An antibacterial and corrosion-resistant Ti-based ternary alloy and its preparation method and application

Abstract

The present invention discloses an antibacterial and corrosion-resistant Ti-based ternary alloy and its preparation method and application. The alloy is a Ti-Ta-Cu alloy, and its element mass ratio is: Ti is 70-75wt%, Ta is 23-27wt%, Cu is 0.3-1.3wt%, and inevitable impurities are ≤0.01wt%. The preparation process of the alloy is: metal raw material powders including Ti, Ta and Cu are evenly mixed and then subjected to a smelting process to obtain a class of samples; the mechanical properties and chemical properties of the class of samples are tested, and when its comprehensive performance meets the ternary alloy design requirements, the data is recorded. Based on the excellent comprehensive performance of the alloy, it can be used as a biomedical skeleton material. While ensuring that the ternary alloy has excellent mechanical properties, it also gives the alloy excellent antibacterial and corrosion resistance. In addition, a certain proportion of Cu can not only kill bacteria in direct contact with the material, but free copper ions can also effectively inhibit the free bacteria from forming "surface competition" on the titanium-bone interface, effectively preventing the formation of bacterial biofilms.

Description

Technical Field

[0001] The present invention relates to a Ti-based ternary alloy, in particular to a Ti-based ternary alloy and a preparation method and application thereof, belonging to the technical field of biomedical materials. Background Art

[0002] Because titanium is similar to human bone and exhibits excellent biocompatibility and mechanical properties, titanium and its alloys are commonly used in the production and manufacturing of surgical implants and orthopedic devices. Titanium alloys can be classified into three categories based on their microstructure: α-type, α+β-type, and β-type titanium alloys. Currently, the materials commonly used in the biomedical field are still primarily α-type pure titanium and α+β-type Ti-6Al-4V alloys. However, some researchers have found that while Ti-6Al-4V alloys offer superior strength compared to pure titanium, the presence of Al and V in them is biotoxic. When titanium alloys containing V are implanted in patients for extended periods, V ions accumulate in various organs, potentially causing cancer and secondary damage. Furthermore, Al can accumulate in the body as aluminum salt compounds, leading to organ damage, bone disease, anemia, osteomalacia, and, in severe cases, neurological disorders such as Alzheimer's disease. The elastic modulus of pure titanium and Ti-6Al-4V alloy is much higher than that of bone. Due to the mismatch in elastic modulus between implants and bone, "stress shielding" is highly likely to occur, leading to functional degradation and absorption of surrounding bone tissue, which can cause implant loosening or fracture. Furthermore, these titanium and its alloys lack antibacterial properties, making them susceptible to postoperative infection. Therefore, there is an urgent need to develop medical titanium alloys with excellent mechanical properties, low elastic modulus, good biocompatibility, and superior antibacterial properties.

[0003] As an essential trace element in the human body, copper (Cu) has excellent biocompatibility and is a metal material with antibacterial properties. A sufficient concentration of copper ions can kill over 99% of bacteria within two hours. However, Cu is also a heavy metal, and its release through corrosion in the human body poses a risk of heavy metal poisoning. Furthermore, the loss of Cu due to irresistible friction and corrosion can also reduce its antibacterial properties at the implant site, leading to localized infection. Therefore, the market urgently needs an antibacterial, corrosion-resistant, and non-biotoxic medical alloy. Summary of the Invention

[0004] In response to the problems existing in the prior art, the first purpose of the present invention is to provide an antibacterial and corrosion-resistant Ti-based ternary alloy. Based on the synergistic effect between the various components, the alloy strictly limits the doping ratio of each metal element. While ensuring that the ternary alloy has excellent mechanical properties, it also gives the alloy excellent antibacterial and corrosion resistance. In particular, the strict control of the addition amount of the Cu element ensures that the alloy has appropriate antibacterial properties and avoids bacterial infection at the alloy implantation site. On the other hand, it also greatly reduces the biotoxicity to other normal cells at the implantation site.

