A composite precipitation strengthening type high-entropy alloy and a preparation method thereof

Abstract

The application discloses a composite precipitation strengthening type high-entropy alloy and a preparation method thereof, and belongs to the field of metal material preparation. The high-entropy alloy is composed of Al, Co, Cr, Fe, Ni, Cu, V and Ti elements, and a general formula thereof is Al a Co b Cr c Fe d Ni e Cu f V g Ti h , wherein 2 <= a <= 4, 16 <= b <= 20, 16 <= c <= 20, 16 <= d <= 20, 35 <= e <= 40, 0 <= f <= 3, 0 <= g <= 3, 0 <= h <= 3, and a + b + c + d + e + f + g + h = 100. The high-entropy alloy is prepared through vacuum arc melting and heat treatment, and has excellent mechanical properties. The various metal raw materials used are environment-friendly, the preparation process is relatively safe, and the high-entropy alloy can be industrially produced.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of metal material preparation, and particularly relates to a composite precipitation strengthening type high-entropy alloy and a preparation method thereof. BACKGROUND

[0002] In recent years, a kind of high-entropy alloy based on configuration entropy for multi-principal element alloy design, breaks away from the shackles of traditional alloy with mixed enthalpy as the main single principal element design, is a good opportunity to cut into the field of high-function, high-value special alloy materials. Among them, the face-centered cubic (FCC) structure of high-entropy alloy causes the widespread attention of researchers due to its good plasticity and many excellent characteristics, but the intrinsic characteristics of the crystal structure determine that the strength of the alloy is low, thereby limiting its industrial application.

[0003] Precipitation strengthening is an effective strengthening method. However, in most cases, precipitation strengthening improves the strength of the alloy while reducing the plasticity. How to improve the strength and plasticity of the alloy at the same time is still the primary problem faced by the precipitation phase strengthened alloy, which is largely affected by the size and characteristics of the precipitate phase. When the size of the precipitate phase is large, the strengthening mechanism can be attributed to the Orowan bypass mechanism. Although this large size precipitate phase also has good strengthening effect on high-entropy alloy, it usually comes at the cost of damaging the plasticity of the alloy, mainly due to the negative effect of the hard and brittle nature of the precipitate phase itself, resulting in reduced ductility of the alloy.

[0004] How to solve the problem of maintaining high strength of high-entropy alloy while having high ductility is a key problem that needs to be solved. SUMMARY

[0005] In order to improve the strength of high-entropy alloy while maintaining high ductility, the application designs a nanoscale precipitate phase having a coherent relationship with the matrix, which can make the strength and plasticity of the alloy achieve a good combination.

[0006] A composite precipitation strengthening type high-entropy alloy, the high-entropy alloy described is composed of Al, Co, Cr, Fe, Ni, Cu, V and Ti elements, and the general formula of the high-entropy alloy is Al a Co b Cr c Fe d Ni e Cu f V g Ti h , wherein 2≤a≤4, 16≤b≤20, 16≤c≤20, 16≤d≤20, 35≤e≤40, 0≤f≤3, 0≤g≤3, 0≤h≤3, and a+b+c+d+e+f+g+h=100.

[0007] As a preferred technical scheme of the present application, a composite precipitation strengthening type high-entropy alloy Al a Co b Cr c Fe d Ni e Cu f V g Ti h The alloy components satisfy the following conditions: 3≤a≤4, 17≤b≤19, 17≤c≤19, 17≤d≤19, 37≤e≤39, 0≤f≤2, 0≤g≤2, 0≤h≤2, and a+b+c+d+e+f+g+h=100.

[0008] The preparation method of the composite precipitation strengthening type high-entropy alloy as described above comprises the following steps:

[0009] Step one: taking Al, Co, Cr, Fe, Ni, Cu, V and Ti as raw materials, the raw materials are cleaned and weighed, and then placed in a smelting furnace, vacuumized and then filled with argon for smelting, and the mother alloy ingot is obtained after cooling, and the mother alloy ingot is repeatedly smelted for 3-5 times, and the final high-entropy alloy ingot is obtained after cooling.

