A rare earth phase precipitation strengthened high entropy alloy and preparation method thereof

Abstract

A rare earth phase precipitation strengthened high entropy alloy and its preparation method. The present invention discloses a rare earth phase precipitation strengthened high entropy alloy and its preparation method. The present invention is to solve the problem of insufficient strength of existing high entropy alloys. The chemical formula of the rare earth phase precipitation strengthened high entropy alloy is Al a Co b Cr c Fe d Ni e X f . Wherein, X is rare earth element Y or rare earth element La. Mainly by adding rare earth elements Y and La, the composition supercooling is increased, lattice distortion is caused, and a hard HCP phase is formed. Then, fine grain strengthening, solid solution strengthening and second phase strengthening are achieved, thereby improving the strength of the high entropy alloy. In addition, the smelting method of the present invention is simple and efficient, has high production efficiency and low cost, and is suitable for large-scale production. The present invention is applied to the field of metal materials and their preparation.

Description

Technical Field

[0001] The invention relates to a rare earth phase precipitation strengthened high entropy alloy and a preparation method thereof. Background Art

[0002] With the advancement of science and society, the performance requirements for structural materials have become increasingly stringent. Traditional alloy materials can no longer meet the comprehensive requirements of service conditions. This is why the design concept of high-entropy alloys has emerged. High-entropy alloys are composed of five or more elements and exhibit high entropy effects, lattice distortion effects, hysteresis diffusion effects, and cocktail effects. Due to their unique design concept, high-entropy alloys can achieve excellent properties such as strength, hardness, plasticity, and wear resistance.

[0003] Current research on high-entropy alloys (HEAs) primarily focuses on single-phase FCC HEAs. FCC HEAs exhibit excellent plasticity but relatively poor strength. To achieve a balance between strength and plasticity, eutectic HEAs have been proposed. Currently, the most widely studied eutectic HEAs are FCC / BCC eutectic HEAs, which offer a good balance of strength and plasticity, but their strength still has room for improvement. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of insufficient strength of existing high entropy alloys and to provide a rare earth phase precipitation strengthened high entropy alloy and a preparation method thereof.

[0005] The chemical formula of the rare earth phase precipitation strengthened high entropy alloy of the present invention is Al a Co b Cr c Fe d Ni e X f The atomic percentages of the elements are: 17.05%≤a≤17.25%, 13.60%≤b≤13.80%, 13.60%≤c≤13.80%, 13.60%≤d≤13.80%, 40.90%≤e≤41.40%, 0.05%≤f≤1%, and a+b+c+d+e+f=100%; wherein X is a rare earth element Y or a rare earth element La.

[0006] A method for preparing a rare earth phase precipitation-strengthened high entropy alloy is carried out according to the following steps:

[0007] 1. Weigh the raw materials according to the atomic percentage;

[0008] 2. Place the raw materials and titanium block into a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, evacuate the furnace, fill it with argon gas for protective melting, and cool it to obtain an alloy ingot.

[0009] 3. The alloy ingot is repeatedly smelted 5 times and cooled to obtain a rare earth phase precipitation strengthened high entropy alloy.

[0010] The present invention provides a rare earth phase precipitation strengthened high entropy alloy and a preparation method thereof. By adding rare earth elements to increase component supercooling, the surface tension and nucleation energy of the phase interface are reduced, the growth of grains is prevented, the grains are refined, and a hard rare earth phase is formed, thereby significantly improving the strength of the alloy.

[0011] Beneficial effects of the present invention:

[0012] 1. The elements Al, Co, Cr, Fe, and Ni and their relative contents are selected in the present invention because these five elements can form an FCC / BCC dual-phase high-entropy alloy. This allows the alloy to achieve both the excellent plasticity of the FCC phase and the high strength of the BCC phase.

[0013] Second, since Y and La have negative segregation energy, they segregate at the grain boundaries during the preparation process, inhibiting the growth of grains, thereby playing a role in grain refinement and strengthening, and improving the strength of the alloy.

[0014] Third, the atomic radii of Y and La are 181 pm and 187.7 pm, respectively, significantly larger than those of Al, Co, Cr, Fe, and Ni atoms. Therefore, when Y and La are dissolved into the FCC and BCC phases, they induce significant lattice distortion, acting as a solid solution strengthening agent and thereby increasing the strength of the alloy.

