A cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy and its preparation method and application

Abstract

The present invention relates to the field of metal materials technology, and more particularly to a cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy, its preparation method, and application. The cellular heterogeneous nano-precipitation high-entropy alloy comprises, by mass, 32-38% Co, 22-28% Cr, 22-28% Ni, 12-18% W, and 0.05-0.15% C. The preparation method comprises the following steps: subjecting the desired CoCrNiW high-entropy alloy powder to laser additive manufacturing to obtain a high-entropy alloy blank; and heat treating the high-entropy alloy blank to obtain the cellular heterogeneous nano-precipitation high-entropy alloy. The cellular heterogeneous nano-precipitation high-entropy alloy prepared by the present invention has a multi-level cellular heterogeneous structure with a size of 0.8 to 1.8 μm, and nano-scale coherent carbides are present at the boundaries of the cellular heterogeneous structure. The alloy exhibits excellent high-temperature performance and has great development prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of metal materials, and in particular to a cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy and a preparation method and application thereof. Background Art

[0002] High-entropy alloys (HEAs) have broad application prospects due to their excellent properties such as high strength, high hardness, high wear resistance, and high corrosion resistance. Due to the presence of multiple main elements in near-equiatomic ratios, HEAs exhibit four unique effects: high entropy effect, hysteresis diffusion effect, lattice distortion effect, and cocktail effect. HEAs have broad application prospects in the field of structural materials due to their unique composition, microstructure, and tunable properties. However, extensive in-depth research has found that the inverted "strength-ductility" relationship, which has long restricted the development of traditional metal structural materials, is still prevalent in HEAs. This is because their plastic deformation mechanism is often considered to be essentially the same as that of traditional metal materials. Therefore, there is an urgent need to construct novel microstructures to effectively strengthen and toughen HEAs.

[0003] Strengthening a material is achieved by hindering dislocation motion, while toughening requires plastic deformation, such as by promoting dislocation activation, to release stress concentration and delay crack initiation. In their ongoing efforts to overcome the strength-ductility contradiction in materials, researchers have proposed the new concept of heterogeneous materials, which achieves high strength while maintaining high ductility. Heterogeneous materials can be defined as materials with significant heterogeneity in strength from one region to another. This strength heterogeneity may be caused by microstructural heterogeneity, crystal structure heterogeneity, or compositional heterogeneity. A team led by Researcher Lu Lei from the Shenyang National Research Center for Materials Science, Institute of Metal Research, published (Pan Q, Zhang L, Feng R, et al. Gradient cell–structured high-entropy alloy with exceptional strength and ductility [J]. Science, 2021, 374(6570):984-989.). By introducing a cellular multi-level structure within the grains of a high-entropy alloy, they achieved high strength while maintaining good ductility and stable work hardening, thus realizing a high-entropy alloy with ultra-high strength and ductility. This report provides new ideas for the study of strength and toughness of high entropy alloys.

[0004] Single-phase face-centered cubic (FCC) structured metal materials prepared by selective laser cladding (SLM) technology usually exhibit a multi-level cellular structure and chemical composition segregation. In fact, the preparation of multi-level cellular heterogeneous strengthening and toughening materials by SLM technology has been reported many times and applied to 316L stainless steel (Wang YM, Voisin T, Mckeown JT, et al. Additively manufactured hierarchical stainless steels with high strength and ductility[J]. NATURE MATERIALS, 2018, 17(1): 63.), CoCrFeMnNi high entropy alloy (Zhu ZG, Nguyen QB, NgF L, et al. Hierarchical microstructure and strengthening mechanisms of a CoCrFeNiMn high entropy alloy additively manufactured by selective laser meltin g[J]. Scripta Materialia, 2018, 154: 20-24), CoCrNi medium entropy alloy (Han B, Zhan g C, Feng K, et al. Additively manufactured high strength and ductility Cr CoNi mediumentropy alloy with hierarchical microstructure[J]. Materials Science The method of preparing multi-level heterogeneous metal materials through selective laser cladding technology to achieve strengthening and toughening has been recognized by most researchers. This method has great potential in the engineering preparation of heterogeneous metal materials and has great development prospects and research value.

