratio. In addition, magnesium alloys also show great potential in the biomedical field due to their excellent comprehensive properties. As a biomedical material, the elastic modulus of magnesium alloys is closest to that of human bones, and will not produce stress shielding effects. At the same time, it has good biosafety and biocompatibility. In the human body fluid environment, magnesium alloy implants degrade to generate soluble magnesium hydroxide and hydroxyapatite. Hydroxyapatite is the main component of human bones and has a stimulating effect on the growth of new bone tissue. Commonly used traditional magnesium alloy material systems such as pure magnesium, magnesium-zinc-based and magnesium-calcium-based have too fast degradation rates, poor mechanical support and integrity. After the device is implanted, the human bone has failed before it is fully healed, and is not suitable for use as a biomedical material.

[0003] Therefore, how to design and develop a more suitable biomedical magnesium alloy material to solve the above-mentioned problems of existing biomedical magnesium alloys and meet the needs of being used as biomedical implant materials and processed into related devices has become one of the urgent issues 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 biomedical rare earth magnesium alloy and its preparation method and application, in particular, a biomedical magnesium neodymium silver scandium rare earth magnesium alloy material. The biomedical rare earth magnesium alloy provided by the present invention has a specific alloy element ratio of raw materials. After smelting, solution treatment and hot extrusion deformation, the ductility is maintained while the strength is significantly improved, and it has basic biosafety and biocompatibility. At the same time, its preparation method is simple and easy, the conditions are mild and controllable, and the operability is strong, which is more suitable for industrial production, promotion and application.

[0005] The present invention provides a biomedical rare earth magnesium alloy, wherein the rare earth magnesium alloy includes a dynamically recrystallized eutectic phase;

[0006] The dynamically recrystallized eutectic phase includes hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 ;

[0007] The dynamically recrystallized eutectic phase is located at the grain boundary of the alloy;

[0008] The dynamic recrystallization eutectic phase contains Mg element, Nd element and Ag element.

[0009] Preferably, the dynamically recrystallized eutectic phase is specifically twin grain boundary precipitates;

[0010] The size of the dynamic recrystallization eutectic phase is 2 to 15 μm;

[0011] The morphology of the dynamically recrystallized eutectic phase includes a hexagonal structure and an orthorhombic structure.

[0012] Preferably, the dynamically recrystallized eutectic phase is in a coherent relationship and / or a semi-coherent relationship with the matrix;

[0013] The dynamic recrystallization eutectic phase is distributed in a fine and dispersed state;

[0014] The interaction between the dynamic recrystallization eutectic phases hinders the dislocation movement of the rare earth magnesium alloy.

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

[0016] Nd: 0.5wt% to 2.5wt%;

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

[0018] Sc: 0.1wt% to 0.5wt%;

[0019] The balance is magnesium;

[0020] Among them, the mass ratio of (Nd+Sc) / Ag is 3-6.

[0021] Preferably, the biomedical rare earth magnesium alloy further includes impurity elements;

[0022] The impurity elements include one or more of Fe, Cu, Si and Ni;

[0023] Among the impurity elements, Fe≤0.005wt%;

[0024] Cu≤0.0005wt%;

[0025] Si≤0.005wt%;

[0026] Ni≤0.0005wt%.

[0027] The present invention provides a method for preparing a biomedical rare earth magnesium alloy, comprising the following steps:

[0028] 1) smelting a magnesium source, a neodymium source, a scandium source and a silver source to obtain a biomedical rare earth magnesium alloy ingot;

[0029] 2) The biomedical rare earth magnesium alloy ingot obtained in the above steps is subjected to solid solution treatment and hot extrusion to obtain a biomedical rare earth magnesium alloy material.

[0030] Preferably, the magnesium source comprises high-purity magnesium;

[0031] The neodymium source includes a magnesium-neodymium master alloy;

[0032] The silver source includes silver ingots;

[0033] The scandium source includes a magnesium-scandium master alloy.

[0034] Preferably, the smelting is specifically carried out in a graphite silicon carbide crucible of a vacuum induction furnace;

[0035] The smelting temperature is 760-800°C;

[0036] The smelting time is 3 to 4 hours;

[0037] The temperature of the solution treatment is 300-500°C;

[0038] The time of the solution treatment is 2 to 3 hours.

[0039] Preferably, the temperature of the hot extrusion is 250-400°C;

[0040] The extrusion speed of the hot extrusion is 0.5 to 1.5 m / s;

[0041] The extrusion ratio of the hot extrusion is (7-12):1.

[0042] The present invention also provides the use of the biomedical rare earth magnesium alloy described in any one of the above technical solutions or the biomedical 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.

