Medical implant titanium-magnesium alloy material and preparation method thereof
The preparation of porous TiMg alloy materials by hot isostatic pressing technology has solved the problems of mechanical properties and biocompatibility of orthopedic implants, promoted bone fusion and reduced immune response, and achieved good matching with human bones.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN UNVERSITY OF ARTS & SCI
- Filing Date
- 2023-11-28
- Publication Date
- 2026-05-15
AI Technical Summary
Existing orthopedic implants present challenges in terms of mechanical properties and biocompatibility, particularly difficulties in implant integration with bone tissue, stress shielding, and immune responses.
Titanium-magnesium alloys were prepared using hot isostatic pressing (HIP). By mixing TC4 titanium alloy powder with Mg metal powder, a porous TiMg alloy material was formed. An oxide layer was formed in high-purity oxygen. The elastic modulus and strength were adjusted to match human bones. Pores were created by chemical etching with NaCl solution.
It improves the bonding strength between the implant and bone tissue, reduces the immune response, promotes bone healing and fusion, solves the problems of stress barrier and immune infection, and the material properties are matched with human bone.
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Figure CN117626054B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of medical implant material preparation, and specifically relates to a titanium-magnesium alloy material for bone implants, including dental implants and femoral head supports, and its preparation method. Background Technology
[0002] Research on orthopedic implants originated in fracture repair in the early 20th century, initially using metal nails and plates to fix fracture sites. With the development of materials science and biotechnology, the design and material selection of orthopedic implants have received more attention, and they are now widely used in the treatment of skeletal diseases and injuries, playing an important role in dental implants, fracture repair, joint replacement surgery, and the treatment of bone tumors.
[0003] Orthopedic implants are broadly classified into five types based on their materials: metals and alloys, ceramics, carbon, polymers, and composite materials. Titanium and titanium alloys are currently the most widely used biomaterials in implants, offering the best biocompatibility and achieving optimal osseointegration and biological integration. However, several challenges remain in osseointegration research. First, the mechanical properties and biocompatibility of pure titanium and titanium alloys need to be balanced to avoid implant damage or immune responses. Second, implants exhibit varying degrees of "stress shielding" after implantation, making integration with surrounding bone tissue a challenge and prolonging the fusion time. Third, a gap of 1-10 μm thickness exists between plant emulsion and bone tissue, but this thickness decreases after 6 months. Therefore, the mechanical problems of orthopedic implants, stress barriers, and immune infections are the three major issues that urgently need to be addressed. Summary of the Invention
[0004] To address the aforementioned deficiencies in existing technologies, this invention employs hot isostatic pressing (HIP) technology to propose a titanium-magnesium alloy and its preparation process suitable for bone implants. This alloy features high strength, low elastic modulus, and osteogenic properties, thus resolving the "stress barrier" effect and mechanical problems after implantation into the bone. It can effectively reduce post-implantation immune responses and improve the integration of the implant with surrounding bone tissue.
[0005] The present invention is achieved through the following technical solution.
[0006] According to one aspect of the present invention, a method for preparing a titanium-magnesium alloy material for medical implants is provided, comprising the following steps:
[0007] TC4 titanium alloy powder and Mg metal powder were mixed at a mass fraction of (80-95): (5-20) and then dried.
[0008] Seal the mixture in a package, place it in the furnace, and evacuate it.
[0009] The hot isostatic pressing process is used to heat and pressurize the material in an argon atmosphere, maintain the pressure, reflux the gas, cool it in the furnace, and remove the pressed material to process it into a medical implant structure.
[0010] Porous TiMg alloy material is formed by chemical etching with NaCl solution. The porous TiMg alloy material is then placed in high-purity oxygen to form an oxide layer, thus obtaining the titanium-magnesium alloy material for medical implants.
[0011] Preferably, the TC4 titanium alloy powder has a particle size of 150-300 mesh, which is medical grade TC4 titanium alloy powder.
[0012] Preferably, the Mg metal powder is high-purity magnesium powder with a mesh size of 150-300 and a purity of 99.99%.
[0013] Preferably, TC4 titanium alloy powder and Mg metal powder are mixed with an appropriate amount of anhydrous ethanol by stirring, or by ball milling under vacuum and Ar gas protection for 120-180 min.
