Antibacterial aluminum-based medium-entropy alloy and preparation method thereof

Abstract

The application relates to the technical field of metal surface treatment, in particular to an antibacterial aluminum-based medium-entropy alloy and a preparation method thereof. The antibacterial aluminum-based medium-entropy alloy is composed of alloy components with the following atomic molar percentages: Al: 79.5-81.0%; Li: 1.5-2.5%; Mg: 1.5-2.5%; Zn: 12.0-14.0%; Cu: 1.5-2.5%; and Ag: 0.50-1.0%. The surface of the antibacterial aluminum-based medium-entropy alloy is loaded with an antibacterial active functional component radix isatidis total protein. The antibacterial aluminum-based medium-entropy alloy prepared by the application has good antibacterial effect and excellent mechanical properties. The main principle lies in that the proportion of Cu and Ag, which are soft in texture, is reduced, and in order to offset the influence of the antibacterial effect caused by the reduction of the antibacterial components Cu and Ag, a macromolecular extract radix isatidis total protein derived from common traditional Chinese medicine radix isatidis is added. The macromolecular plant protein can still enable Ag to exert the antibacterial effect of Ag at a high content in the presence of low-content Ag.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal surface treatment, and particularly relates to an antibacterial aluminum-based medium-entropy alloy and a preparation method thereof. BACKGROUND

[0002] In recent years, researches show that by increasing the total entropy value of the alloy system, medium-entropy or high-entropy alloys are obtained, and some special properties are obtained, such as the strength, hardness, wear resistance, corrosion resistance, high-temperature oxidation resistance, high-temperature softening resistance, low-temperature toughness and radiation resistance of the new alloy, which all break through the performance limit of traditional alloys. At the same time, after increasing the entropy value of the alloy system, the composition will move from the edge of the phase diagram to the middle part of the multi-element phase diagram, and these positions are still a blind area for the exploration of new materials. At present, the high-entropy alloy system that has been widely studied mainly consists of transition metal elements such as Co, Cr, Fe, Ni, Cu, Mn and Ti which have 3d subshell electrons outside the atomic nucleus. However, the addition of a large number of transition metal elements also brings some problems to the application of high-entropy alloys in the field of aerospace, etc. For example: (1) high density. Transition metal elements often have a large density, which will inevitably lead to a large density of multi-component high-entropy alloys; (2) high cost. Obviously, the prices of the raw materials of the existing high-entropy alloy components are not cheap, and combined with the high atomic percentage of each component in the high-entropy alloy, the manufacturing cost of the alloy is greatly increased; (3) high energy consumption. Traditional high-entropy alloy components often have a high melting point, which will inevitably increase the energy consumption of alloy smelting.

[0003] The antibacterial functionalization of the aluminum alloy surface does not change the organizational structure and element composition of the aluminum alloy itself, only the antibacterial modification of the aluminum alloy surface is performed, compared with the preparation of the alloy type antibacterial aluminum-based medium entropy alloy, the biggest advantage of the aluminum alloy surface modification is that the already formed aluminum alloy can be directly modified, and the process is simple, which is the most selected method for the antibacterial functionalization of the aluminum alloy at present. As an inorganic metal material, the most common surface modification method of the aluminum alloy is still to coat an antibacterial coating on the surface of the aluminum alloy. Dogan prepared Ag and Zn loaded zeolite by ion exchange method, then mixed the antibacterial zeolite into vinyl acetate paint, and coated the antibacterial zeolite on the aluminum foil to obtain an antibacterial coating with a thickness of 6-10 mm, which showed good antibacterial effect on Escherichia coli. Zhang Weili et al. prepared a sol by mixing TiO2 into butyl titanate, and then prepared a tight TiO2 antibacterial film on the surface of the aluminum alloy, which showed certain antibacterial activity. The surface coating antibacterial room of the aluminum alloy is currently used more frequently, and the process is simple and convenient, but the aging and falling off of the coating can easily cause poor long-term antibacterial effect. In addition, the surface anodic oxidation of the aluminum alloy is a very mature surface treatment process of the aluminum alloy, which can bring a dense oxide film, and the uniform and regular nanometer pores on the surface become an excellent position for the deposition of functional ions, and the realization of the surface functionalization of many aluminum alloys is realized by a two-step method, that is, first, the surface anodic oxidation treatment is performed, and then a layer of effective active component is deposited. The surface antibacterial functionalization of the aluminum alloy can also be realized by the two-step method. Tomioka et al. formed AAO on the surface of the aluminum alloy by anodic oxidation method, and then filled silver sulfadiazine complex in the pores on the surface of the AAO, to prepare an aluminum alloy product with good antibacterial performance. This method for preparing the antibacterial aluminum-based medium entropy alloy is very extensive for the selection of antibacterial components, but it is not suitable for aluminum alloy components with irregular shapes, in addition, the anodic oxidation can obtain a very regular nanometer pore structure, but the particle deposition does not need such regular pore structure, so the anodic oxidation method is too complex and energy-consuming.

