Rapid preparation method of nano-porous amorphous alloy

Abstract

The invention discloses a rapid preparation method of a nano-porous amorphous alloy. The method comprises the following steps: preparing an amorphous alloy cast ingot through induction melting and electric arc melting, heating the cast ingot in boric oxide to a molten state for a period of time, taking out the cast ingot, performing water quenching to obtain an amorphous alloy ingot, cutting the amorphous alloy ingot into slices through a diamond wire, and performing vacuum heat treatment in a specific temperature interval for a period of time, and finally, soaking in a mixed acid solution to corrode to obtain a porous morphology characteristic. According to the method, the amorphous alloy is annealed for a long time at the temperature lower than the glass transition temperature for the first time to obtain nanocrystals, the nanocrystals are corroded to obtain the nano-porous structure, the method is suitable for various alloy systems, due to the fact that the annealing temperature is low, crystallization kinetics can be effectively controlled, and the uniformity and preparation controllability of the porous structure can be remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of materials science and engineering, and specifically relates to a quick preparation method of nanoporous amorphous alloys, aiming to construct amorphous alloy materials with multi-scale porous structures. Background Art

[0002] Amorphous alloys, due to their disordered atomic structure and excellent physical and chemical properties, have attracted widespread attention in the field of materials science. Compared to crystalline materials, amorphous alloys lack grain boundaries, exhibiting greater chemical stability and surface activity, and therefore hold great potential for applications in catalysis, sensing, and energy storage. In recent years, researchers have attempted to further optimize the microstructure of amorphous alloys through various methods, creating porous structures to enhance their performance.

[0003] The importance of porous structures in materials science is becoming increasingly apparent. Porous materials have a large specific surface area and abundant active sites, which can significantly improve their efficiency in electrochemical reactions, catalyst design and energy storage. For amorphous alloy materials, porosification treatment can not only maintain their excellent chemical stability, but also further enhance their catalytic performance. However, there are some limitations in the existing preparation methods of porous amorphous alloys: 1. In the preparation by dealloying method, the active components are dissolved, and the residual metal atoms undergo short-range diffusion and reorganization due to the local chemical potential gradient, which will cause crystallization and make it difficult to retain complete amorphousness. 2. The method of crystallizing by heating to above the glass transition temperature and then selectively corroding the crystallized part to retain the porous amorphous substrate is difficult to control the size distribution of the precipitated crystal phase due to reasons such as grain coarsening, and thus it is difficult to control the porosity. Moreover, this method is limited to a single or a few alloy systems and lacks versatility. Summary of the Invention

[0004] The purpose of the present invention is to provide a general method for preparing porous amorphous alloy materials of various systems, and to significantly improve the catalytic performance and practical value of the materials by precisely controlling the pore structure. g ) is annealed under low temperature to form nanocrystals, and then acid corrosion is combined to generate nanoporous structures. It is applicable to a variety of alloy systems and has convenient universality. Moreover, due to the low annealing temperature, it is easy to control the pore size distribution and porosity, and is especially suitable for electrochemical catalysis and sensing applications.

[0005] The technical solution adopted in the present invention is as follows:

[0006] A quick preparation method of nanoporous amorphous alloy comprises the following steps:

[0007] Step 1, sequentially adopting induction melting and arc melting methods to prepare alloy ingots;

[0008] Step 2: Add boron oxide to the quartz tube and heat it to 1000-1200° C. in a muffle furnace. Place the alloy ingot into the quartz tube, evacuate the quartz tube, and then continue to heat it to 1200-1300° C. in the furnace and keep it for 2 hours.

[0009] Step 3: After the insulation is completed, the quartz tube is immediately removed and water quenched. After water quenching, the alloy ingot is removed and cut into 500 μm-600 μm thin slices;

[0010] Step 4: take the thin slice obtained in step 3, seal it in a quartz tube and evacuate it, heat the muffle furnace to a temperature range of 0.9Tg to 1Tg, and place it in the muffle furnace and keep it warm for more than 5 hours;

[0011] Step 5: After the insulation is completed, the quartz tube is immediately removed and air-cooled, and the alloy sheet is removed after air-cooling;

[0012] Step 6: soak the slices after heat preservation in step 4 in a mixed solution of concentrated nitric acid: acetic acid = 1.2:1 by volume, soak for 600 seconds, then take them out and dry them.

[0013] Preferably, in step 1, the induction melting current is 32A and the arc melting current is 200A.

[0014] Preferably, in step 2, the mass ratio of the alloy ingot to boron oxide is 1:3 to 1:4. When there is more boron oxide, it can completely wrap the alloy ingot in a high-temperature molten state, thereby avoiding oxidation during the insulation process, thereby obtaining a defect-free alloy ingot.