[0015] Fourth, after the addition of Y and La, a close-packed hexagonal phase is formed at the grain boundaries. This phase has excellent strength, realizes the role of second phase strengthening, and further increases the strength of the alloy.

[0016] Fifth, the composition of the high-entropy alloy of the present invention can simultaneously achieve solid solution strengthening, second phase strengthening, and grain refinement, resulting in the alloy having excellent compressive strength and excellent plasticity, with a strength range of 1.91GPa to 2.51GPa and a plasticity range of 22.88% to 42.41%. In addition, the preparation method is simple to operate, the process is stable, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is Al in Examples 1 to 5 a Co b Cr c Fe d Ni e Y f X-ray diffraction patterns of high entropy alloys;

[0018] Figure 2 is Al in Examples 6 to 10 a Co b Cr c Fed Ni e La f X-ray diffraction patterns of high entropy alloys;

[0019] Figure 3 is Al in Examples 1 to 5 a Co b Cr c Fe d Ni e Y f Microstructure diagram of high entropy alloy;

[0020] Figure 4 is Al in Examples 6 to 10 a Co b Cr c Fe d Ni e La f Microstructure diagram of high entropy alloy;

[0021] Figure 5 is Al in Examples 1 to 5 a Co b Cr c Fe d Ni e Y f Compressive mechanical properties diagram of high entropy alloys;

[0022] Figure 6 is Al in Examples 6 to 10 a Co b Cr c Fe d Ni e La f Graph of the compressive mechanical properties of high-entropy alloys. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any combination of the specific implementation methods.

[0024] Specific embodiment 1: In this embodiment, a rare earth phase precipitation strengthened high entropy alloy has the chemical formula of Al a Co b Cr c Fe d Ni e X fThe atomic percentages of the elements are: 17.05%≤a≤17.25%, 13.60%≤b≤13.80%, 13.60%≤c≤13.80%, 13.60%≤d≤13.80%, 40.90%≤e≤41.40%, 0.05%≤f≤1%, and a+b+c+d+e+f=100%; wherein X is a rare earth element Y or a rare earth element La.

[0025] Specific embodiment 2: This embodiment differs from the specific embodiment 1 in that the alloy is composed of 17.23% Al, 13.77% Co, 13.77% Cr, 13.77% Fe, 41.36% Ni and 0.1% Y in atomic percentage, and the chemical formula is Al 17.23 Co 13.77 Cr 13.77 Fe 13.77 Ni 41.36 Y 0.1 The rest is the same as the first embodiment.

[0026] Specific embodiment three: This embodiment is different from specific embodiment one or two in that the alloy is composed of 17.18% Al, 13.75% Co, 13.75% Cr, 13.75% Fe, 41.27% Ni and 0.3% Y in atomic percentage, and the chemical formula is Al 17.18 Co 13.75 Cr 13.75 Fe 13.75 Ni 41.27 Y 0.3 The rest is the same as the specific implementation method 1 or 2.

[0027] Specific embodiment 4: This embodiment differs from the specific embodiments 1 to 3 in that the alloy is composed of 17.15% Al, 13.72% Co, 13.72% Cr, 13.72% Fe, 41.19% Ni and 0.5% Y in atomic percentage, and the chemical formula is Al 17.15 Co 13.72 Cr 13.72 Fe 13.72 Ni 41.19 Y 0.5 . Other aspects are the same as those of Specific Embodiments 1 to 3.

[0028] Specific embodiment 5: This embodiment differs from the specific embodiments 1 to 4 in that the alloy is composed of 17.07% Al, 13.65% Co, 13.65% Cr, 13.65% Fe, 40.98% Ni and 1% Y in atomic percentage, and has a chemical formula of Al 17.07 Co 13.65 Cr13.65 Fe 13.65 Ni 40.98 Y1. Other aspects are the same as those in Specific Embodiments 1 to 4.

[0029] Specific embodiment 6: This embodiment is different from the specific embodiments 1 to 5 in that the alloy is composed of 17.23% Al, 13.78% Co, 13.78% Cr, 13.78% Fe, 41.38% Ni and 0.05% La in atomic percentage, and the chemical formula is Al 17.23 Co 13.78 Cr 13.78 Fe 13.78 Ni 41.38 La 0.05 The rest is the same as that of the specific implementation modes 1 to 5.

