3D printed porous TC4 alloy bone fracture plate and preparation method thereof
Through the design and surface coating treatment of 3D printed porous TC4 alloy bone plates, the problem of insufficient biocompatibility of traditional bone plates is solved, high stability and bone healing effect are achieved, it adapts to complex anatomical structures, and reduces the risk of loosening.
Patent Information
- Application Number
- CN202510790367.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-13
- Publication Date
- 2025-09-12
AI Technical Summary
Traditional metal bone plates lack biocompatibility and cannot adapt to complex anatomical structures, resulting in poor postoperative stability or loss of correction angle.
A porous TC4 alloy bone plate was 3D printed. By adjusting the raw material composition and preparation method, a porous structure with a pore size of 300-600 μm, a porosity of 60%-75%, and a pore connectivity of >95% was prepared. Tricalcium phosphate and bioglass-hydroxyapatite coating were sprayed on the surface to improve biocompatibility and stability.
It improves the postoperative stability and biocompatibility of the bone plate, reduces the risk of loosening, promotes bone healing, and enhances initial stability and mechanical properties.
Smart Images
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Abstract
Description
Technical Field
[0001] The present application relates to the field of medical devices, and more specifically, to a 3D printed porous TC4 alloy bone plate and a preparation method thereof. Background Art
[0002] In recent years, the incidence of knee deformities caused by genu valgum and congenital developmental abnormalities has increased year by year. Traditional knee deformity correction surgery relies on osteotomy combined with metal plate fixation. However, metal plates have insufficient biocompatibility and require a second surgery to remove. They are also unable to adapt to complex anatomical structures, such as the morphology after distal femoral wedge osteotomy, resulting in poor postoperative stability or loss of correction angle.
[0003] Therefore, there is a great need in the market to develop a deformity correction locking bone plate that can make up for the above-mentioned shortcomings. Summary of the Invention
[0004] In order to improve the problems that the deformity correction locking plate cannot adapt to complex anatomical structures, resulting in poor postoperative stability or loss of deformity correction angle, etc., the present application provides a 3D printed porous TC4 alloy plate and a preparation method.
[0005] In a first aspect, the present application provides a 3D printed porous TC4 alloy bone plate, which adopts the following technical solution: a 3D printed porous TC4 alloy bone plate, which includes the following raw materials in percentage: Fe≤0.30%, C≤0.10%, N≤0.05%, H≤0.015%, O≤0.20%, Al5.5-6.75%, V3.5-4.5%, and the balance is titanium powder; The 3D printed porous TC4 alloy bone plate has a porous structure with a pore size of 300-600 μm, a porosity of 60%-75%, a pore connectivity rate of >95%, and a plurality of fixing holes are provided on the 3D printed porous TC4 alloy bone plate.
[0006] By adopting the above scheme and selecting the above TC4 alloy material, stress shielding can be reduced, callus formation can be promoted, the biocompatibility of the metal bone plate can be improved, and the postoperative stability of the bone plate can be improved without the need for secondary removal.
[0007] The porous structure of the 3D-printed porous TC4 alloy plate allows new bone tissue to grow into the pores, forming a bone-plate interlock and achieving structural biological fixation. By controlling the pore size to 300-600 μm, as well as the porosity and pore connectivity parameters, the plate can adapt to complex anatomies, significantly reducing the risk of loosening caused by traditional smooth interfaces and improving postoperative plate stability. The porous structure of the TC4 alloy plate can also accelerate bone healing, reduce the elastic modulus, mitigate stress shielding effects, and enhance initial stability. The titanium powder preferably has a particle size D50 of 71.703 μm, a sphericity of 0.9424, an aspect ratio of 0.8733, a roundness of 0.9700, a bulk density of 2.58 g / cm³, a tapped density of 2.9 g / cm³, and a powder flowability of 23.8 s / 50 g.
[0008] By adopting the above scheme, the particle size, sphericity, aspect ratio, roundness, loose and tap density, and grinding fluidity of the peptide powder can be further determined, which can improve the problem of titanium powder agglomeration when printing porous structures and significantly improve the uniformity of powder spreading, thereby improving the 3D printing effect.