[0043] The present invention provides a biomedical rare earth magnesium alloy, wherein the rare earth magnesium alloy comprises a dynamic recrystallization eutectic phase; the dynamic recrystallization eutectic phase comprises a hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11; The dynamic recrystallization eutectic phase is located at the grain boundary of the alloy; The dynamic recrystallization eutectic phase contains Mg, Nd and Ag elements. Compared with the prior art, the present invention believes that the rare earth neodymium and scandium are used as alloying components to synergistically improve their strength and processing performance, thereby promoting the development of biomedical magnesium alloy materials. The rare earth neodymium and scandium elements released by degradation in the body diffuse very slowly. After being diluted by human body fluids, the concentration of rare earth neodymium and scandium elements is significantly reduced, and the toxic effect on the human body is significantly weakened. At the same time, because rare earth neodymium and scandium elements have high solubility, they are easily metabolized by the body and excreted from the body with sweat and urine.

[0044] Based on this, the present invention creatively designs a biomedical rare earth magnesium alloy with a specific composition and microstructure, by adding different contents of rare earth neodymium and scandium elements to work together, and then combining silver elements to refine the alloy structure and improve the strength, and controlling the specific ratio between the elements, so as to obtain excellent mechanical properties while ensuring good biosafety and biocompatibility. On the one hand, rare earth neodymium and scandium elements have suitable toxic concentrations, and Nd and Sc have high solubility, showing outstanding biosafety and biocompatibility, and are easily metabolized by organisms and excreted from the body with sweat and urine. The synergistic effect of rare earth neodymium and scandium elements can purify the melt and improve mechanical properties. At the same time, they are non-toxic and have bactericidal functions, and can also promote bone tissue growth, accelerate recovery time and improve wound healing. On the other hand, Mg-Nd-Ag-Sc-based alloys have excellent mechanical properties and can meet the needs of being used as human medical materials and made into related devices. The alloy provided by the present invention has excellent mechanical properties and processing properties, can meet the needs of being used as a biomedical implant material and being made into related devices, and the alloying elements meet strict toxicity restrictions.

[0045] The magnesium-neodymium-silver-scandium rare earth magnesium alloy medical biomaterial provided by the present invention is based on magnesium as the alloy, and rare earth neodymium, scandium and silver elements are added in a certain ratio. After smelting, solid solution treatment and hot extrusion deformation, while maintaining ductility, its strength is significantly improved, and it has good biosafety and biocompatibility. In order to obtain specific metallographic microscope structure, scanning electron microscope structure and mechanical properties, rare earth neodymium and scandium elements are added in the form of intermediate alloys, and silver elements are added in the form of silver ingots. According to this method, appropriate smelting preparation processes are adopted, combined with specific heat treatment and hot extrusion processes for preparation. Due to the synergistic solid solution strengthening and grain refinement effects of rare earth neodymium and scandium elements, and the silver element can change the crystal structure of the alloy and increase the number of grain boundaries, the strength of the alloy is significantly improved. The present invention forms a dynamic recrystallization eutectic phase containing Mg, Nd and Ag elements--hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11As the interaction between the second phases hinders the movement of dislocations, it can greatly improve the strength of the biomedical rare earth magnesium alloy while ensuring its ductility. The material has a tensile strength greater than 330MPa, a yield strength greater than 260MPa, and an elongation greater than 5%. While maintaining ductility, the strength has been significantly improved. At the same time, the results of in vitro cytotoxicity evaluation experiments have proved that it has good biosafety and biocompatibility, and the silver element has antibacterial, anti-inflammatory and wound healing effects.

[0046] The biomedical rare earth magnesium alloy provided by the present invention adopts its specific melting, solid solution and hot extrusion process parameters, has high strength, good ductility, excellent processing performance, is degradable, non-toxic, and the alloy is non-sensitizing, can treat osteoporosis, has a bactericidal function, and is a lightweight magnesium alloy material that can be used as a biomedical material.

[0047] The experimental results show that the magnesium-neodymium-silver-scandium rare earth magnesium alloy prepared by the present invention has excellent mechanical properties and can meet the performance requirements of medical biological substrates. Its room temperature tensile strength, yield strength and elongation reach 80-360MPa, 56-280MPa and 3%-5.5% respectively. At the same time, good ductility also ensures that the alloy of the present invention can be precisely formed and processed, and has the ability to be made into biomedical implants. Moreover, the rare earth magnesium alloy does not contain alloying elements that are toxic to the human body, and is safe and reliable. By analyzing the relative cell growth rate of 100%, 50% and 10% leaching solutions of the alloy of the present invention and 3T3 cells after culture, it is confirmed that the alloy has good biosafety and biocompatibility and can be used in the medical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a metallographic microscope photo of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention;

[0049] Figure 2 This is a scanning electron microscope photograph of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention;

[0050] Figure 3 This is a spectrum scanning photo of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention;

[0051] Figure 4 This is a morphological photograph of 3T3 cells cultured for 3 days after being immersed in the extract of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] The present invention provides a biomedical rare earth magnesium alloy, wherein the rare earth magnesium alloy includes a dynamically recrystallized eutectic phase;

[0058] The dynamically recrystallized eutectic phase includes hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 ;

[0059] The dynamically recrystallized eutectic phase is located at the grain boundary of the alloy;

[0060] The dynamic recrystallization eutectic phase contains Mg element, Nd element and Ag element.