[0015] Preferably, in step 2, the heating rate is 10°C / min to 15°C / min.

[0016] Preferably, in step 4, the temperature is kept at 0.9 to 1 times the glass transition temperature.

[0017] Preferably, in step 6, the volume ratio of concentrated nitric acid to acetic acid is 1.2:1.

[0018] Preferably, in step 6, the mixture is placed in a forced air drying oven at 60° C. and dried for 20 min.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention heat treats an amorphous alloy below its glass transition temperature, then uses acid etching to remove the precipitated nanocrystals, thereby forming a micron / nano composite porous structure. This is the first time that an amorphous alloy has been annealed for a long time below its glass transition temperature to produce nanocrystals, and then etched to produce a nanoporous structure. This method is applicable to a variety of alloy systems. The low annealing temperature effectively controls the crystallization kinetics, significantly improving the uniformity and controllability of the porous structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 (a)Ni 82 P 18 High-angle annular dark field imaging-scanning transmission microscopy (HAADF-TEM) of amorphous alloy (b) Ni after corrosion 82 P 18 HAADF-STEM image of the alloy thin film.

[0022] Figure 2 (a)Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 DSC curve of amorphous alloy; (b) Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 High-resolution electron microscopy (HRTEM) image of amorphous alloy.

[0023] Figure 3 (a) Ni after heat treatment 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 Selected area electron diffraction (SAED) pattern of the alloy (b) Ni after corrosion 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 STEM image of the alloy thin film.

[0024] Figure 4 Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 DSC curve of amorphous alloy.

[0025] Figure 5 (a)Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 Selected area electron diffraction (SAED) pattern of amorphous alloy (b) Ni after corrosion 70.75 Cr7Ta 2.75 P 16.25 B 3.25 HAADF-STEM image of amorphous alloy thin film.

[0026] Figure 6 (a) Ni after heat treatment 73.11 Cr 8.9P 14.62 B 2.92 Si 0.45 STEM image of alloy thin film (b) Ni after corrosion 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 STEM image of the alloy thin film.

[0027] Figure 7 Ni after heat treatment 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 STEM images of alloy thin films at different magnifications. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be further described below with specific implementation methods.

[0029] The following embodiments are all implemented under the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0030] Specifically, several systems disclosed in the prior art were selected for implementation, namely Ni 82 P 18 、Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 and Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 .

[0031] Example 1:

[0032] Step 1: Take high-purity Ni and P (purity above 99.95%) and accurately weigh them according to the ingot composition ratio, and use induction melting and arc melting methods in sequence to obtain Ni 82 P 18 alloy ingots;

[0033] Step 2: Add boron oxide into the quartz tube and heat the muffle furnace to 1000℃. 82 P 18 The alloy ingot is placed in a quartz tube, which is then vacuumed and then heated to 1200°C and kept at this temperature for 2 hours.

[0034] Step 3: After the insulation is completed, take out the quartz tube immediately and quench it with water. After quenching, take out the Ni 82 P 18Alloy ingots are cut into 500μm-600μm slices;

[0035] Step 4: Take the thin slice obtained in step 3 and seal it in a quartz tube and evacuate it. Heat the muffle furnace to 260°C (0.92F). g ), placed in a muffle furnace and kept warm for 6 h;

[0036] Step 5: After the insulation is completed, take out the quartz tube immediately and air cool it. After air cooling, take out the Ni 82 P 18 thin slices;

[0037] Step 6: soak the slice obtained in step 5 in a mixed solution of concentrated nitric acid: acetic acid in a volume ratio of 1.2:1 for 600 seconds, then take it out and dry it;

[0038] To you 82 P 18 The amorphous alloy was tested by transmission electron microscopy (TEM). The absence of lattice fringes in the prepared material proved its amorphous structure. Figure 1 As shown in a in .

[0039] Ni after corrosion 82 P 18 The alloy slices were examined by TEM, which showed that the prepared samples had a uniform nanoporous structure, such as Figure 1 As shown in b.

[0040] Example 2:

[0041] Step 1: Take high-purity Ni, Cr, P, B, Si (purity above 99.95%) and accurately weigh them according to the ingot composition ratio, and use induction melting and arc melting methods in sequence to obtain Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 alloy ingots;

[0042] Step 2: Add boron oxide into the quartz tube and heat the muffle furnace to 1000℃. 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 The alloy ingot is placed in a quartz tube, which is then vacuumed and then heated to 1200°C and kept at this temperature for 2 hours.

