A method for improving the corrosion resistance of laser-added aluminum alloy components through multi-stage aging blocking

Abstract

This invention discloses a method for improving the corrosion resistance of laser-added aluminum alloy components through multi-stage aging blocking. Addressing the technical challenges of insufficient corrosion resistance and rapid intergranular corrosion failure due to precipitation segregation in current laser-added precipitation-strengthened high-performance aluminum alloys, this invention employs a laser / aging coupling process technology that combines high-speed laser scanning solution, high-temperature short-time heat treatment nucleation, and low-temperature long-time aging growth. Utilizing rapid laser melting and solidification, and differentiated precipitation kinetics at grain boundaries and within grains, this method constructs a microstructure characterized by controllable coarsening of grain boundary precipitation and dispersion and refinement of intragranular precipitation. This achieves the technical effect of effectively blocking grain boundary corrosion channels without significantly reducing mechanical properties. This method solves the problem of poor corrosion resistance in current additively manufactured precipitation-strengthened high-performance aluminum alloys.

Description

Technical Field

[0001] This invention belongs to the field of corrosion protection of additive manufacturing aluminum alloys, and specifically relates to a method for improving the corrosion resistance of laser additive aluminum alloy components through multi-stage aging blocking. Background Technology

[0002] Laser additive manufacturing, with its layer-by-layer forming and selective laser melting deposition characteristics, holds great promise for the integrated forming of complex and precise aerospace structures. Aluminum alloys, with their low density and high specific strength, are the preferred material for lightweight aerospace applications. Currently, laser additive manufacturing of high-performance aluminum alloys has become a crucial direction for technological development. Currently, laser additive manufacturing aluminum alloys are mainly divided into two categories: one is cast Al-Si alloys, whose strengthening mechanism is relatively simple and cannot meet the high-performance requirements of the rapidly evolving aerospace industry. The other is precipitation-strengthened aluminum alloys. A representative alloy system developed in recent years is the Al-Mg / Mn alloy system modified with trace rare earth elements such as Sc and Zr. Through in-situ reaction of trace elements to refine nucleation and post-treatment aging precipitation strengthening, it combines good laser additive formability and mechanical properties, and has become an important development direction for laser additive manufacturing of aluminum alloys in the aerospace field.

[0003] However, while laser additive manufacturing (LAM) produces precipitation-strengthened aluminum alloys that combine good formability and mechanical properties, their precipitation characteristics easily lead to localized corrosion microcouples caused by the potential difference between the precipitates and the matrix. In particular, current LAM-manufactured precipitation-strengthened aluminum alloys employ heat treatment processes geared towards optimizing mechanical properties. While peak aging achieves optimal mechanical properties, it readily forms continuously distributed intergranular precipitates at grain boundaries. For example, the common peak aging heat treatment process for Al-Mg-Sc-Zr alloys involves holding at 325℃ for 4 hours, at which point the tensile strength can exceed 500 MPa, but this results in the formation of continuously distributed Al3(Sc,Zr) precipitates along the grain boundaries. During subsequent service, these continuously distributed intergranular precipitates act as corrosion channels, accelerating the corrosion process and reducing the corrosion resistance of the components. This significantly reduces the corrosion resistance of LAM-manufactured precipitation-strengthened aluminum alloy components, representing a pressing technological challenge that needs to be addressed.

[0004] In summary, laser additive manufacturing of precipitation-strengthened aluminum alloy systems has great potential in the field of lightweight high-performance aluminum alloy structures for aerospace. However, current manufacturing processes can lead to problems such as intergranular continuous precipitation and corrosion weakening channels in the formed specimens. At present, there is no dedicated supporting process to significantly improve the corrosion resistance of laser additive manufacturing precipitation-strengthened aluminum alloys. Summary of the Invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is that the precipitation of aluminum alloy structures formed by laser powder bed fusion additive manufacturing is prone to continuous precipitation along the grain, which leads to a significant reduction in corrosion resistance. The present invention proposes a method to improve the corrosion resistance of laser additive aluminum alloy components by means of multi-stage aging blocking.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for improving the corrosion resistance of laser-added aluminum alloy components through multi-stage aging blocking includes the following steps:

[0008] S1, Precipitation-strengthened aluminum alloy powder:

[0009] Aluminum alloy matrix powder materials with precipitation characteristics and good laser additive forming properties were selected.

