An aluminum-copper alloy member, a method for producing the same, and an application thereof

Abstract

The application discloses an aluminum-copper alloy component and a preparation method and application thereof, and is characterized in that: taking aluminum-copper alloy powder as raw material, adopting electron beam additive manufacturing technology, controlling process parameters and scanning paths to melt and form the powder, and obtaining an aluminum-copper alloy component blank, the obtained copper alloy component blank has uniform and small equiaxed crystal structure, and after solid solution and aging treatment, the aluminum-copper alloy component has good mechanical properties and isotropy, the room temperature tensile strength is greater than or equal to 430 MPa, the yield strength is greater than or equal to 300 MPa, and the elongation is greater than or equal to 10%. The application realizes direct preparation of a near-net-shaped aluminum-copper alloy additive manufacturing component, the obtained aluminum-copper alloy component has excellent mechanical properties, the manufacturing period is significantly reduced, the material utilization rate is greatly improved, and the application is suitable for industrial production and practical application.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, and particularly relates to an aluminum-copper alloy component, its preparation method, and its application. Background Technology

[0002] Aluminum alloys, with their low density, high cost-effectiveness, and excellent comprehensive mechanical properties, have been widely used in aerospace, industrial manufacturing, defense equipment, medical devices, automotive industry, and electronic communications. Among them, aluminum-copper alloys, as a typical class of high-strength, heat-resistant aluminum alloys, are widely used in load-bearing structural components of commercial satellites because they maintain good strength even at high temperatures. With the rapid development of the current commercial satellite industry, the demand for integrated, geometrically complex, and rapidly responsive manufacturing of aluminum alloy structural components is becoming increasingly urgent. Traditional forming processes such as casting and forging are no longer sufficient to meet current development requirements in terms of design freedom, manufacturing cycle, and structural adaptability. Therefore, the forming of aluminum alloy components based on additive manufacturing technology has become an inevitable trend in the industry.

[0003] Currently, the more mature additive manufacturing technologies for aluminum alloy components mainly include selective laser melting (SLM), selective arc welding (WAAM), and selective electron beam melting (SEBM). SLM faces challenges such as easy powder oxidation, high laser reflectivity, and high residual stress, leading to problems like excessive oxide inclusions, low manufacturing efficiency (requiring multiple lasers to improve efficiency), and susceptibility to cracking. Therefore, stable manufacturing is currently possible primarily with medium-strength AlSi10Mg or its modified alloys, which have low thermal cracking tendency. However, the strengthening phases of this alloy are prone to coarsening at high temperatures, resulting in poor heat resistance. When using SLM to manufacture Al-Cu high-strength heat-resistant alloy components, it is still difficult to overcome printing defects such as inclusions, porosity, and cracking. While WAAM can also achieve additive manufacturing of Al-Cu high-strength heat-resistant alloy components, it faces challenges such as poor manufacturing precision and difficulty in forming complex components, generally being more suitable for additive manufacturing of larger, simpler-shaped components. SEBM, with its high electron beam energy, can significantly improve the efficiency of additive manufacturing. Its high-vacuum environment prevents oxidation of aluminum alloy powder during printing, resulting in very few oxide inclusions in the additive components. In particular, the high substrate preheating temperature reduces the temperature gradient for molten pool solidification during printing, significantly reducing the tendency of high-strength aluminum alloys to thermally crack. However, using SEBM to prepare high-strength, heat-resistant aluminum alloy components still faces technical challenges such as optimizing alloy composition and forming processes, and controlling substrate or preheating temperatures.

[0004] Currently, numerous documents and patents disclose various alloy compositions suitable for additive manufacturing, which generally contain high proportions of rare earth elements, Sc, Zr, etc. This leads to high costs, and new alloy systems require a long verification period before industrial application. Furthermore, the alloy composition is highly correlated with the chosen additive manufacturing method. For example, patent application CN202410913983.1 discloses a low-cost, high-strength Al-Cu alloy composition suitable for 3D printing. As stated, this alloy composition is suitable for laser additive manufacturing. However, if electron beam additive manufacturing is used, the high energy density of the electron beam and the vacuum printing environment cause severe burning of the Mg element in the alloy, and the amount of burning is difficult to predict quantitatively, resulting in a significant deviation of the final component's composition from the design value. Therefore, when using electron beam additive manufacturing to form aluminum alloys, the Mg content in the alloy typically ranges widely. As described in patent application CN202510091487.7, the Mg content is 0.2%~3%. However, when Mg is used as a strengthening element, a wide composition range can lead to significant deviations in alloy performance.

