Preparation method for preparing aluminum-based composite material powder based on selective laser melting

Abstract

According to the preparation method for preparing the aluminum-based composite material powder based on selective laser melting, in-situ synthesis TiB2 aluminum-based composite material powder and micron SiC particles are mixed, uniform distribution of a reinforced phase in a matrix is achieved, and the in-situ synthesis TiB2 aluminum-based composite material powder obtained through gas atomization powder preparation is approximately spherical, good in fluidity and high in strength. By adding the nano TiB2 reinforcing phase and the micron SiC reinforcing phase, the laser absorptivity of the aluminum-based composite material powder can be improved, the formability can be improved, a formed part has high density, mechanical strength and thermal stability, the aluminum-based composite material powder is suitable for manufacturing high-precision structural parts, in addition, the in-situ synthesis technology and the gas atomization technology are combined, batch production can be achieved, and the aluminum-based composite material powder is suitable for industrial application.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and more specifically, to a method for preparing aluminum-based composite material powder based on selective laser melting. Background Technology

[0002] Selective laser melting (SLM) technology, as an important branch of additive manufacturing, has been widely used in aerospace, automotive manufacturing, medical devices and other fields due to its advantages of high precision and high degree of freedom in forming.

[0003] However, existing aluminum-based composite powders have many problems in SLM forming. The reinforcing phases (such as SiC and carbon nanotubes) introduced by traditional mechanical mixing methods are prone to agglomeration, resulting in uneven performance of composite materials. Aluminum powder is prone to spheroidization under laser irradiation, resulting in rough surface and low density of the formed parts. Powders prepared by ball milling have irregular shapes and poor flowability, affecting the uniformity of powder spreading. During the forming process, cracks and deformation are prone to occur due to thermal stress concentration.

[0004] To address the aforementioned issues, existing technologies have undertaken relevant research. For example, patent CN108330347A discloses a method for preparing aluminum-based composite materials based on laser selective melting, using AlSi... 10 Using Mg-aluminum alloy as the matrix, TiB2 reinforcing phase is generated in situ via a mixed salt reaction method, followed by vacuum atomization to obtain TiB2 / AlSi with a particle size of 15–53 μm. 10 Mg composite powder.

[0005] However, the technical solution of CN108330347A still has limitations: on the one hand, it only uses a single TiB2 reinforcing phase, and the matrix material is limited to AlSi. 10 Mg cannot meet the differentiated requirements of different application scenarios for material mechanical properties (such as tensile strength and wear resistance); on the other hand, the solution does not have a special process design for the interfacial compatibility between the reinforcing phase and the matrix, or for the protection of the flowability during the powder mixing process. It cannot fundamentally solve the problems of easy agglomeration of other reinforcing phases such as SiC and the destruction of the sphericity of the powder after mixing. Furthermore, it does not consider the impact of moisture introduced during the mixing process on SLM forming, and the formed parts still have the risk of high porosity. Summary of the Invention

[0006] In view of this, the present invention aims to propose a method for preparing aluminum-based composite powder based on laser selective melting to solve the problems of easy agglomeration of reinforcing phase introduced by traditional mechanical mixing method in the prior art, resulting in uneven performance of composite material, easy spheroidization effect of aluminum powder under laser action, resulting in rough surface of molded parts, and irregular shape and poor flowability of powder prepared by ball milling.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] A method for preparing aluminum-based composite powder based on laser selective melting includes the following steps:

[0009] Step 1: Select aluminum alloy as the matrix material, add K2TiF6 and KBF4 as reactants, and melt under inert gas protection. Control the melting temperature at 700-800℃ and hold for 10-30 minutes to generate nano-sized TiB2 particles in situ. Cast the melt and cool it to obtain TiB2 aluminum matrix composite ingot.

[0010] Step 2: Under inert gas protection, the TiB2 aluminum matrix composite ingot is heated to a molten state, and the temperature is controlled at 750-850℃. The melt is then atomized into fine droplets to prepare aluminum matrix composite powder containing nanoscale in-situ self-generated TiB2 reinforcing phase. The composite powder is then sieved to control the particle size range to 15-53μm.