[0010] S2, Laser-based rapid solution treatment:

[0011] Laser additive manufacturing process is carried out to promote the formation of supersaturated solid solution of solute elements by rapidly melting and solidifying the aluminum alloy matrix powder material in step S1.

[0012] S3, High-temperature short-time primary heat treatment nucleation:

[0013] High-temperature short-time heat treatment of the formed specimen in step S2 promotes rapid precipitation and nucleation of precipitated phases at grain boundaries;

[0014] S4, Low-temperature long-term two-stage heat treatment blocking:

[0015] Further low-temperature long-term heat treatment was carried out on the specimen after step S3 to achieve controllable coarsening of precipitates at grain boundaries and dispersion and refinement of in-situ precipitates within the grains.

[0016] Specifically, in step S1, the aluminum alloy matrix powder material is selected from any one of Al-Cu-Mg alloy, Al-Mg-Si alloy, Al-Zn-Mg alloy, Al-Ni alloy, Al-Mg alloy modified with trace rare earth elements, Al-Mn alloy modified with trace rare earth elements, and Al-Mg-Mn alloy modified with trace rare earth elements.

[0017] Further, in step S1, in the Al-Cu-Mg alloy, the content of Cu is 3~6 wt.%, the content of Mg is 0.5~4 wt.%, and the balance is Al; in the Al-Mg-Si alloy, the content of Mg is 0.5~2 wt.%, the content of Si is 0.2~1 wt.%, and the balance is Al; in the Al-Zn-Mg alloy, the content of Zn is 3~6 wt.%, the content of Mg is 1.5~2.5 wt.%, and the balance is Al; in the Al-Ni alloy, the content of Ni is 3~7 wt.%, and the balance is Al.

[0018] Further, in step S1, in the Al-Mg alloy modified with trace rare earth elements, the trace rare earth elements are selected from one or more of Sc, Zr, and Er, the total content of trace rare earth elements in the modified alloy is ≤2 wt.%, the Mg content is 2~6 wt.%, and the balance is Al; in the Al-Mn alloy modified with trace rare earth elements, the trace rare earth elements are selected from one or more of Sc, Zr, and Er, the total content of trace rare earth elements in the modified alloy is ≤2 wt.%, the Mn content is 2~6 wt.%, and the balance is Al; in the Al-Mg-Mn alloy modified with trace rare earth elements, the trace rare earth elements are selected from one or more of Sc, Zr, and Er, the total content of trace rare earth elements in the modified alloy is ≤2 wt.%, the Mn content is 1~6 wt.%, the Mg content is 0.5~6 wt.%, and the balance is Al.

[0019] Specifically, in step S1, the aluminum alloy matrix powder material is spherical particles with a particle size distribution of 15~53 μm.

[0020] Specifically, in step S1, the aluminum alloy matrix powder material is further dried before forming, with a drying temperature of 100~120 ℃ and a drying time of 2~4 h.

[0021] Specifically, in step S2, the laser scanning speed in the laser additive manufacturing process should be ≥1000 mm / s, the scanning spacing should be 60~100 μm, the powder layer thickness should be 30~50 μm, and the oxygen content in the cavity atmosphere should be controlled below 50 ppm.

[0022] Specifically, in step S3, the high-temperature short-time primary heat treatment is carried out in an inert gas atmosphere, the heating rate of the heat treatment is ≥5 K / min, and the heat treatment temperature is... T 1 ≤ 450℃ T 1 ≤500℃, heat preservation time t 1 20 min≤ t 1≤1 h, cooling method is air cooling.

[0023] Specifically, in step S3, the laser-formed specimen is ultrasonically cleaned with anhydrous alcohol before heat treatment.

[0024] Specifically, in step S4, the low-temperature long-term secondary heat treatment is carried out in an inert gas atmosphere, with a heating rate ≥ 5 K / min and a heat treatment temperature of ≤ 240℃. T 2 ≤280℃, for 6 hours≤ t 2 ≤20 h, cooling method is furnace cooling.

