A high-temperature resistant alloy powder for additive manufacturing and a preparation method thereof

Abstract

The present invention relates to the field of alloy technology, and particularly to a high-temperature resistant alloy powder for additive manufacturing and a preparation method thereof. The method: dissolve lanthanum chloride in a first solvent, then add graphene oxide, after ultrasonic dispersion, add an ammonia aqueous solution to react, after the reaction, centrifuge, separate, wash, dry and carry out a heat preservation reaction, and obtain a lanthanum oxide-graphene composite after cooling; disperse the lanthanum oxide-graphene composite in a second solvent, add 3-vinylphenylboronic acid to obtain a mixed solution, then place the mixed solution in a 60Co radiation source for irradiation, after the irradiation ends, wash, filter and dry to obtain a lanthanum oxide-boron-containing graphene composite; under a protective atmosphere, carry out primary ball milling on magnesium powder, aluminum powder and zinc powder, then add the lanthanum oxide-boron-containing graphene composite for secondary ball milling to obtain an alloy powder; carry out heat treatment on the alloy powder to obtain a high-temperature resistant alloy. The alloy provided by the present invention has excellent high-temperature resistance, corrosion resistance and wear resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloys, and particularly relates to a high-temperature resistant alloy powder for additive manufacturing and a preparation method thereof. Background Art

[0002] AZ61 magnesium alloy is a wrought magnesium alloy with magnesium as the matrix and aluminum and zinc as the main alloying elements, and contains a small amount of manganese element to improve corrosion resistance. This alloy has high specific strength and specific stiffness, good thermal and electrical conductivity, damping and shock absorption properties, and processing and forming properties, and is widely used in fields such as automobiles, electronic communications, aerospace, etc., such as lightweight components like clutch housings, gearbox housings, and steering wheel brackets. However, although AZ61 performs excellently at room temperature, it still has significant defects in high-temperature resistance, corrosion resistance, and wear resistance. The limitations of AZ61 mainly stem from its alloy composition and phase structure. When the temperature exceeds 120 °C, the phase will gradually dissolve into the α-Mg matrix, resulting in a sharp drop in material strength. In addition, in a medium containing (such as NaCl solution), galvanic corrosion occurs between the α-Mg matrix and the phase. The matrix acts as the anode and preferentially dissolves, while the β phase acts as the cathode to accelerate the local corrosion process. The corrosion rate of as-cast AZ61 can reach 2.86×10⁻ 4 g / (h·cm²), and the corrosion morphology is mainly pitting corrosion expanding to surface corrosion. Although adding rare earth elements (such as Nd) or transition metals (such as Ca) can refine grains and improve the β phase distribution, excessive addition will instead form new phases such as Al-Nd or Al-Ca, exacerbating galvanic corrosion. In addition, AZ61 is prone to oxidative wear under dry friction conditions. The MgO film formed on the surface is brittle and easy to break and peel off, and it is difficult to form a continuous protective layer, further exacerbating material loss.

[0003] Generally speaking, the lightweight advantage of AZ61 magnesium alloy makes it occupy an important position in the field of structural materials. However, its high-temperature resistance is limited by the thermal instability of the β phase and the intrinsic characteristics of the HCP structure, its corrosion resistance is difficult to meet the requirements of harsh environments due to galvanic corrosion and oxide film defects, and its wear resistance highly depends on the heat treatment process and is easily affected by tissue coarsening.

[0004] As disclosed in CN118417556A, a graphene-reinforced nickel-based alloy material, its preparation method, and a graphene-reinforced nickel-based alloy strengthening layer are provided. The method includes: performing a first mixing and a first ultrasonic treatment on graphene powder, a modifier, and a dispersant to obtain a graphene mixed solution; performing a second mixing and a second ultrasonic treatment on the graphene mixed solution and nickel-based alloy powder, followed by filtration and grinding to obtain a graphene-nickel-based alloy mixed powder; and performing a heat treatment on the graphene-nickel-based alloy mixed powder to obtain a graphene-reinforced nickel-based alloy material. Although the graphene-reinforced nickel-based alloy material obtained in this application can solve the problems of insufficient hardness and corrosion resistance of the alloy in high-temperature and corrosive environments, when the modifier undergoes heat treatment, brittle phases (such as carbides) may be generated at the interface, which instead becomes a crack source, resulting in a reduction in the properties such as the strength of the alloy.

