Micro-nano gradient porous Ti-Ta-Cu material as well as preparation method and application thereof

Abstract

The invention discloses a micro-nano gradient porous Ti-Ta-Cu material as well as a preparation method and application thereof. The method comprises the following steps: 1, preparing a Ti-Ta-Cu alloy with uniformly distributed components through electric arc melting; and secondly, a sample is pretreated, then electrochemical gradient dealloying is conducted in an electrolyte containing HF and HNO3, and the micro-nano porous Ti-Ta-Cu material is obtained. According to the method, the Ti-Ta-Cu material with the micro-nano porous surface is prepared through an electrochemical dealloying and oxidation synchronization strategy, and the surface micro-nano porous composite structure is formed through electrochemical anodic oxidation and dealloying process treatment. The structure is formed by interweaving nano-scale pores and micron-scale pores, and the surface layer is covered with a CuO / Ta2O5 composite oxide layer. According to the method, the corrosion resistance of the material is remarkably improved, the surface biological activity of the material is improved, meanwhile, high biocompatibility is reserved, and the method is suitable for severe environments such as ocean engineering and biomedical implants.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to a micro-nano gradient porous Ti-Ta-Cu material and a preparation method and application thereof. Background Art

[0002] Titanium and its alloys have become core materials for biomedical devices such as orthopedic implants, dental prostheses, and cardiovascular stents due to their high specific strength, excellent corrosion resistance, and biocompatibility. However, traditional medical titanium alloys face two key bottlenecks: mechanical mismatch: the elastic modulus of pure titanium (approximately 110 GPa) is significantly higher than that of human bone (approximately 30 GPa), and long-term implantation can easily induce a stress shielding effect, leading to bone resorption and implant loosening; and functional singularity: existing surface modification technologies struggle to simultaneously meet the multiple requirements of corrosion resistance, antibacterial properties, and bone integration.

[0003] Titanium-tantalum (Ti-Ta) alloys have become a research hotspot for the new generation of biomedical metals by adding tantalum (20-25%) to reduce the elastic modulus to 50-60 GPa (close to cortical bone) and significantly improve the strength (tensile strength > 800 MPa) and corrosion resistance (corrosion rate reduced to 1 / 5 of pure titanium).

[0004] However, the existing Ti-Ta alloys still have the following technical defects: 1. Insufficient corrosion resistance and surface function limitations, pitting sensitivity: in the presence of Cl - In body fluid environments (such as saline and blood), the Ti-Ta alloy passivation film still has the risk of local rupture, which can cause metal ion dissolution and inflammatory reactions; it also loses biological activity. 2. Weak antibacterial properties. The "inherent" antibacterial properties of titanium-tantalum alloys are relatively weak. Currently, the main ways to improve the antibacterial properties of titanium-tantalum alloys are surface modification and element doping (Cu, Ag) / alloying. Copper (Cu) elements can be released through ions (Cu 2+ ) gives the material broad-spectrum antibacterial properties, but its solid solubility in the titanium matrix is ​​low, and it is easy to segregate at the grain boundary to form Cu-Ti intermetallic compounds. The Cu / Ti galvanic corrosion accelerates the destruction of the passivation film, and the corrosion current density increases, resulting in a decrease in corrosion resistance. 3. The existing surface modification technology has a bottleneck of structure-function imbalance. At present, the micro-arc oxidation coating is mainly composed of micron pores, lacks nano-scale pores, and has insufficient specific surface area. The micron-scale porous structure formed by traditional surface treatment technologies (such as micro-arc oxidation and anodizing) has a limited specific surface area and insufficient osteoblast adhesion rate. The anodized nanotubes are structurally fragile, and the peeling rate during implantation is greater than 20%; the process is complicated. It requires plasma spraying and other multi-step processing, which consumes high energy and is difficult to achieve uniform modification of complex devices.