[0025] Since laser additive manufacturing (LAM) produces precipitation-strengthened aluminum alloys, the enhanced mechanical properties and toughness primarily stem from the in-situ dispersed nanoscale phases within the grains; the more dispersed and refined the phases, the more significant the improvement in mechanical properties. Corrosion resistance, however, is mainly affected by continuously distributed precipitates at grain boundaries. In humid, salt-spray environments, these precipitates readily form localized microcouples with the matrix, promoting rapid corrosion pathways along the grain boundaries. Therefore, to synergistically improve the mechanical and corrosion resistance of LAM-manufactured precipitation-strengthened aluminum alloys, it is necessary to achieve the process control effects of coarsening precipitates at grain boundaries to block intergranular corrosion pathways and refining and dispersing precipitates within the grains to strengthen the matrix. Currently used direct aging processes (~300℃ / 4-6 h) result in continuous precipitates at grain boundaries, significantly reducing the corrosion resistance of the components.

[0026] This invention achieves its technical objectives through the following mechanism:

[0027] (1) Laser-based rapid solidification. Laser additive manufacturing has the process characteristics of rapidly melting and solidifying metal powder with lasers, and its cooling rate can reach 10. 5 -10 7 K / s, and its solidification rate ( R ) and laser scanning speed ( v )have R = v cos θ The relationship. Therefore, this invention controls the laser scanning speed. v A solidification rate of ≥1000 mm / s ensures that the additively manufactured precipitation-strengthened aluminum alloy has a high solidification rate, which prevents solid solution elements such as Mg and Mn, as well as trace modifying elements such as Sc, Zr, and Er, from fully nucleating and growing in the matrix, thereby forming a supersaturated solid solution that deviates from the equilibrium state. This provides a material basis for subsequent multi-stage aging heat treatment to regulate the coarsening behavior of intragranular / grain boundary precipitates.

[0028] (2) High-temperature short-time first-stage heat treatment. For additive manufacturing of original aluminum alloy specimens with supersaturated solid solutions exhibiting precipitation characteristics, the first step is to use a temperature of 450℃≤ TA first-stage aging heat treatment is performed at a high temperature of ≤500℃. At this temperature, the high-temperature thermal driving effect is significant, which can promote the rapid migration and nucleation of solute atoms in the supersaturated solid solution within the matrix. Because there are numerous crystal defects (dislocations, vacancies, etc.) at grain boundaries in the formed specimen, these defects can serve as migration pathways for solute atoms, promoting rapid nucleation of the supersaturated solid solution. Conversely, the fewer defects within the grain matrix result in a slower equilibrium nucleation rate. Therefore, by utilizing the differentiated solute atom diffusion rates at grain boundaries and within the grains, combined with a high-temperature / short-time first-stage heat treatment process, a differentiated precipitation control effect can be achieved, resulting in rapid nucleation of precipitates at grain boundaries and the absence of significant nucleation sites within the grains.

[0029] (3) Low-temperature short-time two-stage heat treatment. Based on the microstructure of rapidly nucleated precipitates at grain boundaries and no significant nucleation points within the grains after the first-stage aging heat treatment, a second stage of heat treatment is performed at 240℃ ≤ T Low-temperature heat treatment at ≤280℃ for a long time can promote the rapid coarsening and growth of nucleated precipitates at grain boundaries, while the internal grains still need to undergo a longer nucleation process under slow thermal drive at low temperature. Through an aging heat input process with a time of 6 h ≤ t ≤ 20 h, a microstructure of coarsened precipitates at grain boundaries and refined, dispersed precipitates within grains is finally achieved. Beneficial effects

[0030] 1. This invention focuses on laser additive manufacturing to form precipitated aluminum alloys. It selects aluminum alloy systems with precipitation characteristics from the raw materials, and combines rapid melting and solidification at high laser scanning speed to form a supersaturated solid solution, high-temperature short-time primary heat treatment to promote grain boundary nucleation, and low-temperature long-time secondary heat treatment to achieve controllable grain boundary coarsening / intragranular dispersion refinement, thereby effectively improving corrosion resistance.

