Super-hard aluminum-based high-entropy alloy with secondary aluminum as main material and preparation method of super-hard aluminum-based high-entropy alloy

Abstract

The invention discloses a superhard aluminum-based high-entropy alloy with secondary aluminum as a main material and a preparation method of the superhard aluminum-based high-entropy alloy. The preparation method comprises the following steps: taking secondary aluminum, pure titanium, pure vanadium, pure zirconium and pure niobium as raw materials, and weighing according to (M) xTiyVzZrwNbn; wherein M is a secondary aluminum alloy, x + y + z + w + n = 1, x = 0.5-0.6, y = 0.15-0.3, z = 0.03-0.07, w = 0.1-0.2, and n = 0.03-0.07; the regenerated aluminum alloy comprises 0.2 wt%-8 wt% of Si, 0.2 wt%-6 wt% of Mg, 0.1 wt%-0.6 wt% of Mn and 0.1 wt%-0.4 wt% of Fe, and the content of Al is larger than or equal to 90 wt%. The method comprises the following steps: firstly, preparing a TiVZrNb alloy, then smelting the TiVZrNb alloy with a regenerated aluminum alloy, and carrying out heat treatment to obtain the superhard aluminum-based high-entropy alloy. The hardness of the aluminum-based high-entropy alloy is greatly improved, and meanwhile the aluminum-based high-entropy alloy has good toughness and corrosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum-based high entropy alloys, and in particular to a superhard aluminum-based high entropy alloy using recycled aluminum as a main material and a preparation method thereof. Background Art

[0002] High entropy alloys usually contain five or more main elements with relatively high relative concentrations (5-35 at.%) and mixed in equiatomic or near-equiatomic ratios. Unlike traditional alloys with a single matrix element, high entropy alloys have the interaction of multiple main elements, and their performance can show a composite effect. The high mixing entropy effect of high entropy alloys in thermodynamics can effectively inhibit the formation of intermetallic compounds, thereby forming a simple solid solution.

[0003] For aluminum-based high-entropy alloys, in order to improve the performance of the alloy, the aluminum content is usually increased. Generally, as the Al content increases, the volume fraction of the Laves phase in the alloy continues to increase, and the strength of the alloy continues to increase. However, when the Al content exceeds a certain level, the Laves phase will precipitate in large quantities at the grain boundaries, seriously affecting the mechanical properties of the alloy. Therefore, how to prepare super-hard aluminum-based high-entropy alloys with excellent comprehensive performance is a problem that urgently needs to be solved in the existing technology. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of the present invention is to provide a method for preparing a super-hard aluminum-based high-entropy alloy with recycled aluminum as the main material, replacing traditional pure aluminum with recycled aluminum, introducing specific contents of Si, Mn, Mg, and Fe elements, thereby greatly improving the hardness of the aluminum-based high-entropy alloy while having good toughness.

[0005] Another object of the present invention is to provide an aluminum-based high entropy alloy prepared by the above preparation method with recycled aluminum as the main material.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for preparing a superhard aluminum-based high entropy alloy using recycled aluminum as a main material, comprising the following steps:

[0008] (1) Using recycled aluminum, pure titanium, pure vanadium, pure zirconium and pure niobium as raw materials, according to (M) x Ti y V z Zr w Nb n Weigh the raw materials; wherein, M is a recycled aluminum alloy, x+y+z+w+n=1, x=0.5-0.6, y=0.15-0.3, z=0.03-0.07, w=0.1-0.2, n=0.03-0.07;

[0009] The recycled aluminum alloy contains 0.2-8wt% Si, 0.2-6wt% Mg, 0.1-0.6wt% Mn, 0.1-0.4wt% Fe, and the content of Al is greater than or equal to 90wt%;

[0010] (2) placing pure titanium, pure vanadium, pure zirconium and pure niobium in a molten pool and arc melting them in an argon atmosphere to obtain a TiVZrNb alloy;

[0011] (3) placing the recycled aluminum alloy and the TiVZrNb alloy obtained in step (2) in the same molten pool and performing arc melting in an argon atmosphere;

[0012] (4) After smelting, the high entropy alloy is naturally cooled in the furnace. After cooling to room temperature, the alloy ingot is taken out;

[0013] (5) The alloy ingot obtained in step (4) is heat treated in a vacuum environment to obtain an ultra-hard aluminum-based high-entropy alloy.