[0061] In the present invention, the dynamically recrystallized eutectic phase is specifically twin grain boundary precipitates.

[0062] In the present invention, the size of the dynamically recrystallized eutectic phase is preferably 2 to 15 μm, more preferably 4 to 13 μm, and even more preferably 6 to 11 μm.

[0063] In the present invention, the morphology of the dynamically recrystallized eutectic phase preferably includes a hexagonal structure and an orthorhombic structure.

[0064] In the present invention, the dynamically recrystallized eutectic phase and the matrix are preferably in a coherent relationship and / or a semi-coherent relationship, and more preferably in a coherent relationship or a semi-coherent relationship.

[0065] In the present invention, the dynamically recrystallized eutectic phase is preferably distributed in a fine and dispersed state.

[0066] In the present invention, the dynamic recrystallization eutectic phases preferably interact with each other to hinder the dislocation movement of the rare earth magnesium alloy.

[0067] The biomedical rare earth magnesium alloy provided by the present invention has a significantly stronger bonding force between Nd, Ag and Mg than Sc, forming a dynamic recrystallization eutectic phase containing Mg, Nd and Ag elements, namely, hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 As the interaction between the second phases hinders the dislocation movement, it can greatly improve the strength of the biomedical rare earth magnesium alloy while ensuring its ductility. Dynamic recrystallization eutectic phase hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 As twin grain boundary precipitates, they have a pinning effect, strengthening the biomedical rare earth magnesium alloy while improving the processing performance. Dynamically recrystallized eutectic phase hexagonal γ phase Nd2Ag3Mg containing Mg, Nd and Ag elements with a size of 2 to 15 μm 14 and orthorhombic NdAgMg 11 It is fine and dispersed, and is easily dissolved in human body fluids. After being diluted, it is excreted from the body through the skin and kidneys with water. The rare earth element Nd in the dynamic recrystallization eutectic phase hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 The Ag element forms a stable organizational structure in the dynamic recrystallization eutectic phase hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 The presence of Ag in the dynamic recrystallization eutectic phase refines the grains and inhibits the growth of dynamic recrystallization grains during hot extrusion, thereby increasing strength without reducing ductility. 14 and orthorhombic NdAgMg 11 A stable tissue structure is formed in the body, which improves the antibacterial ability, avoids inflammatory response in the organism, and is beneficial to wound recovery. In addition, the dynamic recrystallization eutectic phase hexagonal γ phase Nd2Ag3Mg with a specific composition and tissue structure 14 and orthorhombic NdAgMg 11 The biomedical rare earth magnesium alloy material can promote cell growth and proliferation, as well as the formation of hydroxyapatite, the main component of human bones, further stimulate bone growth and shorten the recovery time of patients. This shows that the biomedical rare earth magnesium alloy is a potential ideal biomaterial.

[0068] The biomedical rare earth magnesium alloy provided by the present invention generates a large number of special dynamic recrystallization eutectic phases at the grain boundaries of the alloy. In addition to containing the Mg element, this phase also contains Nd and Ag elements, and is also a twin grain boundary precipitate with a size of 2 to 15 microns. It has a hexagonal structure and an orthorhombic structure and is coherent or semi-coherent with the matrix. The dynamic recrystallization eutectic phase has high strength and is fine and dispersed. Its interaction hinders dislocation movement and improves the plastic deformation ability of the alloy. At the same time, the dynamic recrystallization eutectic phase also has a pinning effect, which can enhance the mechanical properties of the alloy.

[0069] The present invention provides a biomedical rare earth magnesium alloy, which comprises, by mass percentage:

[0070] Nd: 0.5wt% to 2.5wt%;

[0071] Ag: 0.1wt%~1.0wt%;

[0072] Sc: 0.1wt% to 0.5wt%;

[0073] The balance is magnesium;

[0074] Among them, the mass ratio of (Nd+Sc) / Ag is 3-6.

[0075] In the present invention, the content of Nd is 0.5wt% to 2.5wt%, may be 0.9wt% to 2.1wt%, or may be 1.3wt% to 1.7wt%.

[0076] 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%.

[0077] In the present invention, the mass ratio of (Nd+Sc) / Ag is 3-6, may be 3.5-5.5, or may be 4-5.

[0078] In the present invention, the biomedical rare earth magnesium alloy preferably further includes impurity elements.

[0079] 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.

[0080] In the present invention, in order to meet the medical safety and controllable corrosion rate, the impurity content is required to be as follows:

[0081] 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 %.

[0082] In the present invention, among the impurity elements, preferably Cu≤0.0005wt%, more preferably Cu≤0.0004wt%, and more preferably Cu≤0.0003wt%.

[0083] 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 %.

