Medical ta-xti alloy high-quality powder for additive manufacturing and preparation method thereof

Abstract

The application belongs to the field of biomedical metal materials, and discloses a high-quality medical Ta-xTi alloy powder for additive manufacturing and a preparation method thereof. The powder is composed of titanium powder, tantalum powder, tantalum-doped titanium nitride coated amorphous carbon nanoshell, yttrium-stabilized zirconium coated mesoporous silica nanoparticles and stearic acid in a specific weight ratio. In the preparation process, first, nanometer tantalum powder and two modified compounds are uniformly adsorbed on the surface of micron-sized titanium powder through electrostatic self-assembly technology to form a core-shell structure composite powder; then, the composite powder is spheroidized by radio frequency plasma, and finally, high-quality alloy powder with high sphericity and good fluidity is obtained. The method solves the problems of composition segregation and unmelted particles of high-melting-point tantalum and titanium in the laser selective melting forming process, and at the same time, the method endows the material with lower elastic modulus and enhanced biological activity and antibacterial performance, and is particularly suitable for manufacturing high-performance customized bone implants.

Description

Technical Field

[0001] This invention relates to the field of biomedical metallic materials technology, and in particular to a high-quality medical Ta-xTi alloy powder for additive manufacturing and its preparation method. Background Technology

[0002] With the deepening of personalized medicine concepts and the innovation of advanced manufacturing technologies, artificial intelligence-based biomimetic bone structure design has brought new opportunities for the development of bone implants. Such designs can achieve personalized customization of implants, synergistic optimization of lightweight structures and bone ingrowth effects. However, these data-driven biomimetic structures are often complex in shape and have interwoven internal channels, posing a serious challenge to traditional subtractive or equal-material manufacturing methods. In recent years, laser selective melting additive manufacturing technology, due to its layer-by-layer accumulation forming characteristics, has shown unique advantages in the precise forming of complex metal bone implants and has gradually become a key technology for realizing the integrated forming of customized biomimetic functional gradient structures. Currently, top research institutions at home and abroad have conducted extensive applied basic research on implant materials, represented by traditional titanium alloys, and their additive manufacturing processes. Although traditional titanium alloys formed using additive manufacturing technology exhibit good comprehensive mechanical properties, their material composition itself does not fully consider the technical characteristics of rapid non-equilibrium solidification during additive manufacturing, nor has it comprehensively assessed the long-term biocompatibility of all alloying elements. More significantly, the elastic modulus of traditional titanium-based materials is far higher than the mechanical properties of natural human bone tissue. This makes them highly susceptible to stress shielding after implantation, leading to insufficient stress stimulation and subsequent absorption and atrophy of surrounding bone tissue, ultimately causing implant loosening. Furthermore, existing additively manufactured titanium alloy implants primarily function as mechanical supports within the body, generally lacking bioactivity and posing risks of postoperative infection and poor osseointegration. Therefore, the long-term service performance and safety of existing additively manufactured titanium alloys are no longer sufficient to meet increasingly stringent clinical demands.

[0003] To address the aforementioned material bottlenecks, alloying is considered the most direct and effective strategy for improving the performance of titanium alloys. Introducing biocompatible alloying elements can synergistically optimize elastic modulus and biological properties. Tantalum, due to its excellent biocompatibility and corrosion resistance, has attracted widespread attention in the field of biomedical materials. Notably, tantalum and titanium can form an infinite solid solution, a characteristic that makes reducing the elastic modulus of titanium alloys and improving their additive manufacturing formability a current research hotspot. Existing studies have explored laser selective melting forming of titanium-tantalum mixed powders with different ratios, finding that as the tantalum content increases, the alloy's microstructure gradually transforms from a layered structure to an equiaxed phase structure, significantly reducing the elastic modulus while greatly improving mechanical strength. However, due to the significant differences in melting point, powder sphericity, and flowability between tantalum and titanium, a large number of incompletely melted tantalum particles remain in the formed parts after rapid laser melting and solidification. Subsequent studies have shown that these residual unmelted tantalum particles induce heterogeneous nucleation. While this refines the alloy grains and reduces the material's anisotropy, improving mechanical properties to some extent, the similar particle sizes of tantalum and titanium powders, coupled with the relatively large size of the residual particles, severely impairs the material's corrosion resistance, ductility, and forming accuracy. Another study, through forming porous structures from in-situ titanium-tantalum alloyed powders, found that unmelted tantalum particles adhere to the surface of structural supports, significantly affecting the forming accuracy and designed aperture of the supports. To control the uniformity of in-situ alloyed powders, researchers have proposed using a technique combining micron and nanopowders, in-situ alloying micron-sized metal powders with nano-sized high-melting-point powders to achieve uniform mixing of powders with large melting point differences, effectively avoiding the agglomeration and surface adhesion of high-melting-point powders.

[0004] While current research has made some progress in the additive manufacturing formability and performance control of titanium-tantalum alloys, research on micro / nano composite in-situ alloyed titanium-tantalum powders and related preparation technologies for high-precision forming of biomimetic porous structures remains insufficiently systematic and in-depth. In particular, breakthrough solutions are lacking in key scientific issues such as how to effectively suppress the compositional segregation and agglomeration of high-density tantalum elements, and how to elucidate the influence of powder properties on the overall performance of the final alloy. Therefore, developing novel in-situ alloying technologies capable of precisely controlling material composition distribution, deeply revealing the intrinsic relationship between powder physical properties and alloy performance, and developing specialized powder materials suitable for high-precision additive manufacturing have become crucial prerequisites and important guarantees for promoting the clinical application of high-performance titanium-tantalum alloy bone-like structures. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the purpose of this invention is to provide a high-quality medical Ta-xTi alloy powder for additive manufacturing and its preparation method to solve the above-mentioned technical problems.