[0004] Based on the above situation, the application provides an antibacterial aluminum-based medium entropy alloy and a preparation method thereof. SUMMARY

[0005] The application aims to provide an antibacterial aluminum-based medium entropy alloy and a preparation method thereof.

[0006] To achieve the above-mentioned purpose, the application provides an antibacterial aluminum-based medium entropy alloy, which is composed of the following alloy components with atomic mole percentage:

[0007] Al: 79.5-81.0%; Li: 1.5-2.5%; Mg: 1.5-2.5%; Zn: 12.0-14.0%; Cu: 1.5-2.5%; Ag: 0.50-1.0%.

[0008] Preferably, the antibacterial aluminum-based medium-entropy alloy is composed of the following atomic molar percentages of alloy components: Al: 81.0%; Li: 1.5%; Mg: 1.5%; Zn: 14.0%; Cu: 1.5%; Ag: 0.50%.

[0009] Preferably, the antibacterial aluminum-based medium-entropy alloy is composed of the following atomic molar percentages of alloy components: Al: 79.5%; Li: 2.5%; Mg: 2.5%; Zn: 12.0%; Cu: 2.5%; Ag: 1.0%.

[0010] Preferably, the antibacterial aluminum-based medium-entropy alloy is prepared by the following method:

[0011] (1) Put the prepared Al, Li, Mg, and Zn raw materials into a corundum crucible in order of melting point from low to high, with the element having the lowest melting point placed at the bottom and the element having the highest melting point placed at the top. After placing each element, an equal amount of Cu or Ag is placed.

[0012] (2) Put the corundum crucible containing the alloy into a spiral induction coil, vacuumize to 1x10 -4 Pa, then fill with argon to 0.3-0.5 MPa, start the high-frequency induction device, and gradually increase the heating current to 100-200 A. After the alloy ingot is melted, maintain the alloy in a molten state for 15-20 min to make the alloy components uniform. Pour the uniformly melted alloy into a metal mold to obtain an aluminum-based alloy ingot.

[0013] Preferably, the antibacterial aluminum-based medium-entropy alloy has an antibacterial active functional component loaded on the surface.

[0014] Preferably, the antibacterial active functional component is total protein of isatis root.

[0015] Preferably, the antibacterial aluminum-based medium-entropy alloy with the active functional component loaded on the surface is prepared by the following method:

[0016] (1) Put the prepared Al, Li, Mg, and Zn raw materials into a corundum crucible in order of melting point from low to high, with the element having the lowest melting point placed at the bottom and the element having the highest melting point placed at the top. After placing each element, an equal amount of Cu or Ag is placed.