[0084] In the present invention, among the impurity elements, preferably Ni≤0.0005wt%, more preferably Ni≤0.0004wt%, and more preferably Ni≤0.0003wt%.

[0085] The biomedical rare earth magnesium alloy provided by the present invention has excellent mechanical support performance and processing performance, high strength, good ductility, excellent processing performance, degradability, non-toxicity, dynamic recrystallization eutectic phase hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 It enhances antibacterial capability and avoids inflammatory responses in organisms, while promoting cell growth and proliferation, as well as the formation of hydroxyapatite, the main component of human bones, further stimulating bone growth and shortening patient recovery time. It can meet the needs of being used as a medical implant material and processed into related devices. It is a biodegradable, lightweight magnesium alloy material for biomedical use.

[0086] The present invention provides a method for preparing a biomedical rare earth magnesium alloy, comprising the following steps:

[0087] 1) placing a magnesium source, a neodymium source, a scandium source and a silver source into a graphite silicon carbide crucible of a vacuum induction furnace for smelting to obtain a biomedical rare earth magnesium alloy ingot;

[0088] 2) The biomedical rare earth magnesium alloy ingot obtained in the above steps is subjected to solid solution treatment and hot extrusion to obtain a biomedical rare earth magnesium alloy material.

[0089] The invention firstly puts a magnesium source, a neodymium source, a scandium source and a silver source into a graphite silicon carbide crucible of a vacuum induction furnace for smelting to obtain a rare earth magnesium alloy ingot.

[0090] In the present invention, the magnesium source preferably includes high-purity magnesium. Specifically, the purity of the high-purity magnesium is preferably greater than or equal to 99.99%.

[0091] In the present invention, the neodymium source preferably includes a magnesium-neodymium master alloy.

[0092] In the present invention, the silver source preferably comprises silver ingots.

[0093] In the present invention, the scandium source preferably comprises a magnesium-scandium master alloy.

[0094] In the present invention, the mass content of rare earth elements in the magnesium-neodymium master alloy and the magnesium-scandium master alloy is 30%.

[0095] In the present invention, the smelting is preferably carried out in a graphite silicon carbide crucible of a vacuum induction furnace.

[0096] In the present invention, the smelting temperature is preferably 760-800°C, more preferably 765-795°C, more preferably 770-790°C, and more preferably 775-785°C.

[0097] In the present invention, the smelting time is preferably 3 to 4 hours, more preferably 3.2 to 3.8 hours, and more preferably 3.4 to 3.6 hours.

[0098] The present invention further subject the rare earth magnesium alloy ingot obtained in the above steps to solid solution treatment and hot extrusion to obtain the medical rare earth magnesium alloy.

[0099] In the present invention, the temperature of the solution treatment is preferably 300-500°C, more preferably 320-480°C, more preferably 350-450°C, and more preferably 370-430°C.

[0100] In the present invention, the solution treatment time is preferably 2 to 3 hours, more preferably 2.2 to 2.8 hours, and more preferably 2.4 to 2.6 hours.

[0101] In the present invention, the temperature of the hot extrusion is preferably 250-400°C, more preferably 280-370°C, and even more preferably 310-340°C.

[0102] In the present invention, the extrusion speed of the hot extrusion is 0.5 to 1.5 m / s, more preferably 0.7 to 1.3 m / s, and more preferably 0.9 to 1.1 m / s.

[0103] In the present invention, the extrusion ratio of the hot extrusion is (7-12):1, more preferably (8-11):1, and more preferably (9-10):1.

[0104] The present invention provides the use of the biomedical rare earth magnesium alloy described in any one of the above technical solutions or the biomedical 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.

[0105] The present invention is to complete and refine the overall technical solution, better ensure the proportion and microstructure morphology of the biomedical rare earth magnesium alloy, and further improve the mechanical properties and medical properties of the biomedical rare earth magnesium alloy. The above-mentioned medical biological magnesium neodymium silver scandium rare earth magnesium alloy material and its preparation method may specifically include the following contents:

[0106] The biomedical magnesium-neodymium-silver-scandium rare earth magnesium alloy provided by the present invention is made of magnesium as a base alloy, and rare earth neodymium, scandium and silver elements are added in a certain ratio.

[0107] The chemical composition of the biomedical rare earth magnesium alloy is 0.5-2.5wt.% Nd, 0.1-1.0wt.%, Sc, 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.%.

[0108] Specifically, in order to obtain a specific metallographic microscope and scanning electron microscope structure, the total amount of rare earth neodymium does not exceed 2.5wt.% of the total alloy, and the total amount of rare earth scandium does not exceed 0.5wt.% of the total alloy. Among them, Nd is 0.5-2.5wt.%, and Sc is 0.1-0.5wt.%.