[0005] However, the strengthening effect of this cellular multi-level structure suffers from a drawback: high-temperature instability. When used in high-temperature environments, this strengthening effect significantly decreases, and as the temperature rises, the strengthening effect gradually diminishes until failure occurs. This issue severely restricts the application of cellular heterogeneous materials, particularly cellular heterogeneous high-entropy alloys, in aerospace, gas power generation, and nuclear applications. Summary of the Invention

[0006] The purpose of the present invention is to provide a cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy and its preparation method and application, which can achieve high-temperature strengthening of cellular multi-level structure high-entropy alloy.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy, wherein the raw material components include, by mass fraction, 32-38% Co, 22-28% Cr, 22-28% Ni, 12-18% W and 0.05-0.15% C;

[0009] The high entropy alloy preparation method comprises the following steps:

[0010] The required CoCrNiW high entropy alloy powder is subjected to laser additive manufacturing to obtain a high entropy alloy formed blank;

[0011] The high entropy alloy formed blank is heat treated to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high entropy alloy.

[0012] The present invention also provides a method for preparing a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy, comprising the following steps:

[0013] Performing laser additive manufacturing on the CoCrNiW high entropy alloy powder to obtain a high entropy alloy formed blank;

[0014] The high entropy alloy formed blank is heat treated to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high entropy alloy.

[0015] Preferably, the particle size of the CoCrNiW high entropy alloy powder is 10 to 100 μm.

[0016] Preferably, the CoCrNiW high entropy alloy powder is prepared by subjecting alloy raw materials to gas atomization pulverization treatment.

[0017] Preferably, the conditions of the laser additive manufacturing process include: laser power of 50 to 500 W, scanning speed of 0.5 to 5 m / s, and scanning layer thickness of 15 to 50 μm.

[0018] Preferably, the heat treatment conditions include: keeping the temperature at 730-760° C. for 60-120 minutes.

[0019] Preferably, the heating rate to the heat treatment temperature is 5 to 15° C. / min.

[0020] Preferably, the laser additive manufacturing process steps are as follows:

[0021] 1) Laying a layer of CoCrNiW high entropy alloy powder on a substrate, melting and solidifying and cooling in sequence to obtain a first layer of blank matrix;

[0022] 2) Laying a second layer of CoCrNiW high entropy alloy powder on the surface of the first layer of blank matrix, and sequentially melting and solidifying and cooling to obtain a second layer of blank matrix;

[0023] 3) Repeat steps 1) and 2) in sequence until a high-entropy alloy formed blank of the desired design size and shape is obtained.

[0024] The present invention provides the application of the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy or the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy prepared by the preparation method of the above-mentioned cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy in aerospace, gas power generation or nuclear fields.

[0025] The beneficial effects of the present invention are as follows: the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy provided by the present invention is based on the traditional CoCrNi medium-entropy alloy, and the refractory element W is added. Through the thermo-calc simulation technology, the solute redistribution path under the non-equilibrium solidification state is obtained, thereby confirming the content range of each component, and on the basis of improving the melting point of the material system, the FCC single-phase solid solution matrix (without loss of plasticity) and a small amount of carbide precipitation with a coherent relationship with the matrix are realized to strengthen the CoCrNiW high-entropy alloy composition design. On the basis of this composition design, the special solidification kinetics process in the laser additive manufacturing process is utilized, and the construction of cellular multi-level organization and micro-nanoscale component segregation are realized through the cellular growth mechanism, and a high-entropy alloy with cellular heterogeneous characteristics is prepared. Then, through heat treatment, on the basis of micro-nanoscale component segregation, coherent carbides are precipitated on the boundary of the cellular organization, thereby preparing a high-entropy alloy with cellular multi-level structural characteristics and cellular distributed nano-precipitations.

