Antibacterial titanium-copper-zinc alloy powder and preparation method thereof, and preparation method of antibacterial titanium-copper-zinc alloy

Abstract

The invention relates to antibacterial titanium-copper-zinc alloy powder and a preparation method thereof, and a preparation method of an antibacterial titanium-copper-zinc alloy, and belongs to the technical field of biomedical metal materials. The antibacterial titanium-copper-zinc alloy powder is prepared from, by mass, 3.0%-6.0% of Cu, 0.5%-3.0% of Zn and the balance Ti and inevitable impurities. The selective laser melting technology is adopted for conducting forming treatment on the antibacterial titanium-copper-zinc alloy powder, the antibacterial titanium-copper-zinc alloy is obtained, the microstructure of the obtained alloy is composed of an alpha-Ti phase and a dispersed Ti2Cu phase, the excellent mechanical property and antibacterial property are achieved, the tensile strength ranges from 890 MPa to 1350 MPa, the percentage elongation after fracture ranges from 3.5% to 17.5%, and the antibacterial rate to staphylococcus aureus reaches 93.6%. The method is suitable for manufacturing prostheses such as dental implants and denture supports, and postoperative infection is effectively prevented and controlled while the service reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of biomedical metal materials and additive manufacturing technology, specifically to an antibacterial titanium-copper-zinc (Ti-Cu-Zn) alloy powder and its preparation method for dental additive manufacturing (3D printing), and a method for preparing the antibacterial titanium-copper-zinc alloy. Furthermore, this alloy is mainly used to manufacture clinical oral restorations and implants, such as dental implants, crowns, bridges, and denture frameworks. Background Technology

[0002] Titanium and titanium alloys are widely recognized as ideal materials for dental restorations due to their excellent biocompatibility, high specific strength, and good corrosion resistance. Among them, Ti-6Al-4V (TC4) alloy has dominated the dental implant market for decades thanks to its outstanding comprehensive mechanical properties. However, with the accumulation of clinical application experience, the potential biosafety issues of TC4 alloy have gradually become apparent: the aluminum (Al) and vanadium (V) elements it contains have been shown to gradually release during long-term in vivo service, potentially causing toxicity to surrounding tissues and even triggering adverse neurological reactions. This has prompted the industry to seek aluminum- and vanadium-free titanium alloy systems with higher biosafety.

[0003] Besides biocompatibility, the inherent "bioinertness" of traditional titanium alloys leads to a lack of antibacterial properties, becoming another key drawback in dental applications. The oral environment is densely populated with microorganisms, and bacteria easily adhere to and proliferate on implant surfaces, forming biofilms that can cause infections such as peri-implantitis, significantly impacting the long-term survival rate of restorations. Therefore, developing novel dental titanium alloys that combine excellent mechanical properties with inherent antibacterial characteristics is of significant clinical importance.

[0004] In terms of alloying modification, the introduction of copper (Cu) and zinc (Zn) provides a feasible path to improve the overall performance of titanium alloys. Cu can impart significant antibacterial properties to titanium alloys, and this is achieved through solid solution strengthening and precipitation. While Cu can improve material strength, excessive addition can impair plasticity. Zn, as a bio-friendly element, can not only strengthen the titanium matrix through solid solution but also refine the grain structure, effectively improving the alloy's ductility and toughness. Simultaneously, Zn itself possesses certain antibacterial activity and can synergistically enhance the antibacterial effect with Cu. By rationally proportioning the content of Cu and Zn, it is hoped that synergistic optimization of mechanical properties and antibacterial properties can be achieved.

[0005] Currently, additive manufacturing technology, especially selective laser melting (SLM), has become an important means of preparing complex dental restorations. However, combining Ti-Cu-Zn alloys with SLM technology still faces key bottlenecks: traditional powder preparation processes make it difficult to achieve a highly uniform distribution of Cu and Zn elements in titanium powder, leading to component segregation, uneven microstructure, and performance fluctuations during the printing process, which seriously affects the forming quality and functional reliability of the restoration.

[0006] In summary, there is currently a lack of dental titanium alloy materials that can simultaneously meet the requirements of high biocompatibility, excellent mechanical properties, stable antibacterial characteristics, and good adaptability to SLM processes. Breakthroughs are urgently needed through innovation in composition design and preparation processes. Summary of the Invention

[0007] This invention aims to address the significant challenges faced by existing dental titanium-based materials in clinical applications and additive manufacturing (SLM) processes. Specifically, pure titanium (Pure Ti) is limited in its application in long-term high-stress load-bearing areas due to its relatively insufficient strength and hardness; while the widely used Ti-6Al-4V alloy, although possessing high strength, has the fatal flaws of potentially toxic elements (Al / V) and a lack of antibacterial ability, making it highly susceptible to peri-implantitis. Therefore, the purpose of this invention is to provide a dental antibacterial titanium-copper-zinc alloy powder and its preparation method, which are non-toxic, possess excellent comprehensive mechanical properties (high strength, high toughness), have highly efficient antibacterial functions, and are suitable for SLM forming, thereby overcoming the shortcomings of existing materials and processes and providing a reliable solution for high-performance dental restorations.