[0030] Specific embodiment 7: This embodiment is different from any one of the specific embodiments 1 to 6 in that the alloy is composed of 17.23% Al, 13.77% Co, 13.77% Cr, 13.77% Fe, 41.36% Ni and 0.1% La in atomic percentage, and has a chemical formula of Al 17.23 Co 13.77 Cr 13.77 Fe 13.77 Ni 41.36 La 0.1 The rest is the same as that of the first to sixth embodiments.

[0031] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that the alloy is composed of 17.18% Al, 13.75% Co, 13.75% Cr, 13.75% Fe, 41.27% Ni and 0.3% La in atomic percentage, and has a chemical formula of Al 17.18 Co 13.75 Cr 13.75 Fe 13.75 Ni 41.27 La 0.3 . The rest is the same as that of Specific Implementations 1 to 7.

[0032] Specific embodiment 9: This embodiment is different from any one of specific embodiments 1 to 8 in that the alloy is composed of 17.15% Al, 13.72% Co, 13.72% Cr, 13.72% Fe, 41.19% Ni and 0.5% La in atomic percentage, and has a chemical formula of Al 17.15 Co 13.72 Cr 13.72 Fe 13.72 Ni 41.19 La 0.5. The rest is the same as that of Specific Implementations 1 to 8.

[0033] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the alloy is composed of 17.07% Al, 13.65% Co, 13.65% Cr, 13.65% Fe, 40.98% Ni and 1% La in atomic percentage, and has a chemical formula of Al 17.07 Co 13.65 Cr 13.65 Fe 13.65 Ni 40.98 La1. Other aspects are the same as those in Specific Embodiments 1 to 9.

[0034] Specific embodiment 11: This embodiment is a method for preparing a rare earth phase precipitation strengthened high entropy alloy, which is carried out according to the following steps:

[0035] 1. Weigh the raw materials according to the atomic percentage;

[0036] 2. Place the raw materials and titanium block into a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, evacuate the furnace, fill it with argon gas for protective melting, and cool it to obtain an alloy ingot.

[0037] 3. The alloy ingot is repeatedly smelted 5 times and cooled to obtain a rare earth phase precipitation strengthened high entropy alloy.

[0038] The following examples are used to verify the beneficial effects of the present invention:

[0039] Example 1

[0040] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.23% Al, 13.78% Co, 13.78% Cr, 13.78% Fe, 41.38% Ni and 0.05% Y in atomic percentage. The chemical formula is Al 17.23 Co 13.78 Cr 13.78 Fe 13.78 Ni 41.38 Y 0.05 The preparation method is as follows:

[0041] (1) Weigh the elemental metals according to the mass ratios calculated from the atomic ratios above to obtain the raw materials. The mass ratios of the different elements are Al:Co:Cr:Fe:Ni:Y = 8.95:15.63:13.79:14.81:46.71:0.09. The total weight is 130 g, and the mass of each element is accurate to two decimal places.

[0042] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0043] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0044] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 1 The results show that adding a very small amount of Y does not change the alloy phase composition, and the alloy is composed of FCC phase and BCC phase. The microstructure of the high entropy alloy prepared in this example was observed, as shown in FIG. Figure 3 The alloy basically presents a eutectic structure morphology. A small amount of Y addition does not change the microstructure and grain size. The grain width is about 80 μm. The high entropy alloy prepared in this embodiment was subjected to compression mechanical properties tests. Figure 5 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 1.91 GPa and the plasticity is 42.41%.

[0045] Example 2

[0046] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.23% Al, 13.77% Co, 13.77% Cr, 13.77% Fe, 41.36% Ni and 0.1% Y in atomic percentage, and has the chemical formula Al 17.23 Co 13.77 Cr 13.77 Fe 13.77 Ni 41.36 Y 0.1 The preparation method is as follows:

[0047] (1) Weigh the elemental metals according to the mass ratios calculated from the atomic ratios above to obtain the raw materials. The mass ratios of the different elements are Al:Co:Cr:Fe:Ni:Y = 8.95:15.62:13.78:14.80:46.68:0.17. The total weight is 130 g, and the mass of each element is accurate to two decimal places.

[0048] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0049] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0050] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 1The results show that the addition of Y changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 3 As shown. The alloy grains basically present a eutectic structure morphology. After Y is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 58μm. It can be seen that the addition of Y plays a role in grain refinement. The high entropy alloy prepared in this example was subjected to compression mechanical properties tests, as shown in FIG. Figure 5 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.05 GPa and the plasticity is 36.22%, which shows that the addition of element Y improves the strength of the alloy.