[0014] Preferably, the mixture is sealed with a sheath, using 304 stainless steel as the sheath material.
[0015] Preferably, a vacuum is drawn, and the vacuum level inside the casing is drawn to 10 at room temperature. -2 ~10 -3 Pa, place the sheath at a high temperature of 120-150℃ for pre-vacuuming, and wait for the vacuum degree to stabilize to 10. -4 After Pa, the temperature is raised to 500-600℃ and a vacuum is drawn, achieving a vacuum degree of 6×10⁻⁶. -6 Pa, keep for 3-4 hours.
[0016] Preferably, the heating and pressurization rate is 10-15℃ / min, the heating temperature is 955-1000℃, the pressurization pressure is 20-100MPa, and the pressure is maintained for 3-4 hours.
[0017] Preferably, high-purity argon gas is used for reflux for 2-4 hours, followed by furnace cooling to room temperature.
[0018] Preferably, soaking in 0.9% physiological saline NaCl solution for 2-4 hours is recommended.
[0019] Preferably, the porous TiMg alloy material is placed in high-purity oxygen for 10 to 24 hours to form an oxide layer with a thickness of 2 to 10 μm.
[0020] In another aspect, the present invention provides a titanium-magnesium alloy suitable for dental implants prepared by the method described above.
[0021] The present invention, by adopting the above technical solution, has the following beneficial effects:
[0022] 1. A porous TiMg alloy is formed by chemical etching with 0.9% saline solution (NaCl solution). By placing it in high-purity oxygen, a micron-thick oxide layer is formed, resulting in a material with an elastic modulus and strength that better matches human bone. While ensuring low elastic modulus and high strength, this process promotes bone healing and regeneration. After implantation, the porous structure forms in situ, effectively promoting bone ingrowth and healing. This method achieves a high Mg content and a wide range of elastic modulus adjustments, better promoting the fusion and fixation of the implant and the human bone. It addresses issues such as loosening of the implant due to mechanical properties, stress barriers and resulting inflammation, and immune infections caused by resin materials or toxic elements.
[0023] 2. This invention utilizes hot isostatic pressing technology to prepare a certain proportion of TiMg alloy. Taking dental implants and other implants as the research object, the elastic modulus of the titanium-magnesium alloy material is highly matched with that of human bone and can be adjusted according to age. Attached Figure Description
[0024] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, do not constitute an undue limitation of the invention. In the drawings:
[0025] Figure 1 This invention describes the process for preparing titanium-magnesium alloy materials using hot isostatic pressing.
[0026] Figure 2 This is a schematic diagram of the structure using the encapsulation process in the preparation of this invention using hot isostatic pressing;
[0027] Figures 3(a) and (b) show the surface morphology of the TiMg alloys after etching and creating pores in Examples 2 and 4, respectively. Detailed Implementation
[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.
[0029] The method for preparing titanium-magnesium alloy material for medical implants provided by this invention includes the following steps:
[0030] 1) Select TC4 titanium alloy powder with a particle size of 150-300 mesh and Mg metal powder with a purity of 99.99% and a particle size of 150-300 mesh. The mass fraction of the mixture is: TC4:Mg = (80-95):(5-20).
[0031] 2) Pour into a ceramic jar, add an appropriate amount of anhydrous ethanol and stir to mix (or use vacuum or Ar gas protection before ball milling), mix for 120-180 minutes, and air dry in a ventilated place at room temperature.
[0032] 3) Use 304 stainless steel as the sheath material, with dimensions of φ50mm×70mm and a sheath wall thickness of 2mm. Fill the sheath with the mixed powder and seal it. Vacuum the sheath and bring the vacuum level inside to 10 at room temperature. -2 ~10 -3 Pa, because the powder will release gas violently at 120°C, the packaging is pre-evacuated at a high temperature of 120-150°C until the vacuum degree stabilizes at 10. -4 After Pa, the temperature is raised to 500-600℃ and a vacuum is drawn, achieving a vacuum degree of 6×10⁻⁶. -6 Pa, maintain for 3-4 hours to ensure sufficient removal of gas from the casing. After evacuation, to maintain the vacuum level inside the casing, use hydraulic clamps to clamp and cut the evacuation pipe, and then weld the end face.