[0014] Preferably, y=0.18-0.23, z=0.04-0.06, w=0.12-0.16, and n=0.04-0.06.

[0015] Preferably, the heat treatment temperature is 1050-1150° C. and the time is 10-14 hours.

[0016] Preferably, the recycled aluminum alloy contains:

[0017]

[0018] Preferably, the recycled aluminum is A356 recycled aluminum alloy, 5182 recycled aluminum alloy or 5052 recycled aluminum alloy.

[0019] Preferably, the A356 recycled aluminum alloy contains:

[0020]

[0021] Preferably, the 5052 recycled aluminum alloy contains:

[0022]

[0023] The 5182 recycled aluminum alloy contains:

[0024]

[0025] Preferably, the step (2) of arc melting in an argon atmosphere to obtain a TiVZrNb alloy is specifically:

[0026] (2-1) Turn on the vacuum pump to extract air from the vacuum arc melting furnace so that the pressure inside the furnace is less than or equal to 0.05 Pa, and then turn off the vacuum pump;

[0027] (2-2) Open the argon gas bottle and input argon gas into the vacuum arc melting furnace to keep the pressure in the furnace constant at 0.08 to 0.12 atmospheres; turn on the power supply of the vacuum arc melting furnace, adjust the current intensity to 150 to 300 A, and melt the mixed material;

[0028] (2-3) Repeat step (2-2) 6 to 8 times to obtain TiVZrNb alloy.

[0029] Preferably, the arc melting in step (3) is carried out under an argon atmosphere, specifically:

[0030] (3-1) Turn on the power of the vacuum arc melting furnace, adjust the current intensity to 150-300A, and melt the mixed material;

[0031] (3-2) Repeat step (3-1) 6 to 8 times.

[0032] Preferably, the alloy ingot obtained in step (4) is heat treated in a vacuum environment, specifically: a vacuum tube sealing operation is performed, and then the ingot is placed in a muffle furnace for heat treatment.

[0033] Preferably, the pure titanium, pure vanadium, pure zirconium, pure niobium and the recycled aluminum in step (2) are pretreated pure titanium, pure vanadium, pure zirconium, pure niobium and recycled aluminum;

[0034] The pre-processing is specifically as follows:

[0035] First, a grinder and polisher is used for polishing. The grinder and polisher uses 200 mesh, 600 mesh, and 1500 mesh sandpaper to finely polish and remove the oxide scale; then ultrasonic cleaning is performed for 10 to 20 minutes.

[0036] The present invention also provides a super-hard aluminum-based high-entropy alloy with recycled aluminum as a main material, which is prepared by the preparation method of the super-hard aluminum-based high-entropy alloy with recycled aluminum as a main material.

[0037] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0038] (1) The preparation method of the super-hard aluminum-based high-entropy alloy with recycled aluminum as the main material of the present invention replaces traditional pure aluminum with recycled aluminum, and introduces a small amount of Si, Mn, Mg, and Fe elements into the AlTiVZrNb high-entropy alloy. After heat treatment, the hardness of the super-hard aluminum-based high-entropy alloy is greatly improved while having good toughness, and the comprehensive mechanical properties are significantly improved, and at the same time, it has good corrosion resistance.

[0039] (2) The preparation method of the super-hard aluminum-based high-entropy alloy with recycled aluminum as the main material of the present invention is to first synthesize a TiVZrNb multi-component solid solution, and then mix the recycled aluminum with it. Since the elements in the recycled aluminum are uniformly distributed in the aluminum matrix in a combined state or a solid solution state, low-boiling point elements, such as Mg, are not easy to volatilize during arc melting. Therefore, using recycled aluminum as the main material is beneficial to the precise control of the element ratio in the alloy; at the same time, during the smelting process, the large negative mixing enthalpy between Si, Mn and Mg in the recycled aluminum alloy is utilized to reduce the entropy value of the alloy, thereby increasing the nucleation driving force of the internal intermetallic compounds, and utilizing the self-annealing effect during cooling to precipitate high-density nucleation particles. Then, in the subsequent high-temperature annealing treatment, these nucleation particles can quickly promote the generation of new strengthening phases.