[0010] Step two: the high-entropy alloy ingot is solid solution treated at 1050-1150 DEG C for 6h under argon protection, and then rolled at room temperature with a total deformation of 90%, and then annealed and air-cooled, or further aged to obtain the high-entropy alloy.

[0011] As a preferred technical scheme of the present application, a vacuum arc smelting furnace is selected for alloy smelting in step one.

[0012] As a preferred technical scheme of the present application, the annealing process in step two is annealing at 1000 DEG C for 30min and then air-cooled.

[0013] As a preferred technical scheme of the present application, the aging treatment in step two is aging at 800 DEG C for 4h and then air-cooled.

[0014] The present application prepares a composite precipitation strengthening type high-entropy alloy through component design, and research shows that the high-entropy alloy not only has a tensile strength of 500-1100 MPa, but also has an elongation of 29-68%, which has great potential in practical application.

[0015] The present application has the following beneficial effects:

[0016] (1) The present application uses a small amount of precipitation phase strengthening elements Ti and Cu to form a composite ordered phase.

[0017] (2) The present application adopts six elements Al (600℃), Co (1495℃), Cr (1907℃), Fe (1538℃), Ni (1453℃), Ti (1678℃), Cu (1083.4℃) with large melting point difference as a new type of high-entropy alloy material, and finally obtains a high-entropy alloy with FCC structure.

[0018] (3) The present application strengthens the alloy by precipitating a large number of coherent ordered L12 phases in the FCC matrix, significantly increasing the strength of the high-entropy alloy, with a tensile strength of 1090 MPa and a fracture elongation of 29%. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the preferred embodiments of the present application, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0020] Figure 1 is the XRD pattern of the high-entropy alloy in the homogenization state prepared in Example 1 and Example 2, Example 3 and Example 4, Example 5, Example 6 and Example 7 of the present application;

[0021] Figure 2 is the metallographic pattern of the high-entropy alloy in the homogenization state prepared in Example 1 and Example 2, Example 3 and Example 4, Example 5, Example 6 and Example 7 of the present application;

[0022] Figure 3 is the stress-strain curve comparison diagram of the high-entropy alloy prepared in Example 1 and Example 2, Example 3 and Example 4, Example 5 and Example 6 of the present application;

[0023] Figure 4 is the exploration hardness diagram of the high-entropy alloy prepared in Example 7 of the present application;

[0024] Figure 5 is the stress-strain curve of the high-entropy alloy prepared in Example 7 of the present application. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and do not limit the present application.

[0026] The tests and equipment involved in each embodiment are as follows:

[0027] High vacuum non-consumable arc melting furnace, NF-800 type high vacuum non-consumable arc melting furnace produced by Sichuan Deyang Ona New Material Co., Ltd., China.

[0028] Microstructure: metallographic observation adopts Axio Observer D1M inverted metallographic microscope produced by Carl Zeiss Company; the size of the metallographic sample is 4mmx3mmx1.2mm, first embed the sample with phenolic resin, then polish with 400#, 600#, 1000#, 1500# and 2000# silicon carbide sandpaper in turn, and then polish with diamond polishing paste with a particle size of 2.5μm.

[0029] Quasi-static tensile mechanical property test: according to standard GB / T228.1-2010, indoor axial quasi-static tensile test is carried out by using Zwick Z020 microcomputer control electronic universal testing machine, the strain rate is selected as 10 -3 s -1 , the test sample is a non-standard I-shaped piece with a thickness of 1.20mm, a length of 30mm, a gauge length of 12mm and a gauge width of 3mm.

[0030] Example 1

[0031] A composite precipitation strengthening type high-entropy alloy, which is composed of Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 .

[0032] The preparation method is as follows:

[0033] Step one, weighing: the composite precipitation strengthening type high-entropy alloy provided in the embodiment is composed of the following element components in terms of mole percentage: Al: 3.7%, Co: 18.5%, Cr: 18.5%, Fe: 18.5%, Ni: 37%, Cu: 1.9%, V: 1.9%. According to the above ratio, the corresponding metal raw materials of each element component are weighed respectively, and the total mass is 100g.