[0008] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of the present invention provides an antibacterial titanium-copper-zinc alloy powder, the chemical composition of which, by mass percentage, includes: 3.0% to 6.0% copper, 0.5% to 3.0% zinc, with the balance being titanium and unavoidable impurities.

[0009] Furthermore, the antibacterial titanium-copper-zinc alloy powder has a core-shell structure; the core-shell structure has titanium powder as the core and Zn and Cu layers sequentially coated on the surface of the core as the shell; the particle size of the antibacterial titanium-copper-zinc alloy powder is 15-53 μm.

[0010] Compared with traditional dental titanium alloy powders, the antibacterial titanium-copper-zinc alloy powder provided by this invention has the advantages of simultaneously improving printing adaptability, forming accuracy, and antibacterial performance. Specifically, the powder composition of the antibacterial titanium-copper-zinc alloy powder provided by this invention is perfectly adapted to the SLM process. Dental restorations (such as implants and denture frameworks) printed from it have high forming accuracy, and the antibacterial metal elements are uniformly dispersed in the components.

[0011] A second aspect of this invention provides a method for preparing antibacterial titanium-copper-zinc alloy powder, comprising the following steps: (1) Dissolve C4H6O4Zn in deionized water to prepare zinc salt sol; (2) While continuously stirring the zinc salt sol, add titanium powder and wait for it to disperse evenly. Then, add 0.05 mol / L sodium hydroxide solution dropwise to adjust the pH of the sol system to 9. Stop adding sodium hydroxide solution dropwise and react for 80-120 min. (3) Heat the sol obtained in step (2) in a water bath. Stop stirring after the sol has reached the gel state, and then dry it to obtain the first precursor powder. (4) Place the first precursor powder in a tube furnace and introduce air into it. The mixed gas was heated to 300 ℃ in a tube furnace at a rate of 5 ℃ / min, held at that temperature for 2 h, and then cooled with the furnace to obtain titanium-zinc composite powder; the titanium-zinc composite powder is a core-shell structure with titanium powder as the core and a Zn layer covering the surface of the titanium powder as the shell. (5) Dissolved in deionized water, a copper salt sol was prepared. (6) While the copper salt sol is being continuously stirred, titanium-zinc composite powder is added. After it is evenly dispersed, 0.05 mol / L ammonia solution is added dropwise to adjust the pH of the sol system to 6. The reaction is then carried out for 80-120 min. (7) Heat the sol obtained in step (6) in a water bath. Stop stirring after the sol has reached the gel state, and then dry it to obtain the second precursor powder. (8) Place the second precursor powder in a tube furnace and introduce air into it. The mixed gas is heated to 300 ℃ at a rate of 5 ℃ / min, held at that temperature for 2 h, and then cooled in the furnace to obtain antibacterial titanium-copper-zinc alloy powder; wherein, the antibacterial titanium-copper-zinc alloy powder, by mass percentage, comprises: copper 3.0%~6.0%, zinc 0.5%~3.0%, with the balance being titanium and unavoidable impurities.

[0012] Compared with traditional processes for preparing titanium-copper-zinc alloy powder, the method for preparing antibacterial titanium-copper-zinc alloy powder provided by this invention has the following advantages: This invention solves the challenge of synergistic effects between the dispersibility and functionality of antibacterial elements: Compared to the poor sphericity and segregation issues caused by traditional mechanical mixing methods, and the severe volatilization and segregation problems associated with atomization methods, the two-stage sol-gel method employed in this invention (the first sol-gel method includes steps 1 to 4; the second sol-gel method includes steps 5 to 8) fully leverages its advantages in component control and uniformity, achieving quantitative, uniform, and controllable coating of Zn and Cu on the surface of titanium powder. This process not only significantly improves the component uniformity and microstructure consistency of the composite powder but also perfectly preserves the inherent high sphericity of titanium powder, thus obtaining a composite powder that combines high purity, high sphericity, and ideal flowability.

[0013] The third aspect of the present invention provides a method for preparing an antibacterial titanium-copper-zinc alloy, comprising the following steps: using selective laser melting technology to form the antibacterial titanium-copper-zinc alloy powder described above to obtain the antibacterial titanium-copper-zinc alloy.