[0043] Step 3: After the insulation is completed, take out the quartz tube immediately and quench it with water. After quenching, take out the Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45Alloy ingots are cut into 500μm-600μm slices;

[0044] Step 4: Take the thin slice obtained in step 3 and seal it in a quartz tube and evacuate it. Heat the muffle furnace to 350°C (0.95F). g ), placed in a muffle furnace and kept warm for 5 h;

[0045] Step 5: After the insulation is completed, take out the quartz tube immediately and air cool it. After air cooling, take out the Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 thin slices;

[0046] Step 6: soak the slice obtained in step 5 in a mixed solution of concentrated nitric acid: acetic acid in a volume ratio of 1.2:1 for 600 seconds, then take it out and dry it;

[0047] To you 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 The amorphous alloy was tested by differential scanning calorimetry (DSC), and the results showed that its glass transition temperature was 370℃. Figure 2 As shown in a in .

[0048] To you 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 The amorphous alloy was tested by TEM, and the prepared material had no lattice fringes, proving its amorphous structure. Figure 2 As shown in b.

[0049] After heat treatment, Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 The alloy slices were tested by TEM, and selected area electron scattering showed that there were nanocrystals in the amorphous structure, such as Figure 3 As shown in a in .

[0050] TEM examination of the corroded samples showed that the prepared samples had a uniform nanoporous structure, such as Figure 2 As shown in 3.

[0051] Example 3:

[0052] Step 1: Take high-purity Ni, Cr, Ta, P, and B with a purity of more than 99.95% and accurately weigh them according to the ingot composition ratio, and use induction melting and arc melting methods in sequence to obtain Ni70.75 Cr7Ta 2.75 P 16.25 B 3.25 alloy ingots;

[0053] Step 2: Add boron oxide into the quartz tube and heat the muffle furnace to 1000℃. 70.75 Cr7Ta 2.75 P 16.25 B 3.25 The alloy ingot is placed in a quartz tube, which is then vacuumed and then heated to 1200°C and kept at this temperature for 2 hours.

[0054] Step 3: After the insulation is completed, take out the quartz tube immediately and quench it with water. After quenching, take out the Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 Alloy ingots are cut into 500μm-600μm slices;

[0055] Step 4: Take the thin slice obtained in step 3 and seal it in a quartz tube and evacuate it. Heat the muffle furnace to 410°C (1T g ), placed in a muffle furnace and kept warm for 5 h;

[0056] Step 5: After the insulation is completed, take out the quartz tube immediately and air cool it. After air cooling, take out the Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 thin slices;

[0057] Step 6: soak the slice obtained in step 5 in a mixed solution of concentrated nitric acid: acetic acid in a volume ratio of 1.2:1 for 600 seconds, then take it out and dry it;

[0058] To you 70.75 Cr7Ta 2.75 P 16.25 B 3.25 The amorphous alloy was tested by DSC, and the results showed that its glass transition temperature was 410℃. Figure 4 shown.

[0059] After heat treatment, Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 The alloy slices were tested by TEM, and selected area electron scattering showed that there were nanocrystals in the amorphous structure, such as Figure 5 As shown in a in .

[0060] TEM examination of the corroded samples showed that the prepared samples had a uniform nanoporous structure, such as Figure 5 As shown in b.

[0061] Comparative Example 1:

[0062] Step 1: Take high-purity Ni, Cr, P, B, Si (purity above 99.95%) and accurately weigh them according to the ingot composition ratio, and use induction melting and arc melting methods in sequence to obtain Ni 71.6 Cr 8.7 P 16 B 3.2 Si 0.5 alloy ingots;

[0063] Step 2: Add boron oxide into the quartz tube and heat the muffle furnace to 1000℃. 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 The alloy ingot is placed in a quartz tube, which is then vacuumed and then heated to 1200°C and kept at this temperature for 2 hours.

[0064] Step 3: After the insulation is completed, take out the quartz tube immediately and quench it with water. After quenching, take out the Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 Alloy ingots are cut into 500μm-600μm slices;

[0065] Step 4: Take the slice obtained in step 3 and seal it in a quartz tube and evacuate it. Heat the muffle furnace to 300°C (0.81F). g ), placed in a muffle furnace and kept warm for 96 h;

[0066] Step 5: After the insulation is completed, take out the quartz tube immediately and air cool it. After air cooling, take out the Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 thin slices;

[0067] Step 6: soak the slice obtained in step 5 in a mixed solution of concentrated nitric acid: acetic acid in a volume ratio of 1.2:1 for 600 seconds, then take it out and dry it;

[0068] After heat treatment, Ni 73.11 Cr 8.9 P 14.62 B 2.92 Si 0.45 TEM examination of the alloy slices showed that it was still an amorphous structure with only trace amounts of nanocrystals, such as Figure 6 As shown in a in .