[0033] See the encapsulation structure. Figure 2 As shown, the cylindrical body 2 has an upper cover plate 1 on top and a lower cover plate 3 on the bottom. After the mixed powder is loaded into the body, it is sealed by the upper and lower cover plates.
[0034] 4) Place it in a hot isostatic pressing furnace to complete the hot isostatic pressing process. The hot isostatic pressing process flow is as follows: Figure 1 As shown:
[0035] a) In an argon atmosphere, heating and pressurization are carried out at a rate of 10-15℃ / min, a heating temperature of 955-1000℃, a pressurization pressure of 20-100MPa, and a holding pressure of 3-4h.
[0036] b) Gas reflux: High-purity argon (Ar) gas is used. Reflux time: 2-4 hours. Cooling rate: 10-15℃ / min. Pressed material is discharged at room temperature as the furnace cools.
[0037] c) Peel off the sheath and prepare the required sample using wire cutting.
[0038] 5) Soak the sample in 0.9% physiological saline NaCl solution for 2-4 hours to remove the Mg element on the surface and form a TiMg alloy material with porous characteristics.
[0039] 6) Place the sample in high-purity oxygen for 10–24 h to form an oxide layer with a thickness of 2–10 μm.
[0040] The microstructure and properties of the prepared samples were characterized.
[0041] The advantages of this method are twofold:
[0042] First, the performance is excellent and continuously adjustable: Firstly, titanium and magnesium metal powders with particle sizes of 200 mesh and 300 mesh are selected respectively. By adjusting the particle size and ratio of the alloy powders, the surface hardness (300–490 HB), elastic modulus (40–90 GPa), and compressive strength (400–800 MPa) of the alloy can be adjusted according to performance requirements, closely approximating the elastic modulus of human bone for better matching. Secondly, Mg is an essential element for the human body, has no cytotoxicity, and can promote osteogenic activity around the implant, reducing immune responses. Thirdly, after implantation, the Mg on the surface of the TiMg alloy implant degrades at a controllable rate, forming a porous structure in situ, promoting inward bone growth and healing, and better facilitating the fusion and fixation of the human bone and the implant.
[0043] Secondly, the manufacturing process is innovative and easy to implement: First, hot isostatic pressing is used, during which magnesium is completely liquefied and uniformly distributed in the titanium alloy, forming a highly interconnected alloy structure. Second, the manufacturing process eliminates the need for pressing blanks and adding binders, overcoming the drawbacks of traditional powder metallurgy that produce toxic substances. Finally, a high-purity oxygen oxidation process is used on the alloy surface to regulate the corrosion rate of the implant in the human body, achieving a controllable rate that matches the bone growth and healing speed with the surface porosity formation rate, thus avoiding harm to the human body from reactive gases.
[0044] The present invention will be further described in detail below through specific embodiments.
[0045] Example 1
[0046] TC4 titanium alloy powder with a particle size of 200 mesh and Mg metal powder with a purity of 99.99% were selected; the mixing mass ratio was TC4:Mg = 95:5; the mixture was placed in a ceramic jar, and an appropriate amount of anhydrous ethanol was added and stirred for 120 minutes. The mixture was then air-dried at room temperature in a ventilated area. A 304 stainless steel sheath was selected as the sheath material, with dimensions of φ50mm × 70mm and a sheath wall thickness of 2mm. The mixed powder was placed inside the sheath, and the vacuum level inside the sheath was evacuated to 2 × 10⁻⁶ at room temperature. -3 Pa, place the sheath at 150℃ for pre-evacuation, and wait for the vacuum degree to stabilize to 10. -4 After Pa, the temperature is raised to 500℃ and a vacuum is drawn, achieving a vacuum level of 6×10⁻⁶. -6 Pa, maintained for 4 hours, to complete the vacuuming process under different temperature gradients, achieving a vacuum level of 6 × 10⁻⁶. -6Pa; the sample was placed in a hot isostatic pressing furnace with a heating and pressurization rate of 10℃ / min, a holding temperature of 955℃, a holding pressure of 80MPa, and a holding time of 3h. High-purity argon (Ar) gas was used, with a reflux time of 2h and a heating and cooling / pressurization rate of 15℃ / min. The cladding was removed, and the required sample was prepared by wire cutting. The sample was then immersed in 0.9% physiological saline NaCl solution for 2.5h to create pores through etching. The sample was then placed in high-purity oxygen for 10h to obtain an oxide layer with a thickness of 2μm. A TiMg alloy material with a porous surface was obtained.