[0031] This method combines the rapid solution treatment potential of laser additive manufacturing with the differentiated modulation of grain boundary / intragranular precipitation dynamics through multi-stage aging heat treatment. It achieves an effective synergy between the mechanical properties and corrosion resistance of laser additively formed precipitation-strengthened aluminum alloys, providing a technological foundation for the manufacture of high-strength, corrosion-resistant aluminum alloy structures for aerospace applications. This method solves the problem of low corrosion resistance in current laser additively formed precipitation-strengthened aluminum alloy structures, broadens the application of laser additive manufacturing of complex aluminum alloys, and is highly operable. Attached Figure Description

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0033] Figure 1 This is a comparison diagram of the process effects of the method of the present invention and the traditional process.

[0034] Figure 2 A schematic diagram of the process for improving the corrosion resistance of laser additive aluminum alloy components through multi-stage aging blocking.

[0035] Figure 3 This is a TEM image of grain boundary precipitation in the cross-section of the molten pool in Example 1 of the specific implementation.

[0036] Figure 4 This is a TEM image of the interior of the grains in the molten pool section of Example 1 in a specific implementation.

[0037] Figure 5 This is a TEM image of grain boundary precipitation in the cross-section of the molten pool in Example 2 of the specific implementation.

[0038] Figure 6 This is a TEM image of grain boundary precipitation in the cross-section of the molten pool in Example 3 of the specific implementation.

[0039] Figure 7 This is an optical image of the intergranular corrosion test section in Example 1 of the specific implementation method.

[0040] Figure 8 This is an optical image of the intergranular corrosion test section in Example 2 of the specific implementation method.

[0041] Figure 9 This is an optical image of the intergranular corrosion test section in Example 3 of the specific implementation method.

[0042] Figure 10 This is an optical image of the intergranular corrosion test section in Example 4 of the specific implementation method. Detailed Implementation

[0043] The present invention can be better understood from the following embodiments. Example 1

[0044] Combination Figure 1 This invention discloses a method for improving the corrosion resistance of laser-added aluminum alloy components through multi-stage aging blocking. Compared to traditional forming methods, this method achieves significant intergranular coarsening through continuous precipitation, blocking intergranular corrosion channels without significant coarsening of intragranular precipitation (i.e., without a significant reduction in mechanical properties). Specifically, it includes the following steps (e.g.) Figure 2 ):

[0045] Step 1: Optimize the alloy system with precipitation strengthening properties and good laser additive manufacturing formability. The selected material system is an Al-Mn-Mg-Sc-Zr alloy, with the alloy composition being Mn 2.0 wt.%, Mg 2.0 wt.%, Sc 0.6 wt.%, Zr 0.2 wt.%, and the balance being Al. The raw material is spherical alloy powder with a particle size of 15-53 μm. The powder is dry and has good flowability. Before forming, the raw powder is dried in a vacuum drying oven at 100 ℃ for 4 h.

[0046] Step 2: Rapid Laser Solution Treatment. During the additive manufacturing process, the laser scanning speed is set to 1200 mm / s. The laser power is 400 W, the scanning distance is 80 μm, the powder layer thickness is 30 μm, the oxygen content in the cavity atmosphere is controlled to be less than 50 ppm, and the preheating function of the forming process is turned off.

[0047] Step 3: High-Temperature Short-Time First-Stage Heat Treatment. The laser-processed specimens are ultrasonically cleaned with anhydrous alcohol. An inert gas atmosphere is controlled in an atmosphere furnace to perform aging heat treatment on the formed specimens at a heating rate of 5 K / min. The heat treatment temperature is... T 1 The temperature is 475℃, and the holding time is... t 1 The time is 1 hour, and the cooling method is air cooling.

[0048] Step 4: Low-temperature, long-term secondary heat treatment. An inert gas atmosphere is controlled using an atmosphere furnace, with a heating rate of 5 K / min, and the heat treatment temperature is... T 2 260℃, time t 2 The cooling time is 12 hours, and the cooling method is furnace cooling.