[0040] (3) The preparation method of the super-hard aluminum-based high-entropy alloy with recycled aluminum as the main material of the present invention, within a specific content range of Si, Mn, Mg, and Fe elements, after heat treatment at 1050 to 1150°C, the microstructure shows slender rod-shaped grains with different arrangement directions, and the strengthening phase precipitates within the grains, so that the super-hard aluminum-based high-entropy alloy has excellent hardness and toughness. In addition, the intergranular corrosion caused by the precipitation of Laves phase at the grain boundaries is reduced, further improving the corrosion resistance of the super-hard aluminum-based high-entropy alloy.

[0041] (4) The method for preparing the superhard aluminum-based high entropy alloy with recycled aluminum as the main material of the present invention replaces traditional pure aluminum with recycled aluminum, broadens the source of raw materials, expands the scope of use of recycled aluminum, and greatly reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the XRD test result of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Example 1 of the present invention before heat treatment.

[0043] Figure 2 This is the XRD test result of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Example 1 of the present invention after heat treatment.

[0044] Figure 3 This is the XRD test result of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Comparative Example 1 of the present invention before heat treatment.

[0045] Figure 4 This is the XRD test result of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Comparative Example 1 of the present invention after heat treatment.

[0046] Figure 5 These are the SEM test results of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Example 1 of the present invention before heat treatment.

[0047] Figure 6 These are the SEM test results of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Example 1 of the present invention after heat treatment.

[0048] Figure 7 This is the SEM test result of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Comparative Example 1 of the present invention before heat treatment.

[0049] Figure 8 This is the SEM test result of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Comparative Example 1 of the present invention after heat treatment.

[0050] Fig. 9 Polarization curves of super-hard aluminum-based high-entropy alloy ingot samples prepared in Example 1 and Comparative Example 1 of the present invention; wherein, the blue triangle and red circle curves correspond to the polarization curves of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Example 1 before and after heat treatment; the green diamond curve corresponds to the polarization curve of the super-hard aluminum-based high-entropy alloy ingot sample prepared in Comparative Example 1. DETAILED DESCRIPTION

[0051] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0052] In the embodiment of the present invention, formula A1 0.55 Ti 0.21 V 0.05 Zr 0.14 Nb 0.05 Obtained by:

[0053] Based on the RandomForest model, the importance of features is calculated. According to the importance ranking of elements: Nb>Mo>Cr>Co>Zr>Ni, and Pearson correlation analysis, the order of influence of elements on alloy hardness is obtained: Ti>Al>Nb>Zr>V>other elements. After comprehensive analysis, Al, Ti, V, Zr, and Nb are selected as the component elements of the high entropy alloy system. Then, after many experiments, the ratio of Al, Ti, V, Zr, and Nb is adjusted to obtain the optimized formula: Al 0.55 Ti 0.21 V 0.05 Zr 0.14 Nb 0.05。

[0054] Example 1

[0055] The composition of the recycled aluminum A356 used in this embodiment is as follows:

[0056]

[0057]

[0058] The method for preparing the superhard aluminum-based high entropy alloy using recycled aluminum as the main material in this embodiment is as follows:

[0059] Step 1: Use a grinder and polisher to grind Ti, V, Zr, Nb and recycled aluminum. The grinder and polisher uses 200 mesh, 600 mesh and 1500 mesh sandpaper to finely polish and remove the oxide scale; then perform ultrasonic cleaning for 10 to 20 minutes.

[0060] Step 2: Ti 0.47 V 0.11 Zr 0.31 Nb 0.11 1.8g of Ti, V, Zr and Nb are placed in one molten pool, and the error of each component ratio is within ±0.3%. Recycled aluminum A356 is placed in another molten pool, with a weight of 2.2g.