[0047] The sample surface exhibits porous characteristics and good formability; the microhardness is 465HB, the elastic modulus is 89GPa, the tensile strength is 703MPa, the compressive strength is 1154MPa, the pore size is 10-20μm, and the porosity is 23%; it is bioactive and the Ti element does not detach.
[0048] Example 2
[0049] TC4 titanium alloy powder with a particle size of 300 mesh and Mg metal powder with a purity of 99.99% were selected; the mixing mass ratio was TC4:Mg = 90:10; the mixture was placed in a ceramic jar, and an appropriate amount of anhydrous ethanol was added and stirred for 130 minutes. The mixture was then air-dried at room temperature in a ventilated area. A 304 stainless steel sheath was selected as the sheath material, with dimensions of φ50mm × 70mm and a sheath wall thickness of 2mm. The mixed powder was placed inside the sheath, and the vacuum level inside the sheath was evacuated to 2 × 10⁻⁶ at room temperature. -3 Pa, place the sheath at 120℃ for pre-evacuation, and wait for the vacuum degree to stabilize to 10. -4 After Pa, the temperature is raised to 550℃ and a vacuum is drawn, achieving a vacuum level of 6×10⁻⁶. -6 Pa was maintained for 3.5 hours to complete the vacuuming process under different temperature gradients, achieving a vacuum level of 6 × 10⁻⁶. -6 Pa: The sample was placed in a hot isostatic pressing furnace with a heating and pressurization rate of 12℃ / min, a holding temperature of 970℃, a holding pressure of 100MPa, and a holding time of 4h. High-purity argon (Ar) gas was used, and the reflux time was 2h. The heating and cooling / pressurization rates were 15℃ / min. The cladding was removed, and the required sample was prepared by wire cutting. The sample was soaked in 0.9% physiological saline NaCl solution for 4h to create pores. Then, the sample was placed in high-purity oxygen for 12h to form an oxide layer with a thickness of 3μm, resulting in a TiMg alloy material with a porous surface.
[0050] The surface morphology of TiMg alloy after etching and pore formation is shown in Figure 3(a). The sample surface exhibits porous characteristics and good formability; the microhardness is 406HB, the elastic modulus is 67GPa, the tensile strength is 565MPa, the compressive strength is 840MPa, the pore size is 20-50μm, and the porosity is 34%; it is bioactive and the Ti element does not detach.
[0051] Example 3
[0052] TC4 titanium alloy powder with a particle size of 200 mesh and Mg metal powder with a purity of 99.99% were selected; the mixing mass ratio was TC4:Mg = 80:20; the mixture was placed in a ceramic jar, and an appropriate amount of anhydrous ethanol was added and stirred for 140 minutes. The mixture was then air-dried at room temperature in a ventilated area; 304 stainless steel was used as the sheath material, with dimensions of φ50mm × 70mm and a sheath wall thickness of 2mm. The mixed powder was placed into the sheath, and the vacuum degree inside the sheath was evacuated to 8 × 10⁻⁸ at room temperature. -2 Pa, place the sheath at 140℃ for pre-evacuation, and wait for the vacuum degree to stabilize to 10. -4 After Pa, the temperature is raised to 600℃ and a vacuum is drawn, achieving a vacuum level of 6×10⁻⁶. -6 Pa, maintained for 4 hours, to complete the vacuuming process under different temperature gradients, achieving a vacuum level of 6 × 10⁻⁶. -6 Pa: The sample was placed in a hot isostatic pressing furnace with a heating and pressurization rate of 15℃ / min, a holding temperature of 970℃, a holding pressure of 50MPa, and a holding time of 3.5h. High-purity argon (Ar) gas was used, with a reflux time of 2.5h and a heating and cooling / pressurization rate of 12℃ / min. The cladding was removed, and the required sample was prepared by wire cutting. The sample was then immersed in 0.9% physiological saline NaCl solution for 3 hours to create pores through etching. The sample was then placed in high-purity oxygen for 6 hours to obtain an oxide layer with a thickness of 2μm. A porous TiMg alloy material was thus obtained.