[0005] Although the disclosed method of making titanium-tantalum alloy porous can improve the biocompatibility and bioactivity of the alloy, it has the following limitations: no introduction of Cu element for coordinated regulation, lack of antibacterial properties; the porous structure is a single micron scale, with a limited specific surface area (2-3m 2 / g), and the passivation film composition is not optimized, resulting in insufficient long-term corrosion resistance. Summary of the Invention

[0006] In order to address the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a method for preparing a micro-nano gradient porous Ti-Ta-Cu material with excellent functionality.

[0007] The present invention proposes an electrochemical gradient corrosion strategy, which is achieved through: composition design: optimizing the Cu content (1-10%) and distribution morphology (mainly in solid solution) in Ti-Ta-Cu alloy; structural innovation: constructing a hierarchical structure of micropores (1-3 μm) and nanopores (15-150 nm), increasing the specific surface area to 15-20 m 2 / g; Film modification: In-situ generation of a Ta2O5-CuO composite oxide layer achieves a synergistic effect of corrosion resistance, antibacterial properties, and osteogenic properties. This technology effectively addresses the core issues of existing technologies, such as single function, fragile structure, and complex process, providing a new solution for the upgrading of biomedical titanium alloys.

[0008] Another object of the present invention is to provide a micro-nano gradient porous Ti-Ta-Cu material with excellent functionality obtained by the above preparation method.

[0009] Based on the fact that in an acidic environment, the potential of Ti is -1.63V, the potential of Ta is -0.75V, and the potential of Cu is +0.34V, and the different corrosion potentials of titanium, tantalum, and copper make titanium vulnerable to corrosion in hydrofluoric acid solutions. Electrochemical dealloying is used. The reaction mechanism is as follows: Dealloying: Ti reacts with HF and dissolves preferentially, forming micro-nanopores. Anodic oxidation: Ta oxidizes in an acidic medium to form Ta2O5, which prevents further reaction. Cu reacts slowly in acidic environments and oxidizes in acidic environments.

[0010] The present invention provides the use of the above-mentioned micro-nano gradient porous Ti-Ta-Cu material with excellent functionality in the preparation of biomedical devices.

[0011] The purpose of the present invention is achieved through the following technical solutions:

[0012] A method for preparing a micro-nano porous Ti-Ta-Cu material with excellent functionality comprises the following steps:

[0013] (1) Ti, Ta, and Cu raw materials are mixed in proportion, and smelted to completely melt the raw materials and mix them evenly to obtain a Ti-Ta-Cu alloy ingot;

[0014] (2) The Ti-Ta-Cu alloy ingot is pretreated, and then electrochemical gradient dealloying is carried out in an electrolyte containing HF and HNO3 to obtain a micro-nano porous Ti-Ta-Cu material.

[0015] Preferably, in the Ti-Ta-Cu alloy ingot of step (1), the mass percentage of each element is: Cu 1-10%, Ta 15-30%, and the balance is Ti; more preferably, Cu 1-10%, Ta 25%, and the balance is Ti.

[0016] Preferably, in step (1), the Ti, Ta and Cu raw materials are at least one shape of materials selected from the group consisting of particles, fragments and shavings of Ti, Ta and Cu.

[0017] Preferably, in step (1), the process parameters of the smelting are: current 220-280 A, carried out in an inert protective atmosphere, and the alloy ingot is obtained by vacuum arc smelting furnace (vacuum degree 5x10 -3 ~ 1x10 -2 Pa, inert gas protection) smelting 4-8 times.

[0018] More preferably, the inert protective atmosphere is at least one of nitrogen, argon and helium.

[0019] Preferably, in step (2), the pretreatment refers to cutting the Ti-Ta-Cu alloy ingot into blocks, and then sequentially performing fine grinding and polishing, ultrasonic, drying and sample sealing treatment.

[0020] More preferably, the size of the block is 10x10x3-20x20x8mm.

[0021] More preferably, the fine grinding refers to fine grinding with 200-2000# sandpaper; the ultrasonic refers to ultrasonic in anhydrous ethanol for 5-20min; and the drying refers to drying at 45-55℃ for 3-6h.