[0009] In a second aspect, the present application provides a method for preparing a 3D printed porous TC4 alloy bone plate according to claim 1, which is specifically achieved through the following technical solutions: A method for preparing a 3D printed porous TC4 alloy bone plate according to claim 1, comprising the following steps: S1. Use graphics software to design a three-dimensional geometric model of a 3D-printed porous TC4 alloy bone plate. Based on the three-dimensional geometric model, perform integrated electron beam selective melting of the raw materials under argon atmosphere to obtain a printed part of the porous TC4 alloy bone plate. S2. The printed porous TC4 alloy bone plate is sandblasted, cleaned, dried, heat treated, ground and polished, and surface cleaned to obtain a 3D printed porous TC4 alloy bone plate.
[0010] By adopting the above scheme, according to the three-dimensional geometric model, under the protection of argon atmosphere, the raw materials are subjected to integrated electron beam selective melting, which can accurately control the pores, achieve high porosity in the fracture area to promote healing, and low porosity at both ends to maintain strength; and the porous structure produced by this method is integrated to avoid the risk of falling off. Then sandblasting is performed to remove the metal powder adhering to the surface of the plate and reduce the side effects after implantation. After cleaning and drying, heat treatment is performed to eliminate the residual stress generated by the plate during the 3D printing process, prevent fatigue fracture, and extend the service life. The surface is polished to make it smooth and further eliminate micro-damage after implantation. It not only meets the smoothness requirements of the soft tissue interface and avoids friction damage to blood vessels or nerves, but also retains the undulations for bone cell adhesion. Finally, cleaning is performed to remove residues to ensure the biosafety of the plate, and a 3D printed porous TC4 alloy plate is obtained.
[0011] Preferably, the sandblasting parameters in step S2 are: a sandblasting force of 0.1-1 MPa, and a sandblasting time of 30-120 s.
[0012] By adopting the above scheme, the sandblasting processing force and sandblasting time during sandblasting are controlled, which is more conducive to removing metal powder adhered to the surface and reducing adverse reactions after bone plate implantation.
[0013] Preferably, the heat treatment parameters in step S2 are: heat treatment temperature of 700-900°C, heating rate of 5-10°C / min, and heat preservation time of 30min-120min.
[0014] By adopting the above scheme, the heat treatment temperature, heating rate and holding time of the heat treatment are controlled, which is more conducive to eliminating the residual stress generated by the bone plate during the 3D printing process and avoiding fatigue fracture.
[0015] As a preferred embodiment, after the surface is cleaned in step S2, a tricalcium phosphate coating and a bioglass-hydroxyapatite coating are sequentially sprayed on the surface of the 3D printed porous TC4 alloy bone plate by a vacuum plasma spraying method; the raw materials of the bioglass-hydroxyapatite coating include bioglass and hydroxyapatite By adopting the above scheme, the tricalcium phosphate coating can slowly release calcium and phosphorus ions, continuously stimulate bone formation, cooperate with the porous structure to facilitate bone tissue growth, enhance the mechanical locking effect, and improve the postoperative stability of the TC4 alloy bone plate.
[0016] The bioglass in the bioglass-hydroxyapatite composite coating contains SiO2, Na2O and other components, which not only has an osteoinductive effect, but also calcium and silicon ions can promote bone cell differentiation. It can also form a silicon-rich gel layer on the surface of the tricalcium phosphate coating, delaying the release of tricalcium phosphate ions and prolonging the effect of tricalcium phosphate on improving the postoperative stability of TC4 alloy bone fracture plates. Hydroxyapatite is rapidly hydrolyzed in the presence of body fluids, releasing Na + , Ca 2+ Elevating the local pH creates a silica-rich gel layer, inducing bone-like apatite deposition within 3 days and initiating early bone regeneration. Bioglass provides a stable scaffold for new bone, preventing mechanical collapse after hydroxyapatite degradation, effectively avoiding the repair window period and enhancing osteoblast ALP activity.
[0017] Preferably, the mass ratio of the hydroxyapatite to the bioglass is 1:(1-3).
[0018] By adopting the above scheme and controlling the mass ratio of hydroxyapatite and bioglass, the structural integrity of the bioglass-hydroxyapatite coating can be maintained, the effect of tricalcium phosphate on improving the postoperative stability of the TC4 alloy bone plate can be prolonged, and the postoperative stability of the TC4 alloy bone plate can be improved.
[0019] Preferably, the thicknesses of the tricalcium phosphate coating and the bioglass-hydroxyapatite coating are 50-150 μm and 200-500 nm, respectively.
