Preparation method of an antibacterial porous titanium-nickel alloy and product thereof

Abstract

The present invention discloses a method for preparing an antibacterial porous titanium-nickel alloy and its products, comprising the following steps: 1) batching: titanium powder, nickel powder, copper agent, selenium agent and pore-forming agent are weighed according to the designed ratio; 2) mixing: the weighed raw materials are mixed in two steps to obtain a uniform mixed powder; 3) green compacting: the uniform mixed powder is pressed to obtain a green compact; 4) sintering: the green compact is placed in a high-temperature sintering furnace and sintered in a hydrogen + argon mixed atmosphere. After sintering, the green compact is cooled to room temperature with the furnace to obtain an antibacterial porous titanium-nickel alloy. The present invention gives full play to the synergistic antibacterial effect of copper and selenium, combines the pore-forming agent and the sintering process to regulate the pore structure, and prepares a porous titanium-nickel alloy with excellent and long-term antibacterial properties and an elastic modulus that matches human bone. The production process of the present invention is simple and easy to implement, has low production cost, is suitable for mass production, and has good prospects for application in various medical bone substitute materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of powder metallurgy, and in particular relates to a preparation method of an antibacterial porous titanium-nickel alloy and a product thereof. Background Art

[0002] Porous titanium-nickel alloys not only have good biocompatibility, shape memory effect, excellent corrosion resistance and mechanical properties, but also the introduction of porous structure eliminates the "stress shielding" effect and is conducive to tissue ingrowth and body fluid transport, so they are widely used in the field of medical implant materials. However, like other medical metal materials, porous titanium-nickel alloys face a problem that needs to be solved urgently - bacterial infection. With the goal of inhibiting the formation of bacterial biofilms, the development of new medical metal materials with their own anti-infection functions is an important way to effectively reduce the occurrence of the above-mentioned infections. Among them, surface modification of existing medical metal materials or the addition of appropriate amounts of elements with antibacterial effects are direct measures to deal with infections related to metal implants.

[0003] CN109730802 discloses a method for preparing a fluoride layer on the surface of NiTi alloy by femtosecond laser technology to improve antibacterial properties, and CN05343941 improves antibacterial properties by forming a selenium-rich nanolayer on the surface of NiTi alloy by alkaline heat treatment. These surface treatment methods are undoubtedly simple in process, but the antibacterial effect is poor and has a certain timeliness. After a long time, the antibacterial effect drops sharply or even disappears. CN102212717 and CN108456804 introduce antibacterial elements into pure titanium to improve its antibacterial properties and prove its antibacterial effectiveness, but the elastic modulus of the prepared material is much larger than that of human bone, which affects its application. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing an antibacterial porous titanium-nickel alloy and its product, so that the alloy has both excellent and long-term antibacterial properties and an elastic modulus that matches that of human bones.

[0005] The method for preparing the antibacterial porous titanium-nickel alloy provided by the present invention comprises the following steps:

[0006] 1) Ingredients: Weigh titanium powder, nickel powder, copper agent and selenium agent according to the designed ratio, and then prepare the copper agent and selenium agent into solutions with a concentration of 5% to 35% respectively;

[0007] 2) Mixing: ball milling the titanium powder, nickel powder and the prepared solution weighed in step 1), mixing them evenly, and then vacuum drying to obtain a mixture;

[0008] 3) Adding a pore-forming agent: weighing the pore-forming agent and the mixture obtained in step 2) according to the designed ratio and ball milling to obtain a uniform mixed powder;

[0009] 4) Green compact: Compress the mixed powder obtained in step 3) to obtain a green compact;

[0010] 5) Sintering: Sinter the green compact obtained in step 4) to obtain an antibacterial porous titanium-nickel alloy.

[0011] Preferably, in the antibacterial porous titanium-nickel alloy, in terms of atomic percentage content, the atomic percentage content of copper is 0.5-1.5%, the atomic percentage content of selenium is 0.2-1%, and the balance is titanium and nickel with an equiatomic ratio.

[0012] Preferably, in step 1), the copper agent is any one of copper chloride, copper acetate, and copper selenite; the selenium agent is any one of copper selenite, polyol selenite ester, selenate polysaccharide, phenyl selenocyanate, phenyl selenol ester, triphenyl selenium chloride, 3,3-diselenodipropylamine, selenium methionine, didodecyl selenium, and 2-nitrophenyl selenocyanate.

[0013] Preferably, in step 1), the particle size of the titanium powder is 5-75 μm and the purity > 99.5%; the particle size of the nickel powder is 2-75 μm and the purity > 99.5%.

[0014] Preferably, in step 1), the copper agent and the selenium agent are respectively formulated into solutions, and the solvent can be ethanol, water, acetone, toluene, etc. according to the selected copper agent and selenium agent.