[0022] Preferably, in step (2), in the electrolyte containing HF and HNO3, the volume percentage of HF is 2-6%; the volume percentage of concentrated HNO3 is 2-10%, and the balance is deionized water; more preferably, the volume percentage of HF is 2-4%; the volume percentage of concentrated HNO3 is 4-6%, and the balance is water. The concentrated nitric acid is commercially available concentrated nitric acid.

[0023] Preferably, in step (2), the process of electrochemical gradient dealloying is: temperature is room temperature, platinum electrode is cathode, pretreated Ti-Ta-Cu alloy is anode, constant voltage is 1-10V, current is 0.001-0.01A, and time is 30-180min.

[0024] Preferably, during the electrochemical gradient dealloying in step (2), the ratio of the amount of electrolyte to the surface area of ​​the pre-treated Ti-Ta-Cu alloy is 50-500 mL: 100-1000 mm 2 .

[0025] Preferably, the temperature of the electrochemical gradient dealloying in step (2) is room temperature, which is 20-35°C.

[0026] Preferably, during the electrochemical gradient dealloying process in step (2), the stirring speed of the electrolyte is 100 to 300 rpm.

[0027] Preferably, the electrochemical gradient dealloying in step (2) is followed by rinsing with water and then ultrasonication in anhydrous ethanol for 5 to 20 minutes.

[0028] The present invention provides a micro-nano porous Ti-Ta-Cu material with excellent functionality, which is prepared by the above preparation method.

[0029] In the micro-nano porous material, the micron pore diameter is about 1 to 5 μm, the nano pore diameter is 15 to 60 nm, and the pore depth is between 1 and 5 μm.

[0030] This study uses a simultaneous electrochemical dealloying and oxidation strategy to prepare a Ti-Ta-Cu material with a micro-nanoporous surface. Electrochemical anodic oxidation combined with dealloying, treated at a specific voltage and time, creates a surface micro-nanoporous composite structure. This structure is composed of interwoven nanoscale pores and micron-scale pores, covered with a CuO / Ta2O5 composite oxide layer. This method significantly improves the material's corrosion resistance and surface bioactivity while maintaining high biocompatibility, making it suitable for harsh environments such as marine engineering and biomedical implants.

[0031] The present invention provides the use of the above-mentioned micro-nano porous Ti-Ta-Cu material with excellent functionality in the preparation of biomedical devices.

[0032] Preferably, the biomedical device is an orthopedic implant, a dental prosthesis, and a cardiovascular stent.

[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0034] 1) The porous layer of the present invention is in situ bonded to the Ti-Ta-Cu substrate through a "surface ingrowth" mode, with no interface defects and better bonding strength than anodized coatings. It also has antibacterial and osteogenic dual functions: Antibacterial: CuO particles embedded in the nanopores slowly release Cu 2+The 24-hour antibacterial rate against Staphylococcus aureus reaches 99.3%; osteogenic activity: micron pores (2-5μm) promote the directional migration and differentiation of osteoblasts; implantation safety: the thickness of the porous layer is 1-5μm and controllable, avoiding stress concentration caused by excessively thick coating, and is suitable for the repair of load-bearing bone defects.

[0035] 2) This invention achieves in-situ bonding of the porous layer to the substrate through electrochemical treatment. This process is simple and efficient (taking less than 3 hours) and is suitable for complex implantable devices (such as porous scaffolds, porous bone screws, porous bone rods, and porous patches). The porous structure reduces the elastic modulus and mitigates the stress shielding effect.

[0036] 3) The comprehensive performance of the porous layer of the present invention far exceeds that of similar materials. In terms of corrosion resistance, the passivation range in simulated body fluid (SBF) is extended to 1.6V (compared to 0.8V for traditional Ti-Ta alloys). In terms of anti-bacterial adhesion, the adhesion rate of Staphylococcus aureus on the surface is reduced. In terms of bone ingrowth advantage, the bone ingrowth rate is increased compared with porous titanium with the same pore size, thanks to the osteoconductivity of Ta2O5 and the angiogenesis-promoting effect of CuO.