[0051] Example 3

[0052] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.18% Al, 13.75% Co, 13.75% Cr, 13.75% Fe, 41.27% Ni and 0.3% Y in atomic percentage, and has the chemical formula Al 17.18 Co 13.75 Cr 13.75 Fe 13.75 Ni 41.27 Y 0.3 , the preparation method is as follows:

[0053] (1) Weigh the elemental metals according to the above atomic ratio conversion mass ratio to obtain the raw material. The mass ratio of the different elements is Al:Co:Cr:Fe:Ni:Y = 8.92:15.56:13.73:14.75:46.52:0.52. The total weight is 130g, and the mass of each element is accurate to two decimal places;

[0054] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0055] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0056] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 1 The results show that the addition of Y changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 3As shown. The alloy grains basically present a eutectic structure morphology. After Y is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 43μm. It can be seen that the addition of Y plays a role in grain refinement. The high entropy alloy prepared in this example was subjected to compression mechanical properties tests, as shown in FIG. Figure 5 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.16 GPa and the plasticity is 33.06%, which shows that the addition of element Y improves the strength of the alloy.

[0057] Example 4

[0058] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.15% Al, 13.72% Co, 13.72% Cr, 13.72% Fe, 41.19% Ni and 0.5% Y in atomic percentage, and has the chemical formula Al 17.15 Co 13.72 Cr 13.72 Fe 13.72 Ni 41.19 Y 0.5 , the preparation method is as follows:

[0059] (1) Weigh the elemental metals according to the above atomic ratio conversion mass ratio to obtain the raw material. The mass ratio of the different elements is Al:Co:Cr:Fe:Ni:Y = 8.88:15.51:13.69:14.70:46.37:0.85. The total weight is 130g, and the mass of each element is accurate to two decimal places;

[0060] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0061] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0062] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 1 The results show that the addition of Y changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 3 As shown. The alloy grains basically present a eutectic structure morphology. After Y is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 35μm. It can be seen that the addition of Y plays a role in grain refinement. The high entropy alloy prepared in this example was subjected to compression mechanical properties tests, as shown in FIG. Figure 5As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.19 GPa and the plasticity is 24.25%, which shows that the addition of element Y improves the strength of the alloy.

[0063] Example 5

[0064] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.07% Al, 13.65% Co, 13.65% Cr, 13.65% Fe, 40.98% Ni and 1% Y in atomic percentage, and has the chemical formula Al 17.07 Co 13.65 Cr 13.65 Fe 13.6 5Ni 40.98 Y1, prepared as follows:

[0065] (1) Weigh the elemental metals according to the mass ratios calculated from the atomic ratios above to obtain the raw materials. The mass ratios of the different elements are Al:Co:Cr:Fe:Ni:Y = 8.81:15.38:13.57:14.57:45.97:1.70. The total weight is 130 g, and the mass of each element is accurate to two decimal places.

[0066] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0067] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0068] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 1 The results show that the addition of Y changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 3 As shown. The alloy grains basically present a eutectic structure morphology. After Y is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 20μm. It can be seen that the addition of Y plays a role in grain refinement. The high entropy alloy prepared in this example was subjected to compression mechanical properties tests. Figure 5 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.28 GPa and the plasticity is 23.76%, which shows that the addition of element Y improves the strength of the alloy.

[0069] Example 6

[0070] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.23% Al, 13.78% Co, 13.78% Cr, 13.78% Fe, 41.38% Ni and 0.05% La in atomic percentage. The chemical formula is Al 17.23 Co 13.78 Cr 13.78 Fe 13.78 Ni 41.38 La 0.05 The preparation method is as follows:

[0071] (1) Weigh the elemental metals according to the mass ratios calculated from the atomic ratios above to obtain the raw materials. The mass ratios of the different elements are Al:Co:Cr:Fe:Ni:La = 8.95:15.62:13.79:14.81:46.70:0.13. The total weight is 130 g, and the mass of each element is accurate to two decimal places.

[0072] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0073] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0074] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 2 The results show that the addition of La changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 4 As shown. The alloy grains basically present a eutectic structure morphology. After La is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 65.6μm. The high entropy alloy prepared in this embodiment was subjected to compression mechanical properties tests, as shown in FIG. Figure 6 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.19 GPa and the plasticity is 40.21%, which shows that the addition of La element improves the strength of the alloy.