[0026] The cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy provided by the present invention has a micron-scale (0.8-1.8 μm) multi-level cellular heterogeneous structure within its grains, and dense nano-scale coherent carbides are present at the boundaries of the cellular heterogeneous structure. Under high-temperature service conditions of 550-950°C, the dense nano-coherent precipitated carbides at the boundaries of the cellular heterogeneous structure effectively pin the cellular multi-level structure, enhancing the cellular multi-level structure's dislocation-blocking effect at high temperatures, achieving high-temperature strengthening. This solves the problem of the cellular multi-level strengthening and toughening effect of cellular heterogeneous materials being strongly weakened in high-temperature environments.

[0027] The cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy provided by the present invention has excellent performance. At room temperature, its yield strength is not less than 760 MPa, its tensile strength is not less than 1 GPa, and its uniform elongation is not less than 40%; at 550°C, its yield strength is not less than 550 MPa; at 750°C, its yield strength is not less than 480 MPa.

[0028] Due to the ultra-fast cooling rate and large temperature gradient characteristics during the laser additive manufacturing process, the CoCrNiW high-entropy alloy with a specific composition in the present invention forms a multi-level structure of fine cellular tissue (micrometer level), and there is composition segregation at the boundaries of its cellular tissue. Utilizing this composition segregation feature, the heat treatment process provided by the present invention controls the precipitation of carbides, achieving the precipitation of a large number of nano-level carbides that are coherent with the blank matrix at the boundaries of the cellular tissue. This type of carbide has little effect on the plasticity and toughness of the material, but can effectively pin the cellular tissue in a high-temperature environment, enhancing the barrier effect of the cellular multi-level structure on dislocations, thereby achieving high-temperature strengthening. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The microstructure of the cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy prepared in Example 1 of the present invention is shown in Figure 1, wherein a is a bright field image of the nano-precipitated cellular structure, the upper left corner of a is an electron diffraction image of the cellular structure, and b is a dark field image of the nano-precipitated cellular structure.

[0030] Figure 2 The microstructure photos of the high entropy alloy prepared in Comparative Example 1 of the present invention, wherein a is a bright field image of the cellular structure without nanoprecipitates, and b is a dark field image of the cellular structure without nanoprecipitates;

[0031] Figure 3 This is a microstructure photograph of the high entropy alloy prepared in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] The present invention provides a cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy, wherein the raw material components include, by mass fraction, 32-38% Co, 22-28% Cr, 22-28% Ni, 12-18% W and 0.05-0.15% C;

[0034] The high entropy alloy preparation method comprises the following steps:

[0035] The required CoCrNiW high entropy alloy powder is subjected to laser additive manufacturing to obtain a high entropy alloy formed blank;

[0036] The high entropy alloy formed blank is heat treated to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high entropy alloy.

[0037] The present invention provides a cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy. Calculated by mass fraction, the raw material components include: 32-38% Co, preferably 33-36%, more preferably 34-45%.

[0038] The raw material composition includes, by mass fraction, 22-28% Cr, preferably 23-27%, more preferably 24-26%.

[0039] Calculated by mass fraction, the raw material composition includes: 22-28% Ni, preferably 23-27%, more preferably 24-26%.

[0040] Calculated by mass fraction, the raw material components include: 12-18% W, preferably 13-17%, more preferably 14-16%.

[0041] Calculated by mass fraction, the raw material components include: 0.05-0.15% C, preferably 0.06-0.12%, more preferably 0.07-0.09%.

[0042] The present invention has no particular limitation on the preparation method of the CoCrNiW high entropy alloy powder, and the powder is smelted according to a process well known in the art.

[0043] The present invention also provides a method for preparing a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy, comprising the following steps:

[0044] The required CoCrNiW high entropy alloy powder is subjected to laser additive manufacturing to obtain a high entropy alloy formed blank;

[0045] The high entropy alloy formed blank is heat treated to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high entropy alloy.

[0046] In the present invention, the particle size of the CoCrNiW high entropy alloy powder is 10 to 100 μm, preferably 15 to 80 μm, and more preferably 20 to 65 μm.