[0011] Step 3: Surface modification of SiC particles with a particle size of 8-10 μm is performed using a silane coupling agent solution. The modified SiC particles are then mixed with in-situ self-generated TiB2 aluminum matrix composite powder.

[0012] Step 4: Place the mixed powder in a vacuum environment with a vacuum degree of 0.1 Pa, a drying temperature of 120℃, and a drying time of 10 hours to obtain the finished powder.

[0013] Furthermore, in step 1, the volume fraction of TiB2 in the TiB2 aluminum matrix composite ingot is 2% to 6%.

[0014] Furthermore, in step 2, the melt is fed into a gas atomizing device, and the melt is atomized using a high-pressure argon nozzle.

[0015] Furthermore, the pressure of the argon gas is 0.6–1.0 MPa.

[0016] Furthermore, in step 3, the volume fraction of SiC particles is 2% to 4%.

[0017] Furthermore, in step 3, the mixing method is mechanical stirring, with a speed of 60-120 rpm and a mixing time of 6 hours.

[0018] Furthermore, in step 1, the melt is poured into a metal mold and cooled using water cooling.

[0019] Furthermore, in step 2, the composite material powder is sieved using a cyclone separation method.

[0020] Furthermore, in step 1, aluminum alloy, K2TiF6 and KBF4 are put into a crucible for melting.

[0021] Furthermore, in step 4, the mixed powder is placed in a vacuum drying oven, vacuumed, and heated to dry.

[0022] Compared with existing technologies, the preparation method of aluminum-based composite powder based on laser selective melting described in this invention has the following advantages:

[0023] By mixing in-situ self-generated TiB2 aluminum matrix composite powder with micron-sized SiC particles, a uniform distribution of the reinforcing phase in the matrix is ​​achieved. The in-situ self-generated TiB2 aluminum matrix composite powder obtained by gas atomization powdering is nearly spherical with good flowability. The addition of nano-TiB2 reinforcing phase and micron-sized SiC reinforcing phase can improve the laser absorption rate of aluminum matrix composite powder, improve formability, and give the molded parts high density, mechanical strength and thermal stability, making them suitable for the manufacture of high-precision structural parts. In addition, the combination of in-situ self-generation and gas atomization technology can realize mass production, making it suitable for industrial applications. Attached Figure Description

[0024] Figure 1 This is a scan image of the micro / nano hybrid reinforced aluminum matrix composite powder described in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the described embodiments are only some, not all, of the embodiments of this invention. The specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] like Figure 1 As shown, this application provides a method for preparing aluminum-based composite material powder based on laser selective melting, comprising the following steps:

[0027] Step 1: Select aluminum alloy as the matrix material, add K2TiF6 and KBF4 as reactants, and melt under inert gas protection. Control the melting temperature at 700-800℃ and hold for 10-30 minutes to generate nano-sized TiB2 particles in situ. Cast the melt and cool it to obtain TiB2 aluminum matrix composite ingot.

[0028] Step 2: Under inert gas protection, the TiB2 aluminum matrix composite ingot is heated to a molten state, and the temperature is controlled at 750-850℃. The melt is then atomized into fine droplets to prepare aluminum matrix composite powder containing nanoscale in-situ self-generated TiB2 reinforcing phase. The composite powder is then sieved to control the particle size range to 15-53μm.

[0029] Step 3: Surface modification of SiC particles with a particle size of 8-10 μm is performed using a silane coupling agent solution. The modified SiC particles are then mixed with in-situ self-generated TiB2 aluminum matrix composite powder.

[0030] Step 4: Place the mixed powder in a vacuum environment with a vacuum degree of 0.1 Pa, a drying temperature of 120℃, and a drying time of 10 hours to obtain the finished powder.

[0031] Step 1 generates nano-sized TiB2 particles in situ, avoiding the agglomeration defect of the reinforcing phase in traditional methods. During the smelting process, the TiB2 particles generated by the direct reaction of K2TiF6 and KBF4 can be uniformly dispersed in the aluminum matrix. Step 3 further modifies the surface of the micron-sized SiC particles with a silane coupling agent, which not only improves the interfacial bonding force between SiC and the aluminum matrix, but also further reduces the agglomeration tendency of SiC particles. Finally, a hybrid reinforcement structure of "nano-TiB2 + micron-sized SiC" is achieved, ensuring that the reinforcing phase does not agglomerate significantly in the overall powder.