[0109] Specifically, in order to obtain specific metallographic microscope structure, scanning electron microscope structure and stable mechanical properties, rare earth neodymium and scandium elements are added in the form of master alloy, and an appropriate smelting preparation process is adopted according to this method. The master alloy used is: a magnesium-neodymium master alloy made of 70wt.% magnesium and 30wt.% rare earth neodymium. A magnesium-scandium master alloy made of 70wt.% magnesium and 30wt.% rare earth scandium.

[0110] Specifically, the alloy adopts its specific melting, solution treatment, hot extrusion process parameters and preparation sequence. The alloy is non-allergenic, can treat osteoporosis, and has a bactericidal function.

[0111] The above content of the present invention provides a medical biological magnesium neodymium silver scandium rare earth magnesium alloy material and its preparation method and application. The biomedical rare earth magnesium alloy designed by the present invention has a specific composition and microstructure, and is synergistically added with different contents of rare earth neodymium and scandium elements, and then combined with silver elements to refine the alloy structure and improve the strength, and control the specific ratio between the elements, so as to obtain excellent mechanical properties while ensuring good biosafety and biocompatibility. On the one hand, the rare earth neodymium element and the scandium element have a suitable toxic concentration, and Nd and Sc have high solubility, showing outstanding biosafety and biocompatibility, and are easily metabolized by the organism and excreted from the body with sweat and urine, while the rare earth neodymium element and the scandium element synergistically can purify the melt and improve the mechanical properties. At the same time, it is non-toxic and has a bactericidal function, and can also promote bone tissue growth, accelerate recovery time and improve wound healing. On the other hand, the Mg-Nd-Ag-Sc-based alloy has excellent mechanical properties and can meet the needs of being used as a human medical material and made into related devices. The alloy provided by the present invention has good mechanical properties and processing properties, can meet the needs of being used as a biomedical implant material and being made into related devices, and the alloying elements meet strict toxicity restrictions.

[0112] The magnesium-neodymium-silver-scandium rare earth magnesium alloy medical biomaterial provided by the present invention is based on magnesium as the alloy, and rare earth neodymium, scandium and silver elements are added in a certain ratio. While maintaining ductility, its strength is significantly improved, and it has good biosafety and biocompatibility. In order to obtain specific metallographic microscope structure, scanning electron microscope structure and mechanical properties, rare earth neodymium and scandium elements are added in the form of intermediate alloys, and silver elements are added in the form of silver ingots. According to this method, appropriate smelting preparation processes are adopted, combined with specific heat treatment and hot extrusion processes for preparation. Due to the synergistic solid solution strengthening and grain refinement effects of rare earth neodymium and scandium elements, and the fact that silver elements can change the crystal structure of the alloy and increase the number of grain boundaries, the strength of the alloy is significantly improved. The present invention forms a dynamically recrystallized eutectic phase containing Mg, Nd and Ag elements--hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 As the interaction between the second phases hinders the movement of dislocations, it can greatly improve the strength of the biomedical rare earth magnesium alloy while ensuring its ductility. The material has a tensile strength greater than 330MPa, a yield strength greater than 260MPa, and an elongation greater than 5%. While maintaining ductility, the strength has been significantly improved. At the same time, the results of in vitro cytotoxicity evaluation experiments have proved that it has good biosafety and biocompatibility, and the silver element has antibacterial, anti-inflammatory and wound healing effects.

[0113] The biomedical rare earth magnesium alloy provided by the present invention adopts its specific melting, solution treatment, and hot extrusion process parameters, has high strength, good ductility, excellent processing performance, is degradable, non-toxic, and the alloy is non-sensitizing, can treat osteoporosis, has a bactericidal function, is a lightweight magnesium alloy material that can be used as a biomedical material, and can be mechanically processed into related biological components.

[0114] The experimental results show that the magnesium-neodymium-silver-scandium rare earth magnesium alloy prepared by the present invention has excellent mechanical properties and can meet the performance requirements of medical biological substrates. Its room temperature tensile strength, yield strength and elongation reach 80-360MPa, 56-280MPa and 3%-5.5% respectively. At the same time, good ductility also ensures that the alloy of the present invention can be precisely formed and processed, and has the ability to be made into biomedical related devices. Moreover, the rare earth magnesium alloy does not contain alloy elements that are toxic to the human body, and is safe and reliable. By analyzing the relative cell growth rate of 100%, 50% and 10% leaching solutions of the alloy of the present invention and 3T3 cells after culture, it is confirmed that the alloy has good biosafety and biocompatibility and can be used in the medical field.

[0115] In order to further illustrate the present invention, a biomedical 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.

