Self-removal method of 3D printing rare earth modified high-strength aluminum alloy constraint structure

Abstract

The application discloses a self-removing method of a 3D printing rare earth modified high-strength aluminum alloy constraint structure, which comprises the following steps: (1) obtaining a rare earth modified aluminum alloy powder; (2) forming a rare earth modified aluminum alloy solid member and a constraint structure by using laser 3D printing on the rare earth modified aluminum alloy powder; the laser scanning speed of the solid member is smaller than that of the constraint structure by 800-1600 mm / s; (3) performing aging post-treatment after the forming processing is completed. According to the application, the difference laser scanning speed is set for the solid member and the constraint structure, the mechanical property of the constraint structure after the aging treatment can be remarkably reduced, the intergranular brittle fracture under external load is avoided, the high-quality forming of the laser 3D printing rare earth modified high-strength aluminum alloy complex component is ensured, and the self-removing effect of the constraint structure is realized. The formed part can be applied to the aviation, aerospace, communication transmission and other industries with great demand for light high-strength complex structure parts, has high operability and wide application range.

Description

Technical Field

[0001] This invention relates to a self-removal method for 3D printed metal alloy constraint structures, and more particularly to a self-removal method for 3D printed rare earth modified high-strength aluminum alloy constraint structures. Background Technology

[0002] Laser 3D printing is a new manufacturing technology that has emerged in recent years. It employs a layered manufacturing method, using micron-sized metal powders as raw materials and a high-energy laser beam as a heat source. This allows it to overcome the limitations of traditional forming methods and freely create complex components in a single, integrated form. Due to its high degree of freedom in forming, high material utilization, and high forming precision, laser 3D printing technology has gained widespread application. Currently, numerous metals, including aluminum alloys, titanium alloys, nickel-based superalloys, and iron-based alloys, are used in laser 3D printing.

[0003] Rare-earth modified Al-Mg alloys are a new type of high-strength aluminum alloy that can be strengthened by heat treatment. Al-Mg alloys are widely used in aerospace and shipbuilding due to their good weldability, corrosion resistance, and moderate mechanical strength. The addition of the rare-earth element Sc significantly refines the grain size of Al-Mg alloys. During processing, the formation of intermetallic compounds Al3(Sc,Zr) acts as a nucleating agent and strengthening phase, improving the overall mechanical properties of Al-Mg alloys. Laser 3D printing can be an effective method for forming rare-earth modified Al-Mg alloys. Its free-form process characteristics, combined with the lightweight and high-strength material properties of rare-earth modified Al-Mg alloys, broaden the avenues for the integrated forming of lightweight complex components for the aerospace field.

[0004] Lightweight components for aerospace applications often possess complex geometries, presenting challenges in laser additive manufacturing (LAM) such as overhanging surfaces and large tilt angles. Furthermore, the extremely rapid melting / solidification process in LLM, with instantaneous cooling rates reaching 10⁶-10⁷ K / s, often results in high levels of internal stress within the formed components. To support the successful forming of these challenging surfaces and prevent component failure due to localized deformation caused by internal stress, constraint structures are typically added during LLM. These constraint structures, located between the component and the substrate, also known as support structures, firmly restrain component deformation, ensuring the successful completion of laser additive manufacturing of complex components.

[0005] Due to the strong metallurgical bond between the constraint structure and the formed component, and the limited internal space of complex components making tooling deployment difficult, laser additive manufacturing of complex components often faces the bottleneck problem of difficult post-processing removal of the constraint structure. The difficulty in removing the constraint structure, the long removal cycle, and the time and labor-intensive nature of the removal process, coupled with a significant increase in the surface roughness of the formed surface after removal, have become one of the key technical challenges in the field of laser additive manufacturing of complex components. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures that can achieve self-removal of the constraint structure while the component is being formed.

[0007] Technical solution: The self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures according to the present invention includes the following steps:

[0008] (1) Obtain rare earth modified aluminum alloy powder;

[0009] (2) Rare earth modified aluminum alloy powder is used to form rare earth modified aluminum alloy solid components and constraint structures by laser 3D printing; the laser scanning speed of the solid components is controlled to be 800-1600 mm / s lower than that of the constraint structures.

[0010] (3) After the forming process is completed, an aging post-treatment is performed.