[0006] According to a first aspect of the present invention, the present invention provides a method for preparing high-quality medical Ta-xTi alloy powder for additive manufacturing, the steps of which include:

[0007] S1. Titanium powder and stearic acid are mixed in a powder mixer to obtain surface-activated dry-mixed powder; tantalum powder, tantalum-doped titanium nitride@amorphous carbon nanoshells and yttrium-stabilized zirconium oxide@mesoporous silica are dispersed in a mixed solvent composed of deionized water and isopropanol to form a nano-suspension; the surface-activated dry-mixed powder is added to the nano-suspension, and the pH value is adjusted to 3.5-4.5 by mechanical stirring and ultrasonic treatment, and the reaction is continuously stirred to form a core-shell structured composite powder;

[0008] S2. After filtering and drying, the core-shell composite powder is fed into... In radio frequency plasma, spheroidization is performed.

[0009] In this invention, the integrated preparation mechanism of high-quality medical Ta-xTi alloy powder is a cross-scale precise control process that integrates surface physicochemistry, colloidal chemistry, and plasma physics. Its core objective is to construct composite metal powders with uniform composition, high sphericity, and specific functions. The process begins with the surface activation and electrostatic self-assembly of micron-sized titanium powder. The mechanism of dry mixing of titanium powder and stearic acid lies in the fact that stearic acid molecules above their melting point can be mechanically induced to undergo physicochemical adsorption between their carboxyl ends and the oxide layer on the surface of titanium powder, forming a monomolecular lubricating film. This film not only significantly improves the flowability of the powder, but more importantly, it provides suitable interfacial energy conditions for subsequent nanoparticle adsorption. Subsequently, the surface-activated titanium powder was combined with a mixed suspension containing nano-tantalum powder and two modified compounds. The reaction mechanism at this stage was carried out in a water-alcohol mixed solvent with precisely controlled pH. When the pH of the system was adjusted to a specific range, the Zeta potential on the surface of the micron-sized titanium powder turned positive, while the dispersed nanoparticles carried negative charges due to the protonation or deprotonation of surface groups. Driven by electrostatic attraction, these negatively charged nanoparticles spontaneously and uniformly migrated and firmly adsorbed onto the surface of the positively charged micron-sized titanium powder, forming a secondary composite structure with micron-sized titanium powder as the "core" and nanoparticles as the "shell". Ultrasonic treatment provided the necessary energy to break the soft agglomeration of nanoparticles, ensuring the uniformity and density of the coating. Finally, radio frequency plasma was used to spheroidize the core-shell composite powder. The physicochemical mechanism of this process is crucial: when the irregularly shaped composite powder is fed into a high-temperature, high-energy plasma torch, its surface instantly absorbs enormous energy and melts. Under extremely high surface tension, the molten droplets spontaneously shrink into spheres to reduce the system's energy. During this extremely short molten state, the nano-tantalum powder coated on the surface rapidly dissolves and diffuses into the titanium matrix, while the two modified compounds partially dissolve or are uniformly distributed in the molten droplets, forming a strong bond with the matrix. The presence of hydrogen helps reduce any oxides that may form on the powder surface, improving the powder's cleanliness. After the powder leaves the plasma region, it is rapidly cooled and solidified in an inert gas flow, ultimately yielding high-quality Ta-xTi alloy spherical powder with high sphericity, highly uniform composition, and excellent flowability. This unique preparation mechanism ensures that the material can achieve uniform melting, good powder spreading performance, and precise shaping during subsequent laser selective melting.

[0010] In some implementations, the mixing time in step S1 is 30-40 minutes.

[0011] In some implementations, the power of the spheroidizing process in step S2 is 15-25 kW.

[0012] In some embodiments, the preparation method of the tantalum-doped titanium nitride@amorphous carbon nanoshell includes: A1, dissolving tantalum pentachloride and titanium tetrachloride in anhydrous ethanol, adding acetylacetone, and carrying out a hydrothermal reaction at a temperature of 175-185℃ to obtain a Ta-Ti-O precursor; subsequently calcining the Ta-Ti-O precursor under an ammonia atmosphere and at a temperature of 795-805℃ to form Ta:TiN nanoparticles; A2, loading the Ta:TiN nanoparticles into a fluidized bed reactor, introducing argon gas, and adding a mixture of methane and hydrogen gas at 440-460℃.

[0013] In this invention, the preparation of tantalum-doped titanium nitride@amorphous carbon nanoshells is a complex process involving solvothermal synthesis, high-temperature nitriding, and chemical vapor deposition. The core of this process lies in constructing a functional nano-additive with a core-shell structure that can actively control the laser-metal interface reaction. Tantalum pentachloride and titanium tetrachloride are co-dissolved in anhydrous ethanol, and acetylacetone is introduced as a key integrator. The chemical reaction mechanism in this step involves the carbonyl and enol groups in the acetylacetone molecule forming stable five-membered ring chelates with tantalum and titanium metal ions. This complexation effectively inhibits the rapid hydrolysis and spontaneous precipitation of metal ions during the hydrothermal reaction, laying the molecular foundation for the formation of a homogeneous precursor. The subsequent hydrothermal reaction creates a unique high-temperature and high-pressure environment within a closed system, promoting the slow decomposition and co-precipitation of the metal chelates, ultimately crystallizing to form a tantalum-titanium oxide composite precursor. In this precursor, tantalum atoms replace titanium atoms in the crystal lattice in a solid solution form, achieving atomic-level uniform doping at the nanoscale. Next, the precursor is calcined at high temperature in an ammonia atmosphere. The reaction mechanism of this process is a gas-solid phase displacement reaction. The active nitrogen species generated by the decomposition of ammonia will gradually penetrate into the crystal lattice of the oxide precursor and drive out oxygen atoms, thereby converting tantalum titanium oxide into tantalum-doped titanium nitride nanoparticles. The doped tantalum atoms not only stabilize the crystal structure of titanium nitride, but more importantly, they regulate its electron cloud density and interface energy. Finally, an amorphous carbon layer was coated onto the surface of titanium nitride nanoparticles using fluidized bed chemical vapor deposition. The mechanism is that at a specific temperature, a mixture of methane and hydrogen gas is introduced and cracked under the catalysis of the metal nitride particles. The generated carbon atoms are deposited on the surface of titanium nitride and grow in a disordered sp² and sp³ hybrid form to form a dense amorphous carbon nanoshell. This carbon shell plays multiple roles in the subsequent additive manufacturing process. On the one hand, its low laser absorption rate can generate a local micro-cooling effect, delaying the solidification of the molten pool to promote element diffusion. On the other hand, it acts as a solid lubricant to improve the flowability of the powder, and the carbon partially dissolved in the molten pool can also play a role in solid solution strengthening.