[0032] SLM forming requires extremely high powder flowability. The "atomization powder preparation + sieving" design in step 2 solves the problem of irregular powder shape and poor flowability in traditional ball milling. Atomization technology can prepare near-spherical TiB2 aluminum-based composite powder. The near-spherical structure has excellent flowability. At the same time, the powder particle size is strictly controlled between 15 and 53 μm through sieving, which can ensure the uniformity of powder spreading. In addition, step 3 uses "stirring and mixing" instead of ball milling, which can avoid destroying the near-spherical structure of the powder during the mixing process and further preserve the good flowability of the powder.

[0033] The nano-sized TiB2 particles introduced in step 1 and the micron-sized SiC particles added in step 3 are both reinforcing phases with high laser absorption characteristics. Compared with pure aluminum alloy powder, the addition of these two reinforcing phases can significantly improve the absorption rate of aluminum-based composite powder to laser and reduce the reflection loss of laser energy. The higher laser absorption rate can ensure that the powder is fully melted during SLM forming, avoiding problems such as low density and many internal defects in the formed parts due to insufficient melting, thus optimizing the forming quality and density of the formed parts.

[0034] The vacuum drying in step 4 can completely remove moisture from the powder, avoid defects such as pores and cracks during SLM forming, and improve the thermal stability of the formed parts.

[0035] This setup achieves uniform distribution of the reinforcing phase in the matrix by mixing in-situ self-generated TiB2 aluminum matrix composite powder with micron-sized SiC particles. The in-situ self-generated TiB2 aluminum matrix composite powder obtained by gas atomization is nearly spherical with good flowability. The addition of nano-TiB2 and micron-sized SiC reinforcing phases can improve the laser absorption rate of the aluminum matrix composite powder, enhance its formability, and give the molded parts high density, mechanical strength, and thermal stability, making it suitable for manufacturing high-precision structural parts. In addition, the combination of in-situ self-generation and gas atomization technology enables mass production, making it suitable for industrial applications.

[0036] In detail, surface modification of SiC particles using silane coupling agents can improve the interfacial bonding force between SiC particles and the aluminum matrix.

[0037] Preferably, in step 1, the aluminum alloy used is 6061 aluminum alloy, 7075 aluminum alloy, or AlSi. 10 Mg aluminum alloy.

[0038] Preferably, the inert gas is argon or nitrogen.

[0039] In detail, Figure 1 In this structure, the Al matrix is ​​an aluminum alloy matrix, Nano-TiB2 is an in-situ self-generated nanoscale TiB2 reinforcing phase, and Micro-SiC is a surface-modified micron-scale SiC reinforcing phase. Figure 1 The reinforcing phase is visible to be uniformly distributed in the matrix, with no obvious agglomeration.

[0040] As a preferred example of this application, in step 1, the volume fraction of TiB2 in the TiB2 aluminum matrix composite ingot is 2% to 6%.

[0041] In the preparation of traditional aluminum matrix composites, the agglomeration of the reinforcing phase is one of the core problems leading to uneven performance and increased defects in the formed parts. If the TiB2 volume fraction is below 2%, although the risk of agglomeration can be theoretically reduced, the reinforcement effect will be weak due to the insufficient amount of reinforcing phase, rendering the addition meaningless. If the volume fraction is above 6%, the small spacing between nanoparticles will easily lead to mutual attraction and aggregation during the in-situ generation process of melting, forming agglomerates larger than micrometers. These agglomerates not only fail to play a reinforcing role, but also form stress concentration points in the aluminum matrix, leading to defects such as cracks and pores during subsequent SLM forming. At the same time, they destroy the uniformity of the material's microstructure, resulting in significant differences in the mechanical properties of different regions of the formed part. The volume fraction range of 2% to 6% ensures that a sufficient number of TiB2 particles play a reinforcing role, and the in-situ self-generation process can achieve uniform dispersion of particles, fundamentally avoiding the agglomeration problem.

[0042] As a preferred example of this application, in step 2, the melt is fed into a gas atomizing device and atomized using a high-pressure argon nozzle.