[0011] In step (2), the laser scanning speed of the solid component is controlled to be 600-1000 mm / s; the laser scanning speed of the constrained structure is 1800-2200 mm / s. This invention sets different laser scanning speeds for the solid component and the constrained structure, with the solid component at 600-1000 mm / s and the constrained structure at 1800-2200 mm / s. On the one hand, this can achieve high-quality integrated forming of complex rare earth modified high-strength aluminum alloy components by laser 3D printing. After aging treatment, the formed components can obtain excellent mechanical properties and service performance. On the other hand, due to the use of a higher laser scanning rate when forming the constrained structure, a large temperature gradient and cooling rate will be generated in the molten pool. Rare earth elements and impurity elements cannot diffuse fully in the liquid phase, so they will be enriched at the grain boundary at the end of solidification. After aging treatment, impurity elements and rare earth elements will precipitate along the molten pool boundary, forming a second phase continuously distributed along the grain boundary, which will significantly reduce the mechanical properties of the constrained structure after aging treatment. It can undergo intergranular brittle fracture under external load, achieving an easy self-removal effect after the constrained structure is processed.

[0012] In step (2), the laser power for forming the solid component is 375W-425W; the scanning layer thickness is 25-35μm; the scanning spacing is 60-70μm; and the oxygen content in the forming cavity is less than or equal to 50ppm. These process parameters ensure that the laser 3D printed rare-earth modified Al-Mg alloy solid component has good forming quality, no obvious internal metallurgical defects, and a smooth and bright surface.

[0013] In step (2), the laser power for forming the constraint structure is 375W-425W; the scanning layer thickness is 25-35μm; the scanning interval is 60-70μm; and the oxygen content in the forming cavity is less than or equal to 50ppm. Based on these process parameters, the number of internal metallurgical defects in the forming constraint structure is relatively small, giving it a certain mechanical strength. This allows it to withstand the tensile stress generated by stress deformation during the forming process of laser-modified rare-earth high-strength aluminum alloy parts, ensuring a stable forming process.

[0014] In step (3), the aging treatment temperature is 300-325℃ and the heat treatment time is 4-8h; the heating rate of the aging treatment is 3-5K / min; the aging treatment is carried out under an inert atmosphere; preferably an argon atmosphere.

[0015] In step (1), rare earth modified aluminum alloy is prepared using laser powder bed melting technology; the mass percentage of its powder composition is as follows: Mg 4.0%~4.5%, Sc 0.35%~0.55%, Zr 0.10%~0.20%, Fe 0.01%~0.02%, Mn 0.001%~0.006%, with the balance being Al.

[0016] The powder has a particle size of 15-53 μm, is nearly spherical, and has an oxygen content of less than 80 ppm.

[0017] Through the above aging process, dispersed nano-precipitates of strengthening phase can be generated inside the component, resulting in good mechanical properties. For constrained structures, continuous precipitates can be generated at the micro-grain boundaries, significantly weakening the grain boundary strength and reducing the tensile strength. Under external loads, intergranular brittle fracture is very likely to occur, thus the constrained structure can be easily removed.

[0018] Invention Principle: Based on the differentiated division of laser processing parameters for the solid parts and constraint structures during the 3D printing of complex components, and supplemented by an aging post-processing technique, the constraint structure can maintain appropriate mechanical properties during laser 3D printing to ensure smooth printing. After aging, the component performance is significantly improved while the constraint structure becomes brittle, achieving a self-removal effect. Figure 2As shown, the underlying mechanism is as follows: when printing solid parts, an optimized laser scanning speed range of 600-1000 mm / s is used, while a faster laser scanning speed is used when printing constrained structures. The faster laser scanning speed accelerates the solidification process of the molten pool, causing solid solution elements and impurity atoms in the melt to accumulate at the solidification ends (around the grain boundaries) before they can diffuse. Under these conditions, the constrained structure can possess certain mechanical properties based on good metallurgical bonding during printing, ensuring that the constrained structure will not crack due to stress deformation. After processing, the aging process promotes the continuous precipitation of solid solution atoms accumulated around the grain boundaries within the constrained structure, significantly weakening the grain boundary bonding and mechanical properties. Under limited external force, intergranular brittle fracture can occur, achieving self-removal of the constrained structure.