[0014] Furthermore, the molding process includes: (1) In an inert gas protected environment, antibacterial titanium-copper-zinc alloy powder with the above-mentioned raw material composition is spread on the substrate to form a powder layer; (2) Based on the three-dimensional model slice data of the dental restoration, the powder layer is melted by selective laser scanning; (3) Repeat the above powder spreading and laser selective scanning melting steps layer by layer until a dense titanium-copper-zinc alloy is produced.

[0015] Furthermore, the process parameters for the laser selective scanning melting are: laser power 160~260 W, scanning speed 800~1500 mm / s, powder layer thickness 30 μm, and scanning spacing 65~105 μm.

[0016] Furthermore, the laser power is 200~250 W, and the scanning speed is 1000~1500 mm / s.

[0017] Furthermore, the microstructure of the prepared antibacterial titanium-copper-zinc alloy includes an α-Ti phase and diffusely distributed Ti2Cu intermetallic compounds.

[0018] Furthermore, the prepared antibacterial titanium-copper-zinc alloy has the following properties: tensile strength not less than 890 MPa; elongation after fracture not less than 3.5%; and antibacterial rate against Staphylococcus aureus greater than 93.6%.

[0019] Furthermore, the prepared antibacterial titanium-copper-zinc alloy is used as a dental restoration, which is applied in the preparation of dental implants, fixed restorations, removable denture frameworks, or orthodontic appliances.

[0020] Compared with traditional dental titanium alloys, the antibacterial titanium-copper-zinc alloy prepared in this invention has the following advantages: 1. Collaborative Innovation in Composition Design: Through the scientific ratio of Cu and Zn elements, synergistic optimization of performance is achieved. The addition of Cu endows the alloy with strong and long-lasting antibacterial properties, and significantly improves strength through solid solution strengthening and precipitation of nano-sized Ti2Cu phase; the addition of Zn not only contributes to solid solution strengthening, but more importantly, effectively improves the plasticity and toughness of the alloy by refining the grain structure, offsetting the brittleness tendency that may be caused by the addition of Cu. This alloy system does not contain toxic elements such as Al and V, and has high biosafety.

[0021] 2. Excellent Mechanical and Antibacterial Properties: The alloy prepared from the antibacterial titanium-copper-zinc alloy powder provided by this invention, after being formed using SLM technology, can achieve different strength-plasticity matches according to the composition adjustment: tensile strength ranges from 890 to 1350 MPa, and elongation after fracture ranges from 3.5% to 17.5%. Simultaneously, it exhibits highly efficient killing ability against common oral pathogens such as Staphylococcus aureus, with an antibacterial rate exceeding 93.6% (up to 99.7%), and its overall performance is significantly superior to that of traditional Ti-6Al-4V alloys.

[0022] 3. Strong process adaptability: The specific component range designed in this invention, combined with optimized SLM process parameters, is conducive to obtaining a uniform and fine-grained structure during the SLM process, effectively avoiding forming defects caused by element segregation, and enabling the stable manufacture of complex dental restorations with different performance characteristics according to clinical needs.

[0023] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0024] Figure 1 The images shown are SEM images and corresponding EDS spectra of the antibacterial titanium-copper-zinc alloy powder prepared in Example 1 of this invention; (a) SEM image of the antibacterial titanium-copper-zinc alloy powder; (b) EDS spectra of Ti element in the antibacterial titanium-copper-zinc alloy powder; (c) EDS spectra of Cu element in the antibacterial titanium-copper-zinc alloy powder; (d) EDS spectra of Zn element in the antibacterial titanium-copper-zinc alloy powder. Figure 2 This is a SEM image of the microstructure of the antibacterial titanium-copper-zinc alloy sample in the printed state in Example 2 of the present invention; Figure 3 The XRD pattern of the antibacterial titanium-copper-zinc alloy prepared in Example 2 of this invention; Figure 4 The engineering stress-strain curves of the antibacterial titanium-copper-zinc alloys prepared in Examples 2 and 3 of this invention are shown. Figure 5 The image shows the colony growth of the antibacterial titanium-copper-zinc alloy prepared in Example 2 of this invention after co-culturing with Staphylococcus aureus for 24 hours. Figure 6 The colony growth of the Ti-6Al-4V printed sample of Comparative Example 1 after co-culturing with Staphylococcus aureus for 24 hours is shown. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] The present invention provides an antibacterial titanium-copper-zinc alloy powder, the chemical composition of which, by mass percentage, includes: 3.0%~6.0% copper, 0.5%~3.0% zinc, and the balance being titanium and unavoidable impurities.

[0027] The pretreatment of Ti-Cu-Zn alloy powder includes the following steps: drying the Ti-Cu-Zn alloy powder at 60~80℃ for 2~4 hours to remove the moisture adsorbed on the powder surface. After drying, it is cooled to room temperature under inert gas protection and then loaded into the feeding system of the SLM equipment.