[0005] As disclosed in CN102251162A, a preparation method of a high-performance nano-lanthanum oxide-doped molybdenum-silicon-boron alloy is provided. Using molybdenum powder, silicon powder, and boron powder as raw materials, different contents of nano-lanthanum oxide powder are doped, and after ball milling and mixing evenly, pre-pressing and pre-sintering are carried out. The obtained sintered body is melted in a vacuum arc furnace, and the melting working current is 800 - 1000A. The obtained alloy ingot is crushed and ball milled to make powder, and the alloy powder is sieved with a 200 - 300 mesh Tyler sieve. The obtained alloy powder is sintered in a vacuum hot pressing sintering furnace at a temperature of 1500 - 1700°C, a pressure of 30 - 50MPa, and a time of 1 - 3 hours. After sintering, it is cooled to room temperature with the furnace. The nano-lanthanum oxide-doped molybdenum-silicon-boron alloy obtained in this application has the characteristics of uniform microstructure, high density, and high strength. However, when the solid-solid doping method (direct mixing of molybdenum powder and nano-lanthanum oxide) is used in this application, nanoparticle agglomeration is likely to occur, resulting in uneven distribution of rare earth phases, and thus leading to a decline in the performance of the alloy.

[0006] In view of this, the present invention is specifically proposed. Summary of the Invention

[0007] The object of the present invention is to provide a high-temperature resistant alloy powder for additive manufacturing and its preparation method. The alloy provided by the present invention has excellent high-temperature resistance, corrosion resistance, and wear resistance.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] In a first aspect, an embodiment of the present invention provides a preparation method of a high-temperature resistant alloy for additive manufacturing, including the following steps:

[0010] Step (1): Dissolve lanthanum chloride in the first solvent, then add graphene oxide. After ultrasonic dispersion, add ammonia water solution for the first reaction. After the reaction is completed, centrifuge to separate the solid phase, wash, dry, and conduct a heat preservation reaction. After cooling, grind and screen to obtain a lanthanum oxide-graphene composite;

[0011] Step (2): Disperse the lanthanum oxide-graphene composite in the second solvent, ultrasonically disperse it evenly, then add 3-vinylphenylboronic acid to obtain a mixed solution. Then place the mixed solution in a 60Co radiation source for irradiation. After the irradiation is completed, wash, filter, dry, grind, and screen to obtain a lanthanum oxide-boron-containing graphene composite.

[0012] Step (3): Under a protective atmosphere, conduct the first ball milling of magnesium powder, aluminum powder, and zinc powder, then add the lanthanum oxide-boron-containing graphene composite for the second ball milling to obtain alloy powder;

[0013] Step (4): Heat-treat the alloy powder to obtain a high-temperature resistant alloy.

[0014] In the present invention, by compounding lanthanum oxide and graphene oxide together, the dispersion of lanthanum oxide in the alloy is improved, thereby enhancing the high-temperature resistance, corrosion resistance, wear resistance, etc. of the alloy powder.

[0015] In addition, in the present invention, boron modification is simultaneously carried out on graphene oxide. Boron, graphene oxide, and lanthanum oxide synergistically improve the high-temperature resistance, corrosion resistance, wear resistance, etc. of the alloy powder in the alloy matrix.