[0019] Beneficial Effects: Compared with existing technologies, this invention achieves the following significant effects: 1. By setting differentiated laser scanning speeds for solid components and constraint structures, the mechanical properties of the constraint structures after aging treatment can be significantly reduced, preventing intergranular brittle fracture under external loads. This ensures high-quality forming of complex rare-earth modified high-strength aluminum alloy components through laser 3D printing while achieving self-removal of the constraint structures. 2. Real-time control of the mechanical properties of the constraint structures is achieved. 3. During the laser 3D printing process, the constraint structures can achieve near-densification based on the set laser parameters, possessing certain mechanical properties and capable of withstanding the tensile forces generated by internal stress during laser 3D printing, ensuring stability in the forming process. 4. The post-processing procedures for 3D printed rare-earth modified high-strength aluminum alloy components are simplified, shortening the part forming cycle. The formed parts can be applied to industries such as aerospace and communication transmission, which have a high demand for lightweight, high-strength, and complex structural parts. It is highly operable and has a wide range of applications. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process flow of a laser 3D printing method for self-removal of rare earth modified high-strength aluminum alloy constraint structures according to the present invention.

[0021] Figure 2 This is a schematic diagram of the constraint self-removal process method described in this invention;

[0022] Figure 3 This is a micrograph of the rare-earth modified high-strength aluminum alloy obtained by laser 3D printing in Example 3 of the present invention.

[0023] Figure 4 This is a photograph of the tensile fracture surface of the laser 3D printed rare earth modified high-strength aluminum alloy before heat treatment, obtained in Example 3 of the present invention.

[0024] Figure 5 This is a photograph of the tensile fracture surface of the laser 3D printed rare earth modified high-strength aluminum alloy after heat treatment, obtained in Example 3 of the present invention.

[0025] Figure 6 The image shows the microstructure of the laser 3D printed rare earth modified high-strength aluminum alloy obtained in Example 6 of this invention.

[0026] Figure 7 This is a photograph of the tensile fracture surface of the laser 3D printed rare earth modified high-strength aluminum alloy before heat treatment, obtained in Example 6 of the present invention.

[0027] Figure 8 This is a photograph of the tensile fracture surface of the laser 3D printed rare earth modified high-strength aluminum alloy after heat treatment, obtained in Example 6 of the present invention.

[0028] Figure 9 This is a micrograph of the rare-earth modified high-strength aluminum alloy obtained by laser 3D printing in Example 8 of the present invention.

[0029] Figure 10 This is a photograph of the tensile fracture surface of the laser 3D printed rare earth modified high-strength aluminum alloy before heat treatment, obtained in Example 8 of the present invention.

[0030] Figure 11 This is a photograph of the tensile fracture surface of the laser 3D printed rare earth modified high-strength aluminum alloy after heat treatment, obtained in Example 8 of the present invention. Detailed Implementation

[0031] The present invention will now be described in further detail.

[0032] Example 1

[0033] like Figure 1 As shown, this invention provides a self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures, comprising the following steps:

[0034] (1) The Al-4.2Mg-0.4Sc-0.2Zr powder prepared by gas atomization has a particle size of 15-45μm.

[0035] (2) Use a computer to slice the data model, divide the three-dimensional model into several two-dimensional plane information, and import the slice information into laser additive manufacturing 3D printing equipment.

[0036] (3) The laser additive manufacturing equipment is divided into a forming chamber and a powder chamber. The atomized high-strength aluminum alloy powder is placed in the powder chamber. The precision powder supply device evenly spreads the powder onto the substrate of the forming chamber. Under computer control, the high-energy laser beam performs high-speed scanning based on the two-dimensional slice information, and the powder quickly melts / solidifies to form a solid.

[0037] (4) After the single-layer scanning is completed, the substrate of the forming chamber drops by one slice thickness, the powder spreading device re-supplyes powder, and the above process is repeated until the three-dimensional part forming is completed.

[0038] The rare earth modified aluminum alloy powder of the present invention can be a commercially available rare earth modified high-strength aluminum alloy powder, or it can be prepared by methods in the prior art.

[0039] Throughout the forming process, the cavity is kept under an argon atmosphere with an oxygen content below 50 ppm. The laser scanning speed is set to 400 mm / s, the laser power is 400 W, the powder thickness is 30 μm, the scanning interval is 60 μm, the forming strategy is a zoned island scanning, and the laser spot diameter is 70 μm.

[0040] In this embodiment, the tensile strength of the formed specimen before heat treatment was 262.3 MPa, and the tensile strength after heat treatment was 458.3 MPa. The underlying mechanism of this invention is as follows: Figure 2 As shown.

[0041] Example 2

[0042] Based on Example 1, the difference is that the laser scanning speed was set to 600 mm / s. The tensile strength of the formed sample before heat treatment was 312.2 MPa, and the tensile strength after heat treatment was 510.4 MPa.