[0015] Preferably, in step 2), when ball milling, the ball-to-material ratio is (3-8):1, the rotation speed is 100-150 rpm, and the time is 2-8 h; the drying time is 1-2 h and the drying temperature is 100°C-120°C.

[0016] Preferably, in step 3), the pore-forming agent is preferably a substance that is easily thermally decomposed at low temperature and has no residue.

[0017] More preferably, in step 3), the pore-forming agent is any one of ammonium bicarbonate, ammonium carbonate, urea, naphthalene, and polymethyl methacrylate (PMMA).

[0018] Preferably, in step 3), the pore-forming agent and the mixture obtained in step 2) are weighed according to the designed ratio, and the dosage of the pore-forming agent is 10-40 wt% of the weight of the mixture.

[0019] Preferably, in step 3), when ball milling, the ball-to-material ratio is (3-8):1, the rotation speed is 100-150 rpm, and the duration is 2-5 h.

[0020] Preferably, in step 4), the pressing pressure is 70-120 MPa.

[0021] Preferably, in step 5), the sintering is carried out in an atmosphere of 30% hydrogen + 70% argon mixture gas.

[0022] Preferably, in the step 5), the sintering process is specifically as follows: firstly, heating at 3 - 5 °C / min to the decomposition temperature of the pore-forming agent and holding for 1 - 2 h to completely remove the pore-forming agent, then heating at 4 - 6 °C / min to the decomposition and reduction temperature of the copper agent and selenium agent and holding for 1 - 2 h, and finally rapidly heating at 8 - 10 °C / min to 980 - 1100 °C for sintering and holding for 2 - 6 h. After sintering, cooling at 2 - 7 °C / min to 600 °C, and finally cooling with the furnace to obtain the antibacterial porous titanium-nickel alloy.

[0023] The antibacterial porous titanium-nickel alloy prepared according to the above preparation method.

[0024] Advantages of the present invention:

[0025] The antibacterial porous nickel-titanium alloy prepared by the present invention uniformly dissolves copper and selenium elements in the nickel-titanium alloy and forms an antibacterial phase, so its antibacterial property has long-term effectiveness; secondly, the added copper and selenium have a synergistic effect, which not only improves its antibacterial effect but also expands the range of antibacterial types, and also has a certain promoting effect on cancer prevention and anti-cancer; in addition, through pore structure regulation, the mechanical properties matching various implant substitutes can be prepared, thus greatly improving the implantation effect; finally, the production process is simple and easy to implement, suitable for large-scale industrial production, effectively reducing the production cost, and having good prospects for the application of various medical bone substitute materials. Description of the drawings

[0026] Figure 1 SEM image and elemental surface scan image of the porous Ni 49.25 Ti 49.25 -Cu-Se 0.5 prepared in Example 1. Detailed implementation manners

[0027] Example 1

[0028] Ingredients are proportioned as follows: Using copper chloride as the copper agent and polyol selenite as the selenium agent, by atomic percentage, copper is 1%, selenium is 0.5%, titanium is 49.25%, and nickel is 49.25%. Weigh copper chloride, polyol selenite, titanium powder (average particle size 25 μm, purity 99.6%) and nickel powder (particle size -300 mesh, purity 99.8%). Dissolve copper chloride in water and polyol selenite in ethanol to prepare two solutions with a concentration of 25% each. Then, put the titanium powder, nickel powder and the two prepared solutions into a drum-type jar mill and mix them in a pair-roll ball mill at a ball-to-material ratio of 3:1 and a rotation speed of 120 r / min for 5 h, and dry them in a vacuum drying oven at 100 °C for 1 h. Subsequently, mix them with 35 wt% ammonium bicarbonate in a pair-roll ball mill at a ball-to-material ratio of 3:1 and a rotation speed of 120 r / min for 3 h to obtain a uniform mixed powder. Put the uniform mixed powder into a mold and press it with a pressing pressure of 80 MPa to obtain a green compact. Place the green compact in a high-temperature sintering furnace, using a mixed gas of 30% hydrogen + 70% argon as the atmosphere. First, heat it at a rate of 3 °C / min to 150 °C and hold for 1 h to remove ammonium bicarbonate, then heat it at a rate of 5 °C / min to 650 °C and hold for 1 h to reduce the copper agent and selenium agent. Finally, quickly heat it to 1050 °C at a rate of 10 °C / min and sinter for 2 h, and cool it to 600 °C at a rate of 5 °C / min, and finally cool it in the furnace to obtain an antibacterial porous titanium-nickel alloy. The obtained antibacterial porous titanium-nickel alloy has a porosity of 65%, an elastic modulus of 3.5 GPa, an electrochemical corrosion potential of -0.4861 mV, an antibacterial rate against Staphylococcus aureus and Escherichia coli as high as 99.9%, an antibacterial rate against Porphyromonas gingivalis and Streptococcus mutans of 97%, and the microstructure is shown in Figure 1 as shown, it can be seen that the incorporated copper and selenium trace elements are evenly distributed in the NiTi phase alloy.