[0075] Example 7

[0076] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.23% Al, 13.77% Co, 13.77% Cr, 13.77% Fe, 41.36% Ni and 0.1% La in atomic percentage, and has the chemical formula Al 17.23 Co 13.77 Cr 13.77 Fe13.77 Ni 41.36 La 0.1 The preparation method is as follows:

[0077] (1) Weigh the elemental metals according to the above atomic ratio conversion mass ratio to obtain the raw material. The mass ratio of the different elements is Al:Co:Cr:Fe:Ni:La = 8.94:15.60:13.77:14.79:46.64:0.26. The total weight is 130g, and the mass of each element is accurate to two decimal places;

[0078] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0079] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0080] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 2 The results show that the addition of La changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 4 As shown. The alloy grains basically present a eutectic structure morphology. After La is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 60.5μm. The high entropy alloy prepared in this embodiment was subjected to compression mechanical properties tests, as shown in FIG. Figure 6 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.37 GPa and the plasticity is 37.53%, which shows that the addition of La element improves the strength of the alloy.

[0081] Example 8

[0082] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.18% Al, 13.75% Co, 13.75% Cr, 13.75% Fe, 41.27% Ni and 0.3% La in atomic percentage, and has the chemical formula Al 17.18 Co 13.75 Cr 13.75 Fe 13.75 Ni 41.27 La 0.3 , the preparation method is as follows:

[0083] (1) Weigh the elemental metals according to the mass ratios calculated from the atomic ratios above to obtain the raw materials. The mass ratios of the different elements are Al:Co:Cr:Fe:Ni:La = 8.89:15.52:13.69:14.71:46.39:0.80. The total weight is 130 g, and the mass of each element is accurate to two decimal places.

[0084] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0085] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0086] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 2 The results show that the addition of La changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 4 As shown. The alloy grains basically present a eutectic structure morphology. After La is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 55.4μm. The high entropy alloy prepared in this embodiment was subjected to compression mechanical properties tests, as shown in FIG. Figure 6 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.40 GPa and the plasticity is 23.68%, which shows that the addition of La element improves the strength of the alloy.

[0087] Example 9

[0088] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.15% Al, 13.72% Co, 13.72% Cr, 13.72% Fe, 41.19% Ni and 0.5% La in atomic percentage, and has the chemical formula Al 17.15 Co 13.72 Cr 13.72 Fe 13.72 Ni 41.19 La 0.5 The preparation method is as follows:

[0089] (1) Weigh the elemental metals according to the mass ratios calculated from the atomic ratios above to obtain the raw materials. The mass ratios of the different elements are Al:Co:Cr:Fe:Ni:La = 8.84:15.45:13.61:14.63:46.14:1.33. The total weight is 130 g, and the mass of each element is accurate to two decimal places.

[0090] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0091] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0092] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 2 The results show that the addition of La changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 4 As shown. The alloy grains basically present a eutectic structure morphology. After La is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 30.4μm. The high entropy alloy prepared in this embodiment was subjected to compression mechanical properties tests, as shown in FIG. Figure 6 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.47 GPa and the plasticity is 23.01%, which shows that the addition of La element improves the strength of the alloy.

[0093] Example 10

[0094] A rare earth phase precipitation strengthened high entropy alloy is composed of 17.07% Al, 13.65% Co, 13.65% Cr, 13.65% Fe, 40.98% Ni and 1% La in atomic percentage, and has the chemical formula Al 17.07 Co 13.65 Cr 13.65 Fe 13.65 Ni 40.98 La1, prepared as follows:

[0095] (1) Weigh the elemental metals according to the above atomic ratio conversion mass ratio to obtain the raw material. The mass ratio of the different elements is Al:Co:Cr:Fe:Ni:La = 8.73:15.23:13.44:14.44:45.53:2.63. The total weight is 130g, and the mass of each element is accurate to two decimal places;

[0096] (2) Place the raw materials into a crucible of a non-consumable vacuum melting furnace, and place 50 g of pure Ti into another crucible;

[0097] (3) Evacuate the furnace to 3×10 -3 After the pressure reaches 50 Pa, argon gas is introduced to 50 Pa. Then, smelting is started, first smelting Ti to exhaust the remaining oxygen in the furnace. The alloy ingot is repeatedly smelted 5 times to obtain the high entropy alloy.