[0043] Example 3

[0044] Based on Example 1, the difference is that the laser scanning speed is set to 800 mm / s. At this time, the tensile strength of the formed sample before heat treatment is 321.6 MPa, and the tensile strength after heat treatment is 515.7 MPa.

[0045] Example 4

[0046] Based on Example 1, the difference is that the laser scanning speed is set to 1000 mm / s. At this time, the tensile strength of the formed sample before heat treatment is 319.7 MPa and the tensile strength after heat treatment is 513.6 MPa.

[0047] Example 5

[0048] Based on Example 1, the difference is that the laser scanning speed is set to 1400 mm / s. At this time, the tensile strength of the formed sample before heat treatment is 280.9 MPa, and the tensile strength after heat treatment is 470.1 MPa.

[0049] Examples 1-5 show that superior mechanical properties were obtained both before and after heat treatment. In particular, when the laser scanning speed was 600-1000 mm / s, the tensile strength of the samples after aging treatment exceeded 500 MPa, meeting the standards for high-strength composite aluminum alloys. This process range can be used as the process parameters for the solid parts of complex high-strength aluminum alloy components, resulting in superior performance in the formed parts. Examples 1-5 also indicate that at lower laser scanning speeds (≤1400 mm / s), the mechanical properties did not show a significant decrease after aging treatment, making it impossible to achieve the self-removal effect of the constraint structure.

[0050] Figure 3 The image shows an optical image of the formed sample from Example 3. It can be seen that the formed sample is dense and has no obvious metallurgical defects or pores.

[0051] Figure 4 The image shows a tensile fracture surface of the formed specimen in Example 3 before heat treatment. The fracture surface is rough and has dimples, with no obvious brittle fracture.

[0052] Figure 5 The image shows a tensile fracture surface of the formed specimen after heat treatment in Example 3. The fracture surface is rough and has dimples, with no obvious brittle fracture.

[0053] Example 6

[0054] Based on Example 1, but differing from Example 1, the laser scanning speed was set to 1800 mm / s. Under these conditions, the tensile strength of the formed sample before heat treatment was 275.3 MPa, and the tensile strength after heat treatment was 130.2 MPa. In this case, the mechanical properties of the sample before aging exceeded 250 MPa, exhibiting superior mechanical properties that could support local stress deformation of the component and ensure successful printing. After aging treatment, the mechanical properties of the formed sample decreased significantly. Using these process parameters to form the constraint structure, the constraint structure could be easily removed after aging treatment, achieving a self-removal effect for the constraint structure.

[0055] Figure 6 The image shown is an optical image of the formed sample of Example 6. It can be seen that there are a few metallurgical defects inside the sample, which is one of the reasons for the decrease in mechanical properties compared with the previous 5 examples.

[0056] Figure 7 The image shows a tensile fracture surface of the formed specimen in Example 6 before heat treatment. The fracture surface is rough and dimples are visible, indicating that the specimen exhibits ductile fracture before heat treatment and has superior mechanical properties.

[0057] Figure 8 The image shown is a SEM image of the tensile fracture surface of the formed specimen from Example 6 after heat treatment. The fracture surface exhibits a typical brittle fracture mode, with numerous dissociation surfaces and almost no dimples. This indicates that the specimen in this example underwent brittle fracture after aging treatment, which is also the reason for the significant decrease in mechanical properties. The underlying metallurgical and phase transformation principles are as follows:Figure 2 As stated above.

[0058] Example 7

[0059] Based on Example 1, but differing from Example 1, the laser scanning speed was set to 2200 mm / s. Under these conditions, the tensile strength of the formed sample before heat treatment was 253.9 MPa, and the tensile strength after heat treatment was 130.2 MPa. The mechanical properties of the formed sample decreased significantly after aging treatment. Using these process parameters to form the constraint structure, the constraint structure can be easily removed after aging treatment, achieving a self-removal effect for the constraint structure.

[0060] Example 8

[0061] Based on Example 1, but differing from Example 1, the laser scanning speed was set to 2600 mm / s. Under these conditions, the tensile strength of the formed sample before heat treatment was 150.3 MPa, and the tensile strength after heat treatment was 112.3 MPa. Since the tensile strength of the sample before heat treatment was only 150 MPa, its mechanical properties were poor, and it could not be guaranteed that the constraint structure would not experience localized fracture during the printing of complex components. Therefore, it was not suitable for printing constraint structures.

