In-situ converted porous members based on selective laser melting and methods of making the same

Abstract

The application discloses an in-situ transformed porous component based on selective laser melting and a manufacturing method thereof, and the manufacturing method comprises the following steps: providing an aluminum-based powder; using a selective laser melting device to perform layer-by-layer scanning printing on the aluminum-based powder in an incomplete melting manner under a protective atmosphere, so as to form a porous aluminum alloy blank; the porous aluminum alloy blank has a continuous porous skeleton structure, and un-melted aluminum nanoparticles are distributed in the pores of the porous skeleton structure and between layers; the porous aluminum alloy blank is placed in an oxygen-containing atmosphere and subjected to heat treatment at 600-640 DEG C, so that the aluminum in the blank is oxidized, and the in-situ transformed porous component is obtained. The porous aluminum alloy blank is prepared through the SLM technology, and then the low-temperature in-situ transformation is realized to realize the high-precision near-net-shape manufacturing of the porous component, so that the problems that the existing metal SLM technology is difficult to realize special functional characteristics and the size precision control is difficult due to the complex process and high-temperature shrinkage caused by the traditional indirect forming method are solved.

Description

Technical Field

[0001] This invention relates to the field of metal additive manufacturing technology, and in particular to an in-situ conversion porous component based on selective laser melting and its manufacturing method. Background Technology

[0002] With the upgrading of high-end manufacturing, the demand for components with complex three-dimensional structures that can operate stably in harsh environments such as high temperature and corrosion is becoming increasingly urgent. Such components require both excellent mechanical properties and special functional characteristics, such as high hardness, electrical insulation, and chemical stability, and have important application value in aerospace, energy and chemical industries.

[0003] Selective laser melting (SLM) technology, as a core technology of metal additive manufacturing, has shown significant advantages in the integrated forming of complex metal structures and has been widely used in the manufacturing of metal components such as aluminum alloys and titanium alloys. However, metal components produced by traditional SLM technology face inherent limitations during service: their surface hardness is limited, their wear resistance is insufficient, and they lack electrical insulation properties. This severely restricts their application in high-end scenarios that require special functional characteristics such as high hardness, high wear resistance, corrosion resistance, and insulation.

[0004] To improve the performance of SLM-formed metal components, existing technologies typically employ post-processing techniques. Conventional heat treatments (such as solution treatment and aging treatment) are mainly used to optimize the microstructure of the metal material. While they can improve the strength and toughness of the component to some extent, they cannot change the material's inherent properties and contribute little to significantly improving surface hardness or achieving functional indicators such as electrical insulation. Another technical approach is to borrow from the indirect forming concept in ceramics, using techniques such as binder spraying to prepare green bodies, followed by debinding and high-temperature sintering to obtain the final part. However, this method has significant drawbacks: the debinding process easily leads to deformation and cracking of the green body, and high-temperature sintering causes significant volume shrinkage, resulting in loss of dimensional accuracy and making it difficult to achieve near-net-shape forming of complex structures.

[0005] Therefore, a significant gap exists in the current technological field: how to fully leverage the advantages of selective laser melting (SLM) technology in forming complex metal structures while simultaneously overcoming the functional limitations of metallic materials to develop an innovative method that enables precision-formed metal blanks to achieve functional leaps through efficient post-processing. Thus, the current technological field urgently needs to develop a new technological path that can inherit the complex forming capabilities of SLM technology while achieving a significant performance improvement in metal components. A manufacturing method that can achieve functional enhancement through controllable changes in material composition while maintaining the integrity of the precision structure will become key to driving the upgrading of high-end equipment manufacturing. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide an in-situ transformation porous component based on selective laser melting (SLM) and its manufacturing method. This invention prepares a metal billet with a specific porous structure and unmelted nanoparticles using SLM technology, and then performs a controlled in-situ transformation process to fundamentally improve material properties while maintaining the precise structure of the billet, thereby obtaining a porous component with special functional characteristics. This method effectively solves the problems of achieving special functional characteristics using existing metal SLM technology and the dimensional accuracy control difficulties caused by the complexity of the process and high-temperature shrinkage in traditional indirect forming methods.