[0037] 4) Environmentally friendly process: Low-concentration acid is used, and waste liquid is easy to handle, meeting the requirements of green manufacturing. The composite layer with high corrosion resistance and antibacterial function breaks through the bottleneck of existing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is the SEM image of the micro-nanoscale gradient porous structure prepared in Example 1 of the present invention.

[0039] Figure 2 This is the SEM image of the micro-nanoscale gradient porous structure prepared in Example 1 of the present invention.

[0040] Figure 3 This is the SEM image of the micro-nanoscale gradient porous structure prepared in Example 1 of the present invention.

[0041] Figure 4 SEM image of the micro-nanoscale gradient porous structure prepared in Example 2 of the present invention

[0042] Figure 5 This is the SEM image of the micron-scale gradient porous structure prepared in Comparative Example 1 of the present invention.

[0043] Figure 6 This is the SEM image of the micron-scale gradient porous structure prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be described in further detail below with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

[0045] In the examples of the present invention, if the specific conditions are not specified, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. All raw materials and reagents used without specifying the manufacturer are conventional products that can be purchased from the market.

[0046] Example 1

[0047] Step 1: Alloy melting and sample preparation, raw material ratio: weigh high-purity titanium particles (99.99%), tantalum particles (99.95%), and copper particles (99.9%) according to the mass fraction of Ti-74%, Ta-25%, and Cu-1%. Vacuum arc melting: place the mixed raw materials in a water-cooled copper crucible, with a current of 220A, in a vacuum arc melting furnace (vacuum degree ≤ 1×10 -4 The alloy was melted four times in an argon atmosphere (Pa) to ensure uniform composition and obtain a dense Ti74-Ta25-Cu1 alloy ingot. Sample processing: The alloy ingot was processed into a block sample of 10 mm × 10 mm × 3 mm by wire cutting, with a surface roughness Ra < 0.1 μm.

[0048] Step 2: Preparation of electrolyte components and proportions: the volume fraction of concentrated nitric acid (commercially available) is 6%, the volume fraction of hydrofluoric acid is 4%, and the balance is deionized water.

[0049] Step 3: Sample pretreatment, surface grinding and polishing: Use 200#, 500#, 1000#, and 2000# silicon carbide sandpaper to grind the sample surface step by step; perform mirror polishing, cleaning, and drying; place in a vacuum drying oven and dry at 60℃ for 60 minutes.

[0050] Step 4. Electrochemical dealloying treatment equipment and parameters: Electrochemical workstation: sample as working electrode, platinum sheet as counter electrode; voltage: 3 V (constant potential mode); current density: 0.004 A / cm 2 ; Time: 60min; Electrolyte dosage: 50mL / 100mm 2 (Surface area of ​​sample) Process control: The electrolyte temperature was maintained at 25±1°C and magnetic stirring (200 rpm) was used to ensure uniform mass transfer.

[0051] Step 5. Post-treatment and characterization: Cleaning and drying: After dealloying, the sample was rinsed with distilled water three times, immersed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, and vacuum dried at 60° C. for 60 minutes to obtain a surface micro-nano gradient porous structure sample.

[0052] Step 6. Electrochemical performance test Test conditions: electrolyte: simulated body fluid (SBF, pH=7.4); temperature: 37±0.5° C. (constant temperature in a water bath); test method: potentiodynamic polarization curve, electrochemical impedance spectroscopy.

[0053] Step 7. Antibacterial Activity Evaluation Bacterial Species and Standards: Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 25922 were subjected to quantitative antibacterial experiments in accordance with ISO 22196.