[0047] In the present invention, the CoCrNiW high-entropy alloy powder is produced by gas atomization pulverization of a smelted alloy raw material. Specifically, the master alloy is smelted in a vacuum induction melting furnace, then passed through a gas atomization device and introduced with a high-purity inert gas to produce the alloy powder. The powder is then sieved to obtain the target particle size and retained for later use. The high-purity inert gas is preferably argon.

[0048] In the present invention, the conditions of the laser additive manufacturing process include: laser power of 50 to 500 W, scanning speed of 0.5 to 5 m / s, and scanning layer thickness of 15 to 50 μm.

[0049] The conditions of the laser additive manufacturing process of the present invention include: a laser power of 50 to 500 W, preferably 100 to 400 W, and more preferably 250 to 350 W.

[0050] The conditions of the laser additive manufacturing process of the present invention include: a scanning speed of 0.5 to 5 m / s, preferably 0.6 to 3 m / s, and more preferably 0.8 to 1.5 m / s.

[0051] The conditions of the laser additive manufacturing process of the present invention include: the thickness after scanning the layer is 15 to 50 μm, preferably 20 to 45 μm, and more preferably 35 to 42 μm.

[0052] In the present invention, the heat treatment conditions include: keeping the temperature at 730-760° C. for 60-120 minutes.

[0053] In the present invention, the heat treatment conditions include: keeping warm at 730-760°C, preferably keeping warm at 740-755°C, and more preferably keeping warm at 745-752°C.

[0054] In the present invention, the heat treatment conditions include: keeping warm for 60 to 120 minutes, preferably 60 to 100 minutes, and more preferably 60 to 80 minutes.

[0055] In the present invention, the laser additive manufacturing process steps are as follows:

[0056] 1) Laying a layer of CoCrNiW high entropy alloy powder on a substrate, melting and solidifying and cooling in sequence to obtain a first layer of blank matrix;

[0057] 2) laying a second layer of CoCrNiW high entropy alloy powder on the surface of the first layer of blank matrix, and sequentially melting and solidifying and cooling to obtain a second layer of blank matrix;

[0058] 3) Repeating step 1) and step 2) in sequence until a high entropy alloy formed blank of the desired design size and shape is obtained.

[0059] The present invention provides the application of the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy described in the above technical solution or the cellular heterogeneous nano-precipitation high-entropy alloy prepared by the above-mentioned preparation method of the cellular heterogeneous nano-precipitation high-entropy alloy in aerospace, gas power generation or nuclear fields. The cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy prepared by the present invention is preferably used for the use of high-temperature materials in aerospace, gas power generation or nuclear fields. The present invention has no special limitation on the method of the application, and it can be applied according to the methods well known in the art.

[0060] Example 1

[0061] The preparation method of the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy of this embodiment is as follows:

[0062] (1) CoCrNiW high entropy alloy powder is used as raw material, which, calculated by weight percentage, includes 25% Cr, 25% Ni, 15% W, 0.08% C, and the rest is Co. The CoCrNiW high entropy alloy powder is obtained by melting the master alloy into a melt in a vacuum induction melting furnace, then passing through a gas atomization device, introducing argon gas, and finally solidifying and cooling to form CoCrNiW high entropy alloy powder, and collecting the powder with a particle size of 20 to 65 μm by sieving for use;

[0063] (2) Laying a layer of CoCrNiW high entropy alloy powder on the substrate, scanning the powder layer using SLM technology to melt it, and then solidifying and cooling to obtain the first layer of blank matrix;

[0064] (3) Laying a second layer of CoCrNiW high entropy alloy powder on the surface of the first layer of blank matrix, scanning the layer of powder using SLM technology to melt it, and obtaining the second layer of blank matrix after solidification and cooling;

[0065] (4) Repeat steps (2) and (3) 250 times to obtain a molded blank with a thickness of about 7 mm. The specific process parameters are as follows: laser power of 300 W, scanning speed of 950 mm / s, and scanning layer thickness of 40 μm;

[0066] (5) The cladding formed blank is heat treated, and the specific process parameters are: heating to 750°C at a heating rate of 5°C / min, placing the formed blank of step (4), keeping it warm for 60 minutes, taking it out and water cooling it to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy.

