Heat-resistant aluminum-based composite material and selective laser melting forming preparation method and application thereof

Abstract

The invention discloses a heat-resistant aluminum-based composite material and a selective laser melting forming preparation method and application thereof, and belongs to the technical field of metal material additive manufacturing. According to the method, aluminum-silicon alloy matrix powder and nano CuO powder are mixed to serve as cladding powder, Al2O3 and Al2Cu nano particles and precipitated phases which are evenly distributed are directly generated in matrix alloy through in-situ reaction of Al-CuO in a selective laser melting process under the action of high-energy laser, and an aluminum-silicon eutectic structure can be refined to 200-300 nm. Cooperative strengthening of multiple precipitated phases and multiple interfaces is achieved, and the problems of coarse precipitated phases, unmelted particles and the like generated by traditional alloying methods and the like are solved. According to the method, the high-temperature mechanical property of the selective laser melting forming aluminum-based composite material can be remarkably improved. The prepared composite material is suitable for high-temperature light-weight components such as aerospace and nuclear energy equipment, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing of metal materials, and in particular to a heat-resistant aluminum-based composite material and a selective laser melting forming preparation method and application thereof. Background Art

[0002] Although traditional heat-resistant alloys (such as steel, nickel alloys and tungsten alloys) have excellent high-temperature strength and creep resistance, their high density (>7.5g / cm 3 ) and low thermal conductivity limit its application in lightweight scenarios. Although aluminum-based composite materials have the advantage of light weight (density ~ 2.7g / cm 3 ), but traditional casting or powder metallurgy methods struggle to achieve a uniform distribution of nano-reinforcement phases. Furthermore, exogenously added reinforcement phases (such as Y2O3, MgO, and Al2O3) poorly bond with the aluminum matrix interface, resulting in a reduction in the strengthening effect. Furthermore, heat-resistant aluminum-based composites produced using traditional casting or powder metallurgy methods can only form simple, dense structures that cannot meet the needs of modern industry.

[0003] While selective laser melting (SLM) technology can achieve rapid prototyping of complex metal components, existing aluminum-based composites formed using SLM suffer from insufficient high-temperature performance. For example, tensile strength at 200°C is typically less than 300 MPa, and at 400°C less than 50 MPa. Conventional strengthening methods (such as microalloying, nanoparticle addition, and heat treatment) struggle to overcome performance bottlenecks. Furthermore, high-energy laser input in the SLM process can easily lead to dissolution of exogenously added nanoparticles or interfacial stress concentration, forming pores or cracks, further reducing the density, processing window, and mechanical properties of the composite material.

[0004] In the prior art, patent applications CN202510192398 and CN202310030680 respectively involve methods for preparing two heat-resistant aluminum alloys using selective laser melting: an Al-Si-Fe-Ni-Mn alloy and an Al-Mg-Ni-Ti-Zr-B alloy. However, the performance of these two alloys remains insufficient, especially at high temperatures above 200°C. The ultimate tensile strengths of these two alloys at 300°C are approximately 200 MPa and 60 MPa, respectively. Patent application CN202411405195.8 reports an additive manufacturing method for aluminum-silicon alloys using in-situ reaction to generate nanoparticle reinforcements. This method involves introducing reactive gases such as N2 and C2H2 into the selective laser melting additive forming process. Under the action of a high-energy laser beam, the gases and metal react on the surface of the molten pool to produce a variety of nano-sized granular reinforcements. However, this method is relatively cumbersome and lacks production safety, making it difficult to implement in large-scale industrial production.

[0005] In summary, existing selective laser melting aluminum-based composites still lack strength and durability in high-temperature environments. Current technical methods and modification approaches still suffer from insufficient strength, high costs, and limitations in large-scale industrial production. Therefore, a new method is needed to enhance the heat resistance of aluminum-based composites and expand the application range of selective laser melting aluminum-based composites. Summary of the Invention

[0006] To address the existing challenges of selective laser melting (SLM) aluminum-based composites, including insufficient high-temperature performance, complex preparation processes using traditional strengthening methods, and uneven distribution of the reinforcing phase, the present invention aims to provide a heat-resistant aluminum-based composite material and its selective laser melting preparation method and application. By utilizing the in-situ reaction of Al-CuO, nanoparticles and precipitated phases are generated in situ within the SLM aluminum-based composite material, significantly improving the high-temperature mechanical properties of the aluminum-based composite material. The resulting aluminum-based composite material is suitable for engineering applications in lightweight, high-temperature components, such as aerospace engine hot-end components, nuclear reactor cladding, and other lightweight, high-temperature structural components.