[0098] X-ray diffraction experiments were carried out on the high entropy alloy prepared in this embodiment. Figure 2 The results show that the addition of La changes the phase composition of the alloy. In addition to the FCC phase and BCC phase, the alloy also generates a diffraction peak of the HCP phase. The microstructure of the high entropy alloy prepared in this example was observed. Figure 4 As shown. The alloy grains basically present a eutectic structure morphology. After La is added, it is enriched at the grain boundaries to form an HCP phase. The grain width is about 24.2μm. The high entropy alloy prepared in this example was subjected to compression mechanical properties tests, as shown in the following figure. Figure 6 As shown, it can be concluded that the compressive strength of the high entropy alloy prepared in this embodiment is 2.51 GPa and the plasticity is 22.88%, which shows that the addition of La element improves the strength of the alloy.

Claims

1. A rare earth phase precipitation strengthened high entropy alloy, characterized in that: The chemical formula of the rare earth phase precipitation strengthened high entropy alloy is Al a Co b Cr c Fe d Ni e X f The atomic percentage of each element is: 17.05%≤a≤17.25%, 13.60%≤b≤13.80%, 13.60%≤c≤13.80%, 13.60%≤d≤13.80%, 40.90%≤e≤41.40%, 0.05%≤f≤1%, and a+b+c+d+e+f=100%; wherein X is rare earth element Y or rare earth element La. After Y or La is added, a close-packed hexagonal phase is formed at the grain boundary.

2. A rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.23% Al, 13.77% Co, 13.77% Cr, 13.77% Fe, 41.36% Ni and 0.1% Y in atomic percentage, and its chemical formula is Al 17.23 Co 13.77 Cr 13.77 Fe 13.77 Ni 41.36 Y 0.1 .

3. The rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.18% Al, 13.75% Co, 13.75% Cr, 13.75% Fe, 41.27% Ni and 0.3% Y in atomic percentage, and its chemical formula is Al 17.18 Co 13.75 Cr 13.75 Fe 13.75 Ni 41.27 Y 0.3 .

4. The rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.15% Al, 13.72% Co, 13.72% Cr, 13.72% Fe, 41.19% Ni and 0.5% Y in atomic percentage, and its chemical formula is Al 17.15 Co 13.72 Cr 13.72 Fe 13.72 Ni 41.19 Y 0.5 .

5. The rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.07% Al, 13.65% Co, 13.65% Cr, 13.65% Fe, 40.98% Ni and 1% Y in atomic percentage, and its chemical formula is Al 17.07 Co 13.65 Cr 13.65 Fe 13.65 Ni 40.98 Y1.

6. The rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.23% Al, 13.78% Co, 13.78% Cr, 13.78% Fe, 41.38% Ni and 0.05% La in atomic percentage, and its chemical formula is Al 17.23 Co 13.78 Cr 13.78 Fe 13.78 Ni 41.38 La 0.05 .

7. The rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.23% Al, 13.77% Co, 13.77% Cr, 13.77% Fe, 41.36% Ni and 0.1% La in atomic percentage, and its chemical formula is Al 17.23 Co 13.77 Cr 13.77 Fe 13.77 Ni 41.36 La 0.1 .

8. The rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.18% Al, 13.75% Co, 13.75% Cr, 13.75% Fe, 41.27% Ni and 0.3% La in atomic percentage, and its chemical formula is Al 17.18 Co 13.75 Cr 13.75 Fe 13.75 Ni 41.27 La 0.3 .

9. The rare earth phase precipitation strengthened high entropy alloy according to claim 1, characterized in that: The alloy consists of 17.15% Al, 13.72% Co, 13.72% Cr, 13.72% Fe, 41.19% Ni and 0.5% La in atomic percentage, and its chemical formula is Al 17.15 Co 13.72 Cr 13.72 Fe 13.72 Ni 41.19 La 0.5 .

10. The method for preparing a rare earth phase precipitation strengthened high entropy alloy according to claim 1, wherein: The preparation method is carried out according to the following steps:

1. Weigh the raw materials according to the atomic percentage; 2. Place the raw materials into a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, place pure Ti in another crucible, evacuate the crucible, fill it with argon gas for protective melting, and cool it to obtain an alloy ingot.

3. The alloy ingot is repeatedly smelted 5 times and cooled to obtain a rare earth phase precipitation strengthened high entropy alloy.

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