[0049] Figure 3 This is a bright-field TEM image of the microstructure of the precipitated aluminum alloy material formed in Example 1. It can be seen that the precipitates at the grain boundaries are significantly coarsened to ~500 nm. Figure 4 This is a TEM dark-field image of the internal microstructure of the precipitated aluminum alloy material formed in Example 1. It shows a large number of in-situ particles with a size of ~5 nm precipitated inside the grains. Example 2

[0050] The difference between this embodiment and Embodiment 1 is that the aging heat treatment process does not involve a secondary heat treatment, but adopts a conventional direct aging heat treatment regime of 325℃ / 4 h. Figure 5 This is a bright-field TEM image of the grain boundary precipitation microstructure of the precipitated aluminum alloy material formed in Example 2. It can be seen that under the conventional direct aging process, a large number of intergranular precipitates with a size of ~20 nm are formed at the grain boundaries and are continuously distributed along the grain boundaries. Example 3

[0051] The difference between this embodiment and Embodiment 1 is that in the aging two-stage heat treatment process, the first-stage heat treatment regime is 425℃ / 1 h, and the second-stage heat treatment regime is 260℃ / 12 h. Figure 6 This is a bright-field TEM image of the grain boundary precipitation microstructure of the precipitated aluminum alloy material formed in Example 3. It can be seen that when the first-stage aging temperature is low, even after the specimen undergoes the second-stage aging heat treatment, a large number of continuous precipitations along the grain boundary size of ~20 nm will still be generated at the grain boundary. Example 4

[0052] The difference between this embodiment and Embodiment 1 is that in the secondary heat treatment process, the primary heat treatment regime is 525℃ / 1 h, and the secondary heat treatment regime is 260℃ / 12 h. Example 5

[0053] The difference between this embodiment and Embodiment 1 is that in the secondary heat treatment process, the primary heat treatment regime is 475℃ / 10 min, and the secondary heat treatment regime is 260℃ / 12 h. Example 6

[0054] The difference between this embodiment and Embodiment 1 is that in the aging two-stage heat treatment process, the first-stage heat treatment regime is 475℃ / 1 h, and the second-stage heat treatment is 260℃ / 4 h. Example 7

[0055] The difference between this embodiment and Embodiment 1 is that in the secondary heat treatment process, the primary heat treatment regime is 475℃ / 1 h, and the secondary heat treatment regime is 300℃ / 12 h. Example 8

[0056] The difference between this embodiment and Embodiment 1 is that the laser scanning speed used in the laser additive manufacturing process is 800 mm / s.

[0057] The formed specimens were cut and polished. Standard room temperature tensile tests and intergranular corrosion tests were performed on the specimens in accordance with national standards GB / T 228.1-2021 and GB / T 7998-2023. The test results of different embodiments are shown in Table 1.

[0058] Table 1. Strength and intergranular corrosion depth of specimens formed in different embodiments

[0059]

[0060] As can be seen from Table 1:

[0061] Comparing Example 1 and Example 2, wherein Figure 7 This is an optical image of the cross-section of the molded specimen from Example 1 after intergranular corrosion testing. At this point, the specimen cross-section is flat and continuous, with no significant intergranular corrosion channels, indicating controllable coarsening of intergranular precipitation after multi-stage aging treatment. Figure 3 This effectively blocked the corrosion channels. Figure 8The image shows the cross-sectional optical image of the formed specimen after intergranular corrosion testing in Example 2. It can be seen that after traditional direct aging, the formed specimen is prone to intergranular corrosion pathways, with deep corrosion depths that easily lead to component failure, resulting in poor corrosion resistance. Combined with the test data in Table 1, it is shown that the multi-stage aging process used in this method, compared to the traditional direct aging process for additively manufactured high-strength aluminum alloys, significantly reduces the intergranular corrosion depth from 182.7 μm in the traditional manufacturing process to 18.2 μm without a significant decrease in yield strength (521 MPa). This indicates that the multi-stage aging treatment using this method can effectively control the differentiated precipitation of grain boundary / intragranular precipitates, achieving the effect of coarsening corrosion channels through grain boundary precipitation / strengthening the matrix through intragranular precipitation dispersion. Figure 2 , Figure 3 and Figure 4 ).