[0007] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0008] A selective laser melting method for preparing a heat-resistant aluminum-based composite material comprises adding a certain amount of nano-CuO powder to an aluminum-silicon alloy matrix powder as a cladding powder, and then utilizing selective laser melting technology to prepare the heat-resistant aluminum-based composite material. Under the action of a high-energy laser, the molten CuO reacts with the liquid aluminum-silicon alloy, achieving in-situ generation of oxides (Al2O3) and intermetallic phases (Al2Cu) within the aluminum-silicon alloy.

[0009] The method specifically comprises the following steps:

[0010] (1) Model building and printing parameter setting: Determine the placement and angle of the part to be formed, slice and layer the three-dimensional model of the part through slicing software, plan the forming path, and set the forming parameters;

[0011] (2) Substrate and cladding powder processing: Before printing, clean the aluminum substrate and dry the cladding powder. After cooling, load the substrate and cladding powder into the forming chamber.

[0012] (3) Using cladding powder and selective laser melting technology, parts are formed under argon protection. The forming process parameters are: laser power 240-300W, scanning speed 1300-1600mm / s, layer thickness 0.03-0.05mm, overlap distance 0.1-0.13mm, and adjacent layers rotated 67°. After the forming is completed, the formed parts and substrate are cooled and taken out.

[0013] Furthermore, the cladding powder is prepared by mechanically mixing aluminum-silicon alloy matrix powder and nano-CuO powder to obtain the cladding powder; the mixing speed during the mechanical mixing process is 60-70 r / min, and the mixing time is ≥60 min.

[0014] Furthermore, the content of nano CuO powder in the cladding powder is 0.2-0.5 wt.%; the nano CuO powder is irregularly shaped powder with a particle size range of 50-200 nm and a purity of ≥99.99%.

[0015] Furthermore, the Si content in the aluminum-silicon alloy matrix powder is 5-15 wt.%, and the Al content is 75-95 wt.%. The aluminum-silicon alloy matrix powder is spherical powder with a particle size range of 35-55 μm.

[0016] Furthermore, before the part is formed in step (3), the substrate is preheated at a temperature of 120-180°C.

[0017] Furthermore, when forming the part in step (3), high-purity argon is used as the protective gas, and the oxygen content in the high-purity argon is less than 500 ppm.

[0018] Furthermore, the aluminum-based composite material prepared by the above method has an aluminum-silicon alloy as a matrix, in which Al2O3 and Al2Cu nanoparticle reinforcement phases with a content of 0.1-0.2 vol.% are uniformly distributed; the average size of the aluminum-silicon eutectic structure in the aluminum-based composite material is 200-300 nm.

[0019] Furthermore, the ultimate tensile strength of the composite material at room temperature is greater than 600 MPa, the ultimate tensile strength at 200° C. is greater than 400 MPa, and the ultimate tensile strength at 400° C. is greater than 130 MPa.

[0020] Furthermore, the heat-resistant aluminum-based composite material is applied to aerospace engine turbine blades, nuclear reactor cladding or high-temperature lightweight structural parts; or, the heat-resistant aluminum-based composite material is applied to thermal protection devices, heat exchangers or radiators.

[0021] The design mechanism of the present invention is as follows:

[0022] Traditional aluminum-based composites are typically formed through casting or hot-pressing sintering, using methods such as microalloying, nanoparticle addition, and heat treatment to create a certain volume fraction of reinforcement phase within the alloy matrix. However, the reinforcement phases obtained by these methods are often large and unevenly distributed.

[0023] In the selective laser melting method for preparing a heat-resistant aluminum-based composite material provided by the present invention, a certain amount of nano-CuO powder is added to an aluminum-silicon alloy matrix powder as a cladding powder. Through an in-situ reaction of Al-CuO during the selective laser melting process, high-energy laser light is used to directly generate uniformly distributed and stable nanoparticles in situ within the matrix. This method ensures near-net-shape formation of the alloy material while reducing subsequent processing costs and improving the high-temperature performance of the selective laser melted aluminum-based composite material. The aluminum element, as the main component of the composite material, provides a lightweight foundation and forms a fine-grained α-Al matrix during the rapid solidification process. Silicon reduces the surface tension of the molten pool and improves the fluidity of the liquid metal, allowing the laser-melted aluminum-based composite material to spread more evenly, thereby reducing the formation of defects. Furthermore, the aluminum-silicon eutectic structure can be significantly refined under rapid solidification conditions, improving the mechanical properties of the alloy. Silicon also inhibits grain coarsening and reduces the tendency to hot cracking, giving the selective laser melted aluminum-based composite material superior dimensional stability and processing performance.