[0069] TEM examination of the corroded samples showed that there was no uniform nanoporous structure in the prepared samples, e.g. Figure 6 As shown in b.

[0070] Comparative Example 2:

[0071] Step 1: Take high-purity Ni, Cr, Ta, P, and B with a purity of more than 99.95% and accurately weigh them according to the ingot composition ratio, and use induction melting and arc melting methods in sequence to obtain Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 alloy ingots;

[0072] Step 2: Add boron oxide into the quartz tube and heat the muffle furnace to 1000℃. 70.75 Cr7Ta 2.75 P 16.25 B 3.25 The alloy ingot is placed in a quartz tube, which is then vacuumed and then heated to 1200°C and kept at this temperature for 2 hours.

[0073] Step 3: After the insulation is completed, take out the quartz tube immediately and quench it with water. After quenching, take out the Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 Alloy ingots are cut into 500μm-600μm slices;

[0074] Step 4: Take the thin slice obtained in step 3 and seal it in a quartz tube and evacuate it. Heat the muffle furnace to 410°C (1T g ), placed in a muffle furnace and kept warm for 0.5h;

[0075] Step 5: After the insulation is completed, take out the quartz tube immediately and air cool it. After air cooling, take out the Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 thin slices;

[0076] Step 6: soak the slice obtained in step 4 in a mixed solution of concentrated nitric acid:acetic acid in a volume ratio of 1.2:1 for 600 seconds, then take it out and dry it;

[0077] After heat treatment, Ni 70.75 Cr7Ta 2.75 P 16.25 B 3.25 The alloy slices were examined by TEM, and selected area electron scattering showed that there were no nanocrystals in the amorphous structure, such as Figure 7 shown.

[0078] In summary, a large amount of nanocrystals are formed when the amorphous alloy is annealed for a long time below the glass transition temperature. Due to the difference in acid corrosion resistance between amorphous and nanocrystals, nanocrystals can be removed by acid corrosion to form a nanoporous structure.

Claims

1. A quick preparation method of nanoporous amorphous alloy, characterized in that: The following steps are involved: Step 1, sequentially adopting induction melting and arc melting methods to prepare alloy ingots; Step 2: Add boron oxide to the quartz tube and heat it to 1000-1200° C. in a muffle furnace. Place the alloy ingot into the quartz tube, evacuate the quartz tube, and then continue to heat it to 1200-1300° C. in the furnace and keep it for 2 hours. Step 3: After the insulation is completed, the quartz tube is immediately removed and water quenched. After water quenching, the alloy ingot is removed and cut into thin slices with a thickness of 500 μm-600 μm; Step 4: The thin slice obtained in step 3 is sealed in a quartz tube and evacuated, and the temperature of the muffle furnace is raised to a temperature lower than the glass transition temperature of the alloy, that is, 0.9 times the glass transition temperature Tg to 1 times the glass transition temperature Tg, and the temperature is kept in the muffle furnace; Step 5: After the heat preservation is completed, the quartz tube is immediately removed and cooled to room temperature in air, and the alloy sheet is removed after cooling; Step 6: soak the slices after keeping warm in step 4 in a mixed solution of concentrated nitric acid and acetic acid for 600 seconds, then take them out and dry them.

2. The method according to claim 1, wherein In step 1, the induction melting current is 32A and the arc melting current is 200A.

3. The method according to claim 1, wherein In step 2, the mass ratio of the alloy ingot to boron oxide is 1:3 to 1:

4. When there is more boron oxide, it completely wraps the alloy ingot in a high-temperature molten state, thereby avoiding oxidation during the insulation process, thereby obtaining a defect-free alloy ingot.

4. The method according to claim 1, wherein In step 2, the heating rate is 10°C / min to 15°C / min.

5. The method according to claim 1, wherein In step 3, the alloy ingot is sliced into 1 mm slices.

6. The method according to claim 1, wherein In step 4, the mixture is placed at 0.9 to 1 times the glass transition temperature and kept warm for more than 5 hours.

7. The method according to claim 6, wherein In step 4, the holding time is 5 h or 6 h.

8. The method according to claim 1, wherein In step 6, the volume ratio of concentrated nitric acid to acetic acid is 1.2:

1.

9. The method according to claim 1, wherein In step 6, the mixture was placed in a forced air drying oven at 60° C. and dried for 20 min.

10. A nanoporous amorphous alloy prepared by the method according to any one of claims 1 to 9.

Images