[0054] After testing and analysis, it was found that after the Ti74-Ta25-Cu1 alloy was treated with electrochemical gradient dealloying, a multi-scale composite gradient porous structure was successfully constructed on its surface. The porous morphology features: the thickness of the micron-scale porous layer is 3μm, and the pore size is evenly distributed in the range of 2-4μm (average value is 3μm); dense nano-scale pores are distributed on the pore wall, with a pore size of 30-40nm (average value is 35nm), forming a hierarchical porous network. Improved corrosion resistance: The electrochemical polarization curve shows that in a simulated physiological environment (SBF solution, 37°C), the corrosion current density is reduced from 1.149μA / cm 2 Reduced to 0.84μA / cm 2 The corrosion potential shifted positively from -0.42V to -0.19V, expanding the passivation range. Antibacterial properties: Quantitative antibacterial testing based on ISO 22196 demonstrated 92% and 88% inhibition rates against Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 25922 within 6 hours, respectively, representing 30 and 70 percentage points higher than the untreated substrate (32% and 18%).

[0055] Example 2

[0056] Step 1: Alloy melting and sample preparation, raw material ratio: weigh high-purity titanium particles (99.99%), tantalum particles (99.95%), and copper particles (99.9%) according to the mass fraction of Ti-70%, Ta-25%, and Cu-5%. Vacuum arc melting: Place the mixed raw materials in a water-cooled copper crucible with a current of 220A in a vacuum arc melting furnace (vacuum degree ≤ 1×10 -4 The alloy was melted five times in an argon atmosphere (Pa) to ensure uniform composition and obtain a dense Ti70-Ta25-Cu5 alloy ingot. Sample processing: The alloy ingot was processed into a 10mm×10mm×3mm sheet sample by wire cutting, with a surface roughness Ra <0.1μm.

[0057] Step 2: Preparation of electrolyte components and proportions: the volume fraction of concentrated nitric acid (commercially available) is 6%, the volume fraction of hydrofluoric acid is 4%, and the balance is deionized water.

[0058] Step 3: Sample pretreatment, surface grinding and polishing: Use 200#, 500#, 1000#, and 2000# silicon carbide sandpaper to grind the sample surface step by step; perform mirror polishing, cleaning, and drying; place in a vacuum drying oven and dry at 60℃ for 60 minutes.

[0059] Step 4. Electrochemical dealloying treatment equipment and parameters: Electrochemical workstation (three-electrode system): sample as working electrode, platinum sheet as counter electrode; voltage: 3 V (potential constant mode); current density: 0.002 A / cm 2 ; Time: 60min; Electrolyte dosage: 50mL / 100mm 2 (Surface area of ​​sample) Process control: The electrolyte temperature was maintained at 25±1°C and magnetic stirring (200 rpm) was used to ensure uniform mass transfer.

[0060] Step 5. Post-treatment and characterization: Cleaning and drying: After dealloying, the sample was rinsed with distilled water three times, immersed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, and vacuum dried at 60° C. for 60 minutes to obtain a sample with a surface micro-nano porous structure.

[0061] Step 6. Electrochemical performance test Test conditions: electrolyte: simulated body fluid (SBF, pH=7.4); temperature: 37±0.5° C. (constant temperature in a water bath); test method: potentiodynamic polarization curve, electrochemical impedance spectroscopy.

[0062] After testing and analysis, the Ti70-Ta25-Cu5 alloy successfully constructed a multi-scale composite gradient porous structure on its surface after electrochemical gradient dealloying treatment. The porous morphology features: the thickness of the micron-scale porous layer is 2μm, and the pore size is evenly distributed in the range of 1-2μm (average value 1.5μm); dense nano-scale pores are distributed on the pore wall, with a pore size of 30-40nm (average value 35nm), forming a hierarchical porous network. Improved corrosion resistance: The electrochemical polarization curve shows that in a simulated physiological environment (SBF solution, 37°C), the corrosion current density is reduced from 1.09μA / cm 2 Reduced to 0.75μA / cm 2 The corrosion potential shifts positively from -0.35 V to -0.18 V, and the passivation range expands.