[0016] Specifically, in terms of compatibility, the nanoparticles of lanthanum oxide form chemical bonds with the oxygen-containing functional groups (such as carboxyl groups and epoxy groups) of graphene oxide (GO) through surface hydroxyl groups, constituting a stable composite structure. This composite is evenly dispersed in the magnesium, aluminum, and zinc matrices during the subsequent ball milling process. Its interfacial bonding force is enhanced due to the two-dimensional sheet structure of GO, effectively inhibiting the agglomeration of metal particles. In addition, boron atoms generated by the decomposition of 3-vinylphenylboronic acid after irradiation bind to the defect sites on the surface of GO through chemical bonding to form a boron-doped graphene network. This network not only serves as a bridge to connect lanthanum oxide and the metal matrix but also reduces the interfacial energy difference through the hybridization of the p orbitals of boron atoms and the d orbitals of metals, promoting the compatibility of the heterogeneous interface. At the same time, the nano-size effect of lanthanum oxide makes it easier to embed into the interstitial sites of the metal lattice, alleviating the micro-stress concentration caused by the difference in thermal expansion coefficients.

[0017] In terms of high-temperature resistance, first of all, lanthanum oxide remains thermodynamically stable at high temperatures. Its nanoparticles inhibit grain coarsening by pinning grain boundaries, thereby increasing the recrystallization temperature of the alloy. The two-dimensional structure of GO forms a continuous three-dimensional heat conduction network at high temperatures, accelerating heat diffusion and reducing local thermal stress. Its high modulus property can also hinder dislocation slip and enhance the high-temperature creep resistance. The introduction of boron element plays a role through two ways: on the one hand, boron atoms react with aluminum and magnesium during heat treatment to generate , and other borides. These high-melting-point phases act as dispersion strengthening phases to hinder high-temperature deformation. On the other hand, boron-doped graphene formed by the combination of boron and GO preferentially generates glassy film in a high-temperature oxidation environment. This film has self-healing properties and can jointly form a double-layer antioxidant barrier with . Experiments show that the oxygen diffusion coefficient of this composite oxide film is 2-3 orders of magnitude lower than that of a single film, significantly delaying the high-temperature oxidation process.

[0018] Finally, in terms of corrosion resistance, the ternary synergistic effect of lanthanum oxide-graphene-boron is manifested as the coupling effect of physical barrier and electrochemical protection. The sheet structure of GO forms a dense physical isolation layer on the surface of the alloy, and the theoretical tortuosity of its penetration path can reach 10 4 orders of magnitude, greatly extending the diffusion path of the corrosive medium. Lanthanum oxide promotes the formation of a passivation film rich in on the surface of the metal matrix (such as La-doped ). This film has a lower oxygen vacancy concentration and a higher breakdown potential (which can be increased by about 0.3V). The addition of boron further optimizes the chemical stability of the passivation film: in a erosion environment, boron atoms preferentially combine with to form soluble , consuming the local corrosive medium. At the same time, the high bond energy of the B-O bond (about 809 kJ / mol) enhances the structural integrity of the passivation film. The multi-level protection system of "physical barrier-chemical passivation-medium consumption" formed by the three synergistically reduces the corrosion rate of the alloy in the salt spray test to less than 1 / 5 of that of traditional magnesium alloys.

[0019] In a preferred embodiment, in step (1), the first solvent is deionized water.

[0020] In a preferred embodiment, in step (1), the dosage ratio of lanthanum chloride, the first solvent and graphene oxide is (5-10 g): (100-200 ml): 1 g.

[0021] In a preferred embodiment, in step (1), the time of ultrasonic treatment is 30-60 min.

[0022] In a preferred embodiment, in step (1), the volume ratio of the aqueous ammonia solution to the first solvent is (0.2 - 0.5):(0.5 - 1).

[0023] In a preferred embodiment, in step (1), the primary reaction conditions are: reaction temperature 50 - 100 °C, reaction time 0.5 - 2 h.

[0024] In a preferred embodiment, in step (1), the conditions for the heat preservation reaction are: under nitrogen protection, heat preservation at 500 - 800 °C for 1 - 5 h.

[0025] In a preferred embodiment, in step (2), the second solvent is a mixture of water and ethanol, and the volume ratio of water to ethanol is 1:(1 - 2).

[0026] In a preferred embodiment, in step (2), the dosage ratio of the lanthanum oxide - graphene composite, the second solvent, and 3 - vinylphenylboronic acid is 1 g:(100 - 200 ml):(10 - 50 g).