[0024] After extensive theoretical research and experimental verification, the present invention has also concluded that during the selective laser melting process, the in-situ reaction of Al-CuO can be divided into two parts: an oxidation-reduction reaction and a dissolution reaction. Both reactions can form Al2O3 and Al2Cu nanoparticles and precipitated phases in situ in the aluminum-based composite material. Furthermore, both reactions have a high thermodynamic driving force. With the activation of the in-situ reaction in the composite material, the energy released can compensate for the energy input during the selective laser melting process. The prepared aluminum-based composite material has good formability, a material density of ≥99.9%, and a heat-affected zone width of 2.2-2.6μm. The Al2O3 and Al2Cu strengthening phases generated by the in-situ reaction of Al-CuO are uniformly distributed in the alloy matrix, with a volume fraction of 0.1-0.2%.

[0025] The advantages and beneficial effects of the present invention are as follows:

[0026] 1. The aluminum-based composite material prepared by the selective laser melting technology of the present invention has the characteristics of high density and low defects, with a relative density greater than 99.9%, a porosity less than 0.1%, and a heat-affected zone width less than 3μm.

[0027] 2. The aluminum-based composite material prepared by the selective laser melting technology of the present invention has excellent organizational stability, high intrinsic thermal stability of nano-oxides, and excellent alloy organizational stability.

[0028] 3. When the present invention adopts the selective laser melting technology to prepare the aluminum-based composite material, when the addition amount of nano-CuO is controlled at 0.2-0.5wt%, the prepared aluminum-based composite material can have good comprehensive mechanical properties in the temperature range of room temperature to 400°C, meeting the current design requirements of engineering equipment. Specifically, its ultimate tensile strength at room temperature and 200°C is higher than 600MPa and 400MPa, respectively. In particular, its ultimate tensile strength at 400°C is greater than 130MPa, which is much higher than that of traditional 1-7 series aluminum alloys (generally not exceeding 50MPa), and has significant advantages. It meets the current design requirements of lightweight thermal management structural parts such as thermal protection, heat exchangers and radiators.

[0029] 4. The aluminum-based composite material prepared by the selective laser melting technology of the present invention has a cost advantage. No rare earth elements (such as Sc and Zr) need to be added to the composite material, and the material cost of the heat-resistant aluminum alloy is reduced by more than 40%.

[0030] 5. The selective laser melting technology used in the present invention to prepare aluminum-based composite materials has process compatibility, supports the integrated forming of complex components, and reduces machining volume by more than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is an optical microscopic image of the surface of the aluminum-based composite material sample prepared in Example 1, characterizing the defect distribution of the composite material.

[0032] Figure 2 This is a scanning electron microscope image of the heat-affected zone of the aluminum-based composite material sample prepared in Example 1, with a width of approximately 2.4 μm.

[0033] Figure 3 The transmission electron microscope morphology of the aluminum-based composite material sample prepared in Example 1 shows the phase composition and organizational characteristics of the alloy. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0035] The present invention provides a heat-resistant aluminum-based composite material and a selective laser melting preparation method and application thereof. During the preparation process, a certain amount of irregularly shaped CuO powder is mechanically mixed with spherical aluminum-silicon alloy matrix powder and used as cladding powder. Under the action of a high-energy laser beam in selective laser melting, an in-situ reaction occurs, and nanoparticles such as Al2O3 and Al2Cu are directly synthesized in the aluminum-silicon alloy matrix, thereby achieving a uniform distribution of the reinforcement phase and improving the high-temperature performance of the aluminum-based composite material.

[0036] In the following examples, the chemical composition of the aluminum-silicon alloy matrix powder is (wt.%): Si is 10.0%, Fe is 3%, Mn is 2%, Ni is 1%, and the balance is aluminum; the particle size range of the aluminum-silicon alloy matrix powder is 35-55 μm.

[0037] The CuO content in the cladding powder used in the following examples is 0.2-0.5 wt %, the particle size of the CuO powder is in the range of 50-200 nm, and the purity is ≥99.99%.

[0038] The purity of the high-purity argon gas used in the following examples is above 99.99%, and the oxygen content in the high-purity argon gas is less than 500 ppm.