[0014] In some embodiments, in step A1, the mass ratio of tantalum pentachloride to titanium tetrachloride is 1:(1.2-4.8); the hydrothermal reaction time at 175-185°C is 12-14 h; and the calcination time at 795-805°C is 4-6 h.

[0015] In some embodiments, in step A2, the volume ratio of methane to hydrogen in the mixture is 1:4.

[0016] In some embodiments, the preparation method of the yttrium-stabilized zirconium oxide@mesoporous silica includes: B1, dissolving zirconium oxychloride and yttrium nitrate in deionized water, adjusting the pH to 9.8-10.2 by adding ammonia dropwise, filtering to collect the precipitate, washing the precipitate by filtration, and calcining it at a temperature of 995-1005℃ to obtain YSZ nanoparticles; B2, dispersing the YSZ nanoparticles in an ethanol-water mixed solution containing hexadecyltrimethylammonium bromide, adding tetraethyl orthosilicate, adjusting the pH to 10-11 by adding ammonia, and carrying out a hydrolysis-condensation reaction; to obtain... Nanoparticles, Nanoparticles were immersed in a sodium acetate solution containing strontium and magnesium ions to obtain the immersed nanoparticles. Nanoparticles, after soaking The nanoparticles were calcined at 445-455℃.

[0017] In this invention, the construction of the yttrium-stabilized zirconia@mesoporous silica nanoreactor is based on the synergy of co-precipitation, template-based self-assembly, and ion exchange mechanisms, aiming to create a smart nanocontainer capable of storing and controlling the release of bioactive ions. Its preparation begins with the synthesis of yttrium-stabilized zirconia nanocores using a co-precipitation method. An aqueous solution of zirconium oxychloride and yttrium nitrate is mixed with ammonia under vigorous stirring. The reaction mechanism in this process involves precisely controlling the pH of the system so that zirconium and yttrium ions simultaneously reach the precipitation solubility product of their hydroxides, thereby instantaneously forming a large number of crystal nuclei and growing synchronously. Due to its similar ionic radius to zirconium ions, yttrium ions can be incorporated into the zirconia lattice. During subsequent high-temperature calcination, these doped yttrium ions occupy specific lattice sites, generating oxygen vacancies to maintain electroneutrality. This defect structure effectively suppresses the phase transition of zirconia from a high-temperature phase to a low-temperature phase, thus obtaining tetragonal zirconia nanocrystals that are stable at room temperature and possess excellent mechanical properties. Subsequently, a mesoporous silica shell was constructed around the zirconia core using a template-assisted sol-gel method. The mechanism involves dispersing the nanoparticles in an alcohol-water system containing surfactants, where the surfactant molecules self-assemble to form a micelle template. Tetraethyl orthosilicate is then added and hydrolyzes under alkaline catalysis to generate silicic acid monomers. These monomers subsequently condense to form a silica network surrounding the micelle template and the zirconia core. After calcination to remove the template, a silica shell with ordered radial mesoporous channels remains. The final ion-loading step utilizes the large specific surface area and coordination ability of the surface silanol groups of mesoporous silica. It is immersed in an acetate solution containing bioactive ions such as strontium and magnesium. Through a combination of physical and chemical adsorption, these cations are captured and stored within the mesoporous channels and shell. After medium-temperature calcination, these ions are further stabilized within the silica network, forming miniature "nanoreactors." When the material is implanted into a biological environment, body fluids gradually permeate the mesoporous channels, and the silica shell undergoes slow biodegradation, thereby releasing strontium magnesium ions in a controllable manner. These ions have been shown to effectively activate specific signaling pathways of osteoblasts, promoting bone tissue regeneration and integration.

[0018] In some embodiments, in step B1, the mass ratio of zirconium oxychloride to yttrium nitrate is 100:3.6; and the calcination time at 995-1005°C is 2-4 hours.

[0019] In some embodiments, in step B2, the calcination time at 445-455°C is 3-4 hours.

[0020] According to a second aspect of the present invention, the present invention provides a method for preparing high-quality medical Ta-xTi alloy powder for additive manufacturing, the high-quality medical Ta-xTi alloy powder for additive manufacturing obtained by the method described above comprises the following raw materials in parts by weight: 70-85 parts of titanium powder; 15-30 parts of tantalum powder; 0.5-2 parts of tantalum-doped titanium nitride@amorphous carbon nanoshell; 1-3 parts of yttrium-stabilized zirconium oxide@mesoporous silica; and 0.1-0.5 parts of stearic acid.