[0027] In a preferred embodiment, in step (2), the absorbed dose of the irradiation is 1 - 500 kGy.

[0028] In a preferred embodiment, in step (2), the sieve mesh used for sieving is 200 - 400 mesh.

[0029] In a preferred embodiment, in step (3), the protective atmosphere is nitrogen or argon.

[0030] In a preferred embodiment, in step (3), the mass ratio of the magnesium powder, aluminum powder, zinc powder, and lanthanum oxide - boron - containing graphene composite is 100:(10 - 20):(1 - 10):(5 - 10).

[0031] In a preferred embodiment, in step (3), the conditions for the first ball milling are: ball milling at 300 - 500 r / min for 1 - 3 h.

[0032] In a preferred embodiment, in step (3), the conditions for the second ball milling are: ball milling at 300 - 500 r / min for 2 - 5 h.

[0033] In a preferred embodiment, in step (4), the conditions for the heat treatment are: in a nitrogen atmosphere, heating at 5 - 10 °C / min to 600 - 800 °C and holding for 30 - 60 min, cooling to 400 - 600 °C and holding for 4 - 8 h, and then cooling to room temperature and heating again at 5 - 10 °C / min to 200 - 300 °C and holding for 2 - 6 h.

[0034] Second aspect, an embodiment of the present invention provides a high-temperature resistant alloy obtained by the preparation method of the high-temperature resistant alloy as described above.

[0035] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0036] 1. By combining lanthanum oxide and graphene oxide, the present invention improves the dispersion of lanthanum oxide in the alloy, thereby enhancing the high-temperature resistance, corrosion resistance, wear resistance and other properties of the alloy powder.

[0037] 2. The present invention simultaneously performs boron modification on graphene oxide, and boron, graphene oxide and lanthanum oxide synergistically improve the high-temperature resistance, corrosion resistance, wear resistance and other properties of the alloy powder in the alloy matrix. Specific Embodiments

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0039] Unless otherwise specified, the raw materials and reagents used in the present invention are all commercially available. Example 1

[0040] This example provides a preparation method of a high-temperature resistant alloy for additive manufacturing, including the following steps:

[0041] Step (1): Dissolve 6 g of lanthanum chloride in 150 ml of deionized water, then add 1 g of graphene oxide, ultrasonically disperse for 40 min, then add 50 ml of ammonia water solution (28 - 32%), heat to 65 °C, react for 1 h. After the reaction, centrifuge and separate the solid phase, wash, dry, and under nitrogen protection, keep warm at 650 °C for 2 h, cool, and then grind and pass through a 300-mesh sieve to obtain a lanthanum oxide-graphene composite.

[0042] Step (2): Disperse 4 g of the lanthanum oxide-graphene composite in a mixed liquid of 200 ml of deionized water and 200 ml of ethanol, ultrasonically disperse for 30 min, then add 50 g of 3-vinylphenylboronic acid to obtain a mixed liquid. Then place the mixed liquid in a 60Co radiation source for irradiation, the absorbed dose of irradiation is 200 kGy. After the irradiation, wash, filter, dry, grind and pass through a 300-mesh sieve to obtain a lanthanum oxide-boron-containing graphene composite.

[0043] Step (3): Under nitrogen protection, 100 g of magnesium powder, 12.4 g of aluminum powder, and 6.7 g of zinc powder were mixed evenly and ball-milled at 400 r / min for 2 h. Then, 6.7 g of lanthanum oxide-boron-containing graphene composite was added and ball-milled at 400 r / min for 3 h to obtain alloy powder;

[0044] Step (4): Under a nitrogen atmosphere, the alloy powder was heated to 700 °C at a rate of 5 °C / min and held for 40 min. Then, it was cooled to 500 °C and held for 5 h. After cooling to room temperature, it was heated to 250 °C at a rate of 5 °C / min and held for 5 h. After cooling, high-temperature resistant alloy powder was obtained. Example 2

[0045] This example provides a preparation method of a high-temperature resistant alloy for additive manufacturing, including the following steps:

[0046] Step (1): 8 g of lanthanum chloride was dissolved in 180 ml of deionized water. Then, 1 g of graphene oxide was added. After ultrasonic dispersion for 40 min, 60 ml of ammonia water solution (28 - 32%) was added and heated to 75 °C. The reaction was carried out for 1 h. After the reaction ended, the solid phase was separated by centrifugation, washed, dried, and held at 600 °C for 2 h under nitrogen protection. After cooling, it was ground and passed through a 300-mesh sieve to obtain lanthanum oxide-graphene composite;

[0047] Step (2): 4 g of lanthanum oxide-graphene composite was dispersed in a mixed liquid of 200 ml of deionized water and 200 ml of ethanol. After ultrasonic dispersion for 30 min, 80 g of 3-vinylphenylboronic acid was added to obtain a mixed solution. Then, the mixed solution was placed in a 60Co radiation source for irradiation. The absorbed dose of irradiation was 400 kGy. After irradiation ended, it was washed, filtered, dried, ground, and passed through a 300-mesh sieve to obtain lanthanum oxide-boron-containing graphene composite.

[0048] Step (3): Under nitrogen protection, 100 g of magnesium powder, 16.6 g of aluminum powder, and 7.8 g of zinc powder were mixed evenly and ball-milled at 400 r / min for 2 h. Then, 8.5 g of lanthanum oxide-boron-containing graphene composite was added and ball-milled at 400 r / min for 3 h to obtain alloy powder;

[0049] Step (4): Under a nitrogen atmosphere, the alloy powder was heated to 750 °C at a rate of 5 °C / min and held for 40 min. Then, it was cooled to 400 °C and held for 5 h. After cooling to room temperature, it was heated to 250 °C at a rate of 5 °C / min and held for 5 h. After cooling, high-temperature resistant alloy powder was obtained.

[0050] Comparative Example 1

[0051] This comparative example provides a preparation method of a high-temperature resistant alloy for additive manufacturing, including the following steps:

[0052] Step (1): Disperse 4 g of graphene oxide in a mixed liquid of 200 ml of deionized water and 200 ml of ethanol, ultrasonically disperse for 30 min, then add 50 g of 3-vinylphenylboronic acid to obtain a mixed solution. Then, place the mixed solution in a 60Co radiation source for irradiation, with an absorbed dose of irradiation being 200 kGy. After irradiation, wash, filter, dry, and grind through a 300-mesh sieve to obtain boron-containing graphene oxide.

[0053] Step (2): Under nitrogen protection, mix 100 g of magnesium powder, 12.4 g of aluminum powder, and 6.7 g of zinc powder evenly and ball-mill at 400 r / min for 2 h. Then, add 6.7 g of boron-containing graphene oxide and ball-mill at 400 r / min for 3 h to obtain alloy powder.

[0054] Step (3): Under a nitrogen atmosphere, heat the alloy powder from room temperature to 700 °C at a rate of 5 °C / min and hold for 40 min, then cool to 500 °C and hold for 5 h. After cooling to room temperature, heat to 250 °C at a rate of 5 °C / min and hold for 5 h. After cooling, obtain high-temperature resistant alloy powder.

[0055] Comparative Example 2

[0056] This comparative example provides a preparation method of a high-temperature resistant alloy for additive manufacturing, including the following steps:

[0057] Step (1): Dissolve 6 g of lanthanum chloride in 150 ml of deionized water, then add 1 g of graphene oxide, ultrasonically disperse for 40 min, add 50 ml of ammonia water solution (28 - 32%) and heat to 65 °C, react for 1 h. After the reaction, centrifuge to separate the solid phase, wash, dry, and under nitrogen protection, hold at 650 °C for 2 h. After cooling, grind through a 300-mesh sieve to obtain a lanthanum oxide-graphene composite.

[0058] Step (2): Under nitrogen protection, mix 100 g of magnesium powder, 12.4 g of aluminum powder, and 6.7 g of zinc powder evenly and ball-mill at 400 r / min for 2 h. Then, add 6.7 g of lanthanum oxide-graphene composite and ball-mill at 400 r / min for 3 h to obtain alloy powder.