[0061] Step 3: Melting TiVZrNb alloy, ① turn on the vacuum pump, extract the air in the furnace, make the pressure in the furnace reach 0.05Pa, and turn off the vacuum pump; ② turn on the argon bottle, and input argon into the vacuum arc melting furnace. The argon input rate is 150cm 3 / min, so that the pressure in the furnace is constant at 0.08 atmospheres; ③ Turn the arc gun lifting device to keep the arc gun head at an appropriate distance from the raw material, turn on the power of the vacuum arc melting furnace, adjust the current intensity to steadily increase to 200A, and melt the mixture; ④ In order to avoid uneven melting of the alloy, use a flip metal spoon to flip the smelting ingot, and repeat the melting 6 times;

[0062] Step 4: Melting the new high-entropy alloy, using a metal spoon to transfer the recycled aluminum and the alloy obtained in step 2 into a molten pool, then turning on the power of the vacuum arc melting furnace, adjusting the current intensity to steadily increase to 200A, and melting the mixture; in order to avoid uneven melting of the alloy, use a flip metal spoon to flip the molten ingot, and repeat the melting 6 times;

[0063] Step 5: Cooling: After smelting, the high entropy alloy is naturally cooled in the furnace. After cooling to 25°C, the alloy ingot is taken out;

[0064] Step 6: Heat treatment: the ingot is cut into two halves by wire cutting, one half is vacuum sealed, and then placed in a muffle furnace for heat treatment at a temperature of 1100°C for 12 hours;

[0065] Step 7: Cleaning: Grind the surface of the ingot with fine sandpaper and polish it with abrasive paste, then rinse it with anhydrous ethanol to make the surface of the casting clean.

[0066] The superhard aluminum-based high entropy alloy prepared in this embodiment is denoted as (A356) 0.55 (Ti 0.47 V 0.11 Zr 0.31 Nb 0.11 ) 0.45 .

[0067] Example 2

[0068] The composition of the recycled aluminum 5182 used in this embodiment is as follows:

[0069]

[0070] The method for preparing the superhard aluminum-based high entropy alloy using recycled aluminum as the main material in this embodiment is as follows:

[0071] Step 1: Use a grinder and polisher to grind Ti, V, Zr, Nb and recycled aluminum. The grinder and polisher uses 200 mesh, 600 mesh and 1500 mesh sandpaper to finely polish and remove the oxide scale; then perform ultrasonic cleaning for 10 to 20 minutes.

[0072] Step 2: Ti 0.47 V 0.11 Zr 0.31 Nb 0.11 1.8g of Ti, V, Zr and Nb in the composition are placed in a molten pool, and the error of the proportion of each component is within the range of ±0.3%. 5182 recycled aluminum alloy is placed in another molten pool, with a weight of 2.2g.

[0073] Step 3: Melting TiVZrNb alloy, ① turn on the vacuum pump, extract the air in the furnace, make the pressure in the furnace reach 0.05Pa, and turn off the vacuum pump; ② turn on the argon bottle, and input argon into the vacuum arc melting furnace. The argon input rate is 150cm 3 / min, so that the pressure in the furnace is constant at 0.08 atmospheres; ③ Turn the arc gun lifting device to keep the arc gun head at an appropriate distance from the raw material, turn on the power of the vacuum arc melting furnace, adjust the current intensity to steadily increase to 200A, and melt the mixture; ④ In order to avoid uneven melting of the alloy, use a flip metal spoon to flip the smelting ingot, and repeat the melting 6 times;

[0074] Step 4: Melting the new high-entropy alloy, using a metal spoon to transfer the recycled aluminum and the alloy obtained in step 2 into a molten pool, then turning on the power of the vacuum arc melting furnace, adjusting the current intensity to steadily increase to 200A, and melting the mixture; in order to avoid uneven melting of the alloy, use a flip metal spoon to flip the molten ingot, and repeat the melting 6 times;

[0075] Step 5: Cooling: After smelting, the high entropy alloy is naturally cooled in the furnace. After cooling to 25°C, the alloy ingot is taken out;

[0076] Step 6: Heat treatment: the ingot is cut into two halves by wire cutting, one half is vacuum sealed, and then placed in a muffle furnace for heat treatment at a temperature of 1100°C for 12 hours;

[0077] Step 7: Cleaning: Grind the surface of the ingot with fine sandpaper and polish it with abrasive paste, then rinse it with anhydrous ethanol to make the surface of the casting clean.