[0005] A second objective of the present invention is to provide a method for preparing an antibacterial and corrosion-resistant Ti-based ternary alloy. This method, based on traditional smelting techniques, rapidly achieves uniform dispersion and forming of the alloy elements, effectively overcoming the difficulty in combining Ti and Ta due to their significant differences in melting points and densities. Furthermore, it promotes the formation of a β-eutectoid stabilization between Cu and Ta, further reducing the alloy's elastic modulus.

[0006] The third object of the present invention is to provide an application of an antibacterial and corrosion-resistant Ti-based ternary alloy as a biomedical skeleton material.

[0007] To achieve the above technical objectives, the present invention provides an antibacterial and corrosion-resistant Ti-based ternary alloy, wherein the ternary alloy is a Ti-Ta-Cu alloy, and its element mass ratio is: Ti is 70-75wt%, Ta is 23-27wt%, Cu is 0.3-1.3wt%, and unavoidable impurities are ≤0.01wt%.

[0008] As a preferred solution, the mass ratio of the elements in the Ti-Ta-Cu alloy is: Ti is 73-75wt%, Ta is 24-26wt%, Cu is 0.5-1.0wt%, and unavoidable impurities are less than 0.01wt%.

[0009] The present invention also provides a method for preparing an antibacterial and corrosion-resistant Ti-based ternary alloy, comprising:

[0010] 1) Metal raw material powders including Ti, Ta and Cu are uniformly mixed and then subjected to a smelting process to obtain a type of sample;

[0011] 2) Conduct mechanical and chemical property tests on a type of specimen. When its comprehensive performance meets the design requirements of the ternary alloy, record the data and obtain it.

[0012] As a preferred solution, the smelting process is as follows: the alloy raw materials are melted by vacuum arc melting, and then the alloy is turned over and melted after cooling, and the number of repetitions is ≥10.

[0013] As a preferred solution, the metal raw material powder needs to be polished and ultrasonically cleaned in sequence before mixing to remove organic pollutants on the raw material surface.

[0014] As a preferred solution, the vacuum arc melting process is as follows: the alloy raw materials are fed into the sample chamber, and when the vacuum degree reaches 5x10 -3 After Pa, argon gas was introduced until the pressure in the sample chamber reached 0.5 atm.

[0015] As a preferred solution, electromagnetic stirring is also required during the vacuum arc melting process, and the current is 3 to 4A.

[0016] As a preferred solution, during the vacuum arc melting process, the arc holding time is 100 to 120 seconds and the current is 300 to 450A.

[0017] As a preferred solution, the design requirements of the ternary alloy are: yield strength of 800-1200 MPa, elongation of 23-33%, and Young's modulus of 110-115 GPa.

[0018] The present invention also provides an application of an antibacterial and corrosion-resistant Ti-based ternary alloy as a biomedical skeleton material.

[0019] Ti has good biological properties and is a high-quality substrate for biomedical skeletons. Cu has excellent antibacterial properties. Ta is non-biotoxic, has excellent biocompatibility, and is very chemically stable in body fluid environments. However, the melting points and densities of Ti and Ta differ greatly, making it difficult to combine them, and the resulting alloys are not uniform. Although Cu has excellent antibacterial properties, it is also a heavy metal. When the free concentration in the human body environment is too high, there is a potential risk of heavy metal poisoning. The ternary alloy provided by the present invention strictly defines the ratio range between the three elements. It uses Ti as the substrate and incorporates a small amount of Ta and a trace amount of Cu. On the one hand, during the smelting process, the Ti is liquefied by melting and stirring to disperse and encapsulate the Ta element. During the smelting process, the Cu element and the Ti element are both in a liquid phase, forming a homogeneous dispersion, ensuring the dispersion and uniformity of Cu in the alloy. On the other hand, Cu and Ta elements can also form a β-type eutectoid stabilization, thereby reducing the elastic modulus of the ternary alloy.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are:

[0021] 1) The ternary alloy provided by the present invention, based on the synergistic effect between the various components, strictly limits the doping ratio of each metal element. While ensuring that the ternary alloy has excellent mechanical properties, it also gives the alloy excellent antibacterial and corrosion resistance. In particular, the strict control of the addition amount of the Cu element ensures that the alloy has appropriate antibacterial properties, avoiding bacterial infection at the alloy implantation site, and significantly reduces the biotoxicity to other normal cells at the implantation site.