[0059] Step (4): Under a nitrogen atmosphere, heat the alloy powder from room temperature to 700 °C at a rate of 5 °C / min and hold for 40 min, then cool to 500 °C and hold for 5 h. After cooling to room temperature, heat to 250 °C at a rate of 5 °C / min and hold for 5 h. After cooling, obtain high-temperature resistant alloy powder.

[0060] Comparative Example 3

[0061] Step (1): Disperse 4 g of graphene oxide in a mixed liquid of 200 ml of deionized water and 200 ml of ethanol, ultrasonically disperse for 30 min, then add 50 g of 3-vinylphenylboronic acid to obtain a mixed solution. Then place the mixed solution in a 60Co radiation source for irradiation, with an absorbed dose of irradiation being 200 kGy. After irradiation, wash, filter, dry, and grind through a 300-mesh sieve to obtain boron-containing graphene oxide.

[0062] Step (2): Under nitrogen protection, mix 100 g of magnesium powder, 16.6 g of aluminum powder, and 7.8 g of zinc powder evenly and ball-mill at 400 r / min for 2 h. Then add 4.25 g of boron-containing graphene oxide and 4.25 g of lanthanum oxide and ball-mill at 400 r / min for 3 h to obtain an alloy powder.

[0063] Step (3): Under a nitrogen atmosphere, heat the alloy powder from room temperature to 750 °C at a rate of 5 °C / min, hold for 40 min, then cool to 400 °C and hold for 5 h. After cooling to room temperature, heat to 250 °C at a rate of 5 °C / min and hold for 5 h, and then cool to obtain a high-temperature resistant alloy powder.

[0064] Comparative Example 4

[0065] Compared with Example 1, the difference in this comparative example lies in the specific heat treatment method: heat the alloy powder from room temperature to 250 °C at a rate of 5 °C / min, hold for 5 h, and then cool to obtain a high-temperature resistant alloy powder.

[0066] Comparative Example 5

[0067] This comparative example provides a preparation method for a high-temperature resistant alloy for additive manufacturing, including the following steps:

[0068] Step (1): Under nitrogen protection, mix 100 g of magnesium powder, 12.4 g of aluminum powder, and 6.7 g of zinc powder evenly and ball-mill at 400 r / min for 2 h to obtain an alloy powder.

[0069] Step (2): Under a nitrogen atmosphere, heat the alloy powder from room temperature to 700 °C at a rate of 5 °C / min, hold for 40 min, then cool to 500 °C and hold for 5 h. After cooling to room temperature, heat to 250 °C at a rate of 5 °C / min and hold for 5 h, and then cool to obtain a high-temperature resistant alloy powder.

[0070] Test Example

[0071] 1. Refer to GB / T228.1 - 2010 to test the tensile strength of the high-temperature resistant alloy powders obtained in the examples and comparative examples at room temperature of 25 °C and 600 °C. The results are shown in Table 1.

[0072] 2. Use a UMT-3 controlled environment friction and wear testing machine to conduct anti-wear tests on the high-temperature resistant alloy powders obtained in the examples and comparative examples: pressure 100 N, rotation speed 300 r / min, time 90 min, and measure their wear amounts. The results are shown in Table 1.

[0073] 3. Refer to GB / T 10125-199, expose the high-temperature resistant alloy powders obtained in the examples and comparative examples to a salt spray formed by a 5 wt% NaCl solution for 8 h, and then leave them for 16 h. Measure the average corrosion rate to investigate the corrosion resistance of the alloy. The results are shown in Table 1.

[0074]

[0075] From the above performance test results, it can be seen that the high-temperature resistance, wear resistance, and corrosion resistance of Examples 1-2 have been significantly improved. In particular, the comprehensive performance of Example 2 is the most prominent. This is mainly because the synergistic effect between the lanthanum oxide and boron-containing graphene obtained in the present invention improves the performance of the alloy.