[0028] In some possible embodiments, the antibacterial titanium-copper-zinc alloy powder has a core-shell structure; the core-shell structure has titanium powder as the core and Zn and Cu layers sequentially coated on the surface of the core as the shell; the particle size of the antibacterial titanium-copper-zinc alloy powder is 15–53 μm. Because the antibacterial titanium-copper-zinc alloy powder has a core-shell structure, it has good sphericity, making it suitable for selective laser melting printing.

[0029] The antibacterial titanium-copper-zinc alloy powder provided by this invention enables simultaneous improvement in printing adaptability, forming accuracy, and antibacterial performance, and is perfectly compatible with SLM (Self-Made Dental Lattice) processes. Dental restorations (such as implants and prosthesis frameworks) printed with this powder exhibit high forming accuracy, and the antibacterial metallic elements are uniformly dispersed throughout the components. This material demonstrates excellent comprehensive performance: tensile strength reaches 890-1350 MPa, elongation after fracture is 3.5-17.5%, and the antibacterial rate against common oral pathogens such as Staphylococcus aureus exceeds 93.6%, while completely avoiding the risks associated with toxic elements such as Al and V. This provides a crucial material basis for manufacturing high-performance, highly reliable customized antibacterial dental restorations, possessing significant clinical application value and promising prospects for widespread application.

[0030] In some possible embodiments, the mass percentage of copper is 3.0% to 5.0%.

[0031] In some possible embodiments, the zinc content is 0.8% to 1.5% by mass.

[0032] The present invention provides a method for preparing antibacterial titanium-copper-zinc alloy powder, comprising the following steps: (1) Dissolve C4H6O4Zn in deionized water to prepare zinc salt sol; (2) While continuously stirring the zinc salt sol, add titanium powder and wait for it to disperse evenly. Then, add 0.05 mol / L sodium hydroxide solution dropwise to adjust the pH of the sol system to 9. Stop adding sodium hydroxide solution dropwise and react for 80-120 min. (3) Heat the sol obtained in step (2) in a water bath. Stop stirring after the sol has reached the gel state, and then dry it to obtain the first precursor powder. (4) Place the first precursor powder in a tube furnace and introduce air into it. The mixed gas was heated to 300 ℃ in a tube furnace at a rate of 5 ℃ / min, held at that temperature for 2 h, and then cooled with the furnace to obtain titanium-zinc composite powder; the titanium-zinc composite powder has a core-shell structure with titanium powder as the core and a Zn layer covering the surface of the titanium powder as the shell.

[0033] (5) Dissolved in deionized water, a copper salt sol was prepared. (6) While the copper salt sol is being continuously stirred, titanium-zinc composite powder is added. After it is evenly dispersed, 0.05 mol / L ammonia solution is added dropwise to adjust the pH of the sol system to 6. The reaction is then carried out for 80-120 min. (7) Heat the sol obtained in step (6) in a water bath. Stop stirring after the sol has reached the gel state, and then dry it to obtain the second precursor powder. (8) Place the second precursor powder in a tube furnace and introduce air into it. The mixed gas is heated to 300 ℃ at a rate of 5 ℃ / min, held at that temperature for 2 h, and then cooled in the furnace to obtain antibacterial titanium-copper-zinc alloy powder; wherein, the antibacterial titanium-copper-zinc alloy powder, by mass percentage, comprises: copper 3.0%~6.0%, zinc 0.5%~3.0%, with the balance being titanium and unavoidable impurities.

[0034] Furthermore, the purity of the titanium powder is not less than 99.9 wt.%.

[0035] Furthermore, the concentration of zinc salt sol is 0.05–0.5 mol / L; the concentration of copper salt sol is 0.05–0.65 mol / L.

[0036] Furthermore, the stirring speed in steps (3) and (7) is 200–800 r / min, and the reaction temperature is 40–80℃.

[0037] The method for preparing antibacterial titanium-copper-zinc alloy powder provided by this invention solves the problem of synergistic effect between the dispersion and functionality of antibacterial elements. Compared with the problems of poor sphericity and easy segregation caused by traditional mechanical mixing methods, and the serious problems of element volatilization and segregation in atomization methods, the secondary sol-gel method used in this invention fully leverages its advantages in composition control and uniformity, achieving quantitative, uniform, and controllable coating of Zn and Cu on the surface of titanium powder. This process not only significantly improves the compositional uniformity and microstructure consistency of the composite powder, but also perfectly preserves the inherent high sphericity of titanium powder, thus obtaining a composite powder with high purity, high sphericity, and ideal flowability.