[0017] (2) Put the corundum crucible containing the alloy into a spiral induction coil, vacuumize to 1x10 -4Pa and below, re-argon to 0.3-0.5 MPa, start high-frequency induction device, heating current in the range of 100-200 A, gradually increase the heating current, when the alloy ingot is melted, keep the alloy melting state for 15-20 min, make the alloy composition uniform, pour the alloy liquid which is melted uniformly into a metal mold, and the aluminum-based alloy ingot is obtained;

[0018] (3) Put the surface cleaned aluminum-based alloy ingot into a H2O2 solution containing 20% mass concentration, and make the H2O2 solution immerse the surface of the aluminum-based alloy ingot, seal the treatment for 12 h, take out and clean with deionized water and dry, and the aluminum-based alloy ingot with nano voids is obtained;

[0019] (4) Add the silane coupling agent into 50% ethanol to prepare a silane coupling agent solution with a volume fraction of 5%, and add radix isatidis total protein in the silane coupling agent solution according to 250-350 mg / mL, then uniformly spread the silane coupling agent solution containing the radix isatidis total protein on the surface of the aluminum-based alloy ingot with nano voids, and solidify at 150°C for 2-3 h, and the antibacterial aluminum-based entropy alloy is obtained.

[0020] Preferably, the silane coupling agent is an epoxy silane coupling agent.

[0021] Preferably, the epoxy silane coupling agent includes one of 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl dimethoxysilane and 3-glycidyloxypropyl methyl diethoxysilane.

[0022] Preferably, the epoxy silane coupling agent is 3-glycidyloxypropyl trimethoxysilane.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] 1. The antibacterial aluminum-based entropy alloy prepared by the present application has good antibacterial effect and excellent mechanical properties, and the main principle is to reduce the proportion of Cu and Ag metals with soft texture, and in order to offset the influence of the antibacterial effect of the reduction of the content of antibacterial components Cu and Ag, a macromolecular extract radix isatidis total protein derived from common traditional Chinese medicine radix isatidis is added, and the macromolecular plant protein can still make Ag play the antibacterial effect at a high content in the presence of a lower content of Ag.

[0025] 2. The present application uses a silane coupling agent as one of the solvent media in the process of loading the antibacterial component macromolecular extract radix isatidis total protein, which can effectively improve the high temperature and high humidity resistance of the macromolecular extract radix isatidis total protein.

[0026] 3. The raw materials of the application are abundant in the domestic market and have a suitable price, so that the large-scale production of the application does not have too high cost constraints; at the same time, the antibacterial aluminum-based medium-entropy alloy is simple and has a low overall production cost, which is conducive to large-scale industrial production. DETAILED DESCRIPTION

[0027] Example 1

[0028] The specific raw materials are weighed according to Table 1, and the preparation steps are as follows:

[0029] (1) Put the prepared Al, Li, Mg and Zn raw materials into a corundum crucible in order of low to high melting point, with the element having the lowest melting point placed at the bottom and the element having the highest melting point placed at the top. After each element is placed, an equal amount of Cu or Ag is placed.

[0030] (2) Put the corundum crucible containing the alloy into a spiral induction coil, vacuumize to 1x10- 4 Pa, then fill with argon to 0.3 MPa, start the high-frequency induction device, and gradually increase the heating current to 200 A. When the alloy ingot is melted, maintain the alloy in a molten state for 15 min to make the alloy composition uniform. Pour the uniformly melted alloy liquid into a metal mold to obtain an aluminum-based alloy ingot.

[0031] (3) Put the cleaned aluminum-based alloy ingot into a 20% mass concentration H2O2 solution, and immerse the surface of the aluminum-based alloy ingot in the H2O2 solution. Seal the treatment for 12 h, then take out and wash with deionized water and dry to obtain an aluminum-based alloy ingot with nano voids.

[0032] (4) Add a silane coupling agent to 50% ethanol to prepare a silane coupling agent solution with a volume fraction of 5%, and add radix isatidis total protein to the silane coupling agent solution at 250 mg / mL. Then evenly apply the silane coupling agent solution containing radix isatidis total protein to the surface of the aluminum-based alloy ingot with nano voids, and solidify at 150°C for 2 h to obtain the antibacterial aluminum-based medium-entropy alloy.