[0078] The superhard aluminum-based high entropy alloy prepared in this embodiment is denoted as (5182) 0.55 (Ti 0.47 V 0.11 Zr 0.31 Nb 0.11 ) 0.45 .

[0079] Example 3

[0080] The composition of recycled aluminum 5052 in this embodiment is as follows:

[0081]

[0082] The method for preparing the superhard aluminum-based high entropy alloy using recycled aluminum as the main material in this embodiment is as follows:

[0083] Step 1: Use a grinder and polisher to grind Ti, V, Zr, Nb and recycled aluminum. The grinder and polisher uses 200 mesh, 600 mesh and 1500 mesh sandpaper to finely polish and remove the oxide scale; then perform ultrasonic cleaning for 10 to 20 minutes.

[0084] Step 2: Ti 0.47 V 0.11 Zr 0.31 Nb 0.11 1.8g of Ti, V, Zr and Nb in the composition are placed in one molten pool, and the error of the proportion of each component is within the range of ±0.3%. 5052 recycled aluminum alloy is placed in another molten pool, with a weight of 2.2g.

[0085] Step 3: Melting TiVZrNb alloy, ① turn on the vacuum pump, extract the air in the furnace, make the pressure in the furnace reach 0.05Pa, and turn off the vacuum pump; ② turn on the argon bottle, and input argon into the vacuum arc melting furnace. The argon input rate is 150cm 3 / min, so that the pressure in the furnace is constant at 0.08 atmospheres; ③ Turn the arc gun lifting device to keep the arc gun head at an appropriate distance from the raw material, turn on the power of the vacuum arc melting furnace, adjust the current intensity to steadily increase to 200A, and melt the mixture; ④ In order to avoid uneven melting of the alloy, use a flip metal spoon to flip the smelting ingot, and repeat the melting 6 times;

[0086] Step 4: Melting the new high-entropy alloy, using a metal spoon to transfer the recycled aluminum and the alloy obtained in step 2 into a molten pool, then turning on the power of the vacuum arc melting furnace, adjusting the current intensity to steadily increase to 200A, and melting the mixture; in order to avoid uneven melting of the alloy, use a flip metal spoon to flip the molten ingot, and repeat the melting 6 times;

[0087] Step 5: Cooling: After smelting, the high entropy alloy is naturally cooled in the furnace. After cooling to 25°C, the alloy ingot is taken out;

[0088] Step 6: Heat treatment: the ingot is cut into two halves by wire cutting, one half is vacuum sealed, and then placed in a muffle furnace for heat treatment at a temperature of 1100°C for 12 hours;

[0089] Step 7: Cleaning: Grind the surface of the ingot with fine sandpaper and polish it with abrasive paste, then rinse it with anhydrous ethanol to make the surface of the casting clean.

[0090] The superhard aluminum-based high entropy alloy prepared in this embodiment is denoted as (5052) 0.55 (Ti 0.47 V 0.11 Zr 0.31 Nb 0.11 ) 0.45 .

[0091] Comparative Example 1

[0092] The preparation method of the ultra-hard aluminum-based high entropy alloy with pure aluminum as the main material in this comparative example is as follows:

[0093] Step 1: Use a grinder and polisher to grind the raw materials Al, Ti, V, Zr, and Nb. The grinder and polisher uses 200 mesh, 600 mesh, and 1500 mesh sandpaper to finely grind and remove the oxide scale; then perform ultrasonic cleaning for 10 to 20 minutes.

[0094] Step 2: Add Al by weight 0.55 Ti 0.21 V 0.05 Zr 0.14 Nb 0.05The Al, Ti, V, Zr and Nb ingredients are placed in a molten pool, the error of the proportion of each component is within the range of ±0.3%, and the total weight of the ingredients is 4g.