[0043] The high-speed, high-pressure argon gas flow exerts a strong impact and shearing effect on the molten aluminum-based composite material, breaking the continuous melt flow into countless tiny droplets. As the droplets travel rapidly in the inert gas flow, they spontaneously contract into spherical (or near-spherical) shapes due to surface tension, and then rapidly cool and solidify, ultimately forming near-spherical powder particles. This forming mechanism fundamentally avoids the sharp edges and irregular morphologies of particles caused by mechanical impact in ball milling, ensuring that the powder possesses excellent flowability.

[0044] Preferably, the composite material powder is rapidly solidified into a spherical shape after the melt is atomized.

[0045] As a preferred example of this application, the pressure of argon gas is 0.6 to 1.0 MPa.

[0046] SLM forming has strict requirements on the particle size of aluminum-based composite powder, and argon pressure is a key parameter that determines the particle size of the atomized powder. The gas flow pressure directly affects the impact and crushing ability of the molten melt.

[0047] If the argon pressure is below 0.6 MPa, the airflow impact force is insufficient to fully break the continuous aluminum-based melt flow into fine droplets, easily forming coarse powder with a particle size exceeding 53 μm. An excessively high proportion of coarse powder leads to decreased powder flowability, and the laser energy required to melt coarse powder during SLM forming is higher, easily resulting in "incomplete fusion" defects and reducing the density of the formed part.

[0048] If the argon pressure exceeds 1.0 MPa, the excessive airflow impact will break the melt into fine powder with a particle size of less than 15 μm. Fine powder has a large specific surface area and is prone to agglomeration due to surface adsorption, which also impairs powder flowability. Furthermore, during SLM scanning, fine powder is easily "blown away" by the laser airflow, resulting in localized powder loss and the formation of pores. A pressure range of 0.6–1.0 MPa perfectly balances the "fragmentation intensity" and "droplet size," allowing the airflow to break the melt into droplets of suitable diameter. After rapid solidification, the droplets naturally fall within the optimal SLM range of 15–53 μm, eliminating the need for excessive sieving and meeting subsequent powder spreading and melting requirements.

[0049] As a preferred example of this application, in step 3, the volume fraction of SiC particles is 2% to 4%.

[0050] TiB2 is a nanoscale reinforcing phase that mainly hinders dislocation movement in the aluminum matrix through dispersion strengthening, thereby improving the strength and hardness of the material. SiC (2%–4%) is a micron-scale reinforcing phase that can further share external forces through the "load transfer" mechanism, while filling the gaps between nano-TiB2 particles to form a complementary reinforcing structure.

[0051] If the volume fraction of SiC is less than 2%, the number of micron-scale reinforcing phases is insufficient, and it cannot effectively cooperate with nano-TiB2 to achieve synergistic reinforcement. As a result, the performance of the molded part is only slightly improved in terms of wear resistance, deformation resistance and other properties.

[0052] While a SiC volume fraction exceeding 4% can further enhance strength, it disrupts the complementary reinforcement balance. Excessive micron-sized particles can easily interfere with nano-TiB2, leading to uneven distribution of the reinforcing phase. Furthermore, an excessively large interface area between SiC and the aluminum matrix can cause interfacial stress concentration, increasing the risk of cracking in the formed part. This configuration, however, can both push the mechanical properties of the formed part to a higher level and avoid the defects of excessive single reinforcing phase, achieving a balance between strength enhancement and structural stability.

[0053] As a preferred example of this application, in step 3, the mixing method is mechanical stirring, the speed is 60-120 rpm, and the mixing time is 6 hours.

[0054] The core objective of the mixing process is to achieve uniform dispersion of micron-sized SiC particles and near-spherical TiB2 aluminum-based composite powder, thereby avoiding localized accumulation or uneven distribution of SiC particles.

[0055] Low-speed stirring can create a stable convective mixing field, allowing the two powders to come into slow and full contact during the stirring process. The TiB2 aluminum-based composite powder can drive the SiC particles to diffuse evenly, avoiding "mixing dead zones" caused by excessively low speed and "centrifugal segregation" caused by excessively high speed.