[0067] Example 2

[0068] The preparation method of the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy of this embodiment is as follows:

[0069] (2) CoCrNiW high entropy alloy powder is used as raw material, which, calculated by weight percentage, includes 23% Cr, 26% Ni, 16% W, 0.14% C, and the rest is Co. The CoCrNiW high entropy alloy powder is obtained by melting the master alloy into a melt in a vacuum induction melting furnace, then passing through a gas atomization device, introducing argon gas, and finally solidifying and cooling to form CoCrNiW high entropy alloy powder, and collecting the powder with a particle size of 20 to 65 μm by sieving for use;

[0070] (2) Laying a layer of CoCrNiW high entropy alloy powder on the substrate, scanning the powder layer using SLM technology to melt it, and then solidifying and cooling to obtain the first layer of blank matrix;

[0071] (3) Laying a second layer of CoCrNiW high entropy alloy powder on the surface of the first layer of blank matrix, scanning the layer of powder using SLM technology to melt it, and obtaining the second layer of blank matrix after solidification and cooling;

[0072] (4) Repeat steps (2) and (3) 100 times to obtain a molded blank with a thickness of about 3 mm. The specific process parameters are as follows: laser power of 300 W, scanning speed of 950 mm / s, and scanning layer thickness of 30 μm;

[0073] (5) The cladding formed blank is heat treated, and the specific process parameters are: heating to 750°C at a heating rate of 5°C / min, placing the formed blank of step (4), keeping it warm for 60 minutes, taking it out and water cooling it to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy.

[0074] Comparative Example 1

[0075] The only difference from Example 1 is that the formed blank is not subjected to the heat treatment of step (5), and the rest is the same as Example 1.

[0076] Comparative Example 2

[0077] Compared with Example 1, Comparative Example 2 was prepared using a traditional forging method, and the specific method is as follows:

[0078] CoCrNiW high entropy alloy forging billets were used as raw materials. The master alloy was smelted in a vacuum induction melting furnace. After homogenization treatment, component segregation was eliminated. After repeated forging and rolling, the grains were refined. The alloy was then kept at 1180°C for 40 minutes and finally air-cooled.

[0079] The CoCrNiW high entropy alloy forging blank used in this comparative example comprises, by weight percentage, 25% Cr, 25% Ni, 15% W, 0.08% C, and the remainder Co.

[0080] Performance testing and characterization

[0081] Through Figure 1 a and Figure 1 b, the cellular structure can be clearly observed, and there is a dense nanoscale precipitate phase at the boundary of the cellular tissue. Figure 1 The electron diffraction in the upper left corner of a shows that the precipitate phase is M in a coherent relationship with the matrix. 23 C6 carbide.

[0082] pass Figure 2 Bright field image ( Figure 2 a) and dark field image ( Figure 2 b) From the observation, it can be seen that the high-entropy alloy with cellular heterogeneous characteristics prepared directly by laser cladding technology without heat treatment has a cellular multi-level structure but no nano-precipitation structure.

[0083] Through Figure 3 Observation shows that the product prepared by conventional forging and rolling does not have a cellular isomeric structure and nano-precipitation characteristics distributed along the cellular boundaries.

[0084] The products prepared in Examples 1-3 of the present invention and Comparative Examples 1-2 were subjected to room temperature stretching, 550°C stretching, and 750°C stretching tests. The specific test method was to conduct high-temperature tensile tests in accordance with the standard GB / T228.2-2015 "Tensile Tests on Metallic Materials - Part 2: High-Temperature Test Methods". The test results are shown in Table 1 below.