[0038] The present invention provides a method for preparing an antibacterial titanium-copper-zinc alloy, comprising the following steps: using selective laser melting technology to form the antibacterial titanium-copper-zinc alloy powder to obtain the antibacterial titanium-copper-zinc alloy.

[0039] The process of forming the aforementioned raw material using selective laser melting technology includes the following steps: printing the raw material under an inert atmosphere, with the system oxygen content controlled below 1000 ppm; preheating the printing platform to 50-100°C and holding it at that temperature for 20-40 minutes; and after antibacterial titanium-copper-zinc alloy printing, cooling under a protective atmosphere, separating the component from the substrate using wire cutting, and then performing powder removal and cleaning.

[0040] In some possible embodiments, the molding process includes: (1) In an inert gas protected environment, antibacterial titanium-copper-zinc alloy powder with the above-mentioned raw material composition is spread on the substrate to form a powder layer; (2) Based on the three-dimensional model slice data of the dental restoration, the powder layer is melted by selective laser scanning; (3) Repeat the above powder spreading and laser selective scanning melting steps layer by layer until a dense titanium-copper-zinc alloy is produced.

[0041] In some possible embodiments, the process parameters for the laser selective scanning melting are: laser power 160~260 W, scanning speed 800~1500 mm / s, powder layer thickness 30 μm, and scanning spacing 65~105 μm.

[0042] In some possible embodiments, the laser power is 200-250 W and the scanning speed is 1000-1500 mm / s.

[0043] In some possible embodiments, the microstructure of the prepared antibacterial titanium-copper-zinc alloy comprises an α-Ti phase and diffusely distributed Ti2Cu intermetallic compounds.

[0044] In some possible embodiments, the prepared antibacterial titanium-copper-zinc alloy has the following properties: tensile strength not less than 890 MPa; elongation after fracture not less than 3.5%; and antibacterial rate against Staphylococcus aureus greater than 93.6%.

[0045] In some possible embodiments, the prepared antibacterial titanium-copper-zinc alloy is a dental restoration, which is used in the preparation of dental implants, fixed restorations, removable denture frameworks, or orthodontic appliances.

[0046] The following examples illustrate the antibacterial titanium-copper-zinc alloy powder and its preparation method provided by the present invention, as well as the preparation method of the antibacterial titanium-copper-zinc alloy. It should be noted that, unless otherwise specified, the methods, reagents, and materials described in the following examples are all commercially available; and the experimental methods described are conventional methods unless otherwise specified.

[0047] Example 1 This embodiment provides a method for preparing antibacterial titanium-copper-zinc alloy powder, which includes the following steps: (1) Dissolve 1.5g of C4H6O4Zn in 20 mL of deionized water to prepare zinc salt sol; (2) While continuously stirring the zinc salt sol, add 50 g of spherical titanium powder (purity 99.9 wt.%, purchased from China Nonferrous Metals Holding Group Co., Ltd.), and mechanically stir at 400 r / min to make it evenly dispersed. Add 0.05 mol / L sodium hydroxide solution (dropping rate 0.05 mL / s) dropwise to adjust the pH value of the sol system to 9, then stop adding sodium hydroxide solution and react for 80-120 min. (3) Heat the sol obtained in step (2) in a water bath at 80 °C. Stop stirring when the sol is stirred to a gel state (the sol becomes a viscous, almost non-flowing paste), and then dry it to obtain the first precursor powder. (4) Place the first precursor powder in a tube furnace and introduce air into it. A mixed gas (volume ratio 1:1) was heated to 300 ℃ in a tube furnace at a rate of 5 ℃ / min, held at that temperature for 2 h, and then cooled with the furnace to obtain titanium-zinc composite powder. The titanium-zinc composite powder has a core-shell structure with titanium powder as the core and a Zn layer covering the surface of the titanium powder as the shell, and the Zn coating amount is 1 wt.%.

[0048] (5) Take 5.93 g of Dissolve in 20 mL of deionized water to prepare a copper salt sol; (6) While the copper salt sol is being continuously stirred, 50 g of titanium-zinc composite powder is added and mechanically stirred at 400 r / min to disperse it evenly. Then, 0.05 mol / L ammonia solution is added dropwise (dropping rate 0.05 mL / s) to adjust the pH of the sol system to 6 and react for 80-120 min. (7) Heat the sol obtained in step (6) in a water bath at 80 °C. Stop stirring after the sol has been stirred to a gel state, and then dry it to obtain the second precursor powder. (8) Place the second precursor powder in a tube furnace and introduce air into it. The mixed gas (volume ratio 1:1) was heated to 300 °C at a rate of 5 °C / min, held at that temperature for 2 h, and then cooled in the furnace to obtain antibacterial titanium-copper-zinc alloy powder with a Cu coating of 3 wt.%.