[0056] The two powders have different densities and morphologies (TiB2 aluminum matrix composite powder is nearly spherical, while SiC is polygonal). Sufficient time is needed to break the initial aggregation state between particles. A duration of 6 hours can ensure that SiC particles form a "dispersed distribution" in TiB2 aluminum matrix composite powder. During subsequent SLM forming, the reinforcing phase is evenly distributed in the aluminum matrix, which can evenly bear the load and avoid "weak areas" caused by the absence of local reinforcing phase, ultimately ensuring the consistency of the mechanical properties of the formed parts.

[0057] As a preferred example of this application, in step 1, the melt is poured into a metal mold and cooled by water cooling.

[0058] Metal molds themselves have high thermal conductivity. When combined with an external water cooling system, the cooling rate of the melt can be greatly increased. Rapid solidification can inhibit the growth of aluminum matrix grains. Traditional slow cooling tends to form coarse columnar or equiaxed crystals, resulting in uneven mechanical properties of the ingot. Rapid solidification can refine the grains and shorten the diffusion time of the nano-scale TiB2 reinforcing phase, preventing it from agglomerating due to gravity settling or van der Waals forces during cooling. This ensures that TiB2 is uniformly dispersed in the aluminum matrix.

[0059] During gas atomization powder production, TiB2 remains uniformly dispersed after the ingot melts, avoiding fluctuations in powder properties caused by agglomeration of reinforcing phases inside the ingot, and ensuring the uniformity of mechanical properties of SLM formed parts.

[0060] As a preferred example of this application, in step 2, the composite material powder is sieved using a cyclone separation method.

[0061] In traditional vibrating sieving, powder needs to collide and rub against the screen repeatedly. Even near-spherical powder may have its edges damaged and deformed due to mechanical impact, becoming irregular in shape and disrupting its flowability. If there are a small number of hard and brittle TiB2 agglomerated particles in the powder, they may break during the impact, producing additional fine powder and increasing the risk of agglomeration.

[0062] Cyclone separation achieves classification through the centrifugal force of airflow. The powder only rotates within the airflow, without direct friction or impact from solid components (such as screens or scrapers). This method preserves the morphology and structural integrity of the near-spherical powder, avoiding decreased flowability due to mechanical damage. Simultaneously, this process does not disrupt the uniform distribution of the TiB2 reinforcing phase within the powder, ensuring the stability of the powder's microstructure.

[0063] As a preferred example of this application, in step 1, aluminum alloy, K2TiF6 and KBF4 are put into a crucible for melting.

[0064] As a container with good airtightness, the crucible can completely enclose the aluminum alloy, K2TiF6 and KBF4 in an inert atmosphere (such as argon and nitrogen), which isolates the air from the contact between the melt and prevents the oxidation of the aluminum matrix and the decomposition of fluoride salts from the source.

[0065] Meanwhile, the enclosed space of the crucible can maintain a stable concentration of inert gas, avoid uneven reaction caused by local atmosphere leakage, and ensure that TiB2 is generated in situ in an environment free from oxidation and impurity interference, thus guaranteeing its nanoscale morphology and purity.

[0066] As a preferred example of this application, in step 4, the mixed powder is placed in a vacuum drying oven, vacuumed, and heated to dry.

[0067] During the mixing process of SiC particles and TiB2 aluminum-based composite powder, moisture in the air is easily absorbed due to ambient humidity. At the same time, the silane coupling agent solvent remaining from the surface modification of SiC particles may also adhere to the powder surface. During SLM forming, the high temperature of the laser will cause rapid vaporization, generating a large amount of gas. If the gas cannot escape in time, it will cause pores, cracks, and even spatter inside the formed part, which will seriously reduce the density and mechanical properties of the formed part.

[0068] Under vacuum conditions, the boiling points of water and solvents are significantly reduced. Even under medium-low temperature heating of 120°C, they can quickly vaporize from the powder surface and internal pores, avoiding the oxidation of powder or particle adhesion caused by traditional atmospheric pressure heating which requires high temperatures.

[0069] Preferably, in step 4, the finished powder is vacuum-sealed.

[0070] This application also provides an aluminum-based composite material powder, which is prepared by the aforementioned method for preparing aluminum-based composite material powder.