[0007] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0008] This invention provides a method for manufacturing in-situ transformed porous components based on selective laser melting, comprising the following steps:

[0009] Step 1, Material Preparation: Provide aluminum-based powder;

[0010] Step 2, Selective Laser Melting Printing: Using a selective laser melting device, under a protective atmosphere, the aluminum-based powder is scanned and printed layer by layer in a partially melted manner to form a porous aluminum alloy blank; the porous aluminum alloy blank has a continuous porous framework structure, and unmelted aluminum nanoparticles are distributed in the pores and between layers of the porous framework structure.

[0011] Step 3, heat treatment conversion: The porous aluminum alloy blank obtained in step 2 is placed in an oxygen-containing atmosphere and heat-treated at 600-640℃ to eliminate the internal stress of the blank during printing and enhance the mechanical properties of the porous skeleton structure. At the same time, the aluminum in the blank is oxidized to obtain an in-situ converted porous component.

[0012] This invention combines selective laser melting (SLM) forming technology with a controlled in-situ conversion process. It uses SLM forming of aluminum alloy to prepare a high-precision metal billet with a specific porous structure, followed by a controlled conversion treatment at 600-640℃ to transform the metal material into a high-performance porous component. This technical approach fully leverages the advantages of complex structure forming using metal SLM technology, and through subsequent controlled conversion processing, enables the component to acquire special functional properties such as high hardness, high wear resistance, corrosion resistance, and insulation. It successfully solves the functional limitations of metal SLM components mentioned in the background technology, such as insufficient surface hardness and lack of electrical insulation, while avoiding the problems of dimensional inaccuracy and process complexity caused by degreasing and high-temperature sintering in indirect forming methods.

[0013] Further, in step one, the aluminum-based powder has an aluminum content of ≥95% by mass percentage and contains 0.5-3% magnesium and / or silicon; the particle size range of the aluminum-based powder is 5-50μm, and the proportion of particles of 10-30μm is ≥80%.

[0014] Furthermore, step one also includes pretreatment of the aluminum-based powder, the pretreatment including: airflow classification screening to control the powder particle size distribution, vacuum drying to make the powder moisture content ≤0.05%, and powder mixing operation in an inert gas environment.

[0015] By limiting the addition of magnesium and silicon elements in aluminum-based powder and their specific content range (0.5-3%), and by combining particle size control (5-50μm, of which 10-30μm accounts for ≥80%) and pretreatment processes (air classification, vacuum drying, inert powder mixing), the powder is ensured to have good laser absorption rate, flowability and powder uniformity. This provides material guarantee for printing high-precision, high-porosity blanks with uniform distribution of unmelted nanoparticles from the source. At the same time, it effectively prevents spheroidization, splashing or porosity defects caused by poor powder flowability or excessive moisture content during the printing process.

[0016] Furthermore, in step two, the process parameters for selective laser melting printing are: laser power 100-270W, scanning speed 900-2000mm / s, powder layer thickness 120-200μm, and scanning spacing 0.25-0.5mm.

[0017] Furthermore, in step two, the selective laser melting process is carried out in a mixed atmosphere of inert gas and oxygen, wherein the oxygen volume accounts for 3%-5%.

[0018] Furthermore, in step two, the porosity of the porous aluminum alloy blank is 30-50%.

[0019] Furthermore, in step two, the particle size of the unmelted aluminum nanoparticles is 50-500 nm.

[0020] By limiting key process parameters such as laser power, scanning speed, layer thickness, and scanning spacing, the SLM process was ensured to proceed stably in an "incomplete melting" mode. This allowed for the proactive and repeatable construction of a porous structure with a porosity of 30-50% and embedded with 50-500 nm unmelted aluminum nanoparticles. This structure not only ensured the mechanical strength of the preform to meet the requirements of subsequent operations, but more importantly, it provided optimal kinetic conditions for the subsequent oxidation reaction: the macroscopically interconnected pores became channels for rapid oxygen diffusion, while the nanoparticles, due to their large specific surface area, significantly accelerated the reaction rate.

[0021] By introducing 3-5% oxygen into an inert protective atmosphere, a weakly oxidizing environment is created, which can cause slight oxidation of the molten pool surface during printing, moderately increasing the melt viscosity. This helps to suppress metal splashing and spheroidizing effects, thereby further improving the forming quality and consistency of the porous structure and laying the foundation for obtaining a more uniform in-situ oxidation transformation.

[0022] Furthermore, in step three, the heating rate of the heat treatment is 5-8℃ / min, and the temperature is maintained at 600-640℃ for 4-8 hours.