[0049] Depend on Figure 1 As can be seen from (bd), the Cu and Zn elements in the antibacterial titanium-copper-zinc alloy powder prepared in this embodiment are uniformly distributed on the surface of Ti powder, without significant enrichment or agglomeration.

[0050] Example 2 The antibacterial titanium-copper-zinc alloy powder provided in this embodiment has the following chemical composition by mass percentage: 3% copper, 1% zinc, with the balance being titanium and unavoidable impurities.

[0051] This embodiment provides a method for preparing an antibacterial titanium-copper-zinc alloy, comprising the following steps: 1. Raw material preparation: Select antibacterial titanium-copper-zinc alloy powder with a particle size distribution in the range of 15~53 μm, and ensure that the Cu and Zn elements in the antibacterial titanium-copper-zinc alloy powder are highly uniformly distributed in the Ti matrix, thus ensuring the compositional uniformity during the SLM forming process.

[0052] 2. Powder Pretreatment: The alloy powder is placed in a vacuum drying oven and dried at 60 ℃ for 3 hours to fully remove the moisture adsorbed on the surface of the alloy powder. After drying, it is cooled to room temperature under argon protection and then loaded into the powder feeding system of the SLM equipment.

[0053] 3. Selective Laser Melting Printing Process: The substrate is sandblasted to remove surface oil, dust, oxide film, and other impurities. After drying with alcohol, it is installed and leveled. Printing is performed under an inert atmosphere (Ar) to control the alloy powder. The system oxygen content is controlled below 1000 ppm to prevent oxidation of the titanium alloy during 3D printing. The preheating temperature of the printing platform is controlled at 50 ℃ for 30 min to reduce thermal stress and warping risk. The printing parameters are set as follows: laser power 200 W, scanning speed 1500 mm / s, scanning spacing 70 μm, layer height 30 μm, scanning strategy: rotational scanning, interlayer rotation angle 67°. Through layer-by-layer deposition, a metal block with dimensions of 30×30×30 mm is finally obtained.

[0054] 4. Post-printing processing and performance testing: After printing, the components are cooled to room temperature under argon protection. The components are separated from the substrate by wire EDM and processed into standard tensile specimens. The residual powder on the surface is removed by airflow cleaning and ultrasonic cleaning to obtain the final antibacterial titanium-copper-zinc alloy.

[0055] The resulting antibacterial titanium-copper-zinc alloy has a quasi-static tensile strength of 903±13 MPa, a yield strength of 694±10 MPa, an elongation after fracture of 17.5±0.8%, a Young's modulus of 118±2 GPa, a Vickers hardness of 348±15 HV, and excellent polishability.

[0056] Figure 2 This is a SEM image of the microstructure of the antibacterial titanium-copper-zinc alloy sample in the printed state in Example 2 of this invention. The results show that Ti2Cu is uniformly and diffusely distributed in the printed part, and no obvious defects such as pores or cracks are observed.

[0057] Figure 3 X-ray diffraction analysis of the antibacterial titanium-copper-zinc alloy prepared in this embodiment showed that the alloy mainly consists of α-Ti phase and Ti₂Cu intermetallic compounds. Due to the low solid solubility of Zn in the Ti matrix and its predominantly solid solution form, no obvious diffraction peaks of the titanium-zinc compounds were observed.

[0058] Figure 4 The engineering stress-strain curves of the antibacterial titanium-copper-zinc alloy prepared in this embodiment are shown. The results show that as the Cu content increases from 3% to 5%, the alloy strength increases significantly, but the plasticity decreases accordingly.

[0059] Figure 5The image shows the colony growth of the antibacterial titanium-copper-zinc alloy prepared in this embodiment after co-culturing with Staphylococcus aureus for 24 hours. The antibacterial rate was calculated to be 93.6% using the colony counting method, demonstrating the excellent antibacterial properties of the alloy. This is mainly attributed to the uniform distribution of Cu and Zn elements in the alloy and their continuous and controlled release in the physiological environment.

[0060] Example 3 This embodiment provides an antibacterial titanium-copper-zinc alloy, whose chemical composition, by mass percentage, includes: 5% copper, 1% zinc, with the balance being titanium and unavoidable impurities.

[0061] This embodiment provides a method for preparing an antibacterial titanium-copper-zinc alloy, comprising the following steps: 1. Raw material preparation: Select antibacterial titanium-copper-zinc alloy powder with a particle size distribution in the range of 15~53 μm, and ensure that the Cu and Zn elements in the antibacterial titanium-copper-zinc alloy powder are highly uniformly distributed in the Ti matrix, thus ensuring the compositional uniformity during the SLM forming process.

[0062] 2. Powder Pretreatment: The alloy powder is placed in a vacuum drying oven and dried at 60 ℃ for 3 hours to fully remove the moisture adsorbed on the powder surface. After drying, it is cooled to room temperature under argon protection and then loaded into the powder feeding system of the SLM equipment.