[0076] In the comparative examples, because the necessary technical solutions were not adopted, their performance in the corresponding performance tests was significantly worse than that of the examples. This better proves the irreplaceability of the specific technical solutions of this application for achieving the technical effects and solving the technical problems.

[0077] The above is the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a high-temperature resistant alloy powder for additive manufacturing, characterized in that, It includes the following steps: Step (1): Dissolve lanthanum chloride in the first solvent, then add graphene oxide. After ultrasonic dispersion, add an ammonia aqueous solution for the first reaction. After the reaction ends, centrifuge to separate the solid phase, wash, dry, and conduct a heat preservation reaction. After cooling, grind and sieve to obtain a lanthanum oxide-graphene composite; Step (2): Disperse the lanthanum oxide-graphene composite in the second solvent, ultrasonically disperse it evenly, then add 3-vinylphenylboronic acid to obtain a mixed solution. Then place the mixed solution in a 60Co radiation source for irradiation. After the irradiation ends, wash, filter, dry, grind, and sieve to obtain a lanthanum oxide-boron-containing graphene composite; Step (3): Under a protective atmosphere, conduct primary ball milling on magnesium powder, aluminum powder, and zinc powder, then add the lanthanum oxide-boron-containing graphene composite for secondary ball milling to obtain alloy powder; Step (4): Heat-treat the alloy powder to obtain a high-temperature resistant alloy; In step (2), the second solvent is a mixture of water and ethanol, and the volume ratio of water to ethanol is 1:(1 - 2); And / or, in step (2), the dosage ratio of the lanthanum oxide-graphene composite, the second solvent, and 3-vinylphenylboronic acid is 1 g:(100 - 200 ml):(10 - 50 g); In step (2), the absorbed dose of the irradiation is 1 - 500 kGy; And / or, in step (2), the sieve used for sieving is 200 - 400 mesh; 2. The preparation method of the high-temperature resistant alloy powder for additive manufacturing according to claim 1, wherein, In step (1), the first solvent is deionized water; And / or, in step (1), the dosage ratio of lanthanum chloride, the first solvent, and graphene oxide is (5 - 10 g):(100 - 200 ml):1 g; 3. The method for preparing a high-temperature resistant alloy powder for additive manufacturing according to claim 1, wherein In step (1), the ultrasonic time is 30 - 60 min; And / or, in step (1), the volume ratio of the ammonia aqueous solution to the first solvent is (0.2 - 0.5):(0.5 - 1); 4. The method for preparing a high-temperature resistant alloy powder for additive manufacturing according to claim 1, characterized in that, In step (1), the conditions for the first reaction are: reaction temperature 50 - 100 °C, reaction time 0.5 - 2 h; And / or, in step (1), the conditions for the heat preservation reaction are: under nitrogen protection, heat preservation at 500 - 800 °C for 1 - 5 h; 5. The preparation method of the high-temperature resistant alloy powder for additive manufacturing according to claim 1, characterized in that, In step (3), the protective atmosphere is nitrogen or argon; And / or, in step (3), the mass ratio of magnesium powder, aluminum powder, zinc powder, and the lanthanum oxide-boron-containing graphene composite is 100:(10 - 20):(1 - 10):(5 - 10); 6. The preparation method of the high-temperature resistant alloy powder for additive manufacturing according to claim 1, wherein, In step (3), the conditions for the primary ball milling are: ball milling at 300 - 500 r / min for 1 - 3 h; And / or, in step (3), the conditions for the secondary ball milling are: ball milling at 300 - 500 r / min for 2 - 5 h; 7. The preparation method of the high-temperature resistant alloy powder for additive manufacturing according to claim 1, characterized in that, In step (4), the conditions for the heat treatment are: in a nitrogen atmosphere, heat up to 600 - 800 °C at 5 - 10 °C / min, hold for 30 - 60 min, cool down to 400 - 600 °C, hold for 4 - 8 h, cool to room temperature, then heat up to 200 - 300 °C at 5 - 10 °C / min and hold for 2 - 6 h.

8. A heat-resistant alloy powder prepared by the method for preparing a heat-resistant alloy powder for additive manufacturing according to any one of claims 1-7.

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