[0053] The sample surface exhibits porous characteristics and good formability; the microhardness is 397HB, the elastic modulus is 65GPa, the tensile strength is 547MPa, the compressive strength is 840MPa, the pore size is 20-65μm, and the porosity is 37%; it is bioactive and the Ti element does not detach.
[0054] Example 4
[0055] TC4 titanium alloy powder with a particle size of 150 mesh and Mg metal powder with a purity of 99.99% were selected. The mixing mass ratio was TC4:Mg = 85:15. The mixture was placed in a ceramic jar and ball-milled under vacuum and Ar gas protection for 180 minutes, then air-dried at room temperature. A 304 stainless steel sheath with dimensions of φ50mm × 70mm and a wall thickness of 2mm was selected. The mixed powder was placed inside the sheath, and the vacuum level inside the sheath was increased to 8 × 10⁻⁸ at room temperature. -2 Pa, therefore the sheath was placed at a high temperature of 130℃ for pre-evacuation, and the vacuum degree was stabilized at 10 Pa. -4 After Pa, the temperature is raised to 500℃ and a vacuum is drawn, achieving a vacuum level of 6×10⁻⁶. -6 Pa, maintained for 3 hours, to complete the vacuuming process under different temperature gradients, achieving a vacuum level of 6 × 10⁻⁶. -6 Pa: The sample was placed in a hot isostatic pressing furnace with a heating and pressurization rate of 15℃ / min, a holding temperature of 1000℃, a holding pressure of 20MPa, and a holding time of 3h. High-purity argon (Ar) gas was used, and the reflux time was 4h. The heating and cooling / pressurization rates were 10℃ / min. The cladding was removed, and the required sample was prepared by wire cutting. The sample was then immersed in 0.9% physiological saline NaCl solution for 2 hours to create pores. The sample was then placed in high-purity oxygen for 24 hours to obtain an oxide layer with a thickness of 10μm. A porous TiMg alloy material was thus obtained.
[0056] The surface morphology of TiMg alloy after etching and pore formation is shown in Figure 3(b). The sample surface exhibits porous characteristics and good formability; the microhardness is 306HB, the elastic modulus is 58GPa, the tensile strength is 457MPa, the compressive strength is 640MPa, the pore size is 30-80μm, and the porosity is 57%; it is bioactive and the Ti element does not detach.
[0057] The following comparative examples are provided to further illustrate the effects of the present invention.
[0058] Comparative Example 1: The alloying elements selected are Ti, Mo, Nb and Zr. The Ti-30Nb-8Zr-2Mo alloy was smelted in a non-consumable vacuum arc furnace. Hot forging and solution treatment were performed. The microhardness was 390HV, the compressive strength was 1054MPa, the elastic modulus was 16.5GPa, and there was no porous structure.
[0059] Comparative Example 2: Using titanium, magnesium, silicon, and vanadium as basic materials, aTi-bMg-cSi-dV-eAg-f (TiC-SiC-VC) was prepared in a uniform ratio of a=40, b=10, c=45, d=3, e=1.5, and f=0.5. The powder blend was weighed in an argon-filled glove box, mixed with 1% isopropanol by weight, and stirred for 3 minutes. The mixture was poured into a press mold, cold-pressed at 50 MPa, and dried at room temperature for 5 minutes to form a rod-shaped sample with a diameter of 10 mm × 68 mm. The titanium-magnesium alloy composite material was obtained by repeated 6 cycles of intense plastic deformation extrusion through a three-pronged die channel. The Si was removed by immersion in 5 L of NaOH solution at 60 °C for 12 hours, followed by washing and air drying for 24 hours to obtain a porous titanium-magnesium composite material with a porosity of 45%.
[0060] Table 1 shows a comparison of the performance test results of the examples and the comparative examples.