[0063] 3. Selective Laser Melting Printing Process: The substrate is sandblasted to remove surface oil, dust, oxide film, and other impurities. After drying with alcohol, it is installed and leveled. Printing is performed under an inert atmosphere (Ar) to control the alloy powder. The system oxygen content is controlled below 1000 ppm to prevent oxidation of the titanium alloy during 3D printing. The preheating temperature of the printing platform is controlled at 50 ℃ for 30 min to reduce thermal stress and warping risk. The parameters set during the printing process are: laser power 250 W, scanning speed 1200 mm / s, scanning spacing 70 μm, layer height 30 μm, scanning strategy: rotational scanning, interlayer rotation angle 67°. Through layer-by-layer deposition, a metal block with dimensions of 30×30×30 mm is finally obtained.

[0064] 4. Post-printing processing and performance testing: After printing, the components are cooled to room temperature under argon protection. Wire EDM is then used to separate the components from the substrate, and they are processed into standard tensile specimens. Residual powder on the surface is removed by airflow cleaning and ultrasonic cleaning to obtain the final antibacterial titanium-copper-zinc alloy.

[0065] The resulting antibacterial titanium-copper-zinc alloy has a quasi-static tensile strength of 1350±15 MPa, a yield strength of 1050±12 MPa, an elongation after fracture of 3.5±0.5%, a Young's modulus of 120±3 GPa, a Vickers hardness of 430±10 HV, and an antibacterial rate of 99.6%.

[0066] According to the stress-strain curve ( Figure 4 The results showed that the antibacterial titanium-copper-zinc alloy exhibited the highest strength level, with a tensile strength of approximately 1200 MPa, but its plasticity was significantly reduced compared to Ti-3Cu-1Zn.

[0067] Comparative Example 1 To investigate the antibacterial properties of the material, the antibacterial titanium-copper-zinc alloy prepared in Example 2 was set as the experimental group; the sample prepared by printing from Ti-6Al-4V powder under the same conditions was set as the control group; wherein, in the Ti-6Al-4V powder, (the mass ratio of Al to V is 6:4, for example, in this powder, the mass of Al is 6%, the mass of V is 4%, and the balance is titanium and unavoidable impurities).

[0068] Subsequently, the experimental group samples ( Figure 5 ) and control group samples ( Figure 6 The colony growth was observed after co-culturing with Staphylococcus aureus for 24 h.

[0069] The Staphylococcus aureus standard strain (ATCC 25923) was provided by the Microbiology Laboratory of Peking University First Hospital. First, 6 g of tryptone soybean broth (TSB) powder was weighed and placed in a flask, 200 ml of distilled water was added, and the mixture was stirred until completely dissolved to prepare TSB medium. After autoclaving, the medium was aliquoted and stored at 4 ℃ for later use. The standard strain was revived and subcultured three times on agar plates. A suitable amount of colonies was scraped off using a sterile swab and inoculated into physiological saline to prepare a bacterial suspension. The turbidity of the bacterial suspension was adjusted to 0.5 McFarland ratio (approximately 1.5 × 10⁻⁶) using an optical turbidimeter. 4 (CFU / ml), then serially diluted with TSB medium to obtain a concentration of 1.5 × 10⁻⁶ CFU / ml. 4 CFU / ml bacterial culture was prepared for subsequent experiments.

[0070] Place the printed samples in a 24-well plate, adding 700 μl of TSB medium to each well, ensuring the material is completely submerged. Then add 50 μl of the above bacterial suspension (1.5 × 10⁻⁶). 4The samples (CFU / ml) were incubated at 37 ℃ for 24 h. After the incubation time, the samples were removed and gently washed three times with phosphate-buffered saline (PBS). The washed samples were then placed in sterile centrifuge tubes containing 5 ml PBS and subjected to sonication (60 W, 20 min) to separate bacteria adhering to the material surface. The resulting bacterial suspension was collected for later use. The collected bacterial suspension was serially diluted, and 100 μl of the diluted solution was evenly spread on agar plates. After incubation for 24 hours, the colony count was counted, and the inhibition rate was calculated using the following formula:

[0071] Where R represents the inhibition rate and CFU represents colony forming units. The criterion is: R ≥ 90% indicates that the material has a strong bactericidal effect (WS / T 650—2019).

[0072] Depend on Figure 5 and Figure 6 The comparison shows that, compared with the control group Ti-6Al-4V, the antibacterial titanium-copper-zinc alloy prepared in Example 2 exhibits superior antibacterial properties, with an antibacterial rate as high as 93.6%.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An antibacterial titanium-copper-zinc alloy powder, characterized in that, Its chemical composition, by mass percentage, includes: copper 3.0% to 6.0%, zinc 0.5% to 3.0%, with the balance being titanium and unavoidable impurities.