[0033] Example 2

[0034] The specific raw materials are weighed according to Table 1, and the preparation steps are as follows:

[0035] (1) Put the prepared Al, Li, Mg and Zn raw materials into a corundum crucible in order of low to high melting point, with the element having the lowest melting point placed at the bottom and the element having the highest melting point placed at the top. After each element is placed, an equal amount of Cu or Ag is placed.

[0036] (2) Put the corundum crucible with the alloy into the spiral induction coil, and vacuumize to 1x10 4 Pa, and then fill argon to 0.5 MPa. Start the high-frequency induction device, and gradually increase the heating current in the range of 100 A. When the alloy ingot is melted, maintain the alloy melting state for 20 min to make the alloy composition uniform. Pour the alloy liquid with uniform melting into a metal mold to obtain an aluminum-based alloy ingot.

[0037] (3) Put the aluminum-based alloy ingot with clean surface into a H2O2 solution with a mass concentration of 20%, and immerse the surface of the aluminum-based alloy ingot in the H2O2 solution. Seal the treatment for 12 h, take out, wash with deionized water, and dry to obtain an aluminum-based alloy ingot with nano voids.

[0038] (4) Add a silane coupling agent into 50% ethanol to prepare a silane coupling agent solution with a volume fraction of 5%. Meanwhile, add radix isatidis total protein into the silane coupling agent solution at 300 mg / mL. Then evenly apply the silane coupling agent solution containing radix isatidis total protein on the surface of the aluminum-based alloy ingot with nano voids, and solidify at 150°C for 3 h to obtain the antibacterial aluminum-based entropy alloy.

[0039] Example 3

[0040] Weigh the specific raw materials according to Table 1, and the preparation steps are as follows:

[0041] (1) Put the prepared Al, Li, Mg, and Zn raw materials into a corundum crucible in order of melting point from low to high. The element with the lowest melting point is placed at the bottom, and the element with the highest melting point is placed at the top. After placing each element, an equal amount of Cu or Ag is added.

[0042] (2) Put the corundum crucible with the alloy into the spiral induction coil, and vacuumize to 1x10 -4 Pa, and then fill argon to 0.5 MPa. Start the high-frequency induction device, and gradually increase the heating current in the range of 200 A. When the alloy ingot is melted, maintain the alloy melting state for 20 min to make the alloy composition uniform. Pour the alloy liquid with uniform melting into a metal mold to obtain an aluminum-based alloy ingot.

[0043] (3) Put the aluminum-based alloy ingot with clean surface into a H2O2 solution with a mass concentration of 20%, and immerse the surface of the aluminum-based alloy ingot in the H2O2 solution. Seal the treatment for 12 h, take out, wash with deionized water, and dry to obtain an aluminum-based alloy ingot with nano voids.

[0044] (4) adding silane coupling agent into 50% ethanol to prepare a silane coupling agent solution with a volume fraction of 5%, adding radix isatidis total protein into the silane coupling agent solution at 350 mg / mL, and then uniformly applying the silane coupling agent solution containing the radix isatidis total protein on the surface of the aluminum-based alloy ingot with nano voids, and curing at 150°C for 2-3 h to obtain the antibacterial aluminum-based entropy alloy.

[0045] Comparative Example 1

[0046] The specific raw materials were weighed according to Table 1, and different from Example 3, steps (3) and (4) of loading the antibacterial active functional component were omitted, and the remaining steps were prepared according to the steps of Example 3.

[0047] Comparative Example 2

[0048] The specific raw materials were weighed according to Table 1, and different from Example 3, the proportion of Ag was increased and the proportion of Al was decreased, and steps (3) and (4) of loading the antibacterial active functional component were omitted, and the remaining steps were prepared according to the steps of Example 3.