[0095] Step 3: Melting high entropy alloy, ① turn on the vacuum pump, extract the air in the furnace, make the pressure in the furnace reach 0.05Pa, and turn off the vacuum pump; ② turn on the argon bottle and input argon into the vacuum arc melting furnace, the argon input rate is 150cm 3 / min, so that the pressure in the furnace is constant at 0.08 atmospheres; ③ Turn the arc gun lifting device to keep the arc gun head at an appropriate distance from the raw material, turn on the power of the vacuum arc melting furnace, adjust the current intensity to steadily increase to 200A, and melt the mixture; ④ In order to avoid uneven melting of the alloy, use a flip metal spoon to flip the smelting ingot, and repeat the melting 6 times;

[0096] Step 4: Cooling: After smelting, the high entropy alloy is naturally cooled in the furnace. After cooling to 25°C, the alloy ingot is taken out;

[0097] Step 5: Heat treatment: the ingot is cut into two halves by wire cutting, one half is vacuum sealed, and then placed in a muffle furnace for heat treatment at a temperature of 1100°C for 12 hours;

[0098] Step 6: Cleaning: Grind the surface of the ingot with fine sandpaper and scrub it with anhydrous ethanol to make the surface of the casting clean.

[0099] The superhard aluminum-based high entropy alloy prepared in this comparative example is denoted as Al 0.55 Ti 0.21 V 0.05 Zr 0.14 Nb 0.05 .

[0100] Test Characterization:

[0101] The ingot samples obtained in Examples 1 to 3 and Comparative Example 1 before and after heat treatment were surface-grinded, and after polishing, XRD, SEM, hardness test, and corrosion resistance test were performed.

[0102] Hardness and toughness characterization results:

[0103] The loading force of the hardness test is 1kg, the number of measurement points is 20, and the proportion of crack indentations is counted after the test to evaluate its toughness. The test results of the ingot samples prepared in Examples 1 to 3 and Comparative Example 1 before and after heat treatment are shown in Table 1. It can be seen that the strength of the high entropy alloy smelted with recycled aluminum as the main material before and after heat treatment is significantly improved compared with the high entropy alloy smelted with pure aluminum as the main material, and from the probability of occurrence of crack indentations, the toughness of the material is also significantly improved.

[0104] Table 1

[0105]

[0106] XRD characterization results:

[0107] The XRD test results of the ingot samples before and after the heat treatment of Example 1 are as follows: Figure 1 , Figure 2 As shown in the figure, due to the addition of Si, Mn, Mg, and Fe elements, a variety of alloy strengthening phases containing Si, Mn, Mg, and Fe appeared in the ingot sample before heat treatment, such as Al3Ti 0.75 Fe 0.18 V 0.06 、Nb3Si、(Al 2.68 Mn 0.32 )Ti, the alloy crystal undergoes a significant change after heat treatment, generating more alloy strengthening phases containing Si, Mn, Mg, and Fe, such as Al 75 Fe 25 , Zr3Al4Si5, TiSi2, Al8Si6Mg3Fe, ZrMnSi2.

[0108] The XRD test results of the ingot samples before and after heat treatment of Comparative Example 1 are as follows: Figure 3 , Figure 4 As shown in the figure, the phase structure of the alloy has not changed, and it is a two-phase structure composed of FCC and BCC. After the alloy is heat treated, the ratio of the two phases changes, but no other alloy phases are found.

[0109] SEM characterization results:

[0110] The SEM test results of the ingot samples before and after heat treatment of Example 1 are as follows: Figure 5 , 6 As shown in the figure, the ingot sample before heat treatment has less precipitated phase, which is basically distributed at the phase boundary, while the ingot sample after heat treatment shows that slender rod-shaped grains with different arrangement directions are generated, the precipitated phase increases significantly, and most of them are precipitated in the crystal. The above microstructure can effectively improve the hardness and toughness of the ingot sample.

[0111] The SEM test results of the ingot samples before and after heat treatment of Comparative Example 1 are as follows: Figure 7 , 8 As shown, there is no obvious change in the grain size and morphology, and no other alloy phases are found.