[0063] Example 3

[0064] Step 1: Alloy melting and sample preparation, raw material ratio: weigh high-purity titanium particles (99.99%), tantalum particles (99.95%), and copper particles (99.9%) according to the mass fraction of Ti-65%, Ta-25%, and Cu-10%. Vacuum arc melting: place the mixed raw materials in a water-cooled copper crucible, with a current of 220A, in a vacuum arc melting furnace (vacuum degree ≤ 1×10 -4The alloy was melted four times in an argon atmosphere (Pa) to ensure uniform composition and obtain a dense Ti65-Ta25-Cu10 alloy ingot. Sample processing: The alloy ingot was processed into a block sample of 10 mm × 10 mm × 3 mm by wire cutting, with a surface roughness Ra < 0.1 μm.

[0065] Step 2: Preparation of electrolyte components and proportions: the volume fraction of concentrated nitric acid (commercially available) is 6%, the volume fraction of hydrofluoric acid is 4%, and the balance is deionized water.

[0066] Step 3: Sample pretreatment, surface grinding and polishing: Use 200#, 500#, 1000#, and 2000# silicon carbide sandpaper to grind the sample surface step by step; perform mirror polishing, cleaning, and drying; place in a vacuum drying oven and dry at 60℃ for 60 minutes.

[0067] Step 4. Electrochemical dealloying treatment equipment and parameters: Electrochemical workstation (three-electrode system): sample as working electrode, platinum sheet as counter electrode; voltage: 3 V (potential constant mode); current density: 0.001 A / cm 2 ; Time: 60min; Electrolyte dosage: 50mL / 100mm 2 (Surface area of ​​sample) Process control: The electrolyte temperature was maintained at 25±1°C and magnetic stirring (200 rpm) was used to ensure uniform mass transfer.

[0068] Step 5. Post-treatment and characterization: Cleaning and drying: After dealloying, the sample was rinsed with distilled water three times, immersed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, and vacuum dried at 60° C. for 60 minutes to obtain a sample with a surface micro-nano porous structure.

[0069] Step 6. Electrochemical performance test Test conditions: electrolyte: simulated body fluid (SBF, pH=7.4); temperature: 37±0.5° C. (constant temperature in a water bath); test method: potentiodynamic polarization curve, electrochemical impedance spectroscopy.

[0070] After testing and analysis, the Ti65-Ta25-Cu10 alloy successfully constructed a multi-scale composite porous structure on its surface after electrochemical gradient dealloying treatment: porous morphology features: micron-scale porous layer thickness of 1μm, pore size uniformly distributed within the 1μm range; dense nano-scale pores with pore size of 10-20nm (average 15nm) distributed on the pore wall, forming a hierarchical porous network. Corrosion resistance is improved: electrochemical polarization curves show that in a simulated physiological environment (SBF solution, 37°C), the corrosion current density is reduced from 0.81μA / cm 2 Reduced to 0.64μA / cm 2 The corrosion potential shifts positively from -0.36 V to -0.16 V, and the passivation range expands.

[0071] Example 4

[0072] Step one, alloy smelting and sample preparation, raw material ratio: according to the mass fraction Ti-74%, Ta-25%, Cu-1% high purity titanium particles (99.99%), tantalum particles (99.95%) and copper particles (99.9%) are weighed. Vacuum arc melting: the mixed raw materials are placed in a water-cooled copper crucible, the current is 220A, and the alloy ingot is obtained by melting 6 times in a vacuum arc melting furnace (vacuum degree ≤1×10 -4 Pa, argon protection). Sample processing: the alloy ingot is processed into a 10mm×10mm×3mm block sample by wire cutting, and the surface roughness Ra is less than 0.1μm.

[0073] Step two, electrolyte preparation components and ratio: the volume fraction of concentrated nitric acid (marketed) is 4%, the volume fraction of hydrofluoric acid is 2%, and the rest is deionized water.

[0074] Step three, sample pretreatment, surface grinding and polishing: the sample surface is polished by using 200#, 500#, 1000#, 2000# silicon carbide sandpaper in turn; mirror polishing and cleaning, drying; placed in a vacuum drying oven, 60℃ drying for 60min.