[0049] Comparative Example 3

[0050] The specific raw materials were weighed according to Table 1, and different from Example 3, the alloy composition did not contain Ag and Cu, and the remaining steps were prepared according to the steps of Example 3.

[0051] Comparative Example 4

[0052] The specific raw materials were weighed according to Table 1, and different from Example 3, no silane coupling agent was used, and the radix isatidis total protein was directly added to a 50% ethanol solution and then applied on the surface of the aluminum-based alloy ingot. The remaining steps were prepared according to the steps of Example 3.

[0053] Comparative Example 5

[0054] The specific raw materials were weighed according to Table 1, and different from Example 3, a silane coupling agent containing no epoxy group, 3-aminopropyl triethoxysilane, was used. The remaining steps were prepared according to the steps of Example 3.

[0055] Table 1

[0056]

[0057] Performance Evaluation

[0058] Bacteriostatic performance test: The prepared antibacterial aluminum-based entropy alloy of examples 1-3 and comparative examples 1-5 was cut into cylindrical samples with a specification of R=3mm, H=3mm. The detection method used the film coating method for detection, and then the antibacterial rate was calculated by the plate counting method. The sample to be tested and all the instruments used in this experiment were sterilized in a high-pressure sterilization pot, the temperature was 121℃, and after sterilization, it was ready for use; 0.5g of beef extract, 0.5g of sodium chloride, 1g of peptone and 1.5g of agar powder were weighed with a high-precision electronic balance, and 100mL of nutrient solution was prepared in a 250mL container, and then sterilized to prepare for subsequent solid culture medium and bacterial liquid; 100μL of E. coli (or Staphylococcus aureus) was added to the liquid medium, and after 12h of culture in a shaking incubator, an inoculum was obtained, and then 100μL of the inoculum was diluted to 104 times, and then 100μL of the bacterial liquid was inoculated into the solid culture medium, and after 24h, the culture results were observed to obtain the best dilution multiple and the original concentration of E. coli; the bacterial liquid with the best dilution was added to the test surface of the sample at a rate of 0.02mL / cm 2 of inoculation area, covered with a sterilized polyethylene film and folded neatly at the edge to prevent the bacterial liquid from flowing out, and cultured in a constant temperature incubator at 35.5℃ for 24h; the sample was taken out, and 1mL of eluent was used to repeatedly clean the polyethylene film and the test surface of the sample, and after shaking, the bacterial liquid was diluted to 104CFU / mL, 1mL of the bacterial liquid was inoculated into the solid culture medium to prepare three parallel groups, and cultured in a constant temperature incubator at 35.5℃ for 24h, and the number of bacterial colonies on the culture medium was observed and counted to calculate the antibacterial rate (%) according to the formula: R(%)=(B-A) / Bx100%; wherein R is the antibacterial rate, B is the number of viable bacteria (CFU / mL) of the blank sample, and A is the number of viable bacteria (CFU / mL) of the antibacterial sample. The specific results are shown in Table 2.

[0059] Mechanical property test: According to the national standard GB / T7314-2005 "Metal material compression test method at room temperature". The compression test was carried out by using a mechanical testing machine (WDW-100D type) for quasi-static compression test at room temperature. The specific results are shown in Table 2.

[0060] The aluminum alloy samples of example 3 and comparative examples 4 and 5 were placed in an environment with a humidity of 75% and a temperature of 85℃ for 2h, and then the bacteriostatic performance was tested again according to the above method. The specific results are shown in Table 3.