[0020] By adopting the above scheme, the thickness of tricalcium phosphate coating and bioglass-hydroxyapatite coating is determined to promote cell penetration and the sustained release of ions to match the bone regeneration rate.
[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. This application adjusts the raw materials and preparation methods of 3D printed porous TC4 alloy bone plates, so that the tensile strength, elongation at break and fatigue limit of the 3D printed porous TC4 alloy bone plates reach 1496MPa, 26% and 645MPa respectively, with high mechanical properties, which improves the postoperative stability of the TC4 alloy bone plates.
[0022] 2. This application adopts a vacuum plasma spraying method to spray tricalcium phosphate coating and bioglass-hydroxyapatite coating on the surface of a 3D printed porous TC4 alloy plate in sequence, so that the tensile strength, elongation at break and fatigue limit of the 3D printed porous TC4 alloy plate reach 1602MPa, 30% and 665MPa, respectively. It has high mechanical properties and improves the problem that the deformity correction locking plate cannot adapt to complex anatomical structures, resulting in poor postoperative stability or loss of deformity correction angle. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 3D schematic diagram of the 3D printed porous TC4 alloy bone plate in this application Figure 2 Actual image of the 3D printed porous TC4 alloy bone plate in this application DETAILED DESCRIPTION
[0024] The following describes this application in further detail with reference to specific examples. The following raw materials in this application are all commercially available products. This information is provided for the purpose of providing sufficient disclosure of the raw materials in this application and should not be construed as limiting the sources of the raw materials. Specifically, they are: tricalcium phosphate, with an active ingredient content of 95%; bioglass, with an active substance content of 99%; and hydroxyapatite, with a particle size of 20 nm.
[0025] Example 1 The 3D printed porous TC4 alloy bone plate of Example 1 includes the following raw materials in percentage: Fe 0.30%, C 0.10%, N 0.05%, H 0.015%, O 0.20%, Al 6%, V 4%, and the balance is titanium powder.
[0026] Among them, the titanium powder particle size D50 is 45μm, the sphericity is 0.92, the aspect ratio is 1.0, the roundness is 0.95, the bulk density is 2.8g / cm3, the tap density is 3.6g / cm3, and the powder flowability is 25s / 50g. The method for preparing the 3D printed porous TC4 alloy bone plate of Example 1 comprises the following steps: S1. Use graphics software to design a three-dimensional geometric model of a 3D-printed porous TC4 alloy bone plate. Based on the three-dimensional geometric model, perform integrated electron beam selective melting of the raw materials under argon atmosphere to obtain a printed part of the porous TC4 alloy bone plate. S2. The printed porous TC4 alloy bone plate was sandblasted (the sandblasting force was 0.1 MPa and the sandblasting time was 30 s), cleaned, dried, heat treated (the heat treatment temperature was 700 ° C, the heating rate was 5 ° C / min, and the heat preservation was 30 min), polished, and the surface was cleaned to obtain a 3D printed porous TC4 alloy bone plate.
[0027] like Figure 1 and Figure 2 As shown, the obtained 3D printed porous TC4 alloy bone plate is T-shaped, the pore size of the porous structure on its surface is 450 μm, the porosity is 65%, the pore connectivity is 96%, and the 3D printed porous TC4 alloy bone plate is provided with a plurality of fixing holes.
[0028] Example 2 The 3D printed porous TC4 alloy bone plate of Example 2 differs from that of Example 1 in that the titanium powder particle size D50 is 71.703 μm, the sphericity is 0.9424, the aspect ratio is 0.8733, the roundness is 0.9700, the loose density is 2.58 g / cm3, the tap density is 2.9 g / cm3, and the powder flowability is 23.8 s / 50 g. The remaining raw materials and preparation methods are the same as those of Example 1.
[0029] Example 3 The preparation method of the 3D printed porous TC4 alloy bone plate in Example 3 differs from that in Example 2 in that the sandblasting force is 0.5 MPa, the sandblasting time is 70 s, and the remaining steps are the same as in Example 2.
[0030] Example 4 The preparation method of the 3D printed porous TC4 alloy bone plate of Example 4 differs from that of Example 3 in that the heat treatment temperature is 800°C, the heating rate is 8°C / min, and the heat preservation time is 70 minutes. The remaining steps are the same as those of Example 3.