[0034] Step two, smelting: after the above weighed metal particles are cleaned with alcohol and dried in an electric oven, the above cleaned and dried metal particles are stacked in the water-cooled copper crucible from low to high according to the melting point, then vacuumizing, when the vacuum degree reaches 3x10 -3 Pa, then filling argon as smelting anti-oxidation protective gas, then smelting high-entropy alloy, cooling to get alloy ingot, then repeating smelting 5 times to get Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 master alloy ingot.

[0035] Step three, homogenization treatment: the obtained Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 After the master alloy ingot is vacuum sealed with quartz glass and filled with argon protection, it is placed in a heat treatment furnace, heated to 1100℃ at a rate of 10℃ / min, and then taken out after holding for 6h and air cooling to obtain a homogenized Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 alloy sample.

[0036] Step four, deformation treatment: the homogenized sample is rolled at room temperature in multiple passes with a total reduction of 90% to obtain a rolled high-entropy alloy sample.

[0037] Step five, annealing treatment: the rolled high-entropy alloy is recrystallized annealed at 1000℃ for 1h.

[0038] The homogenized sample Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 is obtained after smelting, and XRD detection analysis is performed, as shown in Figure 1 , the annealed sample is mainly composed of FCC and L12, according to Figure 3 and the tensile test results in Table 1, the tensile strength of the prepared high-entropy alloy 1 is 578MPa, and the elongation at break is 68%.

[0039] Example 2

[0040] A composite precipitation strengthened high-entropy alloy has a composition of Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 .

[0041] The preparation method is as follows:

[0042] Step one, weighing: the present embodiment provides a kind of composite precipitation strengthening type high-entropy alloy, by following element composition consisting of: Al:3.7%, Co:18.5%, Cr:18.5%, Fe:18.5%, Ni:37%, Cu:1.9%, V:1.9%, according to above-mentioned proportion relationship, the corresponding metal raw material of each element component is weighed, and total mass is 100g.

[0043] Step two, smelting: the above weighed metal particles are cleaned with alcohol and then placed in an electric oven for drying, the above cleaned and dried metal particles are stacked in a water-cooled copper crucible in order from low to high melting point from top to bottom, then vacuum is extracted, and when the vacuum degree reaches 3×10 -3 Pa, then argon is filled as smelting anti-oxidation protective gas, then high-entropy alloy smelting is carried out, alloy ingot is obtained after cooling, and then smelting is repeated 5 times, to obtain Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 master alloy ingot.

[0044] Step three, homogenization treatment: the obtained Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 master alloy ingot is vacuum sealed with quartz glass and filled with argon protection, and then placed in a heat treatment furnace, heated to 1100℃ at 10℃ / min, and after 6h of heat preservation, the sample is taken out for air cooling, to obtain homogenized Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 alloy sample.

[0045] Step four, deformation treatment: the homogenized sample is subjected to multi-pass rolling at room temperature, and the total reduction is 90%, to obtain a rolled high-entropy alloy sample.

[0046] Step five, annealing treatment: the rolled high-entropy alloy is subjected to recrystallization annealing treatment at 1000℃ for 1h.

[0047] Step six, aging treatment: the annealed sample is subjected to heat preservation at 600℃ for 24h, and then taken out from the furnace for air cooling, to obtain an aged high-entropy alloy.

[0048] The homogenized sample Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 V 1.9 XRD detection analysis shows that the homogenized sample is mainly composed of FCC and L12, and the homogenized sample Al Figure 3 According to the tensile test results in Table 1, the tensile strength of the prepared high-entropy alloy 2 is 678 MPa, and the elongation at break is 67%.

[0049] Example 3

[0050] A composite precipitation strengthened high-entropy alloy, which is composed of Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 .

[0051] The preparation method is as follows:

[0052] Step one, weighing: the composite precipitation strengthened high-entropy alloy provided in the embodiment is composed of the following elements in terms of mole percentage: Al: 3.7%, Co: 18.5%, Cr: 18.5%, Fe: 18.5%, Ni: 37%, V: 1.9%, Ti: 1.9%. According to the above ratio, the corresponding metal raw materials of each element component are weighed respectively, and the total mass is 100g.