2. The antibacterial titanium-copper-zinc alloy powder according to claim 1, characterized in that, The antibacterial titanium-copper-zinc alloy powder has a core-shell structure; the core-shell structure has titanium powder as the core and Zn and Cu layers sequentially coated on the surface of the core as the shell; the particle size of the antibacterial titanium-copper-zinc alloy powder is 15-53 μm.

3. A method for preparing antibacterial titanium-copper-zinc alloy powder, characterized in that, Includes the following steps: (1) Dissolve C4H6O4Zn in deionized water to prepare zinc salt sol; (2) While continuously stirring the zinc salt sol, add titanium powder and wait for it to disperse evenly. Then, add 0.05 mol / L sodium hydroxide solution dropwise to adjust the pH of the sol system to 9. Stop adding sodium hydroxide solution dropwise and react for 80-120 min. (3) Heat the sol obtained in step (2) in a water bath. Stop stirring after the sol has reached the gel state, and then dry it to obtain the first precursor powder. (4) Place the first precursor powder in a tube furnace and introduce air into it. A mixed gas was heated to 300 °C in a tube furnace at a rate of 5 °C / min, held at that temperature for 2 h, and then cooled with the furnace to obtain titanium-zinc composite powder. The titanium-zinc composite powder has a core-shell structure with titanium powder as the core and a Zn layer covering the surface of the titanium powder as the shell. (5) Dissolved in deionized water, a copper salt sol was prepared. (6) While the copper salt sol is being continuously stirred, titanium-zinc composite powder is added. After it is evenly dispersed, 0.05 mol / L ammonia solution is added dropwise to adjust the pH of the sol system to 6. The reaction is then carried out for 80-120 min. (7) Heat the sol obtained in step (6) in a water bath. Stop stirring after the sol has reached the gel state, and then dry it to obtain the second precursor powder. (8) Place the second precursor powder in a tube furnace and introduce air into it. The mixed gas is heated to 300℃ at a rate of 5℃ / min, held at that temperature for 2 hours, and then cooled in the furnace to obtain antibacterial titanium-copper-zinc alloy powder. The antibacterial titanium-copper-zinc alloy powder has the following chemical composition by mass percentage: copper 3.0%~6.0%, zinc 0.5%~3.0%, with the balance being titanium and unavoidable impurities.

4. A method for preparing an antibacterial titanium-copper-zinc alloy, characterized in that, The process includes the following steps: using selective laser melting technology to shape the antibacterial titanium-copper-zinc alloy powder as described in claim 1 or 3, or the antibacterial titanium-copper-zinc alloy powder prepared in claim 3, to obtain an antibacterial titanium-copper-zinc alloy.

5. The method for preparing the antibacterial titanium-copper-zinc alloy according to claim 4, characterized in that, The molding process includes: (1) In an inert gas protected environment, antibacterial titanium-copper-zinc alloy powder with the raw material composition of any one of claims 1 to 3 is spread on a substrate to form a powder layer; (2) Based on the three-dimensional model slice data of the dental restoration, the powder layer is melted by selective laser scanning; (3) Repeat the above powder spreading and laser selective scanning melting steps layer by layer until a dense titanium-copper-zinc alloy is produced.

6. The method for preparing the antibacterial titanium-copper-zinc alloy according to claim 5, characterized in that, The process parameters for laser selective scanning melting are: laser power 160~260 W, scanning speed 800~1500 mm / s, powder layer thickness 30 μm, and scanning spacing 65~105 μm.

7. The method for preparing the antibacterial titanium-copper-zinc alloy according to claim 6, characterized in that, The laser power is 200~250 W, and the scanning speed is 1000~1500 mm / s.

8. The method for preparing the antibacterial titanium-copper-zinc alloy according to claim 5, characterized in that, The microstructure of the prepared antibacterial titanium-copper-zinc alloy includes α-Ti phase and diffusely distributed Ti2Cu intermetallic compounds.

9. The method for preparing the antibacterial titanium-copper-zinc alloy according to claim 5, characterized in that, The prepared antibacterial titanium-copper-zinc alloy has the following properties: tensile strength not less than 890 MPa; elongation after fracture not less than 3.5%; and antibacterial rate against Staphylococcus aureus greater than 93.6%.

10. The method for preparing the antibacterial titanium-copper-zinc alloy according to any one of claims 4 to 9, characterized in that, The prepared antibacterial titanium-copper-zinc alloy is used as a dental restoration, which is applied in the preparation of dental implants, fixed restorations, removable denture frameworks or orthodontic appliances.

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