[0039] Example 1

[0040] This embodiment uses selective laser melting technology to prepare heat-resistant aluminum-based composite materials. The preparation process is as follows:

[0041] 1. Determine the placement and angle of the part to be formed, slice and layer the 3D model of the part, plan the forming path, and set the forming parameters. In this embodiment, the part to be formed is a tensile sample with a gauge size of 2×2×10mm;

[0042] 2. Before printing, clean the aluminum substrate and dry the aluminum-silicon alloy matrix powder and nano-CuO powder. The two powders are then mechanically mixed in a three-dimensional mixer to create the cladding powder. The mixing speed is 65 rpm and the mixing time is 80 minutes. After cooling, the dried substrate and cladding powder are loaded into the forming chamber as required. The nano-CuO powder content in the cladding powder is 0.5 wt%.

[0043] 3. High-purity argon is introduced into the selective laser melting and forming chamber as a protective gas.

[0044] 4. Part forming is performed with the following process parameters: adjacent layers rotated 67°, substrate preheating temperature 180°C, laser power 300W, scanning speed 1600mm / s, layer thickness 0.03mm, overlap distance 0.13mm; after forming, the parts to be formed and the substrate are cooled, and then the formed parts and substrate are removed.

[0045] The surface morphology of the heat-resistant aluminum-based composite material prepared in this embodiment was observed. Figure 1 As shown, it can be seen that the formed samples do not have any obvious defects, the density is greater than 99.9%, and the porosity is less than 0.1%. Figure 2 This is a scanning electron microscope image of the heat-affected zone of the prepared composite material. The width of the heat-affected zone is about 2.4 μm, indicating that the aluminum-based composite material has good organizational stability. Figure 3The transmission electron microscopy (TEM) micromorphology of the prepared composite and the corresponding energy spectrum analysis results show that the composite contains an Al-Si eutectic structure, Fe-rich intermetallic compounds (IMCs), and in-situ generated Al2O3 and Al2Cu phases. These in-situ reinforcing phases are uniformly distributed with no noticeable coarsening. The volume fractions of the Al2O3 and Al2Cu phases are approximately 0.12% and 0.2%, respectively, and the average size of the Al-Si eutectic is approximately 270 nm.

[0046] The tensile test results of the composite material prepared in this embodiment are shown in Table 1.

[0047] Example 2

[0048] This embodiment uses selective laser melting technology to prepare heat-resistant aluminum-based composite materials. The preparation process is as follows:

[0049] 1. Determine the placement and angle of the part to be formed, slice the 3D model of the part, plan the forming path, and set the forming parameters. In this embodiment, the part to be formed is a tensile sample with a gauge size of 2×2×10 mm.

[0050] 2. Before printing, clean the aluminum substrate and dry the aluminum-silicon alloy matrix powder and nano-CuO powder. The two powders are mechanically mixed in a three-dimensional mixer to produce the cladding powder. The mixing speed is 65 rpm and the mixing time is 80 minutes. After cooling, the dried substrate and cladding powder are loaded into the forming chamber as required. The nano-CuO powder content in the cladding powder is 0.3 wt%.

[0051] 3. High-purity argon is introduced into the selective laser melting and forming chamber as a protective gas.

[0052] 4. Part forming is performed using the following process parameters: 67° rotation of adjacent layers, substrate preheat temperature of 150°C, laser power of 260W, scanning speed of 1450mm / s, layer thickness of 0.04mm, and overlap distance of 0.12mm. After forming, the formed part and substrate are cooled before removal.

[0053] The heat-resistant aluminum-based composite material prepared in this embodiment was tested. The volume fractions of the Al2O3 phase and the Al2Cu phase in the composite material were approximately 0.1% and 0.14%, respectively, and the average size of the aluminum-silicon eutectic structure was approximately 240 nm.

[0054] The performance test results of the composite material tensile sample prepared in this example are shown in Table 1.

[0055] Example 3

[0056] This embodiment uses selective laser melting technology to prepare heat-resistant aluminum-based composite materials. The preparation process is as follows:

[0057] 1. Determine the placement and angle of the part to be formed, slice the 3D model of the part using software, plan the forming path, and set the forming parameters. In this embodiment, the part to be formed is a tensile sample with a gauge size of 2×2×10mm;

[0058] 2. Before printing, clean the aluminum substrate and dry the aluminum-silicon alloy matrix powder and nano-CuO powder. The two powders are mechanically mixed in a three-dimensional mixer to produce the cladding powder. The mixing speed is 65 rpm and the mixing time is 80 minutes. After cooling, the dried substrate and cladding powder are loaded into the forming chamber as required. The nano-CuO powder content in the cladding powder is 0.2 wt%.