[0023] Furthermore, in step three, the oxygen-containing atmosphere is an air atmosphere.

[0024] By controlling the heating rate (5-8℃ / min) and holding at 600-640℃ for 4-8 hours, the oxidation reaction is ensured to proceed smoothly and fully. Slow heating avoids excessive thermal stress or localized overheating deformation of the billet due to rapid reaction and concentrated heat release; sufficient holding time ensures that oxygen has enough time to diffuse into the billet and that the nanoparticles and skeletal aluminum are oxidized, thus achieving an in-situ conversion rate of over 99%.

[0025] Another aspect of the present invention provides an in-situ conversion porous component based on selective laser melting, which is prepared by the manufacturing method described above. The in-situ conversion porous component has a three-dimensional shape corresponding to the porous aluminum alloy blank, and its oxidation conversion rate is not less than 99%.

[0026] The beneficial effects of this invention are as follows:

[0027] This invention innovatively combines selective laser melting (SLM) forming of metals with a low-temperature in-situ conversion process. Leveraging the advantages of SLM forming of aluminum alloys, a porous metal billet with a precise three-dimensional structure is first prepared. Then, a controlled conversion treatment at 600-640℃ transforms the metal material into a high-performance porous component. This technical approach effectively solves the key problems raised in the background technology: on the one hand, it overcomes the limitations of traditional metal SLM components in terms of surface hardness, insulation, and other functional properties; on the other hand, it avoids the problems of dimensional inaccuracy and process complexity caused by degreasing and high-temperature sintering in indirect forming methods, achieving high-precision, near-net-shape manufacturing of porous components.

[0028] This invention successfully constructs an open porous network with "interlayer connectivity and intralayer interconnection" through active control of SLM parameters, while retaining unmelted aluminum nanoparticles in situ. This porous structure design provides a dual-path advantage for the subsequent conversion process: macroscopically, the open pores provide a rapid diffusion channel for oxygen, avoiding the significant local unoxidized conversion caused by closed pores in existing technologies; microscopically, the unmelted nanoparticles, due to their large specific surface area, significantly improve the reaction efficiency, thus enabling full material structure conversion even at relatively low temperatures of 600-640℃.

[0029] The 600-640℃ processing temperature range used in this invention is carefully designed to ensure the stability of the matrix structure and provide the necessary conditions for the full progress of the conversion reaction. This method can complete the conversion process using a conventional atmospheric environment, without the need for special protective atmospheres or purification treatments, significantly reducing process complexity and equipment costs.

[0030] This invention organically combines metal SLM forming with a low-temperature conversion process, and leverages the synergistic effect of porous structures and nanoparticles to achieve a significant improvement in material properties while maintaining the precise geometric characteristics of the components. This technical approach not only ensures excellent dimensional stability of the products but also greatly simplifies the manufacturing process, providing a new technical solution for the large-scale and economical production of high-performance porous components. Attached Figure Description

[0031] Figure 1 The image shows the XRD diffraction pattern of the in-situ transformed porous component obtained in Embodiment 1 of the present invention. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention provides a method for manufacturing in-situ transformed porous components based on selective laser melting, comprising the following steps:

[0034] Step 1: Material Preparation

[0035] Provide aluminum-based powder; the aluminum-based powder has an aluminum content of ≥95% by mass percentage and contains 0.5-3% magnesium and / or silicon; the particle size range of the aluminum-based powder is 5-50μm, and the proportion of particles of 10-30μm is ≥80%;

[0036] The pretreatment steps for aluminum-based powders include:

[0037] a) Airflow classification screening is used to remove coarse particles with a particle size >50μm and ultrafine powder with a particle size <5μm, so as to avoid agglomeration or accumulation of unmelted particles during printing.

[0038] b) Dry in a vacuum drying oven at 80-120℃ for 6-8 hours to ensure the powder moisture content is ≤0.05% to prevent air bubbles from forming during printing.

[0039] c) After drying, use an inert gas (such as an argon environment) for powder mixing to ensure that no oxide film regenerates on the powder surface during the mixing process.