[0021] Compared with existing technologies, the beneficial effects of this invention are as follows: The high-quality medical Ta-xTi alloy powder for additive manufacturing and its preparation method provided by this invention have significant technological advancements and outstanding practical application effects. These effects are mainly reflected in the following three aspects: First, this invention fundamentally solves the problem of compositional segregation and unmelted particle residue caused by the significant differences in physical properties between high-melting-point tantalum and titanium during laser selective melting. Through an original core-shell composite powder design, using micron-sized spherical titanium powder as the core, and employing electrostatic self-assembly technology to uniformly coat nano-sized tantalum powder and two functional modification compounds onto its surface, a powder architecture with a compositional gradient transition is constructed. During laser melting, this multi-scale powder structure allows the nano-sized tantalum powder to rapidly melt and diffuse into the titanium matrix, greatly shortening the alloying time and lowering the energy threshold, thereby effectively avoiding compositional inhomogeneity caused by incomplete melting of tantalum powder. The synergistic effect of the two modified compounds further optimized the mass transfer process within the molten pool. The tantalum-doped titanium nitride-coated amorphous carbon nanoshell generated a local energy modulation effect under laser irradiation, promoting interfacial fusion; while the yttrium-stabilized zirconia-coated mesoporous silica nanoreactor stabilized the molten pool flow through its unique core-shell structure. This innovative material system design resulted in an extremely uniform composition distribution in the final alloy part, with almost no observable unmelted tantalum particles, thus significantly improving the material's corrosion resistance and ductility while ensuring precise geometric accuracy of the formed part.

[0022] Secondly, this invention successfully achieves a synergistic improvement in the mechanical properties and biofunctionality of materials, providing an ideal material solution for next-generation high-performance bone implants. By precisely controlling the addition ratio of tantalum and combining the unique effects of two functional modifying compounds, the prepared alloy exhibits a microstructure dominated by the biocompatible β phase, with a significantly reduced elastic modulus, making it more compatible with the mechanical properties of natural human bone tissue. This effectively alleviates the stress shielding effect after implantation, providing the necessary mechanical environment for the long-term health of surrounding bone tissue. Simultaneously, the introduction of the two modifying compounds endows the material with excellent bioactivity and antibacterial properties. The yttrium-stabilized zirconia-coated mesoporous silica nanoreactor can controllably release bioactive ions such as strontium and magnesium at the interface between the implant and bone tissue. These ions have been shown to effectively stimulate osteoblast differentiation and proliferation, accelerating new bone formation and bone integration. Meanwhile, the tantalum-doped titanium nitride-coated amorphous carbon nanoshell exhibits a sustained antibacterial effect in the body fluid environment, significantly reducing the risk of postoperative infection. This multifunctional property, which combines low modulus, high strength, and promotes osseointegration while inhibiting bacterial proliferation, gives the material of this invention a significant advantage in long-term stable service in complex clinical environments.

[0023] Finally, the preparation process developed in this invention provides a reliable and efficient technical path for the large-scale production of high-quality medical alloy powders. The entire process integrates advanced technologies such as powder surface activation, electrostatic self-assembly, and radio frequency plasma spheroidization. The parameters of each step have been carefully optimized, resulting in excellent process repeatability and stability. By controlling the mixed solvent system and pH value, the monolayer uniform self-assembly of nanoparticles on the surface of micron-sized titanium powder was achieved, forming a structurally stable core-shell composite powder. The subsequent radio frequency plasma spheroidization treatment, under precisely controlled power and atmosphere conditions, further improved the sphericity and surface smoothness of the powder, while ensuring a strong metallurgical bond between the nano-coating layer and the micron core. The resulting alloy powder not only possesses excellent flowability, reasonable particle size distribution, and high bulk density, fully meeting the stringent requirements of laser selective melting technology for powder materials, but also avoids the contamination and component segregation that may be introduced by traditional mechanical alloying, ensuring batch-to-batch consistency and reliability of the powder. This high-quality powder can achieve high-precision and high-density forming effects when additively manufacturing complex biomimetic bone structures, laying a solid material foundation for manufacturing personalized, functionally integrated next-generation bone implant devices. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the micro-nano composite in-situ alloying preparation process adapted to Ti-xTa alloy design and agglomeration suppression for additive manufacturing. Detailed Implementation

[0026] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] The present invention will now be described in further detail with reference to the accompanying drawings.

[0029] The sources of some components in the examples and comparative examples are as follows:

[0030] The titanium powder was purchased from BaoTi Co., Ltd.

[0031] The stearic acid was purchased from Zibo Haishun Chemical Co., Ltd.

[0032] The tantalum powder was purchased from Ningxia Oriental Tantalum Industry Co., Ltd.

[0033] The radio frequency plasma was purchased from Dongguan Shanshi Technology Co., Ltd.

[0034] The tantalum pentachloride was purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0035] The titanium tetrachloride was purchased from Luoyang Haohai Chemical Reagent Co., Ltd.

[0036] The acetylacetone was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0037] The zirconium oxychloride was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.

[0038] The yttrium nitrate was purchased from Shanghai Maclean Biotechnology Co., Ltd.

[0039] The hexadecyltrimethylammonium bromide was purchased from Aladdin Reagent (Shanghai) Co., Ltd.

[0040] The tetraethyl orthosilicate was purchased from Tianjin Xiens Biochemical Technology Co., Ltd.