[0022] 2) The preparation method provided by the present invention is based on traditional smelting technology, which can quickly achieve uniform dispersion and molding among the alloy elements, effectively overcoming the problem that Ti and Ta are difficult to combine due to the large difference in melting point and density. In addition, it also promotes the formation of β-type eutectoid stability of Cu and Ta elements, further reducing the elastic modulus of the alloy.

[0023] 3) In the ternary alloy provided by the present invention, the Cu element under the above-mentioned ratio requirements can not only kill bacteria that are in direct contact with the material, but also the free copper ions still have a killing effect on bacteria within a certain range around it, which can effectively inhibit the free bacteria from forming "surface competition" on the titanium-bone interface and effectively prevent the formation of bacterial biofilm. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Graph showing compression test data of Ti-Ta-Cu alloys according to Examples 1, 2, and 3 of the present invention;

[0025] Figure 2 Graph showing nanoindentation experimental data of Ti-Ta-Cu alloys according to Examples 1, 2, and 3 of the present invention;

[0026] Figure 3 1 is a bar graph of elastic modulus obtained from nanoindentation experiments of Ti-Ta-Cu alloys according to Examples 1, 2, and 3 of the present invention;

[0027] Figure 4 is a hardness histogram obtained from a Vickers hardness test of the Ti-Ta-Cu alloys of Examples 1, 2, and 3 of the present invention;

[0028] Figure 5 The Tafel curves of the Ti-Ta-Cu alloy and the Ti-6Al-4V alloy of Examples 1, 2 and 3 of the present invention obtained based on electrochemical experiments;

[0029] Figure 6 Compression test data of Ti-Ta-3.00Cu alloy and Ti-Ta-5.00Cu alloy of the present invention;

[0030] Figure 7Graph showing the hemolysis rate data of the Ti-Ta-Cu alloy and the Ti-6Al-4V alloy according to Examples 1, 2 and 3 of the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention. It should be understood that the specific embodiments described are intended only to illustrate the present application and are not intended to limit the present application.

[0032] In the examples of the present invention, if specific conditions are not specified, the reaction was carried out under 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 commercially. Unless otherwise specified, the reagents used in the examples can be purchased from conventional commercial sources.

[0033] The mechanical properties data test method in the following examples is as follows: a compression test is performed on a 4×4×6 mm sample using an MTS E45.305 universal testing machine. The initial strain rate of the test is 2.1×10 -4 s -1 The Vickers hardness of the sample was measured using an HDX-1000TMC Vickers hardness tester; the elastic modulus of the sample was measured using a Berkovich indenter on a TI950TRIBO nanoindentation testing device with a constant load of 80 mN.

[0034] Example 1

[0035] The chemical expression of the qualified product in the present invention is: Ti 74.50 Ta 25 Cu 0.50 , the product is abbreviated as: Ti-Ta-0.50Cu.

[0036] The preparation steps of Ti-Ta-0.50Cu biomedical alloy are as follows:

[0037] 1) Raw Material Preparation: The alloy smelting raw materials used in this invention are high-purity (>99.5%) Ti, Ta, and Cu particles, which are precisely weighed and proportioned according to their mass ratio using a balance with an accuracy of 0.001g. The prepared raw materials are then ultrasonically cleaned in industrial ethanol to remove organic contaminants from the material surface.

[0038] 2) Preparation of alloy: The raw materials prepared in step 1) are fed into a vacuum non-consumable smelting furnace, wherein Ti and Cu are placed at the bottom and Ta is placed at the top. The vacuum degree of the vacuum chamber of the vacuum smelting furnace is adjusted to 5x10 -3Pa, and then fill the furnace chamber with argon to half the atmospheric pressure. Repeat the vacuum purging and washing process for more than three times. Then start the vacuum smelting furnace to melt the alloy raw materials. The arc current is 380A. The melting is repeated for more than 10 times until the alloy is fully melted and uniformly melted. The melting time for each time is 100 seconds. After the alloy is fully melted and cooled, the Ti-Ta-0.50Cu biomedical alloy material is obtained.