[0040] By limiting the addition of magnesium and silicon elements in aluminum-based powder and their specific content range (0.5-3%), and by combining particle size control (5-50μm, of which 10-30μm accounts for ≥80%) and pretreatment processes (air classification, vacuum drying, inert powder mixing), the powder is ensured to have good laser absorption rate, flowability and powder uniformity. This provides material guarantee for printing high-precision, high-porosity blanks with uniform distribution of unmelted nanoparticles from the source. At the same time, it effectively prevents spheroidization, splashing or porosity defects caused by poor powder flowability or excessive moisture content during the printing process.

[0041] Step 2, Selective Laser Melting Printing

[0042] Selective laser melting equipment is used to scan and melt aluminum alloy powder layer by layer according to preset 3D model data. During the printing process, parameters such as laser power, scanning speed, scanning path, and powder layer thickness are precisely controlled to ensure that the aluminum alloy powder is partially melted and deposited layer by layer to form a porous aluminum alloy blank with precise shape and size. Unmelted aluminum nanoparticles are interspersed between layers to form a continuous porous framework structure in the printed blank.

[0043] Furthermore, the preferred process parameters for selective laser melting printing are: laser power 100-270W, scanning speed 900-2000mm / s, powder layer thickness 120-200μm (2-3 times the thickness of conventional metal SLM layers), and scanning spacing 0.25-0.5mm (greater than 1.5 times the laser spot diameter). Specific values ​​can be optimized and adjusted according to the characteristics of the aluminum alloy material and the complexity of the printed model.

[0044] Selective laser melting is carried out in a mixed atmosphere of inert gas and oxygen, with oxygen accounting for 3%-5% of the volume.

[0045] The porosity of the porous aluminum alloy preform obtained by printing is 30-50%. The particle size of the unmelted aluminum nanoparticles is 50-500 nm.

[0046] By limiting key process parameters such as laser power, scanning speed, layer thickness, and scanning spacing, the SLM process was ensured to proceed stably in an "incomplete melting" mode. This allowed for the proactive and repeatable construction of an open porous network structure with a porosity of 30-50% and embedded 50-500nm unmelted aluminum nanoparticles, characterized by "interlayer connectivity and intralayer interconnection." This structural design provides a dual-pathway advantage for the oxidation reaction: macroscopically, the open pores provide a rapid diffusion channel for oxygen, avoiding localized unoxidation caused by closed pores in existing technologies; microscopically, the specific surface area of ​​the unmelted aluminum nanoparticles (approximately 50-100m²) provides a significant advantage. 2 / g) is a conventional micron-sized aluminum powder (1-5m 2 The oxidation rate is increased by 10-20 times (per g), which significantly improves the oxidation reaction rate, thus achieving an oxidation conversion rate of over 99% at a low temperature of 600-640℃, far exceeding the level of existing technologies that require 1400℃ to achieve a 90% conversion rate.

[0047] During selective laser melting, a weak oxidation environment is created by introducing 3-5% oxygen into an inert protective atmosphere. This allows for slight oxidation of the molten pool surface during printing, moderately increasing the melt viscosity and helping to suppress metal splashing and spheroidization effects. This further improves the forming quality and consistency of the porous structure, laying the foundation for obtaining a more uniform in-situ oxidation transformation.

[0048] Step 3, heat treatment conversion

[0049] The porous aluminum alloy blank obtained in step two is placed in an oxygen-containing atmosphere and heat-treated at 600-640℃ to eliminate the internal stress of the blank during printing and enhance the mechanical properties of the porous skeleton structure. At the same time, the aluminum in the blank is oxidized to obtain an in-situ transformed porous component.

[0050] The heat treatment involves a heating rate of 5-8℃ / min and a holding time of 4-8 hours at 600-640℃. The oxygen-containing atmosphere is air, meaning the oxidation process takes place in an atmospheric environment. After the heat treatment conversion, the in-situ converted porous components are cooled to 200℃ in the furnace and then air-cooled to reduce thermal stress.

[0051] The 600-640℃ processing temperature range employed in this invention ensures both the stability of the matrix structure and provides the necessary conditions for the full conduct of the conversion reaction. This method can complete the conversion process using a conventional atmospheric environment, eliminating the need for special protective atmospheres or purification treatments, significantly reducing process complexity and equipment costs.

[0052] By controlling the heating rate (5-8℃ / min) and holding at 600-640℃ for 4-8 hours, the in-situ conversion reaction was ensured to proceed smoothly and fully. Slow heating avoided excessive thermal stress or localized overheating deformation of the billet due to rapid reaction and concentrated heat release; sufficient holding time ensured that oxygen had enough time to diffuse into the billet and that the aluminum nanoparticles and skeletal structure were oxidized and converted, thus achieving a conversion rate of over 99%.