[0053] Step two, smelting: the above weighed metal particles are cleaned with alcohol and then placed in an electric oven for drying. The above cleaned and dried metal particles are stacked in the water-cooled copper crucible from low to high in order of melting point, and then vacuumized until the vacuum degree reaches 3x10 -3 Pa, then argon is filled as a smelting anti-oxidation protective gas, and then high-entropy alloy smelting is carried out, and the alloy ingot is obtained after cooling, and then the smelting is repeated for 5 times to obtain Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 master alloy ingot.

[0054] Step three, homogenization treatment: the obtained Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti1.9 The mother alloy ingot is vacuum sealed with quartz glass and filled with argon protection, and then placed in a heat treatment furnace, heated to 1100°C at a rate of 10°C / min, and then taken out after holding for 6h and air cooling to obtain a homogenized Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 alloy sample.

[0055] Step four, deformation treatment: the homogenized sample is subjected to multi-pass rolling at room temperature, and a total reduction of 90% is obtained to obtain a rolled high-entropy alloy sample.

[0056] Step five, annealing treatment: the rolled high-entropy alloy is subjected to recrystallization annealing treatment at 1000°C for 1h.

[0057] The homogenized sample Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 is subjected to XRD detection analysis, and the results are shown in Figure 1 , the homogenized sample is mainly composed of FCC and L12, and according to Figure 3 and the tensile test results in Table 1, the tensile strength of the prepared high-entropy alloy 3 is 799MPa, and the elongation at break is 55%.

[0058] Example 4

[0059] A composite precipitation strengthened high-entropy alloy, which is composed of Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 .

[0060] The preparation method is as follows:

[0061] Step one, weighing: the composite precipitation strengthened high-entropy alloy provided in the embodiment is composed of the following elements in terms of mole percentage: Al: 3.7%, Co: 18.5%, Cr: 18.5%, Fe: 18.5%, Ni: 37%, V: 1.9%, Ti: 1.9%, and the corresponding metal raw materials of each element component are weighed according to the above ratio, and the total mass is 100g.

[0062] Step two, smelting: the above weighed metal particles were cleaned with alcohol and then placed in an electric oven for drying. The cleaned and dried metal particles were stacked in a water-cooled copper crucible from low to high melting point, and then vacuumized to a vacuum degree of 3x10 -3 Pa, and then filled with argon as a smelting anti-oxidation protective gas. Then, the high-entropy alloy was smelted, and the alloy ingot was cooled to obtain an alloy ingot. The smelting was repeated 5 times to obtain an Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 master alloy ingot.

[0063] Step three, homogenization treatment: the obtained Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 master alloy ingot was vacuum-sealed with quartz glass and filled with argon protection, and then placed in a heat treatment furnace, and heated to 1100℃ at a rate of 10℃ / min, and then held for 6h. The sample was taken out and air-cooled to obtain a homogenized Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 alloy sample.

[0064] Step four, deformation treatment: the homogenized sample was subjected to multi-pass rolling at room temperature, and the total reduction was 90% to obtain a rolled high-entropy alloy sample.

[0065] Step five, annealing treatment: the rolled high-entropy alloy was subjected to recrystallization annealing treatment at 1000℃ for 1h.

[0066] Step six, aging treatment: the annealed sample was held at 600℃ for 24h, and then taken out of the furnace for air cooling to obtain an aged high-entropy alloy.

[0067] The homogenized sample Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 V 1.9 Ti 1.9 was subjected to XRD detection analysis, and the results are shown in Figure 1 The homogenized sample mainly consists of FCC and L12, and according toFigure 3 The tensile test results of Table 1 show that the tensile strength of the prepared high-entropy alloy 4 is 902 MPa, and the elongation at break is 50%.

[0068] Example 5

[0069] A composite precipitation-strengthened high-entropy alloy, which is composed of Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 .

[0070] The preparation method is as follows:

[0071] Step one, weighing: the present embodiment provides a composite precipitation-strengthened high-entropy alloy, which is composed of the following elements in terms of molar percentage: Al: 3.7%, Co: 18.5%, Cr: 18.5%, Fe: 18.5%, Ni: 37%, Ti: 1.9%, Cu: 1.9%. According to the above ratio, the corresponding metal raw materials of each element component are weighed respectively, and the total mass is 100g.