[0029] Example 2

[0030] This example is basically the same as Example 1, except that the copper agent, selenium agent and pore-forming agent are different. Specifically, the copper agent is copper acetate, the selenium agent is copper selenite, and urea is the pore-forming agent. The obtained antibacterial porous titanium-nickel alloy has a porosity of 66.3%, an elastic modulus of 3.4 GPa, an electrochemical corrosion potential of -0.48 mV, and an antibacterial rate against Staphylococcus aureus and Escherichia coli of 99.8%.

[0031] Example 3

[0032] This example is basically the same as Example 1, except that the atomic contents of copper and selenium are different. Specifically, copper is 1% and selenium is 1%. The obtained antibacterial porous titanium-nickel alloy has a porosity of 63.9%, an elastic modulus of 3.5 GPa, an electrochemical corrosion potential of -0.45 mV, and an antibacterial rate against Staphylococcus aureus and Escherichia coli of 99.6%.

[0033] Example 4

[0034] This example is basically the same as Example 1, except for the pore-forming agent and its dosage. Specifically, the pore-forming agent is urea with a dosage of 25 wt%. The prepared antibacterial porous titanium-nickel alloy has a porosity of 55.9%, an elastic modulus of 4.3 GPa, an electrochemical corrosion potential of -0.41 mV, and an antibacterial rate against Staphylococcus aureus and Escherichia coli reaching 99.9%.

[0035] Example 5

[0036] Ingredients are proportioned as follows: Using copper chloride as the copper agent and didodecyl selenide as the selenium agent, by atomic percentage, copper is 1%, selenium is 0.5%, titanium is 49.25%, and nickel is 49.25%. Weigh copper chloride, didodecyl selenide, titanium powder, and nickel powder. Dissolve copper chloride in deionized water and didodecyl selenide in ethanol to prepare two solutions with a concentration of 25% each. Then place the titanium powder, nickel powder, and the two prepared solutions in a drum-type jar mill and mix them in a pair-roll ball mill at a ball-to-material ratio of 3:1 and a rotation speed of 120 r / min for 5 h, and dry them in a vacuum drying oven at 120 °C for 1 h. Subsequently, mix them with 20 wt% polymethyl methacrylate (PMMA) in a pair-roll ball mill at a ball-to-material ratio of 3:1 and a rotation speed of 120 r / min for 3 h to obtain a uniform mixed powder. Load the uniform mixed powder into a mold and press it at a pressing pressure of 120 MPa to obtain a green compact. The green compact is placed in a high-temperature sintering furnace with a mixed gas of 30% hydrogen + 70% argon as the atmosphere. First, heat it at 3 °C / min to 450 °C and hold for 1 h to remove PMMA, then heat it at 5 °C / min to 650 °C and hold for 1 h to reduce the copper agent and selenium agent. Finally, quickly heat it to 1100 °C at 10 °C / min and sinter for 2 h, and cool it to 600 °C at 5 °C / min, and finally cool it with the furnace to obtain the antibacterial porous titanium-nickel alloy. The prepared antibacterial porous titanium-nickel alloy has a porosity of 50%, an elastic modulus of 4.8 GPa, an electrochemical corrosion potential of -0.423 mV, and an antibacterial rate against Staphylococcus aureus and Escherichia coli as high as 99.5%.

[0037] Example 6

[0038] This example is basically the same as Example 1, except for the copper agent, selenium agent, and pore-forming agent and their contents. Specifically, the copper agent is copper acetate with a content of 0.5%, the selenium agent is selenate polysaccharide with a content of 0.2%. Dissolve copper acetate in deionized water to form a 5% solution, dissolve selenate polysaccharide in acetone to form a 35% solution, and naphthalene is used as the pore-forming agent with a dosage of 10 wt%. The prepared antibacterial porous titanium-nickel alloy has a porosity of 38.5%, an elastic modulus of 5.5 GPa, an electrochemical corrosion potential of -0.404 mV, and an antibacterial rate against Staphylococcus aureus and Escherichia coli reaching 96.3%.

[0039] Example 7

[0040] This example is basically the same as Example 1, except for the dosage of copper agent, selenium agent and its dosage, pore-forming agent and sintering temperature. Specifically: the copper content is 1.5%, the selenium agent is 2-nitrophenyl thiocyanate, and the content is 0.5%. Dissolve copper chloride in deionized water and 2-nitrophenyl thiocyanate in toluene to form two solutions with a concentration of 10% each. Ammonium carbonate is used as the pore-forming agent, and the sintering temperature is 980 °C. The prepared antibacterial porous titanium-nickel alloy has a porosity of 66.2%, an elastic modulus of 3.4 GPa, an electrochemical corrosion potential of -0.493 mV, and an antibacterial rate against Staphylococcus aureus and Escherichia coli reaching 99%.