[0061] Table 2

[0062] Staphylococcus aureus inhibition rate % Escherichia coli inhibition rate % Compressive strength (Mpa) Example 1 97.6％ 95.3％ 1173 Mpa Example 2 98.1％ 96.2％ 1158 Mpa Example 3 98.7％ 97.4％ 1124 Mpa Comparative Example 1 74.2％ 71.8％ 1135 Mpa Comparative Example 2 99.2％ 99.6％ 967 Mpa Comparative Example 3 6.3％ 8.5％ 1356 Mpa Comparative Example 4 98.3％ 97.1％ 1118 Mpa Comparative Example 5 97.9％ 97.5％ 1120 Mpa

[0063] Table 3

[0064] Staphylococcus aureus inhibition rate % Escherichia coli inhibition rate % Example 3 96.3％ 94.8％ Comparative Example 4 45.2％ 41.6％ Comparative Example 5 62.8％ 59.4％

[0065] The foregoing description of specific exemplary embodiments of the application has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the application to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the application be limited not with this detailed description, but rather by the claims appended hereto.

Claims

1. An antibacterial aluminum-based medium-entropy alloy, characterized in that, The antibacterial aluminum-based medium-entropy alloy is composed of alloy components with atomic mole percentages of Al: 79.5-81.0%; Li: 1.5-2.5%; Mg: 1.5-2.5%; Zn: 12.0-14.0%; Cu: 1.5-2.5%; Ag: 0.50-1.0%; the antibacterial aluminum-based medium-entropy alloy is loaded with an antibacterial active functional component on the surface; and the antibacterial active functional component is total root of isatis. The antibacterial aluminum-based medium-entropy alloy loaded with the antibacterial active functional component on the surface is prepared by the following steps: (1) Put the prepared Al, Li, Mg and Zn raw materials into a corundum crucible in order of melting point from low to high, with the element having the lowest melting point placed at the bottom and the element having the highest melting point placed at the top, and place the same amount of Cu or Ag after each element is placed until all the Cu or Ag is placed; (2) Put the corundum crucible with alloy into the spiral induction coil, vacuumize to 1x10 -4 Pa, and then recharge argon to 0.3-0.5 MPa, start the high-frequency induction device, and gradually increase the heating current in the range of 100-200 A. When the alloy ingot is melted, maintain the alloy melting state for 15-20 min to make the alloy composition uniform. Pour the alloy liquid melted uniformly into a metal mold to obtain an aluminum-based alloy ingot. (3) Put the cleaned aluminum-based alloy ingot into a 20% mass concentration H2O2 solution, and immerse the surface of the aluminum-based alloy ingot in the H2O2 solution, seal for 12 h, take out, wash with deionized water and dry to obtain an aluminum-based alloy ingot with nano voids; (4) Add a silane coupling agent into 50% ethanol to prepare a silane coupling agent solution with a volume fraction of 5%, and add total root of isatis in the silane coupling agent solution at 250-350 mg / mL, and then uniformly apply the silane coupling agent solution containing total root of isatis on the surface of the aluminum-based alloy ingot with nano voids, and solidify at 150°C for 2-3 h to obtain the antibacterial aluminum-based medium-entropy alloy. 2.The antibacterial aluminum-based medium-entropy alloy according to claim 1, characterized in that, The antibacterial aluminum-based medium-entropy alloy is composed of alloy components with atomic mole percentages of Al: 81.0%; Li: 1.5%; Mg: 1.5%; Zn: 14.0%; Cu: 1.5%; Ag: 0.50%.

3. The antibacterial aluminum-based medium entropy alloy according to claim 1, characterized in that, The antibacterial aluminum-based medium-entropy alloy is composed of alloy components with atomic mole percentages of Al: 79.5%; Li: 2.5%; Mg: 2.5%; Zn: 12.0%; Cu: 2.5%; Ag: 1.0%. The silane coupling agent is an epoxy silane coupling agent. 4.The antibacterial aluminum-based medium-entropy alloy according to claim 1, characterized in that, The epoxy silane coupling agent includes one of 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl dimethoxysilane and 3-glycidyloxypropyl methyl diethoxysilane. 5.The antibacterial aluminum-based medium-entropy alloy according to claim 4, characterized in that, The epoxy silane coupling agent is 3-glycidyloxypropyl trimethoxysilane. 6.The antibacterial aluminum-based medium-entropy alloy according to claim 5, characterized in that, ​

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