[0112] Corrosion resistance test results:

[0113] The ingot samples before and after heat treatment prepared in Example 1 and the ingot samples before heat treatment prepared in Comparative Example 1 were immersed in a 3.5wt% NaCl solution. The results of the ingot samples are shown in Table 2. The Tafel curves are shown in Table 2. Fig. 9 As shown. It can be seen that before heat treatment, the corrosion resistance of the ingot sample with recycled aluminum as raw material is improved compared with the sample with pure aluminum as raw material, and the corrosion resistance of the ingot sample with recycled aluminum as raw material is further improved after heat treatment.

[0114] Table 2

[0115]

[0116] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a superhard aluminum-based high entropy alloy using recycled aluminum as a main material, characterized in that: The following steps are involved: (1) Using recycled aluminum, pure titanium, pure vanadium, pure zirconium and pure niobium as raw materials, according to (M) x Ti y V z Zr w Nb n Weigh the raw materials; wherein, M is a recycled aluminum alloy, x+y+z+w+n=1, x=0.5-0.6, y=0.15-0.3, z=0.03-0.07, w=0.1-0.2, n=0.03-0.07; The recycled aluminum alloy contains 0.2-8wt% Si, 0.2-6wt% Mg, 0.1-0.6wt% Mn, 0.1-0.4wt% Fe, and the content of Al is greater than or equal to 90wt%; (2) placing pure titanium, pure vanadium, pure zirconium and pure niobium in a molten pool and arc melting them in an argon atmosphere to obtain a TiVZrNb alloy; (3) placing the recycled aluminum alloy and the TiVZrNb alloy obtained in step (2) in the same molten pool and performing arc melting in an argon atmosphere; (4) After smelting, the high entropy alloy is naturally cooled in the furnace. After cooling to room temperature, the alloy ingot is taken out; (5) The alloy ingot obtained in step (4) is heat treated in a vacuum environment to obtain an ultra-hard aluminum-based high-entropy alloy.

2. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 1, characterized in that: The recycled aluminum alloy contains:

3. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 1, characterized in that: The recycled aluminum is A356 recycled aluminum alloy, 5182 recycled aluminum alloy or 5052 recycled aluminum alloy.

4. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 3, characterized in that: The A356 recycled aluminum alloy contains:

5. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 1, characterized in that: The 5052 recycled aluminum alloy contains: The 5182 recycled aluminum alloy contains:

6. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 1, characterized in that: The step (2) of arc melting in an argon atmosphere to obtain a TiVZrNb alloy is specifically: (2-1) Turn on the vacuum pump to extract air from the vacuum arc melting furnace so that the pressure inside the furnace is less than or equal to 0.05 Pa, and then turn off the vacuum pump; (2-2) Open the argon gas bottle and input argon gas into the vacuum arc melting furnace to keep the pressure in the furnace constant at 0.08 to 0.12 atmospheres; turn on the power supply of the vacuum arc melting furnace, adjust the current intensity to 150 to 300 A, and melt the mixed material; (2-3) Repeat step (2-2) 6 to 8 times to obtain TiVZrNb alloy.

7. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 6, characterized in that: The step (3) of arc melting in an argon atmosphere is specifically as follows: (3-1) Turn on the power of the vacuum arc melting furnace, adjust the current intensity to 150-300A, and melt the mixed material; (3-2) Repeat step (3-1) 6 to 8 times.

8. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 1, characterized in that: The alloy ingot obtained in step (4) is heat-treated in a vacuum environment, specifically: a vacuum tube sealing operation is performed, and then the ingot is placed in a muffle furnace for heat treatment.

9. The method for preparing a superhard aluminum-based high entropy alloy with recycled aluminum as the main material according to claim 1, characterized in that: The pure titanium, pure vanadium, pure zirconium, pure niobium and the recycled aluminum in step (2) are pretreated pure titanium, pure vanadium, pure zirconium, pure niobium and recycled aluminum; The pre-processing is specifically as follows: First, a grinder and polisher is used for polishing. The grinder and polisher uses 200 mesh, 600 mesh, and 1500 mesh sandpaper to finely polish and remove the oxide scale; then ultrasonic cleaning is performed for 10 to 20 minutes.

10. A superhard aluminum-based high entropy alloy with recycled aluminum as the main material, characterized in that: The super-hard aluminum-based high-entropy alloy is prepared by the preparation method of any one of claims 1 to 9 using recycled aluminum as the main material.

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