[0116] Example 1

[0117] The preparation method of Mg-2.41Nd-0.55Ag-0.41Sc medical biological rare earth magnesium alloy is as follows:

[0118] Equipment: 35Kg vacuum induction melting furnace

[0119] Melting process:

[0120] (1) Prepare 5 kg per furnace, prepare the raw materials according to the alloy ratio, including 4.5026 kg of high-purity magnesium ingot, 0.4016 kg of magnesium-neodymium master alloy, 0.0275 kg of silver ingot, and 0.0683 kg of magnesium-scandium master alloy, preheat to 320°C, put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 320°C, and mix for 6 minutes;

[0121] (2) Evacuate the vacuum and then fill it with protective gas argon;

[0122] (3) By controlling the power, the temperature is raised to 800°C within 30 minutes;

[0123] (4) Observe the vacuum furnace, cool down to 780°C after complete melting, stir and let stand for 20 minutes, heat up to 790°C, keep warm for 3 hours, and then pour into a stainless steel mold;

[0124] (5) After cooling naturally in the stainless steel mold for 40 minutes, the alloy was taken out;

[0125] (6) Solution treatment: Place in a vacuum heat treatment furnace, heat to 400°C, keep warm for 2 hours, take out and air cool;

[0126] (7) Hot extrusion molding: The extruded material is extruded at 370°C, the die and barrel temperature is 355°C, and the extrusion speed is set to 1m / s.

[0127] The chemical composition (mass percentage) of the prepared alloy is: 2.41wt% Nd, 0.55wt% Ag, 0.41wt% Sc, impurity elements (Fe≤0.002wt%; Cu≤0.0002wt%; Si≤0.002wt%; Ni≤0.0002wt%), and the balance is Mg.

[0128] The mechanical properties of the medical rare earth magnesium alloy prepared in Example 1 of the present invention were tested, and the results showed that the tensile strength was 340±4 MPa, the yield strength was 271±1 MPa, and the elongation was 4.1±0.4%.

[0129] The medical rare earth magnesium alloy prepared in Example 1 of the present invention was characterized.

[0130] See also Figure 1 , Figure 1 The metallographic microscope photos of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention are shown in Figures 1 and 2. (a) is cast state, (b) is extruded state (perpendicular to the extrusion direction), and (c) is extruded state (along the extrusion direction).

[0131] See also Figure 2 , Figure 2 The following are scanning electron microscope photos of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention, wherein (ab) are cast state and (cd) are extruded state (along the extrusion direction).

[0132] from Figure 1 and Figure 2 It can be seen that a certain proportion of fine-sized dynamic recrystallized eutectic phase exists at the grain boundaries and is dispersed, which is the main reason why biomedical rare earth magnesium alloys have excellent mechanical properties.

[0133] See also Figure 3 , Figure 3 This is a spectrum scanning photo of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention. Among them, (a) cast state and (b) extruded state (along the extrusion direction).

[0134] from Figure 3 It can be seen that the dynamic recrystallization eutectic phase at the grain boundary contains Mg, Nd and Ag elements. The specific element distribution and the stable organizational structure formed by the elements in the dynamic recrystallization eutectic phase are the main reasons why biomedical rare earth magnesium alloys have excellent mechanical properties.

[0135] See also Figure 4 , Figure 4 The morphological photos of 3T3 cells cultured for 3 days after being immersed in the extract of the biomedical rare earth magnesium alloy prepared in Example 1 of the present invention are shown in Figure 1. Among them, (a) 100% extract, (b) 50% extract, (c) 10% extract and (d) negative control group.

[0136] Compared with the healthy cell morphology (elongated shape attached to the wall) cultured in pure culture medium in 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 (elongated shape attached to the wall), indicating that the alloy of the present invention is non-toxic to human tissue. At the same time, 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 the negative control group, and the cell state is significantly better than that of the negative control group, which is because the dynamic recrystallization eutectic phase containing Mg, Nd and Ag elements enhances the antibacterial ability, avoids inflammatory response of cells, and promotes cell growth and proliferation.

[0137] Example 2

[0138] The preparation method of Mg-2Nd-0.44Ag-0.35Sc medical biological rare earth magnesium alloy is as follows:

[0139] Equipment: 35Kg vacuum induction melting furnace

[0140] Melting process:

[0141] (1) Prepare 5 kg per furnace, prepare the raw materials according to the alloy ratio, including 4.5864 kg of high-purity magnesium ingot, 0.3333 kg of magnesium-neodymium master alloy, 0.022 kg of silver ingot, and 0.0583 kg of magnesium-scandium master alloy, preheat to 315°C, put into a graphite silicon carbide crucible in a vacuum induction furnace preheated at 315°C, and mix for 7 minutes;

[0142] (2) Evacuate the vacuum and then fill it with protective gas argon;

[0143] (3) By controlling the power, the temperature is raised to 790°C within 35 minutes;

[0144] (4) Observe the vacuum furnace, cool down to 775°C after complete melting, stir and let stand for 23 minutes, heat up to 785°C, keep warm for 3.2 hours, and then pour into a stainless steel mold;

[0145] (5) After cooling naturally in the stainless steel mold for 45 minutes, the alloy was taken out;

[0146] (6) Solution treatment: Place in a vacuum heat treatment furnace, heat to 390°C, keep warm for 2.5 hours, take out and air cool;

[0147] (7) Hot extrusion molding: The extruded material is extruded at 375°C, the die and barrel temperature is 360°C, and the extrusion speed is set to 1.2 m / s.