[0071] Example 1

[0072] Base material: 7075 aluminum alloy

[0073] Reinforcing phase: TiB2 (in-situ self-generated nanoscale) + SiC (micrometer scale, particle size 8-10 μm)

[0074] TiB2 content: 2–6 vol.%

[0075] SiC content: 2-4 vol.%

[0076] Melting temperature: 750℃;

[0077] Atomizing gas: Argon, pressure 0.8 MPa;

[0078] Mixing parameters: 60-120 rpm, 6 hours;

[0079] Vacuum drying parameters: 120℃, <0.1Pa, 10 hours;

[0080] The powder prepared by the above process is used for SLM printing. The tensile strength of the formed parts reaches 480-530 MPa, the elastic modulus reaches 80 GPa, the density is 99.5%, the surface roughness Ra≤12μm, and the forming quality is good.

[0081] Example 2

[0082] Base material: 7075 aluminum alloy

[0083] Reinforcing phase: TiB2 (in-situ self-generated nanoscale) + SiC (micrometer scale, particle size 8-10 μm)

[0084] TiB2 content: 2–6 vol.%

[0085] SiC content: 4–6 vol.%

[0086] Melting temperature: 750℃;

[0087] Atomizing gas: Argon, pressure 0.8 MPa;

[0088] Mixing parameters: 60-120 rpm, 6 hours;

[0089] Vacuum drying parameters: 120℃, <0.1Pa, 10 hours;

[0090] The powder prepared by the above process is used for SLM printing. The tensile strength of the formed parts reaches 280-320 MPa, the elastic modulus reaches 85 GPa, the density is 99.5%, the surface roughness Ra≤12μm, and the forming quality is good.

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 1 is that the matrix material in this comparative example is ZL101 aluminum alloy, and the tensile strength of the printed aluminum matrix composite material is 400-430 MPa.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 1 is that the matrix material in this comparative example is 6061 aluminum alloy, and the tensile strength of the printed aluminum matrix composite material is 280-320 MPa.

[0095] Comparative Example 3

[0096] The difference between this comparative example and Example 1 is that the matrix material in this comparative example is 2024 aluminum alloy, and the tensile strength of the printed aluminum matrix composite material is 400-440 MPa.

[0097] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing aluminum-based composite material powder based on laser selective melting, characterized in that, Includes the following steps: Step 1: Select aluminum alloy as the matrix material, add K2TiF6 and KBF4 as reactants, and melt under inert gas protection. Control the melting temperature at 700-800℃ and hold for 10-30 minutes to generate nano-sized TiB2 particles in situ. Cast the melt and cool it to obtain TiB2 aluminum matrix composite ingot. Step 2: Under inert gas protection, the TiB2 aluminum matrix composite ingot is heated to a molten state, and the temperature is controlled at 750-850℃. The melt is then atomized into fine droplets to prepare aluminum matrix composite powder containing nanoscale in-situ self-generated TiB2 reinforcing phase. The composite powder is then sieved to control the particle size range to 15-53μm. Step 3: Surface modification of SiC particles with a particle size of 8-10 μm is performed using a silane coupling agent solution. The modified SiC particles are then mixed with in-situ self-generated TiB2 aluminum matrix composite powder. Step 4: Place the mixed powder in a vacuum environment with a vacuum degree of 0.1 Pa, a drying temperature of 120℃, and a drying time of 10 hours to obtain the finished powder.

2. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 1, the volume fraction of TiB2 in the TiB2 aluminum matrix composite ingot is 2% to 6%.

3. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 2, the melt is fed into the gas atomization device, and the melt is atomized using a high-pressure argon nozzle.

4. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 3, characterized in that, The pressure of argon gas is 0.6–1.0 MPa.

5. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 3, the volume fraction of SiC particles is 2% to 4%.

6. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 3, the mixing method is mechanical stirring, with a speed of 60-120 rpm and a mixing time of 6 hours.

7. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 1, the melt is poured into a metal mold and cooled using water cooling.

8. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 2, the composite material powder is sieved using a cyclone separation method.

9. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 1, aluminum alloy, K2TiF6 and KBF4 are put into a crucible for melting.

10. The method for preparing aluminum-based composite material powder based on laser selective melting according to claim 1, characterized in that, In step 4, the mixed powder is placed in a vacuum drying oven, vacuumed, and heated to dry.

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