[0031] Example 5 The preparation method of the 3D printed porous TC4 alloy bone plate of Example 5 differs from that of Example 4 in that, after surface cleaning in step S2, a tricalcium phosphate coating with a thickness of 100 μm is sprayed on the surface of the 3D printed porous TC4 alloy bone plate by vacuum plasma spraying, and the remaining steps are the same as those of Example 4.
[0032] Example 6 The preparation method of the 3D printed porous TC4 alloy bone plate of Example 6 differs from that of Example 4 in that, after surface cleaning in step S2, a bioglass-hydroxyapatite coating is sprayed on the surface of the 3D printed porous TC4 alloy bone plate by vacuum plasma spraying. The coating raw materials include 1 kg of hydroxyapatite and 2 kg of bioglass with a thickness of 350 μm. The remaining steps are the same as those in Example 4.
[0033] Example 7 The preparation method of the 3D printed porous TC4 alloy bone plate in Example 7 differs from that in Example 4 in that, after the surface is cleaned in step S2, a tricalcium phosphate coating and a bioglass-hydroxyapatite coating are sprayed on the surface of the 3D printed porous TC4 alloy bone plate in sequence by vacuum plasma spraying; the thicknesses of the tricalcium phosphate coating and the bioglass-hydroxyapatite coating are 100 μm and 350 nm, respectively, and the raw materials of the bioglass-hydroxyapatite coating include 1 kg of hydroxyapatite and 2 kg of bioglass. The remaining steps are the same as in Example 4.
[0034] Comparative Example 1 The 3D printed porous TC4 alloy bone plate of Comparative Example 1 is exactly the same as that of Example 1, except that the 3D printed porous TC4 alloy bone plate has a non-porous structure and a smooth surface, and the rest is the same as that of Example 1.
[0035] Comparative Example 2 The 3D printed porous TC4 alloy bone plate of Comparative Example 2 is exactly the same as that of Example 1, except that the 3D printed porous TC4 alloy bone plate has a porous structure with a pore size of 200 μm, a porosity of 50%, and a pore connectivity of 90%. The rest is the same as Example 1.
[0036] Performance testing The following testing standards or methods were used to perform performance tests on the 3D printed porous TC4 alloy bone plates obtained in different Examples 1-7 and Comparative Examples 1-2. The test results are shown in Table 1.
[0037] Tensile strength: The tensile strength of 3D printed porous TC4 alloy bone plates was tested according to GB / T 228.1 standard.
[0038] Elongation at break: The elongation at break of 3D printed porous TC4 alloy bone plates was tested according to GB / T 13810.
[0039] Fatigue limit: The fatigue limit of 3D printed porous TC4 alloy bone plates was tested according to ISO 14801 standard.
[0040] Table 2 Performance test results of different 3D printed porous TC4 alloy bone plates The test results in Table 1 show that the tensile strength, elongation at break and fatigue limit of the 3D printed porous TC4 alloy plate obtained in this application can reach up to 1602 MPa, 30% and 665 MPa, respectively. It has high mechanical properties and improves the problem that the deformity correction locking plate cannot adapt to complex anatomical structures, resulting in poor postoperative stability or loss of deformity correction angle.
[0041] Combining the performance test data of Example 1 and Example 2, it was found that the tensile strength, elongation at break and fatigue limit of the 3D printed porous TC4 alloy bone plate of Example 2 were 1412 MPa, 23% and 628 MPa, respectively, which were higher than those of Example 1, indicating that when the titanium powder particle size D50 is 71.703 μm, the sphericity is 0.9424, the aspect ratio is 0.8733, the roundness is 0.9700, the loose density is 2.58 g / cm3, the tap density is 2.9 g / cm3, and the powder flowability is 23.8 s / 50 g, it is more appropriate, which can improve the mechanical properties of the 3D printed porous TC4 alloy bone plate.
[0042] Combining the performance test data of Example 2 and Example 3, it was found that the tensile strength, elongation at break and fatigue limit of the 3D printed porous TC4 alloy bone plate of Example 3 were 1487 MPa, 24% and 631 MPa, respectively, which were higher than those of Example 2, indicating that a sandblasting force of 0.5 MPa and a sandblasting time of 70 s were more appropriate, which could improve the mechanical properties of the 3D printed porous TC4 alloy bone plate.