[0072] Step two, smelting: the above weighed metal particles are cleaned with alcohol and then placed in an electric oven for drying. The above cleaned and dried metal particles are stacked in the water-cooled copper crucible in the order of low to high melting point from top to bottom, then vacuumized, and when the vacuum degree reaches 3×10 -3 Pa, argon is filled as a smelting anti-oxidation protective gas, then high-entropy alloy smelting is carried out, and the alloy ingot is obtained after cooling. Then the smelting is repeated 5 times to obtain the Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 master alloy ingot.

[0073] Step three, homogenization treatment: the obtained Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 master alloy ingot is vacuum sealed with quartz glass and filled with argon protection, then placed in a heat treatment furnace, heated to 1100℃ at a rate of 10℃ / min, and after holding for 6h, the sample is taken out for air cooling to obtain the homogenized Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni37 Ti 1.9 Cu 1.9 alloy sample.

[0074] Step four, deformation treatment: the homogenized sample was rolled at room temperature in multiple passes with a total reduction of 90% to obtain a rolled high-entropy alloy sample.

[0075] Step five, annealing treatment: the rolled high-entropy alloy was subjected to recrystallization annealing treatment at 1000°C for 1h.

[0076] The homogenized sample Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 was subjected to XRD detection analysis, and the results are shown in Figure 1 The homogenized sample mainly consisted of FCC and L12, according to Figure 3 and the tensile test results in Table 1, the tensile strength of the prepared high-entropy alloy 5 was 958MPa, and the elongation at break was 53%.

[0077] Example 6

[0078] A composite precipitation strengthened high-entropy alloy, which is composed of Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 .

[0079] The preparation method is as follows:

[0080] Step one, weighing: the composite precipitation strengthened high-entropy alloy provided in the embodiment is composed of the following elements in terms of mole percentage: Al: 3.7%, Co: 18.5%, Cr: 18.5%, Fe: 18.5%, Ni: 37%, Ti: 1.9%, and Cu: 1.9%. The corresponding metal raw materials of each element component are weighed according to the above ratio, and the total mass is 100g.

[0081] Step two, melting: the above weighed metal particles are cleaned with alcohol and then placed in an electric oven for drying. The cleaned and dried metal particles are stacked in the water-cooled copper crucible from top to bottom according to the order of melting point from low to high, then vacuumized, and when the vacuum degree reaches 3x10 -3 Pa, argon is filled as a smelting anti-oxidation protective gas, then high-entropy alloy smelting is carried out, and the alloy ingot is cooled to obtain the alloy ingot, and then the smelting is repeated 5 times to obtain Al3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 master alloy ingot.

[0082] Step three, homogenization treatment: the obtained Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 After the master alloy ingot is vacuum sealed with quartz glass and filled with argon protection, it is placed in a heat treatment furnace, heated to 1100°C at a rate of 10°C / min, and after holding for 6h, the sample is taken out for air cooling, to obtain a homogenized Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 alloy sample.

[0083] Step four, deformation treatment: the homogenized sample is subjected to multi-pass rolling at room temperature, with a total reduction of 90%, to obtain a rolled high-entropy alloy sample.

[0084] Step five, annealing treatment: the rolled high-entropy alloy is subjected to recrystallization annealing treatment at 1000°C for 1h.

[0085] Step six, aging treatment: the annealed sample is held at 600°C for 24h, then taken out of the furnace for air cooling, to obtain an aged high-entropy alloy.

[0086] The homogenized sample Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 is subjected to XRD detection analysis, and the results are shown in Figure 1 , the homogenized sample is mainly composed of FCC and L12, according to Figure 3 and the tensile test results in Table 1, the tensile strength of the prepared high-entropy alloy 6 is 1048MPa, and the elongation at break is 46%.

[0087] Example 7

[0088] A composite precipitation strengthened high-entropy alloy, which is composed of Al 3.7 Co18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 .

[0089] The preparation method is as follows:

[0090] Step 1, Weighing: This embodiment provides a composite precipitation-strengthened high-entropy alloy with molar percentage, composed of the following elemental components: Al: 3.7%, Co: 18.5%, Cr: 18.5%, Fe: 18.5%, Ni: 37%, Ti: 1.9%, Cu: 1.9%. According to the above proportions, weigh the metal raw materials corresponding to each elemental component, with a total mass of 100g.