[0148] The chemical composition (mass percentage) of the prepared alloy is: 2wt% Nd, 0.44wt% Ag, 0.35wt% Sc, impurity elements (Fe≤0.0003wt%; Cu≤0.0003wt%; Si≤0.003wt%; Ni≤0.0003wt%), and the balance is Mg.

[0149] The mechanical properties of the medical rare earth magnesium alloy prepared in Example 2 of the present invention were tested, and the results showed that the tensile strength was 334±5 MPa, the yield strength was 262±4 MPa, and the elongation was 3.6±0.3%.

[0150] Example 3

[0151] The preparation method of Mg-1.88Nd-0.37Ag-0.29Sc medical biological rare earth magnesium alloy is as follows:

[0152] Equipment: 35Kg vacuum induction melting furnace

[0153] Melting process:

[0154] (1) Prepare 5 kg per furnace, prepare the raw materials according to the alloy ratio, including 4.6199 kg high-purity magnesium ingot, 0.3133 kg magnesium-neodymium master alloy, 0.0185 kg silver ingot, 0.0483 kg magnesium-scandium 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 5.5 minutes;

[0155] (2) Evacuate the vacuum and then fill it with protective gas argon;

[0156] (3) By controlling the power, the temperature was raised to 785°C within 37 minutes;

[0157] (4) Observe the vacuum furnace, cool down to 770°C after complete melting, stir and let stand for 24 minutes, heat up to 790°C, keep warm for 2.9 hours, and then pour into a stainless steel mold;

[0158] (5) After cooling naturally in the stainless steel mold for 43 minutes, the alloy was taken out;

[0159] (6) Solution treatment: Place in a vacuum heat treatment furnace, heat to 380°C, keep warm for 3 hours, take out and air cool;

[0160] (7) Hot extrusion molding: The extruded material is extruded at 370°C, the die and barrel temperature is 350°C, and the extrusion speed is set to 1.5m / s.

[0161] The chemical composition (mass percentage) of the prepared alloy is: 1.88wt% Nd, 0.37wt% Ag, 0.29wt% Sc, impurity elements (Fe≤0.0004wt%; Cu≤0.0004wt%; Si≤0.004wt%; Ni≤0.0004wt%), and the balance is Mg.

[0162] The mechanical properties of the medical rare earth magnesium alloy prepared in Example 3 of the present invention were tested. The results showed that the tensile strength was 325±8 MPa, the yield strength was 251±3 MPa, and the elongation was 3±0.5%.

[0163] The room temperature mechanical property data results in Examples 1 to 3 of the present invention show that the biomedical rare earth magnesium alloy of the present invention has excellent mechanical properties, meets the requirements of being used as a biomedical material and being processed into related devices, and has optimal strength and ductility when the rare earth Nd content is 2.41wt%, the Ag content is 0.55wt%, and the rare earth Sc content is 0.41wt%.

[0164] Comparative Example 1

[0165] The preparation method of Mg-3Nd-0.35Ag-0.61Sc medical biological rare earth magnesium alloy is as follows:

[0166] Equipment: 35Kg vacuum induction melting furnace

[0167] Melting process:

[0168] (1) Prepare 5 kg per furnace, mix the raw materials according to the alloy ratio, including 4.3808 kg of high-purity magnesium ingot, 0.5 kg of magnesium-neodymium master alloy, 0.0175 kg of silver ingot, and 0.1017 kg of magnesium-scandium 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 5.5 minutes;

[0169] (2) Evacuate the vacuum and then fill it with protective gas argon;

[0170] (3) By controlling the power, the temperature was raised to 785°C within 37 minutes;

[0171] (4) Observe the vacuum furnace, cool down to 770°C after complete melting, stir and let stand for 24 minutes, heat up to 790°C, keep warm for 2.9 hours, and then pour into a stainless steel mold;

[0172] (5) After cooling naturally in the stainless steel mold for 43 minutes, the alloy was taken out;

[0173] (6) Solution treatment: Place in a vacuum heat treatment furnace, heat to 380°C, keep warm for 3 hours, take out and air cool;

[0174] (7) Hot extrusion molding: The extruded material is extruded at 370°C, the die and barrel temperature is 350°C, and the extrusion speed is set to 1.5 m / s.

[0175] The chemical composition (mass percentage) of the prepared alloy is: 3wt% Nd, 0.35wt% Ag, 0.61wt% Sc, impurity elements (Fe≤0.0004wt%; Cu≤0.0004wt%; Si≤0.004wt%; Ni≤0.0004wt%), and the balance is Mg.

[0176] The mechanical properties of the medical rare earth magnesium alloy prepared in Comparative Example 1 of the present invention were tested, and the results showed that the tensile strength was 225±4 MPa, the yield strength was 160±2 MPa, and the elongation was 10±0.3%.