[0053] The in-situ conversion porous component obtained by the additive manufacturing method has a three-dimensional shape corresponding to the porous aluminum alloy blank, and its in-situ oxidation conversion rate is not less than 99%, and its deformation rate is <0.5%.

[0054] The present invention will be further described below through specific embodiments.

[0055] Example 1: Preparation of high-porosity in-situ conversion porous filter element

[0056] This Example 1 aims to prepare a porous filter element suitable for high-temperature corrosive gas environments. The specific preparation process is as follows:

[0057] Material preparation: High-purity aluminum-based powder (97% Al, 2% Mg, 1% Si) with a particle size distribution of 10-30 μm (85% of particles are 10-20 μm). Pretreatment steps include: airflow classification screening to remove coarse particles >50 μm and ultrafine powder <5 μm (98% of the powder has a qualified particle size after screening); vacuum drying at 100℃ for 7 hours to reduce the moisture content to 0.03%; and mixing under argon atmosphere for 30 minutes to ensure uniform powder dispersion and no surface oxidation.

[0058] Selective Laser Melting Printing (SLM): Using an SLM device (model: HBD400T), a 3D model of a φ50mm×100mm tubular filter element (designed porosity 45%) was printed. Printing parameters were set as follows: laser power 180W, scanning speed 1500mm / s, layer thickness 150μm, and scanning spacing 0.4mm; the printing atmosphere was an argon-oxygen mixture (volume ratio 97:3) to balance molten pool protection and moderate oxidation. The resulting aluminum alloy tubular blank had a dimensional deviation of only ±0.1mm, a measured porosity of 44.5% (1.1% deviation from the design value), uniform distribution of unmelted aluminum nanoparticles (80-300nm in diameter) between layers, and a bending strength of 22MPa, meeting the mechanical strength requirements for subsequent processing.

[0059] High-temperature heat treatment: The billet was placed in a box-type resistance furnace and heated to 620°C at a heating rate of 6°C / min, and held at that temperature for 6 hours. It was then cooled in the furnace to 200°C and subsequently air-cooled. XRD analysis showed that the heat-treated product exhibited characteristic diffraction peaks at 2θ of 25.58°, 35.15°, and 37.78°. This diffraction pattern was consistent with the standard characteristics of a fully converted product, and the calculated conversion rate was as high as 99.2%.

[0060] Post-processing and performance testing: The surface was polished with 800-grit sandpaper to reduce the surface roughness Ra to 1.2 μm. Performance test results showed that the final porous filter element had a porosity of 43.8% and an air permeability of 1.2 × 10⁻⁶. -12 m 2 (Test pressure 0.1MPa), flexural strength 430MPa, acid corrosion resistance (immersion in 5% H2SO4 for 24 hours) <0.1%. All performance indicators meet the stringent requirements of high-temperature gas filtration environments.

[0061] Example 2: Fabrication of a precision in-situ conversion porous insulating scaffold

[0062] This embodiment 2 aims to fabricate an insulating support for electronic devices that requires extremely high dimensional accuracy and insulation performance. The specific fabrication process is as follows:

[0063] Material preparation: Aluminum-based powder (98% Al content, 2% Si content) with a particle size distribution of 15-30 μm (82% of particles are 20-25 μm). Pretreatment steps include: airflow classification screening to remove particles >50 μm and <5 μm (97% pass rate); vacuum drying at 120℃ for 6 hours to reduce the moisture content to 0.02%; and mixing in an argon atmosphere for 25 minutes to achieve a powder flowability (Hall flow rate) of 35 s / 50 g.

[0064] Selective Laser Melting Printing (SLM): Using the same SLM equipment, a precision insulating bracket (30mm × 20mm × 5mm, including 4 φ2mm through holes) was printed. Printing parameters were adjusted as follows: laser power 220W, scanning speed 1200mm / s, layer thickness 120μm, scanning spacing 0.3mm; the printing atmosphere was an argon-oxygen mixture (volume ratio 96:4). The printed aluminum alloy bracket blank exhibited extremely high dimensional accuracy (overall deviation ±0.08mm, through hole diameter deviation ±0.05mm), a porosity of 38.2%, uniform distribution of unmelted aluminum nanoparticles (particle size 100-400nm), and a bending strength of 25MPa.