[0041] Example 8

[0042] This example is basically the same as Example 1, except for the copper agent, selenium agent and their contents. Specifically: the copper agent is copper selenite, the selenium agent is phenylselenol ester, and the copper and selenium contents are 0.5% and 1% respectively. Dissolve copper selenite in ethanol and phenylselenol ester in toluene to form two solutions with a concentration of 15% each. The prepared antibacterial porous titanium-nickel alloy has a porosity of 64.8%, an elastic modulus of 3.5 GPa, an electrochemical corrosion potential of -0.487 mV, and an antibacterial rate against Staphylococcus aureus and Escherichia coli reaching 98.4%.

Claims

1. A preparation method of an antibacterial porous titanium-nickel alloy, comprising the following steps: 1) Ingredient preparation: Weigh titanium powder, nickel powder, copper agent and selenium agent according to the designed ratio, and then separately prepare the copper agent and selenium agent into solutions with a concentration of 5% - 35%; 2) Mixing: Ball-mill the titanium powder, nickel powder and the prepared solutions weighed in step 1) until evenly mixed, and then vacuum dry to obtain a mixed material; 3) Adding pore-forming agent: Weigh the pore-forming agent according to the designed ratio and ball-mill it with the mixed material obtained in step 2) to obtain a uniformly mixed powder; 4) Compacting: Compact the mixed powder obtained in step 3) to obtain a green compact; 5) Sintering: Sinter the green compact obtained in step 4) to obtain an antibacterial porous titanium-nickel alloy; In the said antibacterial porous titanium-nickel alloy, by atomic percentage, the atomic percentage of copper is 0.5 - 1.5%, the atomic percentage of selenium is 0.2 - 1%, and the balance is titanium and nickel with an equiatomic ratio; In step 5), the sintering is carried out in an atmosphere of 30% hydrogen + 70% argon mixture gas.

2. The preparation method of the antibacterial porous titanium-nickel alloy according to claim 1, characterized in that, In step 1), the copper agent is any one of copper chloride, copper acetate, copper selenite; the selenium agent is any one of copper selenite, polyol selenite ester, selenate polysaccharide, phenyl selenocyanate, phenyl selenol ester, triphenyl selenium chloride, 3,3 - diselenodipropylamine, selenomethionine, didodecyl selenium, 2 - nitrophenyl selenocyanate.

3. The preparation method of the antibacterial porous titanium-nickel alloy according to claim 1, characterized in that, In step 1), the particle size of the titanium powder is 5 - 75 μm and the purity > 99.5%; the particle size of the nickel powder is 2 - 75 μm and the purity > 99.5%.

4. The preparation method of the antibacterial porous titanium-nickel alloy according to claim 1, characterized in that, In step 2), when ball-milling, the ball-to-material ratio is (3 - 8):1, the rotation speed is 100 - 150 rpm, and the time is 2 - 8 h; the drying time is 1 - 2 h and the drying temperature is 100°C - 120°C.

5. The preparation method of the antibacterial porous titanium-nickel alloy according to claim 1, characterized in that, In step 3), the pore-forming agent is a substance that is easily decomposed by low-temperature heat and has no residue, specifically any one of ammonium bicarbonate, ammonium carbonate, urea, naphthalene, polymethyl methacrylate (PMMA); the dosage of the pore-forming agent is 10 - 40 wt% of the weight of the mixed material.

6. The preparation method of the antibacterial porous titanium-nickel alloy according to claim 1, characterized in that, In step 3), when ball-milling, the ball-to-material ratio is (3 - 8):1, the rotation speed is 100 - 150 rpm, and the duration is 2 - 5 h.

7. The preparation method of the antibacterial porous titanium-nickel alloy according to claim 1, wherein, In step 4), the compaction pressure is 70 - 120 MPa.

8. The preparation method of the antibacterial porous titanium-nickel alloy according to claim 1, wherein, In step 5), the sintering procedure is specifically: First, heat up at 3 - 5°C / min to the decomposition temperature of the pore-forming agent and hold for 1 - 2 h to completely remove the pore-forming agent, then heat up at 4 - 6°C / min to the decomposition and reduction temperature of the copper agent and selenium agent and hold for 1 - 2 h, and finally quickly heat up at 8 - 10°C / min to 980 - 1100°C for sintering and hold for 2 - 6 h. After sintering, cool down at 2 - 7°C / min to 600°C, and finally cool with the furnace to obtain the antibacterial porous titanium-nickel alloy.

9. An antibacterial porous titanium-nickel alloy prepared by the preparation method according to any one of claims 1 - 8.

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