[0041] Example 1

[0042] Reference Figure 1As shown, this embodiment provides a method for preparing high-quality medical Ta-xTi alloy powder for additive manufacturing. First, tantalum-doped titanium nitride@amorphous carbon nanoshells are prepared by dissolving 20g of tantalum pentachloride and 96g of titanium tetrachloride in 1000mL of anhydrous ethanol, adding 150g of acetylacetone, and hydrothermally reacting at 180℃ for 13h to obtain a Ta-Ti-O precursor. Subsequently, the Ta-Ti-O precursor is calcined at 800℃ for 5h under an ammonia atmosphere to form Ta:TiN nanoparticles. 10g of Ta:TiN nanoparticles are loaded into a fluidized bed reactor, and argon gas is introduced. The volume ratio of argon gas in the mixed gas (argon, methane, and hydrogen) is 70%. A mixed gas composed of methane and hydrogen in a volume ratio of 1:4 is introduced at 450℃ for 60min to obtain tantalum-doped titanium nitride@amorphous carbon nanoshells. Subsequently, yttrium-stabilized zirconium oxide@mesoporous silica was prepared. 100 g of zirconium oxychloride and 3.6 g of yttrium nitrate were dissolved in 500 mL of deionized water. Ammonia was added dropwise to adjust the pH to 10.0. The precipitate was filtered, washed, and calcined at 1000 °C for 3 h to obtain YSZ nanoparticles. 1 g of YSZ nanoparticles were dispersed in a 300 mL mixture of ethanol and water (ethanol to water volume ratio 1:1) containing 0.5 g of hexadecyltrimethylammonium bromide. 2 g of tetraethyl orthosilicate was added, and ammonia was added to adjust the pH to 10.5. Hydrolysis and condensation were carried out for 6 h to obtain YSZ@m-SiO2 nanoparticles. The YSZ@m-SiO2 nanoparticles were then immersed in a sodium acetate solution containing strontium and magnesium ions (strontium ion concentration 0.15 mol / L, magnesium ion concentration 0.10 mol / L, sodium acetate concentration 0.10 mol / L). After 24 hours in 1 mol / L solution, the solution was removed and calcined at 450℃ for 3.5 hours to obtain yttrium-stabilized zirconium oxide@mesoporous silica. Finally, alloy powder was prepared by mixing 750g of titanium powder with a particle size of 15-53μm and 3g of stearic acid in a powder mixer for 35min to obtain surface-activated dry-mixed powder. 180g of tantalum powder, 10g of the tantalum-doped titanium nitride@amorphous carbon nanoshell prepared above, and 15g of yttrium-stabilized zirconium oxide@mesoporous silica were dispersed in a mixed solvent consisting of 300mL of deionized water and 600mL of isopropanol to form a nano-suspension. The surface-activated dry-mixed powder was added to the nano-suspension, and the surface-activated dry-mixed powder and nano-suspension were mixed evenly by mechanical stirring and ultrasonic treatment. The pH value was adjusted to 4 with dilute hydrochloric acid, and the reaction was continuously stirred for 60min to form a core-shell structured composite powder. The core-shell structured composite powder was filtered, vacuum dried at 80℃ for 4h, and then sent into an argon-hydrogen mixed gas radio frequency plasma for spheroidization treatment at 20kW power to obtain the final product.

[0043] Example 2

[0044] The difference between this embodiment and Embodiment 1 lies in the preparation of the high-quality medical Ta-xTi alloy powder used for additive manufacturing. First, tantalum-doped titanium nitride@amorphous carbon nanoshells are prepared. 20g of tantalum pentachloride and 48g of titanium tetrachloride are dissolved in 800mL of anhydrous ethanol, and 120g of acetylacetone is added. The mixture is then subjected to a hydrothermal reaction at 175℃ for 14h to obtain a Ta-Ti-O precursor. Subsequently, the Ta-Ti-O precursor is calcined at 795℃ for 6h under an ammonia atmosphere to form Ta:TiN nanoparticles. 8g of Ta:TiN nanoparticles are loaded into a fluidized bed reactor, and argon gas is introduced. A mixed gas consisting of methane and hydrogen in a volume ratio of 1:4 is then introduced at 440℃ for 70min to obtain tantalum-doped titanium nitride@amorphous carbon nanoshells. Subsequently, yttrium-stabilized zirconium oxide@mesoporous silica was prepared. 100 g of zirconium oxychloride and 3.6 g of yttrium nitrate were dissolved in 400 mL of deionized water. Ammonia was added dropwise to adjust the pH to 9.8. The precipitate was filtered, washed, and then calcined at 995 °C for 4 h to obtain YSZ nanoparticles. 1 g of YSZ nanoparticles were dispersed in a mixed solution of ethanol and water containing 0.4 g of hexadecyltrimethylammonium bromide. 1.5 g of tetraethyl orthosilicate was added, and ammonia was added to adjust the pH to 10. Hydrolysis and condensation were carried out for 7 h to obtain… Nanoparticles, Nanoparticles were immersed in a sodium acetate solution containing strontium and magnesium ions (strontium ion concentration of 0.25 mol / L, magnesium ion concentration of 0.05 mol / L, and sodium acetate concentration of 0.15 mol / L) for 20 h, then removed and calcined at 445 °C for 4 h to obtain yttrium-stabilized zirconia@mesoporous silica. Finally, alloy powder was prepared by mixing 700g of titanium powder with a particle size of 15-53μm and 2g of stearic acid in a powder mixer for 30min to obtain surface-activated dry-mixed powder. 150g of tantalum powder, 5g of the tantalum-doped titanium nitride@amorphous carbon nanoshell prepared above, and 10g of yttrium-stabilized zirconium oxide@mesoporous silica were dispersed in a mixed solvent consisting of 250mL of deionized water and 500mL of isopropanol to form a nano-suspension. The surface-activated dry-mixed powder was added to the nano-suspension, and the mixture was mechanically stirred and ultrasonically treated. The pH value was adjusted to 3.5 with dilute hydrochloric acid, and the reaction was continuously stirred for 90min to form a core-shell structured composite powder. The core-shell structured composite powder was filtered, vacuum dried at 75℃ for 5h, and then sent into an argon-hydrogen mixed gas radio frequency plasma for spheroidization treatment at 15kW power to obtain the final product.