[0062] Figure 9 The image shown is an optical image of the formed sample from Example 8. It reveals numerous metallurgical defects inside the sample, indicating that the excessively high laser scanning speed resulted in insufficient energy input, preventing the powder from being fully melted and causing these defects. This is the primary reason for the decrease in mechanical properties under these conditions.

[0063] Figure 10 The image shows a tensile fracture surface of the formed specimen in Example 8 before heat treatment. The fracture surface is rough and contains a large amount of unmelted powder, indicating that the energy input is insufficient and the mechanical properties are poor.

[0064] Figure 11 The image shown is a SEM image of the tensile fracture surface of the formed specimen after heat treatment in Example 8. A large amount of unmelted powder remains at the fracture surface. This indicates that metallurgical defects are the main cause of the decreased mechanical properties in this example, and the mechanical properties of the constrained structure under these process parameters are insufficient to support the completion of the 3D printing process.

[0065] Comparing Examples 5-8, it can be found that when the laser scanning speed is between 1800-2200 mm / s, the mechanical properties of the formed sample before heat treatment are greater than 250 MPa, indicating superior mechanical properties. After aging treatment, the mechanical properties are significantly reduced. This process range can achieve self-removal of the constraint structure.

[0066] Example 9

[0067] Based on Example 1, the difference is that the laser scanning speed is set to 2200 mm / s. Compared to Example 7, the difference in this example is that the aging temperature is 275℃. At this temperature, the tensile strength of the formed sample before heat treatment is 251.9 MPa, and the tensile strength after heat treatment is 220.3 MPa. Comparing with Example 7, it can be found that when the aging temperature is reduced from 325℃ to 275℃, the mechanical properties do not decrease significantly after aging, and the self-removal of the constraint structure cannot be achieved at this temperature. This is because the lower heat treatment temperature reduces the thermal driving force, decreases the migration ability of solid solution atoms at grain boundaries, and prevents the formation of continuous precipitates distributed along the grain boundaries, thus weakening the mechanical properties.

[0068] Example 10

[0069] Based on Example 1, the difference is that the laser scanning speed is set to 2200 mm / s. Compared to Example 7, the difference in this example is that the aging temperature is 375℃. At this temperature, the tensile strength of the formed sample before heat treatment is 254.8 MPa, and the tensile strength after heat treatment is 240.6 MPa. Comparing with Example 7, it can be found that when the aging temperature increases from 325℃ to 375℃, the mechanical properties do not decrease significantly after aging, and the self-removal of the constraint structure cannot be achieved at this temperature. This is because the higher heat treatment temperature increases the thermal driving force, significantly improving the migration ability of solid solution atoms at grain boundaries. The continuous precipitates distributed along the grain boundaries coarsen, disrupting the continuous distribution channels along the grains, thus the mechanical properties do not decrease significantly.

[0070] Example 11

[0071] Based on Example 3, the difference is that the laser power speed is set to 375W. At this time, the tensile strength of the formed sample before heat treatment is 271.6MPa and the tensile strength after heat treatment is 425.7MPa.

[0072] Example 12

[0073] Based on Example 3, the difference is that the laser power speed is set to 425W. At this time, the tensile strength of the formed sample before heat treatment is 264.6MPa and the tensile strength after heat treatment is 443.7MPa.

[0074] Example 13

[0075] Based on Example 6, the difference is that the laser power speed is set to 375W. At this time, the tensile strength of the formed sample before heat treatment is 245.3MPa, and the tensile strength after heat treatment is 120.3MPa.

[0076] Example 14

[0077] Based on Example 6, the difference is that the laser power speed is set to 425W. At this time, the tensile strength of the formed sample before heat treatment is 236.3MPa and the tensile strength after heat treatment is 117.2MPa.

[0078] As can be seen from Examples 11-14, when the laser power range is broadened to 375W to 425W, good mechanical properties can still be achieved for solid materials using a low scanning speed of 800mm / s, while for constrained structures using a high scanning speed of 1800mm / s, the strength can exceed 200MPa before aging, ensuring that the component is not affected by stress deformation. After aging treatment, the mechanical properties are significantly reduced to 120MPa, making it easy to remove in post-processing. Therefore, the laser power range can be broadened to 375W-425W.

[0079] In summary, when the laser power is 375W-425W, the laser scanning speed of the solid sample is 600-1000mm / s, the constraint structure is 1800-2200mm / s, and the heat treatment aging temperature is 325℃, the self-removal method for the constraint structure of rare earth modified high-strength aluminum alloy proposed in this invention can be realized.