[0065] High-temperature heat treatment: The heat treatment regime was adjusted to a heating rate of 7℃ / min to 640℃, followed by holding at that temperature for 5 hours and then cooling in the furnace. After heat treatment, the insulating support remained intact without cracking, and XRD analysis showed that its oxidation conversion rate was as high as 99.5%.

[0066] Post-processing and performance testing: The surface was polished with 1000-grit sandpaper to further reduce the surface roughness Ra to 0.8 μm. Performance testing results showed that the volume resistivity (room temperature) of this insulating support was as high as 1.5 × 10⁻⁶. 14 Its strength is Ω·cm, bending strength is 450MPa, and thermal conductivity (25℃) is 28W / (m·K). Its comprehensive performance fully meets the application requirements of electronic component insulating supports for high temperature resistance (600℃), high insulation and good heat dissipation.

[0067] In the two embodiments above, Embodiment 1 successfully prepared an in-situ conversion porous filter element with both high air permeability and excellent corrosion resistance by optimizing the pore structure; Embodiment 2 obtained a precision structural component that meets the requirements of electronic insulation by finely controlling the dimensional accuracy and surface quality.

[0068] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0069] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for manufacturing in-situ transformed porous components based on selective laser melting, characterized in that, Includes the following steps: Step 1, Material Preparation: Provide aluminum-based powder; Step 2, Selective Laser Melting Printing: Using a selective laser melting device under a protective atmosphere, the aluminum-based powder is scanned and printed layer by layer in a partially melted manner to form a porous aluminum alloy blank. The porous aluminum alloy blank has a continuous porous framework structure, and unmelted aluminum nanoparticles are distributed in the pores and between layers of the porous framework structure. The process parameters for the selective laser melting printing are: laser power 100-270W, scanning speed 900-2000mm / s, powder layer thickness 120-200μm, and scanning spacing 0.25-0.5mm. Step 3, heat treatment conversion: The porous aluminum alloy blank obtained in step 2 is placed in an oxygen-containing atmosphere and heat-treated at 600-640℃ to eliminate the internal stress of the blank during printing and enhance the mechanical properties of the porous skeleton structure. At the same time, the aluminum in the blank is oxidized to obtain an in-situ converted porous component.

2. The method for manufacturing in-situ transformed porous components based on selective laser melting according to claim 1, characterized in that, In step one, the aluminum-based powder has an aluminum content of ≥95% by mass percentage and contains 0.5-3% magnesium and / or silicon; the particle size range of the aluminum-based powder is 5-50μm, and the proportion of particles of 10-30μm is ≥80%.

3. The method for manufacturing in-situ transformed porous components based on selective laser melting according to claim 1, characterized in that, Step one also includes pretreatment of the aluminum-based powder, which includes: airflow classification screening to control the powder particle size distribution, vacuum drying to make the powder moisture content ≤0.05%, and powder mixing operation in an inert gas environment.

4. The method for manufacturing in-situ transformed porous components based on selective laser melting according to claim 1, characterized in that, In step two, the selective laser melting process is carried out in a mixed atmosphere of inert gas and oxygen, with oxygen accounting for 3%-5% of the volume.

5. The method for manufacturing in-situ transformed porous components based on selective laser melting according to claim 1, characterized in that, In step two, the porosity of the porous aluminum alloy blank is 30-50%.

6. The method for manufacturing in-situ transformed porous components based on selective laser melting according to claim 1, characterized in that, In step two, the unmelted aluminum nanoparticles have a particle size of 50-500 nm.

7. The method for manufacturing in-situ transformed porous components based on selective laser melting according to claim 1, characterized in that, In step three, the heating rate of the heat treatment is 5-8℃ / min, and the temperature is held at 600-640℃ for 4-8 hours.

8. The method for manufacturing in-situ transformed porous components based on selective laser melting according to claim 1, characterized in that, In step three, the oxygen-containing atmosphere is an air atmosphere.

9. An in-situ transformation porous component based on selective laser melting, characterized in that, The in-situ converted porous component, prepared by the manufacturing method according to any one of claims 1-8, has a three-dimensional shape corresponding to the porous aluminum alloy blank, and its oxidation conversion rate is not less than 99%.

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