[0085] Table 1 Experimental data of room temperature stretching, 550°C stretching and 750°C stretching of Example 1 and Comparative Examples 1-2

[0086]

[0087] It can be seen from Table 1 that the cellular heterogeneous nano-precipitation high-temperature strengthened alloys obtained in Examples 1 to 2 exhibit a high entropy alloy at room temperature that is no less than that obtained in Comparative Example 1, and are significantly better than Comparative Example 2 in terms of strength and plasticity and toughness. At 550°C and 750°C, the yield strength of Comparative Example 1 is still better than that of Comparative Example 2, but it is significantly reduced. At the same service temperature, the yield strength of Examples 1-2 is significantly better than that of Comparative Example 1 and Comparative Example 2, which shows that the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy provided by the present invention can effectively achieve high-temperature strengthening. At the same time, since the nano-precipitation phase is a carbide coherent with the matrix, the dense nano-carbide does not significantly affect the plasticity and toughness of Example 1, so that its strong and tough characteristics at room temperature are still retained.

[0088] Those skilled in the art will appreciate that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy, characterized in that: The raw material composition includes, by mass fraction, 32-38% Co, 22-28% Cr, 22-28% Ni, 12-18% W and 0.05-0.15% C; The preparation method of the cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy comprises the following steps: The required CoCrNiW high entropy alloy powder is subjected to laser additive manufacturing to obtain a high entropy alloy formed blank; heat-treating the high-entropy alloy formed blank to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy; The steps of laser additive manufacturing are as follows: 1) Laying a layer of CoCrNiW high entropy alloy powder on a substrate, melting and solidifying and cooling in sequence to obtain a first layer of blank matrix; 2) laying a second layer of CoCrNiW high entropy alloy powder on the surface of the first layer of blank matrix, and sequentially melting and solidifying and cooling to obtain a second layer of blank matrix; 3) Repeating steps 1) and 2) in sequence until a high-entropy alloy formed blank of the desired design size and shape is obtained; The conditions of the laser additive manufacturing include: laser power of 50 to 500 W, scanning speed of 0.5 to 5 m / s, and scanning layer thickness of 15 to 50 μm; The heat treatment conditions include: keeping the temperature at 730-760° C. for 60-120 minutes.

2. The method for preparing the cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy according to claim 1, characterized in that: The following steps are involved: The required CoCrNiW high entropy alloy powder is subjected to laser additive manufacturing to obtain a high entropy alloy formed blank; heat-treating the high-entropy alloy formed blank to obtain a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy; The steps of laser additive manufacturing are as follows: 1) Laying a layer of CoCrNiW high entropy alloy powder on a substrate, melting and solidifying and cooling in sequence to obtain a first layer of blank matrix; 2) laying a second layer of CoCrNiW high entropy alloy powder on the surface of the first layer of blank matrix, and sequentially melting and solidifying and cooling to obtain a second layer of blank matrix; 3) Repeating steps 1) and 2) in sequence until a high-entropy alloy formed blank of the desired design size and shape is obtained; The conditions of the laser additive manufacturing include: laser power of 50 to 500 W, scanning speed of 0.5 to 5 m / s, and scanning layer thickness of 15 to 50 μm; The heat treatment conditions include: keeping the temperature at 730-760° C. for 60-120 minutes.

3. The method for preparing a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy according to claim 2, characterized in that: The particle size of the CoCrNiW high entropy alloy powder is 10 to 100 μm.

4. The method for preparing a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy according to claim 3, characterized in that: The CoCrNiW high entropy alloy powder is prepared by subjecting alloy raw materials to gas atomization pulverization treatment.

5. The method for preparing a cellular heterogeneous nano-precipitated high-temperature strengthened high-entropy alloy according to claim 2, characterized in that: The heating rate to the heat treatment temperature is 5 to 15° C. / min.

6. Application of the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy prepared by the preparation method of the cellular heterogeneous nano-precipitation high-temperature strengthened high-entropy alloy according to claim 1 or any one of claims 2 to 5 in the aerospace, gas power generation or nuclear fields.

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