[0059] 3. High-purity argon is introduced into the selective laser melting and forming chamber as a protective gas.

[0060] 4. Part forming is performed using the following process parameters: 67° rotation of adjacent layers, substrate preheat temperature of 120°C, laser power of 240W, scanning speed of 1300mm / s, layer thickness of 0.05mm, and overlap distance of 0.1mm. After forming, the formed part and substrate are allowed to cool before removal.

[0061] According to tests, the volume fractions of the Al2O3 phase and the Al2Cu phase in the composite material prepared in this embodiment are approximately 0.08% and 0.12%, respectively, and the average size of the aluminum-silicon eutectic structure is approximately 200 nm.

[0062] The performance test results of the composite material tensile sample prepared in this example are shown in Table 1.

[0063] Comparative Example 1

[0064] In this example, the selective laser melting technology is used to prepare heat-resistant aluminum-based composite materials. The preparation process is as follows:

[0065] 1. Determine the placement and angle of the part to be formed, slice the 3D model of the part, plan the forming path, and set the forming parameters. In this embodiment, the part to be formed is a tensile sample with a gauge size of 2×2×10 mm.

[0066] 2. Before printing, clean the aluminum substrate and dry the aluminum-silicon alloy matrix powder and nano-CuO powder. The two powders are mechanically mixed in a three-dimensional mixer to produce the cladding powder. The mixing speed is 65 rpm and the mixing time is 80 minutes. After cooling, the dried substrate and cladding powder are loaded into the forming chamber as required. The nano-CuO powder content in the cladding powder is 1.0 wt%.

[0067] 3. High-purity argon is introduced into the selective laser melting and forming chamber as a protective gas.

[0068] 4. Part forming is performed, and the forming process parameters are: adjacent layers rotated 67°, substrate preheating temperature 180°C, laser power 300W, scanning speed 1600mm / s, layer thickness 0.03mm, and overlap distance 0.13mm.

[0069] According to tests, the volume fractions of the Al2O3 phase and the Al2Cu phase in the composite material prepared in this example are approximately 0.23% and 0.27%, respectively, and the average size of the aluminum-silicon eutectic structure is approximately 340 nm.

[0070] The performance test results of the composite material tensile sample prepared in this example are shown in Table 1.

[0071] Comparative Example 2

[0072] In this example, the selective laser melting technology is used to prepare heat-resistant aluminum-based composite materials. The preparation process is as follows:

[0073] 1. Determine the placement and angle of the part to be formed, slice the 3D model of the part, plan the forming path, and set the forming parameters. In this embodiment, the part to be formed is a tensile sample with a gauge size of 2×2×10 mm.

[0074] 2. Before printing, clean the aluminum substrate and dry the aluminum-silicon alloy matrix powder and nano-CuO powder. The two powders are mechanically mixed in a three-dimensional mixer to produce the cladding powder. The mixing speed is 65 rpm and the mixing time is 80 minutes. After cooling, the dried substrate and cladding powder are loaded into the forming chamber as required. The nano-CuO powder content in the cladding powder is 0.1 wt%.

[0075] 3. High-purity argon is introduced into the selective laser melting and forming chamber as a protective gas.

[0076] 4. Part forming is performed, and the forming process parameters are: adjacent layers rotated 67°, substrate preheating temperature 120°C, laser power 240W, scanning speed 1300mm / s, layer thickness 0.05mm, and overlap distance 0.1mm.

[0077] According to tests, the volume fractions of the Al2O3 phase and the Al2Cu phase in the composite material prepared in this example are approximately 0.04% and 0.09%, respectively, and the average size of the aluminum-silicon eutectic structure is approximately 420 nm.

[0078] The performance test results of the composite material tensile sample prepared in this example are shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082] It can be seen from the above test results that the aluminum-based composite material prepared by the present invention has excellent high-temperature mechanical properties. The ultimate tensile strength of the composite material at room temperature exceeds 600MPa, the ultimate tensile strength at 200℃ exceeds 400MPa, and the ultimate tensile strength at 400℃ exceeds 130MPa. Comparing the present invention with existing traditional aluminum alloys and aluminum-based composites, it can be found that the prepared aluminum-based composite has good comprehensive mechanical properties in the range of room temperature to 400℃. Especially at 400℃, the strength index of the aluminum-based composite material of the present invention is much higher than that of traditional 1-7 series aluminum alloys (generally not exceeding 50MPa), and it has significant advantages. It meets the design requirements of lightweight thermal management structural parts such as current thermal protection, heat exchangers and radiators.