[0043] Combining the performance test data of Example 3 and Example 4, it was found that the tensile strength, elongation at break and fatigue limit of the 3D printed porous TC4 alloy bone plate of Example 4 were 1496 MPa, 26% and 645 MPa, respectively, which were higher than those of Example 3, indicating that a heat treatment temperature of 800°C, a heating rate of 8°C / min and a holding time of 70 minutes are more appropriate, which can improve the mechanical properties of the 3D printed porous TC4 alloy bone plate.
[0044] Combined with the performance test data of Examples 5-7, it was found that the tensile strength, elongation at break and fatigue limit of the 3D printed porous TC4 alloy plate of Example 7 were 1602 MPa, 30% and 665 MPa, respectively, which were higher than those of Examples 5-6, indicating that after surface cleaning in step S2, a tricalcium phosphate coating and a bioglass-hydroxyapatite coating were sprayed on the surface of the 3D printed porous TC4 alloy plate in sequence by vacuum plasma spraying; the thicknesses of the tricalcium phosphate coating and the bioglass-hydroxyapatite coating were 100 μm and 350 nm, respectively, and the raw materials of the bioglass-hydroxyapatite coating included 1 kg of hydroxyapatite and 2 kg of bioglass, which can further improve the mechanical properties of the 3D printed porous TC4 alloy plate.
[0045] Combining the performance test data of the 3D printed porous TC4 alloy bone plates of Example 1 and Comparative Examples 1-2, it was found that 3D printing the TC4 alloy bone plate into a porous structure and determining the pore size to be 300-600 μm, the porosity to be 60%-75%, and the pore connectivity to be greater than 95% can all improve the postoperative stability of the 3D printed porous TC4 alloy bone plate to varying degrees.
[0046] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.
Claims
1. A 3D printed porous TC4 alloy bone plate, characterized in that: The raw materials include the following percentage contents: Fe≤0.30%, C≤0.10%, N≤0.05%, H≤0.015%, O≤0.20%, Al5.5-6.75%, V3.5-4.5%, and the balance is titanium powder; The 3D printed porous TC4 alloy bone plate has a porous structure with a pore size of 300-600 μm, a porosity of 60%-75%, a pore connectivity rate of >95%, and a plurality of fixing holes are provided on the 3D printed porous TC4 alloy bone plate.
2. The 3D printed porous TC4 alloy bone plate according to claim 1, characterized in that: The titanium powder particle size D 50 The diameter is 71.703 μm, the sphericity is 0.9424, the aspect ratio is 0.8733, the roundness is 0.9700, and the apparent density is 2.58 g / cm 3 , tap density 2.9g / cm 3 , powder fluidity 23.8s / 50g.
3. A method for preparing the 3D printed porous TC4 alloy bone plate according to claim 1, characterized in that: S1. Use graphics software to design a three-dimensional geometric model of a 3D-printed porous TC4 alloy bone plate. Based on the three-dimensional geometric model, perform integrated electron beam selective melting of the raw materials under argon atmosphere to obtain a printed part of the porous TC4 alloy bone plate. S2. The printed porous TC4 alloy bone plate is sandblasted, cleaned, dried, heat treated, ground and polished, and surface cleaned to obtain a 3D printed porous TC4 alloy bone plate.
4. The method for preparing a 3D printed porous TC4 alloy bone plate according to claim 2, characterized in that: The sandblasting parameters in step S2 are: a sandblasting force of 0.1-1 MPa, and a sandblasting time of 30-120 s.
5. The method for preparing a 3D printed porous TC4 alloy bone plate according to claim 2, characterized in that: The heat treatment parameters in step S2 are: heat treatment temperature of 700-900° C., heating rate of 5-10° C. / min, and heat preservation time of 30-120 min.
6. The method for preparing a 3D printed porous TC4 alloy bone plate according to claim 2, characterized in that: After the surface is cleaned in step S2, a tricalcium phosphate coating and a bioglass-hydroxyapatite coating are sequentially sprayed on the surface of the 3D printed porous TC4 alloy bone plate using a vacuum plasma spraying method; the raw materials of the bioglass-hydroxyapatite coating include bioglass and hydroxyapatite.
7. The method for preparing a 3D printed porous TC4 alloy bone plate according to claim 6, characterized in that: The mass ratio of the hydroxyapatite to the bioglass is 1:(1-3).
8. The method for preparing a 3D printed porous TC4 alloy bone plate according to claim 6, characterized in that: The thicknesses of the tricalcium phosphate coating and the bioglass-hydroxyapatite coating are 50-150 μm and 200-500 nm respectively.