[0075] Step four, electrochemical dealloying treatment equipment and parameters: electrochemical workstation: the sample is the working electrode, and the platinum sheet is the counter electrode; voltage: 3V; current density: 0.003A / cm 2 ; time: 60min; electrolyte dosage: 50mL / 100mm 2 (sample surface area). Process control: the electrolyte temperature is maintained at 25±1℃, and magnetic stirring (200rpm) ensures uniform mass transfer.

[0076] Step five, post-treatment and characterization cleaning and drying: after dealloying, the sample is washed with distilled water for 3 times, immersed in anhydrous ethanol for ultrasonic cleaning for 10min; 60℃ vacuum drying for 60min, to obtain a sample with a surface micro-nano porous structure.

[0077] Step six, electrochemical performance test test conditions: electrolyte: simulated body fluid (SBF, pH=7.4); temperature: 37±0.5℃; test method: potentiodynamic polarization curve, electrochemical impedance spectroscopy.

[0078] Step seven, antibacterial performance evaluation bacteria and standards: Staphylococcus aureus (Staphylococcus aureus) ATCC 6538, Escherichia coli (Escherichia coli) ATCC 25922, quantitative bacteriostatic experiment according to ISO 22196 standard.

[0079] After testing and analysis, it was found that after the Ti74-Ta25-Cu1 alloy was treated with electrochemical gradient dealloying, a multi-scale composite porous structure was successfully constructed on its surface. The porous morphology features: the thickness of the micron-scale porous layer is 2μm, and the pore size is evenly distributed in the range of 2-4μm (average value is 3μm); dense nano-scale pores are distributed on the pore wall, with a pore size of 25-40nm (average value is 30nm), forming a hierarchical porous network. Improved corrosion resistance: The electrochemical polarization curve shows that in a simulated physiological environment (SBF solution, 37°C), the corrosion current density is reduced from 1.136μA / cm 2 Reduced to 0.93μA / cm 2 The corrosion potential shifted positively from -0.44V to -0.35V, expanding the passivation range. Antibacterial properties: Quantitative antibacterial testing based on ISO 22196 demonstrated 90% and 85% inhibition rates against Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 25922 within 6 hours, respectively, representing 30 and 50 percentage points improvements over the untreated substrate.

[0080] Comparative Example 1

[0081] Step 1: Alloy melting and sample preparation, raw material ratio: weigh high-purity titanium particles (99.99%), tantalum particles (99.95%), and copper particles (99.9%) according to the mass fraction of Ti-70%, Ta-25%, and Cu-5%. Vacuum arc melting: place the mixed raw materials in a water-cooled copper crucible, with a current of 220A, in a vacuum arc melting furnace (vacuum degree ≤ 1×10 -4 The alloy was melted five times in an argon atmosphere (Pa) to ensure uniform composition and obtain a dense Ti70-Ta25-Cu5 alloy ingot. Sample processing: The alloy ingot was processed into a 10mm×10mm×3mm sheet sample by wire cutting, with a surface roughness Ra <0.1μm.

[0082] Step 2: Preparation of electrolyte components and proportions: the volume fraction of concentrated nitric acid (commercially available) is 2%, the volume fraction of hydrofluoric acid is 1%, and the balance is deionized water.

[0083] Step 3: Sample pretreatment, surface grinding and polishing: Use 200#, 500#, 1000#, and 2000# silicon carbide sandpaper to grind the sample surface step by step; perform mirror polishing, cleaning, and drying; place in a vacuum drying oven and dry at 60℃ for 60 minutes.

[0084] Step 4. Electrochemical dealloying treatment equipment and parameters: Electrochemical workstation: sample as working electrode, platinum sheet as counter electrode; voltage: 3 V (constant potential mode); current density: 0.001 A / cm 2; Time: 60min; Electrolyte dosage: 50mL / 100mm 2 (Surface area of ​​sample) Process control: The electrolyte temperature was maintained at 25±1°C and magnetic stirring (200 rpm) was used to ensure uniform mass transfer.

[0085] Step 5. Post-treatment and characterization: Cleaning and drying: After dealloying, the sample was rinsed with distilled water three times, immersed in anhydrous ethanol for ultrasonic cleaning for 10 minutes, and vacuum dried at 60° C. for 60 minutes to obtain a sample with a surface micron porous structure.