[0083] The description of the above embodiments is only used to help understand the method of the present application and its core ideas. It should be noted that the above is only a preferred embodiment of the present invention, which should not limit the scope of protection of the technical solutions of the present invention. Any modification of the technical solutions described in the above embodiments and any equivalent replacement of technical features made by ordinary technicians in this field within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a heat-resistant aluminum-based composite material by selective laser melting, characterized in that: The method is to add a certain amount of nano-CuO powder to the aluminum-silicon alloy matrix powder as cladding powder, and then use the selective laser melting technology to prepare the heat-resistant aluminum-based composite material; under the action of high-energy laser, the molten CuO and liquid aluminum-silicon alloy react, realizing the in-situ generation of oxides and intermetallic phases inside the aluminum-silicon alloy.

2. The selective laser melting method for preparing a heat-resistant aluminum-based composite material according to claim 1, characterized in that: The method specifically comprises the following steps: (1) Model building and printing parameter setting: Determine the placement and angle of the part to be formed, slice and layer the three-dimensional model of the part through slicing software, plan the forming path, and set the forming parameters; (2) Substrate and cladding powder processing: Before printing, clean the aluminum substrate and dry the cladding powder. After cooling, load the substrate and cladding powder into the forming chamber. (3) Using cladding powder and selective laser melting technology, parts are formed under argon protection. The forming process parameters are: laser power 240-300W, scanning speed 1300-1600mm / s, layer thickness 0.03-0.05mm, overlap distance 0.1-0.13mm, and adjacent layers rotated 67°. After the forming is completed, the formed parts and substrate are cooled and taken out.

3. The method for preparing a heat-resistant aluminum-based composite material by selective laser melting according to claim 1, characterized in that: The preparation process of the cladding powder is as follows: aluminum silicon alloy matrix powder and nano CuO powder are mechanically mixed to obtain the cladding powder; the mixing speed during the mechanical mixing process is 60-70 r / min, and the mixing time is ≥60 min.

4. The method for preparing a heat-resistant aluminum-based composite material by selective laser melting according to claim 1, characterized in that: The content of nano CuO powder in the cladding powder is 0.2-0.5 wt. %; the nano CuO powder is irregularly shaped powder with a particle size range of 50-200 nm and a purity of ≥99.99%.

5. The method for preparing a heat-resistant aluminum-based composite material by selective laser melting according to claim 1, characterized in that: The aluminum-silicon alloy matrix powder has a Si content of 5-15 wt.%, and an Al content of 75-95 wt.%. The aluminum-silicon alloy matrix powder is spherical powder with a particle size range of 35-55 μm.

6. The method for preparing a heat-resistant aluminum-based composite material by selective laser melting according to claim 2, characterized in that: Before forming the parts in step (3), the substrate is preheated at a temperature of 120-180°C.

7. The method for preparing a heat-resistant aluminum-based composite material by selective laser melting according to claim 2, characterized in that: When forming the part in step (3), high-purity argon is used as the protective gas, and the oxygen content in the high-purity argon is less than 500ppm.

8. A heat-resistant aluminum-based composite material prepared by the method according to any one of claims 1 to 7, characterized in that: The aluminum-based composite material uses aluminum-silicon alloy as a matrix, in which Al2O3 and Al2Cu nanoparticle reinforcement phases are uniformly distributed with a content of 0.1-0.2 vol.% each; the average size of the aluminum-silicon eutectic structure in the aluminum-based composite material is 200-300 nm.

9. The heat-resistant aluminum-based composite material according to claim 8, characterized in that: The ultimate tensile strength of the composite material at room temperature is greater than 600 MPa, the ultimate tensile strength at 200°C is greater than 400 MPa, and the ultimate tensile strength at 400°C is greater than 130 MPa.

10. The use of the heat-resistant aluminum-based composite material according to claim 8, characterized in that: The heat-resistant aluminum-based composite material is applied to aerospace engine turbine blades, nuclear reactor cladding or high-temperature lightweight structural parts; or, the heat-resistant aluminum-based composite material is applied to thermal protection devices, heat exchangers or radiators.

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