[0061] Table 1 Performance Comparison:
[0062]
[0063] As shown in Table 1, compared to Comparative Examples 1 and 2, the present invention prepares medical titanium-magnesium alloy implant materials using the hot isostatic pressing method. This achieves two advantages: firstly, superior mechanical properties of the implant, excellent matching with the elastic modulus of human cortical bone, and continuous adjustability; secondly, the preparation process is innovative and easy to implement. Especially for Comparative Example 2, the material of the present invention is non-toxic and harmless, with an elastic modulus (58–90 GPa) not less than 58 GPa and a porosity (20%–57%) not less than 57%, both within the range of characteristics of human bone, exhibiting good matching and fusion with human cortical bone. The tensile strength (457–703 MPa) of the medical implant titanium-magnesium alloy material is not less than 457 MPa, and the compressive strength (640–1154 MPa) is not less than 640 MPa. The medical implant titanium-magnesium alloy material prepared by the present invention solves problems such as loosening of implants due to mechanical performance issues, stress barriers and resulting inflammation, or immune infections caused by resin materials or toxic elements.
[0064] As can be seen from the above embodiments, the TiMg alloy material provided by this invention, along with the corresponding hot isostatic pressing process, allows for continuous adjustment of the alloy's surface hardness, elastic modulus, tensile / compressive strength, and other properties, achieving an elastic modulus close to that of human bone, thus better matching human bone. The uniform distribution of magnesium in the alloy allows for in-situ formation of porous features that match bone growth rates after implantation, promoting inward bone growth and healing, and better facilitating the fusion and fixation of the human bone and the implant. Furthermore, toxicity tests have shown that the alloy is non-toxic and that no Ti element is leached.
[0065] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.
Claims
1. A method for preparing a titanium-magnesium alloy material for medical implants, characterized in that, Includes the following steps: Mix TC4 titanium alloy powder and Mg metal powder at a mass fraction of (80~95): (5~20), and then dry. Seal the mixture in a package, place it in the furnace, and evacuate it. The process involves heating and pressurizing the material in an argon atmosphere at a rate of 10-15℃ / min, with a heating temperature of 955-1000℃, a pressurization pressure of 20-100MPa, and a holding pressure of 3-4 hours. The gas is then refluxed, and the pressed material is removed after cooling in the furnace and processed into a medical implant structure. The sample is soaked in 0.9% saline NaCl solution for 2-4 hours to chemically etch pores and form a porous TiMg alloy material. The porous TiMg alloy material is then placed in high-purity oxygen for 10-24 hours to form an oxide layer with a thickness of 2-10 μm; thus, the titanium-magnesium alloy material for medical implants is obtained.
2. The method for preparing the titanium-magnesium alloy material for medical implants according to claim 1, characterized in that, TC4 titanium alloy powder has a particle size of 150~300 mesh and is used for medical purposes. The Mg metal powder is 150~300 mesh, and the purity is 99.99%, which is a high-purity magnesium powder.
3. The method for preparing the titanium-magnesium alloy material for medical implants according to claim 1, characterized in that, TC4 titanium alloy powder and Mg metal powder are mixed with an appropriate amount of anhydrous ethanol, or ball-milled under vacuum and Ar gas protection for 120-180 minutes.
4. The method for preparing the titanium-magnesium alloy material for medical implants according to claim 1, characterized in that, The mixture is sealed with a sheath, which is made of 304 stainless steel.
5. The method for preparing the titanium-magnesium alloy material for medical implants according to claim 1, characterized in that, Evacuate the enclosure to a vacuum level of 10 at room temperature. -2 ~10 -3 Pa, place the sheath at a high temperature of 120~150℃ for pre-vacuuming, and wait for the vacuum degree to stabilize to 10. -4 After Pa, the temperature is raised to 500~600℃ and a vacuum is drawn, achieving a vacuum degree of 6×10⁻⁶. -6 Pa, keep for 3-4 hours.
6. The method for preparing the titanium-magnesium alloy material for medical implants according to claim 1, characterized in that, High-purity argon gas was refluxed for 2-4 hours, and then cooled to room temperature with the furnace.
7. A titanium-magnesium alloy material for medical implants prepared by the method according to any one of claims 1-6.