[0062] Comparing Example 1 and Example 3, wherein Figure 9 The image shown is a cross-sectional optical image of the formed specimen from Example 3 after intergranular corrosion testing. It can be seen that despite the second-stage aging heat treatment, significant intergranular corrosion still occurs due to the low temperature during the first-stage aging process (425℃). Combined with the test results in Table 1, although the strength remains at a high level (518MPa), the corrosion depth is 153.5 μm. This is because the low first-stage aging temperature cannot provide sufficient diffusion thermal driving force for the rapid nucleation of precipitates at grain boundaries during the high-temperature short-time heat treatment. Consequently, the precipitates at grain boundaries still require nucleation during the subsequent low-temperature long-time heat treatment, thus affecting their coarsening rate. This result is consistent with... Figure 6 The TEM characterization results of the precipitates at the grain boundaries of the molded specimen in Example 3 were consistent.

[0063] Comparing Example 1 and Example 4, wherein Figure 10 The image shown is an optical image of the cross-section of the formed specimen from Example 4 after intergranular corrosion testing. It can be seen that the intergranular corrosion channels in the cross-section of the formed specimen were effectively blocked after the second-stage aging heat treatment, and no significant intergranular corrosion was observed. However, combined with the test results in Table 1, the mechanical properties of the formed specimen significantly decreased to 314 MPa due to the excessively high temperature (525℃) during the first-stage aging process. This is because the high temperature during the first-stage aging process spurred the nucleation of intragranular precipitates, which then coarsened during the subsequent low-temperature, long-duration second-stage heat treatment, thus reducing the mechanical properties of the formed part. Combined with Examples 1 / 3 / 4, it is shown that the first-stage aging heat treatment temperature should be controlled within a suitable range (450℃≤...). T ≤500℃).

[0064] Comparing Example 1 and Example 5, when the first-stage aging time is shortened to 10 min, the strength of the formed specimen decreases to 475 MPa and the intergranular corrosion depth is 147.8 μm. This indicates that the first-stage aging time is too short to provide sufficient thermal drive for grain boundary precipitation nucleation and coarsening, and to block corrosion.

[0065] Comparing Examples 1 and 6, when the secondary aging time is too short (260℃ / 4 h), the strength of the formed specimen is 368 MPa and the corrosion depth is 157.9 μm, indicating that the strength of the formed specimen is reduced and its corrosion resistance is poor. This is because the short low-temperature aging cannot effectively drive the coarsening of precipitates at the grain boundaries to block the corrosion channels. At the same time, precipitates inside the grains cannot effectively nucleate and grow to strengthen the matrix, thus leading to a significant reduction in both strength and corrosion resistance.

[0066] Comparing Examples 1 and 7, when the secondary aging temperature is too high (300℃ / 12 h), the molded specimen exhibits good intergranular corrosion blocking ability (corrosion depth 15.4 μm), but the strength of the molded specimen is significantly reduced to 429 MPa. This is because the excessively high secondary aging temperature causes the precipitates inside the grains to coarsen and grow, reducing the strengthening effect and thus leading to a decrease in the mechanical properties of the molded part.

[0067] Comparing Examples 1 and 8, when the laser scanning speed during laser additive manufacturing is reduced from 1200 mm / s to 800 mm / s, the strength of the formed part decreases to 459 MPa, and the intergranular corrosion depth is 24.7 μm. Although the formed part exhibits good intergranular corrosion resistance, its strength is low. This is because the slow laser scanning speed cannot effectively form a supersaturated solid solution, resulting in low solid solubility of strengthening elements such as Sc and Zr in the matrix, which reduces the strengthening and toughening effect during subsequent aging. Therefore, to obtain laser additively manufactured precipitated aluminum alloy components with both strength and corrosion resistance, the forming scanning speed should be ≥1000 mm / s.