[0091] Step 2, Smelting: After cleaning the weighed metal particles with alcohol, dry them in an electric oven. Then, stack the cleaned and dried metal particles in a water-cooled copper crucible from top to bottom, according to their melting points from lowest to highest. Next, apply a vacuum until the vacuum level reaches 3 × 10⁻⁶. -3 After Pa, argon gas is introduced as a protective gas against oxidation during melting, followed by the melting of the high-entropy alloy. The alloy ingot is then cooled and cast, and the melting process is repeated five times to obtain Al. 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 Master alloy ingot.

[0092] Step 3, homogenization process: The obtained Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 After the master alloy ingot was vacuum-sealed with quartz glass and protected with argon gas, it was placed in a heat treatment furnace and heated to 1100℃ at a rate of 10℃ / min. After holding at this temperature for 6 hours, the sample was removed and air-cooled to obtain homogenized Al. 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 Alloy sample.

[0093] Step 4, Deformation treatment: The homogenized sample is rolled in multiple passes at room temperature with a total reduction of 90%, resulting in a rolled high-entropy alloy sample.

[0094] Step five, annealing treatment: the rolled high-entropy alloy is annealed at 1000 DEG C for 30 min to perform recrystallization annealing treatment.

[0095] Step six, aging treatment: the annealed sample is aged at 800 DEG C for 4 h, and then is taken out from the furnace to perform air cooling, thereby obtaining the aged high-entropy alloy.

[0096] The homogenized sample Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Ti 1.9 Cu 1.9 is subjected to XRD detection analysis, and the results are shown in Figure 1 The homogenized sample mainly consists of FCC and L12, and according to Figure 3 and the tensile test results in Table 1, the tensile strength of the prepared high-entropy alloy 7 is 1090 MPa, and the elongation at break is 29%.

[0097] Table 1

[0098]

[0099]

[0100] In summary, the composite precipitation strengthening type high-entropy alloy and the preparation method thereof are simple and feasible, the high-entropy alloy obtained through component design and simple vacuum arc melting has high strength and good plasticity, the preparation process is simple, safety is high, industrialized production can be realized, and the high-entropy alloy has great application potential in the engineering field.

[0101] Finally, it should be noted that: the above only describes the preferred embodiments of the present application and is not used to limit the present application, although the present application is described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced equivalently. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A composite precipitation-strengthened high-entropy alloy, characterized by, Alloy general formula is Al 3.7 Co 18.5 Cr 18.5 Fe 18.5 Ni 37 Cu 1.9 Ti 1.9 .

2. The preparation method of the composite precipitation strengthening high-entropy alloy according to claim 1, characterized in that, The preparation steps are as follows: Step one, taking Al, Co, Cr, Fe, Ni, Cu and Ti as raw materials, the raw materials are cleaned and weighed, and then placed in a smelting furnace, vacuumized and then filled with argon for smelting, and the mother alloy ingot is obtained after cooling, the mother alloy ingot is repeatedly smelted for 3-5 times, and the final high-entropy alloy ingot is obtained after cooling; Step two, the high-entropy alloy ingot is subjected to solid solution treatment for 6h under argon protection, and then subjected to room temperature rolling, the total deformation amount is 80-90%, and then subjected to annealing treatment and air cooling to obtain the high-entropy alloy or subjected to annealing treatment and air cooling and then subjected to aging treatment to obtain the high-entropy alloy.

3. The preparation method of the composite precipitation-strengthened high-entropy alloy according to claim 2, characterized in that: The smelting furnace in step one is a vacuum arc smelting furnace.

4. The method of claim 2, wherein the method is characterized by: The solid solution treatment temperature in step two is 1050-1150℃.

5. The method of claim 2, wherein the method comprises: The annealing treatment in step two is annealing at 1000℃ for 30min and then air cooling.

6. The preparation method of the composite precipitation-strengthened high-entropy alloy according to claim 2, characterized in that: The aging treatment in step two is aging at 800℃ for 4h and then air cooling.

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