[0039] Example 2

[0040] The chemical expression of the qualified product in the present invention is: Ti 74.25 Ta 25 Cu 0.75 , the product is abbreviated as: Ti-Ta-0.75Cu.

[0041] The preparation steps of Ti-Ta-0.75Cu biomedical alloy are as follows:

[0042] 1) Raw Material Preparation: The alloy smelting raw materials used in this invention are high-purity (>99.5%) Ti, Ta, and Cu particles, which are precisely weighed and proportioned according to their mass ratio using a balance with an accuracy of 0.001g. The prepared raw materials are then ultrasonically cleaned in industrial ethanol to remove organic contaminants from the material surface.

[0043] 2) Preparation of alloy: The raw materials prepared in step 1) are fed into a vacuum non-consumable smelting furnace, wherein Ti and Cu are placed at the bottom and Ta is placed at the top. The vacuum degree of the vacuum chamber of the vacuum smelting furnace is adjusted to 5x10 -3 Pa, and then fill the furnace chamber with argon to half the atmospheric pressure. Repeat the vacuum purging and purging process for more than three times. Then start the vacuum smelting furnace to melt the alloy raw materials. The arc current is 380A. The melting is repeated for more than 10 times until the alloy is fully melted and uniformly melted. Each melting time is 100 seconds. After the alloy is fully melted and cooled, the Ti-Ta-0.75Cu biomedical alloy material is obtained.

[0044] Example 3

[0045] The chemical expression of the qualified product in the present invention is: Ti 74.00 Ta 25 Cu 1.00 , the product is abbreviated as: Ti-Ta-1.00Cu.

[0046] The preparation steps of Ti-Ta-1.00Cu biomedical alloy are as follows:

[0047] 1) Raw Material Preparation: The alloy smelting raw materials used in this invention are high-purity (>99.5%) Ti, Ta, and Cu particles, which are precisely weighed and proportioned according to their mass ratio using a balance with an accuracy of 0.001g. The prepared raw materials are then ultrasonically cleaned in industrial ethanol to remove organic contaminants from the material surface.

[0048] 2) Preparation of alloy: The raw materials prepared in step 1) are fed into a vacuum non-consumable smelting furnace, wherein Ti and Cu are placed at the bottom and Ta is placed at the top. The vacuum degree of the vacuum chamber of the vacuum smelting furnace is adjusted to 5x10 -3 Pa, and then fill the furnace chamber with argon to half the atmospheric pressure. Repeat the vacuum purge and purge process for more than three times. Then start the vacuum smelting furnace to melt the alloy raw materials. The arc current is 380A. The melting is repeated for more than 10 times until the alloy is fully melted and uniformly melted. The melting time for each time is 100 seconds. After the alloy is fully melted and cooled, the Ti-Ta-1.00Cu biomedical alloy material is obtained.

[0049] The mechanical property test results of the ternary alloy obtained in the above embodiment are shown in Table 1.

[0050] Table 1

[0051] alloy YS(MPa) UTS(MPa) Elongation (%) E(GPa) <![CDATA[MicrohardnessHV 0.05 ]]> Ti-Ta-0.50Cu 1072.9±35.6 1655.1±52.7 31.3±2.8 113.61±1.44 328.2±6.92 Ti-Ta-0.75Cu 1178.8±13.2 1710.3±38.9 26.4±0.7 112.89±3.70 325.9±7.91 Ti-Ta-1.00Cu 886.6±50.0 1426.7±47.4 23.7±3.5 114.89±1.08 337.3±7.16

[0052] As shown in Table 1, the mechanical properties of the alloys provided in Examples 1 to 3 can all meet the design requirements of the alloys. Specifically, with the increase of the Cu element content, the UTS strength of the ternary alloy first increases and then decreases, while the Young's modulus first decreases and then increases. From the macroscopic performance of the mechanical properties, it can be seen that the addition of Cu may directly affect the microstructure of the ternary alloy, and thus affect the corrosion resistance of the alloy.

[0053] In order to further verify the corrosion resistance of the alloys obtained in Examples 1 to 3, the present invention also conducted electrochemical experiments on the above alloys in simulated body fluid at 37° C. The test results are shown in Table 2.