[0080] To verify the self-removal method for constrained structures of rare earth modified high-strength aluminum alloys proposed in this invention, the following examples were conducted using differentiated laser parameters to verify the self-removal effect of this method on constrained structures.

[0081] Example 15

[0082] Based on Example 1, but differing from Example 1, the laser scanning speed was set to 600 mm / s for the solid part and 1800 mm / s for the constraint structure. After laser additive manufacturing, their mechanical properties were tested. The tensile strength of the solid material before heat treatment was 321.4 MPa, and the tensile strength after heat treatment was 508.2 MPa. The tensile strength of the constraint structure before heat treatment was 268.1 MPa, and the tensile strength after heat treatment was 124.3 MPa. The mechanical properties of the solid material and the constraint structure differed significantly after aging treatment. Because the constraint structure had lower mechanical properties, it was easier to remove, achieving a better self-removal effect.

[0083] Example 16

[0084] Based on Example 1, but differing from Example 1, the laser scanning speed was set to 800 mm / s for the solid part and 2200 mm / s for the constraint structure. After laser additive manufacturing, their mechanical properties were tested. The tensile strength of the solid material before heat treatment was 332.4 MPa, and the tensile strength after heat treatment was 513.2 MPa. The tensile strength of the constraint structure before heat treatment was 247.1 MPa, and the tensile strength after heat treatment was 105.2 MPa. The mechanical properties of the solid material and the constraint structure differed significantly after aging treatment. Because the constraint structure had lower mechanical properties, it was easier to remove, achieving a better self-removal effect.

[0085] Example 17

[0086] Based on Example 1, but differing from Example 1, the laser scanning speed was set to 1000 mm / s for the solid part and 1400 mm / s for the constraint structure. After laser additive manufacturing, their mechanical properties were tested. The tensile strength of the solid material before heat treatment was 308.2 MPa, and the tensile strength after heat treatment was 517.2 MPa. The tensile strength of the constraint structure before heat treatment was 287.1 MPa, and the tensile strength after heat treatment was 462.2 MPa. Even after aging treatment, the constraint structure still exhibited superior mechanical properties and could not achieve a self-removal effect.

[0087] The mechanical properties of the laser 3D printed rare earth modified high-strength aluminum alloy materials prepared in each embodiment are shown in Table 1 below.

[0088] Table 1 Mechanical properties of rare earth modified high-strength aluminum alloy materials prepared in Examples 1-14 for laser 3D printing

[0089]

Claims

1. A self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures, characterized in that, Includes the following steps: (1) Obtain rare earth modified aluminum alloy powder; prepare rare earth modified aluminum alloy using laser powder bed melting technology; The powder composition by mass percentage is as follows: Mg 4.0%~4.5%, Sc 0.35%~0.55%, Zr 0.10%~0.20%, Fe 0.01%~0.02%, Mn 0.001%~0.006%, with the balance being Al; (2) Rare earth modified aluminum alloy powder is used to form rare earth modified aluminum alloy solid components and constraint structures by laser 3D printing; the laser scanning speed of the solid components is controlled to be 800~1600mm / s lower than that of the constraint structure; the laser power of forming the constraint structure is 375 W-425 W. (3) After the forming process is completed, an aging post-treatment is performed; the temperature of the aging post-treatment is 300~325℃ and the heat treatment time is 4~8 h.

2. The self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures according to claim 1, characterized in that, In step (2), the laser scanning speed of the solid component is controlled to be 600-1000 mm / s, and the laser scanning speed of the constraint structure is 1800-2200 mm / s.

3. The self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures according to claim 1, characterized in that, In step (2), the laser power of the formed solid component is 375 W-425 W.

4. The self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures according to claim 1, characterized in that, In step (2), the scanning layer thickness of the formed solid component is 25-35 μm, and the scanning spacing is 60-70 μm.

5. The self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures according to claim 1, characterized in that, In step (2), the scanning layer thickness of the forming constraint structure is 25-35 μm, and the scanning spacing is 60-70 μm.

6. The self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures according to claim 1, characterized in that, In step (3), the heating rate of the post-aging treatment is 3-5 K / min.

7. The self-removal method for 3D-printed rare-earth modified high-strength aluminum alloy constraint structures according to claim 1, characterized in that, The powder has a particle size of 15-53 μm.

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