[0045] Example 3

[0046] The difference between this embodiment and Embodiment 1 lies in the preparation of the high-quality medical Ta-xTi alloy powder used for additive manufacturing. First, tantalum-doped titanium nitride@amorphous carbon nanoshells are prepared. 20g of tantalum pentachloride and 24g of titanium tetrachloride are dissolved in 600mL of anhydrous ethanol, and 100g of acetylacetone is added. The mixture is then hydrothermally reacted at 185℃ for 12h to obtain a Ta-Ti-O precursor. Subsequently, the Ta-Ti-O precursor is calcined at 805℃ for 4h under an ammonia atmosphere to form Ta:TiN nanoparticles. 6g of Ta:TiN nanoparticles are loaded into a fluidized bed reactor, argon gas is introduced, and a mixed gas consisting of methane and hydrogen in a volume ratio of 1:4 is introduced at 460℃ for 50min to obtain tantalum-doped titanium nitride@amorphous carbon nanoshells. Subsequently, yttrium-stabilized zirconium oxide@mesoporous silica was prepared. 100 g of zirconium oxychloride and 3.6 g of yttrium nitrate were dissolved in 600 mL of deionized water. Ammonia was added dropwise to adjust the pH to 10.2. The precipitate was filtered, washed, and calcined at 1005 °C for 2 h to obtain YSZ nanoparticles. 1 g of YSZ nanoparticles were dispersed in a mixed solution of ethanol and water containing 0.6 g of hexadecyltrimethylammonium bromide. 2.5 g of tetraethyl orthosilicate was added, and ammonia was added to adjust the pH to 11. Hydrolysis and condensation were carried out for 5 h to obtain… Nanoparticles, Nanoparticles were immersed in a sodium acetate solution containing strontium and magnesium ions (strontium ion concentration of 0.08 mol / L, magnesium ion concentration of 0.20 mol / L, and sodium acetate concentration of 0.08 mol / L) for 28 h, then removed and calcined at 455 °C for 3 h to obtain yttrium-stabilized zirconia@mesoporous silica. Finally, alloy powder was prepared by mixing 850g of titanium powder with a particle size of 15-53μm and 5g of stearic acid in a powder mixer for 40min to obtain surface-activated dry-mixed powder. 300g of tantalum powder, 20g of the tantalum-doped titanium nitride@amorphous carbon nanoshell prepared above, and 30g of yttrium-stabilized zirconium oxide@mesoporous silica were dispersed in a mixed solvent consisting of 350mL of deionized water and 700mL of isopropanol to form a nano-suspension. The surface-activated dry-mixed powder was added to the nano-suspension, and the mixture was mechanically stirred and ultrasonically treated. The pH value was adjusted to 4.5 with dilute hydrochloric acid, and the reaction was continuously stirred for 30min to form a core-shell structured composite powder. The core-shell structured composite powder was filtered, vacuum dried at 85℃ for 3h, and then sent into an argon-hydrogen mixed gas radio frequency plasma for spheroidization treatment at 25kW power to obtain the final product.

[0047] Comparative Example 1

[0048] The difference between this comparative example and Example 1 is that, in the preparation of the medical Ta-xTi alloy powder used for additive manufacturing, 750g of titanium powder with a particle size of 15-53μm and 3g of stearic acid were mixed in a powder mixer for 35min to obtain a surface-activated dry-mixed powder; 180g of tantalum powder was dispersed in a mixed solvent consisting of 300mL of deionized water and 600mL of isopropanol to form a nano-suspension; the surface-activated dry-mixed powder was added to the nano-suspension, and the surface-activated dry-mixed powder and the nano-suspension were mixed evenly by mechanical stirring and ultrasonic treatment; the pH value was adjusted to 4 with dilute hydrochloric acid, and the reaction was continuously stirred for 60min to form a composite powder; the composite powder was filtered, vacuum dried at 80℃ for 4h, and then sent into an argon-hydrogen mixed gas radio frequency plasma for spheroidization treatment at a power of 20kW to obtain the final product.

[0049] Comparative Example 2

[0050] The difference between this comparative example and Example 1 is that, in the preparation of the medical Ta-xTi alloy powder used for additive manufacturing, 750g of titanium powder with a particle size of 15-53μm and 3g of stearic acid were mixed in a powder mixer for 35min to obtain surface-activated dry-mixed powder; 180g of tantalum powder and 10g of tantalum-doped titanium nitride@amorphous carbon nanoshells were dispersed in a mixed solvent consisting of 300mL of deionized water and 600mL of isopropanol to form a nano-suspension; the surface-activated dry-mixed powder was added to the nano-suspension, and the surface-activated dry-mixed powder and the nano-suspension were mixed evenly by mechanical stirring and ultrasonic treatment; the pH value was adjusted to 4 with dilute hydrochloric acid, and the reaction was continuously stirred for 60min to form a composite powder; the composite powder was filtered, vacuum dried at 80℃ for 4h, and then sent into an argon-hydrogen mixed gas radio frequency plasma for spheroidization treatment at 20kW power to obtain the final product.