[0005] Another significant challenge in SEBM fabrication of high-strength, heat-resistant aluminum alloys is controlling the substrate preheating temperature. Too low a temperature can cause cracking in the printed parts and powder blowing during the printing process, while too high a temperature may lead to powder agglomeration and powder pushing. Therefore, patent application CN202311842243.5 addresses the preheating problem in the printing process to achieve high-quality forming of selective electron beam melting (SEBM) aluminum alloys. Its core technology involves controlling the defocusing voltage and current of the defocused electron beam; however, it does not provide the process parameters for the entire printing process. From its examples, it is clear that it primarily focuses on process control for AlZnMgCu alloys, and the prepared samples are regular cuboid specimens. When the target product is a complex component, due to differences in wall thickness, heat dissipation varies at different locations, making it difficult to achieve temperature control of the component using the proposed preheating strategy.

[0006] For Al-Cu alloys, the strengthening process mainly relies on precipitation strengthening through heat treatment. However, unlike conventional methods such as casting and plastic forming of Al-Cu alloy components, the inherent cyclic heating characteristics of the SEBM forming process, as well as the cooling process under preheated substrate conditions, result in significant differences in the grain morphology and second phase morphology of the printed alloy. This makes it impossible to directly refer to conventional methods for heat treatment processes for alloys manufactured using conventional methods. For example, patent documents CN202410913983.1 and CN202210401700.6 disclose heat treatment processes for additive manufacturing of high-strength aluminum alloys, but these are actually heat treatment technologies proposed for Al-Cu-Mg alloys and are not applicable to Al-Cu alloys that do not contain Mg. Although patent document with application number CN202410156212.2 discloses a heat treatment method for additive manufacturing of Al-Cu alloy, it is aimed at electric arc wire additive manufacturing (WAAM) Al-Cu alloy. The significant differences between WAAM and SEBM processes result in different microstructures of the alloy components prepared, and therefore the design basis of their heat treatment processes differs. Summary of the Invention

[0007] To address the aforementioned technical problems and shortcomings in the field, the first objective of this invention is to provide a method for preparing aluminum-copper alloy components. This invention uses aluminum-copper alloy powder as raw material; employs electron beam additive manufacturing technology, and by controlling process parameters and scanning strategies, obtains an aluminum-copper alloy component blank with a uniform and fine equiaxed crystal structure. After heat treatment, an aluminum-copper alloy component with excellent mechanical properties and isotropy is obtained. This method can produce aluminum-copper alloy components with an outer contour dimension greater than 35mm × 50mm × 140mm. After surface finishing, these aluminum-copper alloy components can be directly used as load-bearing components for commercial satellites.

[0008] A second objective of this invention is to provide an aluminum-copper alloy component prepared by the above-described preparation method.

[0009] A third objective of this invention is to provide applications of the aluminum-copper alloy components prepared by the above-described preparation method.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] The present invention discloses a method for preparing aluminum-copper alloy components, which uses aluminum-copper alloy powder as raw material, and uses electron beam additive manufacturing to form an aluminum-copper alloy component blank, and then heat-treats the aluminum-copper alloy component blank to obtain the aluminum-copper alloy component.

[0012] The aluminum-copper alloy powder, by mass percentage, has the following composition: Cu: 4.8~5.8wt%; Mn: 0.4~0.6wt%; Ti: 0.1~0.4wt%; Zr: 0.1~0.3wt%; V: 0.05~0.3wt%; B: 0.005~0.06%; Mg≤0.02wt.%, Fe≤0.1wt.%; Si≤0.03wt.%; the balance being Al and unavoidable impurities.

[0013] This invention uses the above-mentioned aluminum-copper alloy powder and forms it by electron beam additive manufacturing. The resulting aluminum-copper alloy component has both excellent room temperature mechanical properties and high temperature mechanical properties. It can maintain stable mechanical properties for a long time below 250°C, meeting the structural strength requirements under high temperature service conditions.