[0086] After testing and analysis, it was found that after electrochemical gradient dealloying treatment, a micron porous structure was successfully constructed on the surface of Ti70-Ta25-Cu5 alloy. Figure 5 、 Figure 6 , explain and embodiment 2 (attached Figure 4 ), changing the concentration of the acid in the electrolyte solution will lead to changes in the constructed pore structure. The electrolyte conditions of Comparative Example 1 cannot obtain the multi-scale composite gradient (nano-micrometer) porous structure described in Example 2.

[0087] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing micro-nano porous Ti-Ta-Cu material, characterized in that: The following steps are involved: (1) Ti, Ta, and Cu raw materials are mixed in proportion, and smelted to completely melt the raw materials and mix them evenly to obtain a Ti-Ta-Cu alloy ingot; (2) The Ti-Ta-Cu alloy ingot is pretreated and then electrochemically gradient dealloyed in an electrolyte containing HF and HNO3 to obtain a micro-nano porous Ti-Ta-Cu material.

2. The preparation method according to claim 1, characterized in that In the Ti-Ta-Cu alloy ingot of step (1), the mass percentage content of each element is: Cu 1-10%, Ta 15-30%, and the balance is Ti; Furthermore, in the Ti-Ta-Cu alloy ingot, the mass percentage content of each element is: Cu 1-10%, Ta 25%, and the balance is Ti.

3. The preparation method according to claim 1 or 2, characterized in that In the electrolyte containing HF and HNO3 in step (2), the volume proportion of HF is 2-6%; the volume proportion of concentrated HNO3 is 2-10%, and the balance is water.

4. The preparation method according to claim 3, characterized in that In the electrolyte containing HF and HNO3 in step (2), the volume proportion of HF is 2-4%; the volume proportion of concentrated HNO3 is 4-6%, and the balance is water.

5. The preparation method according to claim 1 or 2, characterized in that The electrochemical gradient dealloying process in step (2) is as follows: the temperature is room temperature, the platinum electrode is the cathode, the pre-treated Ti-Ta-Cu alloy is connected to the anode, the constant voltage is 1-10V, the current is 0.001-0.01A, and the time is 30-180min.

6. The preparation method according to claim 1, characterized in that: During the electrochemical gradient dealloying in step (2), the ratio of the amount of electrolyte to the surface area of ​​the pre-treated Ti-Ta-Cu alloy is 50-500 mL: 100-1000 mm 2 ; And / or, the temperature of the electrochemical gradient dealloying in step (2) is room temperature, and the room temperature is 20-35° C.; And / or, during the electrochemical gradient dealloying process in step (2), the stirring speed of the electrolyte is 100 to 300 rpm.

7. The preparation method according to claim 1, characterized in that: The Ti, Ta, and Cu raw materials in step (1) are materials in at least one of the shapes of particles, fragments, and chips corresponding to Ti, Ta, and Cu, respectively; And / or, the process parameters of the smelting in step (1) are: current 220-280A, carried out under inert protective atmosphere, using a vacuum arc melting furnace for 4-6 times, and a vacuum degree of 5×10 -3 ~1×10 -2 Pa, to obtain an alloy ingot with uniform composition.

8. The preparation method according to claim 1, characterized in that: The pre-treatment in step (2) includes cutting the Ti-Ta-Cu alloy ingot into blocks, and then sequentially performing fine grinding and polishing, ultrasonication, drying, and sealing treatments; and / or, the block size is 10×10×3 to 20×20×8 mm; And / or, the fine grinding refers to fine grinding with 200-2000# sandpaper; the ultrasonication refers to ultrasonication in anhydrous ethanol for 5-20 minutes; and the drying refers to drying at 45-55° C. for 3-6 hours.

9. A micro-nano porous Ti-Ta-Cu material prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the micro-nano porous Ti-Ta-Cu material according to claim 9 in the preparation of biomedical devices.

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