[0051] Comparative Example 3

[0052] The difference between this comparative example and Example 1 is that, in the preparation of the medical Ta-xTi alloy powder used for additive manufacturing, 750g of titanium powder with a particle size of 15-53μm and 3g of stearic acid were mixed in a powder mixer for 35min to obtain a surface-activated dry-mixed powder; 180g of tantalum powder and 15g of yttrium-stabilized zirconium oxide@mesoporous silica were dispersed in a mixed solvent consisting of 300mL of deionized water and 600mL of isopropanol to form a nano-suspension; the surface-activated dry-mixed powder was added to the nano-suspension, and the surface-activated dry-mixed powder and the nano-suspension were mixed evenly by mechanical stirring and ultrasonic treatment; the pH value was adjusted to 4 with dilute hydrochloric acid, and the reaction was continuously stirred for 60min to form a composite powder; the composite powder was filtered, vacuum dried at 80℃ for 4h, and then sent into an argon-hydrogen mixed gas radio frequency plasma for spheroidization treatment at 20kW power to obtain the final product.

[0053] The performance of the high-quality medical Ta-xTi alloy powders obtained from Examples 1-3 and Comparative Examples 1-3 for additive manufacturing was tested according to national and industry standards. Specifically, the powder flowability test used a Hall effect flowmeter with a standard stainless steel funnel (smooth inner wall and 2.5mm outlet diameter). 50g of powder sample was allowed to flow naturally into the funnel, and the time required for complete emptying was recorded. This test was repeated five times, and the average value was taken. The unit is expressed as seconds / 50g. The loose density test used a cylindrical measuring cup with a standard volume of 25cm³. Powder was slowly poured into the cup from a fixed height until full. Excess powder was scraped off with a scraper, and the weight was measured. The mass per unit volume was calculated. This test was repeated three times, and the average value was taken. The unit is expressed as g / cm³. The particle size distribution test used a particle size analyzer based on laser diffraction. The powder sample was dispersed in anhydrous ethanol and ultrasonically dispersed for 3 minutes using a circulating pump. The suspension was kept homogeneous at 2000 rpm, and the measurement range was 0.02 to 2000 μm. The cumulative distribution values ​​of D10, D50, and D90 were reported. Powder morphology analysis was performed using field emission scanning electron microscopy. Powder samples were observed under an accelerating voltage of 20 kV, and at least 500 particles were randomly selected to statistically analyze sphericity. The density of the molded parts was tested using the Archimedes displacement method. The sample was dried at 80℃ for 2 h and then weighed in air. The apparent weight in deionized water was then weighed, and the relative density was calculated based on the theoretical density of the material. Mechanical property testing was performed using an electronic universal testing machine. Tensile specimens were processed according to the standard dog bone shape, with a gauge length of 4 mm in diameter and 20 mm in length, and a tensile rate of 0.5 mm / min, load-displacement curves were recorded simultaneously and yield strength, tensile strength, and elongation were calculated; the elastic modulus test used the pulse excitation method, placing the sample on a special support and generating free vibration by tapping, the sensor received the vibration signal and calculated the resonance frequency, and then calculated the elastic modulus based on the sample size and mass; the unmelted particle count used scanning electron microscopy in backscatter mode to observe the polished metallographic sample, randomly selecting 10 regions under 500x magnification, and calculating the area ratio of high atomic number regions using image analysis software; the cytotoxicity test used the MTT colorimetric method, co-culturing the sample extract with osteoblasts for 24 h, adding MTT reagent and continuing culture for 4 h, adding dimethyl sulfoxide to dissolve formazan crystals, and measuring the absorbance value at 570 nm wavelength using an enzyme-linked immunosorbent assay reader to calculate the relative cell proliferation rate compared to the blank control group; the antibacterial performance test used the film-attachment method, dropping the bacterial suspension onto the sample (the sample used for the antibacterial test was not a powder, but a dense block sample (i.e., 10 mm in diameter and 2 mm thick) similar to that used in the electrochemical and cytotoxicity tests). A cylindrical sample (10 mm in diameter and 2 mm thick) was placed on the surface of a micrometer-sized sample and covered with a thin film. The sample was incubated at 37°C and 95% humidity for 24 hours. Colonies were eluted with phosphate buffer and serially diluted. Colony-forming units were counted on pour plates to calculate the antibacterial rate. Electrochemical testing was performed using a three-electrode system in simulated body fluid. The working electrode was the sample to be tested (a cylindrical block sample with a diameter of 10 mm and a thickness of 2 mm), the reference electrode was a saturated calomel electrode, and the auxiliary electrode was a platinum electrode. The scan range was from -0.5 V to +1.5 V, and the scan rate was 1 mV / min. The potentiodynamic polarization curves were recorded, and the self-corrosion potential and corrosion current density were calculated. The preparation of the sample extract in the above cytotoxicity test included:

[0054] Calculate the extraction ratio: Use a ratio of surface area to extraction medium volume of 3 cm² / mL for extraction; for the above cylindrical sample with a diameter of 10 mm and a thickness of 2 mm, the surface area of ​​its single exposed side is about 0.785 cm². After calculating the total surface area (including the side), determine the required extraction medium volume accordingly.

[0055] Extraction medium: High-glucose DMEM medium supplemented with 10% fetal bovine serum;

[0056] Extraction conditions: Extract for 24 hours in a constant temperature incubator at 37 ℃ under a 5% CO2 atmosphere. After extraction, collect the extract and use it immediately, or freeze it at -20 ℃ for later use.

[0057] The performance test data above are shown in Table 1.