[0068] This invention provides a method for improving the corrosion resistance of laser-added aluminum alloy components through multi-stage aging blocking. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A method for improving the corrosion resistance of laser-added aluminum alloy components through multi-stage aging blocking, characterized in that, Includes the following steps: S1, Precipitation-strengthened aluminum alloy powder: Aluminum alloy matrix powder materials with precipitation characteristics and good laser additive forming properties were selected. S2, Laser-based rapid solution treatment: Laser additive manufacturing process is carried out to promote the formation of supersaturated solid solution of solute elements by rapidly melting and solidifying the aluminum alloy matrix powder material in step S1. S3, High-temperature short-time primary heat treatment nucleation: The specimen formed in step S2 undergoes a high-temperature, short-time, primary heat treatment to promote rapid precipitation and nucleation of the precipitated phase at the grain boundaries. This high-temperature, short-time, primary heat treatment is performed in an inert gas atmosphere, with a heating rate ≥ 5 K / min and a heat treatment temperature of [missing information]. T 1 ≤ 450℃ T 1 ≤500℃, heat preservation time t 1 20 min≤ t 1 ≤1 h, cooling method is air cooling; S4, Low-temperature long-term two-stage heat treatment blocking: Further low-temperature long-term secondary heat treatment was carried out on the specimen after step S3 to achieve controllable coarsening of precipitates at grain boundaries and dispersion and refinement of in-situ precipitates within the grains. The low-temperature, long-duration secondary heat treatment is carried out in an inert gas atmosphere, with a heating rate ≥ 5 K / min and a heat treatment temperature of ≤ 240℃. T 2 ≤280℃, for 6 hours≤ t 2 ≤20 h, cooling method is furnace cooling.

2. The method for improving the corrosion resistance of laser-added aluminum alloy components by multi-stage aging blocking according to claim 1, characterized in that, In step S1, the aluminum alloy matrix powder material is selected from any one of Al-Cu-Mg alloy, Al-Mg-Si alloy, Al-Zn-Mg alloy, Al-Ni alloy, Al-Mg alloy modified with trace rare earth elements, Al-Mn alloy modified with trace rare earth elements, and Al-Mg-Mn alloy modified with rare earth elements.

3. The method for improving the corrosion resistance of laser-added aluminum alloy components through multi-stage aging blocking according to claim 2, characterized in that, In step S1, the Al-Cu-Mg alloy contains 3-6 wt.% Cu, 0.5-4 wt.% Mg, and the balance is Al; the Al-Mg-Si alloy contains 0.5-2 wt.% Mg, 0.2-1 wt.% Si, and the balance is Al; the Al-Zn-Mg alloy contains 3-6 wt.% Zn, 1.5-2.5 wt.% Mg, and the balance is Al; and the Al-Ni alloy contains 3-7 wt.% Ni, and the balance is Al.

4. The method for improving the corrosion resistance of laser-added aluminum alloy components by multi-stage aging blocking according to claim 2, characterized in that, In step S1, the trace rare earth element modified Al-Mg alloy contains trace rare earth elements selected from one or more of Sc, Zr, and Er, with a total trace rare earth element content ≤ 2 wt.%, Mg content 2~6 wt.%, and the balance being Al; the trace rare earth element modified Al-Mn alloy contains trace rare earth elements selected from one or more of Sc, Zr, and Er, with a total trace rare earth element content ≤ 2 wt.%, Mn content 2~6 wt.%, and the balance being Al; the trace rare earth element modified Al-Mg-Mn alloy contains trace rare earth elements selected from one or more of Sc, Zr, and Er, with a total trace rare earth element content ≤ 2 wt.%, Mn content 1~6 wt.%, Mg content 0.5~6 wt.%, and the balance being Al.

5. The method for improving the corrosion resistance of laser-added aluminum alloy components by multi-stage aging blocking according to claim 1, characterized in that, In step S1, the aluminum alloy matrix powder material is spherical particles with a particle size distribution of 15~53 μm.

6. The method for improving the corrosion resistance of laser-added aluminum alloy components by multi-stage aging blocking according to claim 1, characterized in that, In step S1, the aluminum alloy matrix powder material is further dried before forming, with a drying temperature of 100~120 ℃ and a drying time of 2~4 h.

7. The method for improving the corrosion resistance of laser-added aluminum alloy components by multi-stage aging blocking according to claim 1, characterized in that, In step S2, the laser scanning speed in the laser additive manufacturing process should be ≥1000 mm / s, the scanning spacing should be 60~100 μm, the powder layer thickness should be 30~50 μm, and the oxygen content in the cavity atmosphere should be controlled below 50 ppm.

8. The method for improving the corrosion resistance of laser-added aluminum alloy components by multi-stage aging blocking according to claim 1, characterized in that, In step S3, the laser-formed specimen is ultrasonically cleaned with anhydrous alcohol before heat treatment.

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