[0177] Comparative Example 2

[0178] The preparation method of Mg-2.5Nd-0.15Ag-0.5Sc medical biological rare earth magnesium alloy is as follows:

[0179] Equipment: 35Kg vacuum induction melting furnace

[0180] Melting process:

[0181] (1) Prepare 5 kg per furnace, prepare the raw materials according to the alloy ratio, including 4.4925 kg of high-purity magnesium ingot, 0.4167 kg of magnesium-neodymium master alloy, 0.0075 kg of silver ingot, and 0.0833 kg of magnesium-scandium 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 5.5 minutes;

[0182] (2) Evacuate the vacuum and then fill it with protective gas argon;

[0183] (3) By controlling the power, the temperature was raised to 785°C within 37 minutes;

[0184] (4) Observe the vacuum furnace, cool down to 770°C after complete melting, stir and let stand for 24 minutes, heat up to 790°C, keep warm for 2.9 hours, and then pour into a stainless steel mold;

[0185] (5) After cooling naturally in the stainless steel mold for 43 minutes, the alloy was taken out;

[0186] (6) Solution treatment: Place in a vacuum heat treatment furnace, heat to 380°C, keep warm for 3 hours, take out and air cool;

[0187] (7) Hot extrusion molding: The extruded material is extruded at 370°C, the die and barrel temperature is 350°C, and the extrusion speed is set to 1.5m / s.

[0188] The chemical composition (mass percentage) of the prepared alloy is: 2.5wt% Nd, 0.15wt% Ag, 0.5wt% Sc, impurity elements (Fe≤0.0004wt%; Cu≤0.0004wt%; Si≤0.004wt%; Ni≤0.0004wt%), and the balance is Mg.

[0189] The mechanical properties of the medical rare earth magnesium alloy prepared in Comparative Example 2 of the present invention were tested, and the results showed that the tensile strength was 200±2MPa, the yield strength was 150±1MPa, and the elongation was 8±0.5%.

[0190] The above is a detailed introduction to a medical biological magnesium-neodymium-silver-scandium 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 of the present invention and its core ideas, including the best mode, and also enables any technician in the field to practice the present invention, including the manufacture and use of any device or system, and the implementation of 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 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 biomedical rare earth magnesium alloy, characterized in that: The rare earth magnesium alloy includes a dynamically recrystallized eutectic phase; The dynamically recrystallized eutectic phase includes hexagonal γ phase Nd2Ag3Mg 14 and orthorhombic NdAgMg 11 ; The dynamically recrystallized eutectic phase is located at the grain boundary of the alloy; The dynamic recrystallization eutectic phase contains Mg element, Nd element and Ag element.

2. The biomedical rare earth magnesium alloy according to claim 1, characterized in that: The dynamic recrystallization eutectic phase is specifically twin grain boundary precipitates; The size of the dynamic recrystallization eutectic phase is 2 to 15 μm; The morphology of the dynamically recrystallized eutectic phase includes a hexagonal structure and an orthorhombic structure.

3. The biomedical rare earth magnesium alloy according to claim 1, characterized in that: The dynamically recrystallized eutectic phase is in a coherent relationship and / or a semi-coherent relationship with the matrix; The dynamic recrystallization eutectic phase is distributed in a fine and dispersed state; The interaction between the dynamic recrystallization eutectic phases hinders the dislocation movement of the rare earth magnesium alloy.

4. A biomedical rare earth magnesium alloy, characterized in that: Included by mass percentage: Nd: 0.5wt% to 2.5wt%; Ag: 0.1wt%~1.0wt%; Sc: 0.1wt% to 0.5wt%; The balance is magnesium; Among them, the mass ratio of (Nd+Sc) / Ag is 3-6.

5. The biomedical rare earth magnesium alloy according to claim 4, characterized in that: The biomedical 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 biomedical rare earth magnesium alloy, characterized in that: The following steps are involved: 1) smelting a magnesium source, a neodymium source, a scandium source and a silver source to obtain a biomedical rare earth magnesium alloy ingot; 2) The biomedical rare earth magnesium alloy ingot obtained in the above steps is subjected to solid solution treatment and hot extrusion to obtain a biomedical rare earth magnesium alloy material.

7. The preparation method according to claim 6, characterized in that: The magnesium source includes high-purity magnesium; The neodymium source includes a magnesium-neodymium master alloy; The silver source includes silver ingots; The scandium source includes a magnesium-scandium master alloy.

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 760-800°C; The smelting time is 3 to 4 hours; The temperature of the solution treatment is 300-500°C; The time of the solution treatment is 2 to 3 hours.

9. The preparation method according to claim 6, characterized in that: The temperature of the hot extrusion is 250-400°C; The extrusion speed of the hot extrusion is 0.5 to 1.5 m / s; The extrusion ratio of the hot extrusion is (7-12):

1.

10. Use of the biomedical rare earth magnesium alloy according to any one of claims 1 to 5 or the biomedical 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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