[0058] Table 1 Performance Test Results

[0059]

[0060] The test results in Table 1 clearly show that Examples 1-3 comprehensively solved the technical problems that this invention aims to overcome compared to Comparative Examples 1-3. Regarding powder processing performance, the powder flowability of the Examples reached 28.5-30.1 s / 50g, and the loose packing density reached 2.58-2.67 g / cm³, significantly better than Comparative Example 1's 35.7 s / 50g and 2.35 g / cm³. This indicates that the core-shell structure design and surface modification treatment effectively improved the powder flowability and packing density, ensuring uniform powder spreading during additive manufacturing. In terms of microstructure control, the unmelted tantalum particle area ratio in the Examples was only 0.8%–1.9%, while in Comparative Example 1 it reached as high as 8.5%. This proves that the synergistic effect of the two modified compounds significantly promoted the melting and diffusion of tantalum, fundamentally solving the problem of component segregation caused by the large difference in melting points between tantalum and titanium. In terms of mechanical property matching, the embodiments successfully reduced the elastic modulus to 58-78 GPa, which is closer to the mechanical properties of natural bone tissue, while the tensile strength reached 810-1050 MPa and the elongation remained at an excellent level of 11%-16%, forming an ideal combination of low modulus and high strength, effectively alleviating the stress shielding effect. Regarding biofunctionalization, the osteoblast proliferation rate of the embodiments reached 1.35-1.42, and the antibacterial rate reached 75.3%-78.6%, far higher than the 1.05 and 15.2% of Comparative Example 1, indicating that the design of the functional nanoreactor achieved a synergistic improvement in bioactivity and antibacterial properties. In terms of corrosion resistance, the self-corrosion potential of the embodiments increased to -0.23 to -0.26 V, and the corrosion current density decreased to 0.12-0.18 μA / cm², indicating that the surface modification layer formed an effective protective barrier. Of particular note is that, while Comparative Example 2, which only added tantalum-doped titanium nitride to coat the amorphous carbon nanoshell, improved formability, it lacked sufficient bioactivity. Similarly, Comparative Example 3, which only added yttrium-stabilized zirconium oxide to coat mesoporous silica, exhibited bioactivity, but the problem of unmelted tantalum particles persisted. This clearly demonstrates that the synergistic effect of the two modified compounds is key to optimizing the overall material performance. In summary, Examples 1-3, through innovative material system design and preparation processes, simultaneously solved key technical challenges such as component uniformity control, mechanical property matching, and biofunctional integration, providing an ideal material solution for manufacturing high-performance medical implants.

[0061] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing, characterized in that the steps include... include: S1. Titanium powder and stearic acid are mixed in a powder mixer to obtain surface-activated dry-mixed powder; tantalum powder, tantalum-doped titanium nitride@amorphous carbon nanoshells and yttrium-stabilized zirconium oxide@mesoporous silica are dispersed in a mixed solvent composed of deionized water and isopropanol to form a nano-suspension; the surface-activated dry-mixed powder is added to the nano-suspension, and the pH value is adjusted to 3.5-4.5 by mechanical stirring and ultrasonic treatment, and the reaction is continuously stirred to form a core-shell structured composite powder; S2. After filtering and drying, the core-shell composite powder is fed into... In radio frequency plasma, spheroidization is performed.

2. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 1, characterized in that, In step S1, the mixing time is 30-40 minutes.

3. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 1, characterized in that, In step S2, the power of the spheroidizing process is 15-25kW.

4. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 1, characterized in that, The preparation method of the tantalum-doped titanium nitride@amorphous carbon nanoshell includes: A1, dissolving tantalum pentachloride and titanium tetrachloride in anhydrous ethanol, adding acetylacetone, and carrying out a hydrothermal reaction at a temperature of 175-185℃ to obtain a Ta-Ti-O precursor; subsequently calcining the Ta-Ti-O precursor under an ammonia atmosphere at a temperature of 795-805℃ to obtain Ta:TiN nanoparticles; A2, loading the Ta:TiN nanoparticles into a fluidized bed reactor, introducing argon gas, and adding a mixture of methane and hydrogen gas at 440-460℃.

5. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 4, characterized in that, In step A1, the mass ratio of tantalum pentachloride to titanium tetrachloride is 1:(1.2-4.8); the hydrothermal reaction time at 175-185℃ is 12-14h; and the calcination time at 795-805℃ is 4-6h.

6. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 4, characterized in that, In step A2, the volume ratio of methane to hydrogen in the mixed gas is 1:

4.

7. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 1, characterized in that, The preparation method of the yttrium-stabilized zirconium oxide@mesoporous silica includes: B1, dissolving zirconium oxychloride and yttrium nitrate in deionized water, adjusting the pH to 9.8-10.2 by adding ammonia dropwise, filtering to collect the precipitate, washing the precipitate, and calcining it at a temperature of 995-1005℃ to obtain YSZ nanoparticles; B2, dispersing the YSZ nanoparticles in an ethanol-water mixed solution containing hexadecyltrimethylammonium bromide, adding tetraethyl orthosilicate, adjusting the pH to 10-11 by adding ammonia, and carrying out a hydrolysis-condensation reaction to obtain... Nanoparticles, Nanoparticles were immersed in a sodium acetate solution containing strontium and magnesium ions to obtain the immersed nanoparticles. Nanoparticles, after soaking The nanoparticles were calcined at 445-455℃.

8. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 7, characterized in that, In step B1, the mass ratio of zirconium oxychloride to yttrium nitrate is 100:3.6; the calcination time is 2-4 hours at 995-1005℃.

9. The method for preparing high-quality medical-grade Ta-xTi alloy powder for additive manufacturing according to claim 7, characterized in that, In step B2, the calcination time is 3-4 hours at 445-455℃.

10. A high-quality medical Ta-xTi alloy powder for additive manufacturing, prepared by the method according to any one of claims 1-9, characterized in that, The raw materials include the following parts by weight: 70-85 parts titanium powder; 15-30 parts tantalum powder; 0.5-2 parts tantalum-doped titanium nitride@amorphous carbon nanoshell; 1-3 parts of yttrium-stabilized zirconium oxide@mesoporous silica; 0.1-0.5 parts of stearic acid.

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