[0054] Table 2

[0055]

[0056]

[0057] As shown in Table 2, taking the Ti-6Al-4V alloy, a common bioalloy in the prior art, as an example, the corrosion resistance of the ternary alloys provided by Examples 1 to 3 of the present invention is better than that of the Ti-6Al-4V alloy. In addition, by comparing the corrosion resistance trends of the ternary alloys obtained in Examples 1 to 3, it can be seen that the corrosion resistance of the ternary alloy provided by the present invention also increases first and then decreases with the addition amount of Cu, and the corrosion resistance of the Ti-Ta-0.75Cu alloy of Example 2 is the best.

[0058] To further evaluate the in vitro biocompatibility of the alloys obtained in Examples 1 to 3, the present invention used a cell counting kit-8 (CCK-8, Dojindo, Japan) to evaluate the proliferation of MC3T3-E1 cells. The test results are shown in Table 3.

[0059] Table 3

[0060] alloy 1 day 3 days Ti-Ta-0.50Cu 94.8％±0.8％ 101.1％±3.2％ Ti-Ta-0.75Cu 98.7％±5％ 121.6％±0.6％ Ti-Ta-1.00Cu 97.9％±1％ 117.8％±6.1％ Ti-6Al-4V 106.9％±3.4％ 108.8％±0.7％

[0061] Cell viability > 75% indicates that the alloy is non-toxic and has good biocompatibility. Combined with the results obtained in Table 1, it can be seen that the amount of Cu added must be within the range required by the present invention. Excessive or insufficient Cu cannot achieve the performance requirements of the ternary alloy and may even reduce the overall performance of the ternary alloy.

[0062] The present invention also conducted hemolysis rate tests on the above-mentioned embodiments and existing bioalloys, the purpose of which is to illustrate the blood compatibility of the alloys. Generally speaking, the upper limit of the hemolysis rate of biomaterials is 5%. When the hemolysis rate of the material exceeds 5%, it may cause acute hemolysis. The hemolysis test results are as follows: Figure 7 As shown, it can be seen that the hemolysis rates of the alloys provided in Examples 1 to 3 are all less than 5%, which meets the hemolysis rate requirements of biomaterials.

Claims

1. An antibacterial and corrosion-resistant Ti-based ternary alloy, characterized by: The ternary alloy is a Ti-Ta-Cu alloy, and its chemical formula is: Ti 74.25 Ta 25 Cu 0.75 ; The preparation process of the ternary alloy includes: 1) Metal raw material powders including Ti, Ta, and Cu are uniformly mixed and then smelted to obtain a type of sample; 2) Mechanical and chemical properties of the type of sample are tested. When the comprehensive properties meet the design requirements of the ternary alloy, the data is recorded and the sample is obtained; The smelting process is as follows: the alloy raw materials are melted by vacuum arc melting, and then the alloy is turned over and melted after cooling, and the number of repetitions is ≥10; Electromagnetic stirring is also required during the vacuum arc melting process, and the current is 3-4A.

2. The method for preparing an antibacterial and corrosion-resistant Ti-based ternary alloy according to claim 1, characterized in that: The metal raw material powders need to be polished and ultrasonically cleaned in sequence before mixing to remove organic pollutants on the raw material surface.

3. The method for preparing an antibacterial and corrosion-resistant Ti-based ternary alloy according to claim 1, characterized in that: The vacuum arc melting process is as follows: the alloy raw materials are sent into the sample chamber, and when the vacuum degree reaches 5x10 -3 After Pa, argon gas was introduced until the pressure in the sample chamber reached 0.5 atm.

4. The method for preparing an antibacterial and corrosion-resistant Ti-based ternary alloy according to claim 1, characterized in that: During the vacuum arc melting process, the arc holding time is 100-120s and the current is 300-450A.

5. The method for preparing an antibacterial and corrosion-resistant Ti-based ternary alloy according to claim 1, characterized in that: The design requirements of the ternary alloy are: yield strength of 800-1200 MPa, elongation of 23-33%, and Young's modulus of 110-115 GPa.

6. Use of an antibacterial and corrosion-resistant Ti-based ternary alloy according to any one of claims 1 to 5, characterized in that: Used to prepare biomedical skeleton materials.

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