[0014] The aluminum-copper alloy powder in this invention does not contain high-cost rare earth elements. The high copper content ensures the precipitation of a large amount of θ′-Al2Cu strengthening phase after aging treatment. Simultaneously, the controlled Mn content, combined with an extremely low Fe content, ensures the precipitation of a heat-resistant Al6Mn phase in the alloy without forming a harmful Al6(Fe,Mn) phase. In electron beam additive manufacturing, to avoid cracking, a higher substrate temperature is typically set to reduce the solidification rate of the molten pool. However, a reduced solidification rate leads to coarse grains in the solidified structure. This invention addresses this by adding various Ti, Zr, and B elements with grain-refining effects, utilizing the heterogeneous nucleation effects of Al3Zr, Al3Ti, and Ti2B to synergistically achieve a significant grain-refining effect. Furthermore, the addition of V element improves dendrite bridging, reduces dendrite spacing, and enhances grain boundary bonding, reducing cracking caused by solidification stress. It also enhances the eutectic liquid film compensation capacity, reducing shrinkage porosity and hot cracking during solidification. In addition, the Al formed after solidification... 11 The V phase can significantly enhance the high-temperature stability of the alloy.

[0015] Experiments have shown that the synergy of the components and their contents is crucial for achieving the excellent room-temperature mechanical properties and high-temperature stability of this invention. The synergistic addition of Ti, Zr, and B effectively refines the grain size. Adding only one or two of these elements, even with increased content, cannot achieve the same grain refinement effect. Furthermore, in this invention, the contents of Mg, Fe, and Si are significantly lower than in conventional alloys. The Mg content is controlled within the limits specified in this invention, effectively preventing Mg burn-off and thus avoiding uncontrollable composition of the printed components, which would severely affect the product yield. Simultaneously, it avoids the formation of the S (Al2CuMg) phase in the alloy. The S phase is prone to dissolution or rapid coarsening above 150℃~200℃, leading to a decrease in alloy strength. The use of a lower Si content improves melt fluidity and casting performance while preventing excessive elemental Si from reducing the thermal stability of the microstructure. Additionally, the addition of a small amount of Fe prevents it from combining with Mn to form the Al6(Fe,Mn) phase, ensuring that Mn precipitates only as the heat-resistant Al6Mn phase, thereby improving heat resistance.

[0016] Furthermore, the use of electron beam additive manufacturing technology for the aluminum-copper alloy powder in this invention is crucial, as it features high copper content, extremely low silicon content, multiple high-melting-point elements, and high alloying properties. When other additive manufacturing processes, such as laser powder bed melting, are used to prepare parts, the wide solidification range, high tendency to hot cracking, and poor molten pool fluidity can lead to porosity and hot cracking. However, this invention, by employing electron beam additive manufacturing, utilizes the high energy density of the electron beam, the excellent vacuum environment, and controllable heat input to effectively suppress the formation of porosity and hot cracking, thereby obtaining high-quality structural parts.

[0017] In a preferred embodiment, the aluminum-copper alloy powder has the following composition by mass percentage: Cu: 5.0~5.7wt%; Mn: 0.5~0.6wt%; Ti: 0.15~0.25wt%; Zr: 0.1~0.2wt%; V: 0.15~0.3wt%; B: 0.005~0.04%; Mg≤0.02wt.%; Fe≤0.1wt.%; Si≤0.03wt.%; the balance being Al and unavoidable impurities, with the total amount of impurities ≤0.05wt.%.

[0018] In a further preferred embodiment, the aluminum-copper alloy powder has the following composition by mass percentage: Cu: 5.0~5.63wt%; Mn: 0.51~0.6wt%; Ti: 0.19~0.25wt%; Zr: 0.1~0.15wt%; V: 0.17~0.3wt%; B: 0.006~0.04%; Mg: 0.0035~0.0039wt.%; Fe: 0.033~0.037wt.%; Si: 0.022~0.024wt.%; with the balance being Al and unavoidable impurities.

[0019] In a preferred embodiment, the aluminum-copper alloy powder has a particle size of 30~150μm and a particle size distribution of Dv(10)=30~40μm, Dv(50)=60~70μm, and Dv(90)=110~130μm.

[0020] Experiments have shown that using aluminum-copper alloy powder with the above-mentioned particle size range and particle size distribution, the final product obtained by electron beam additive manufacturing of the present invention can achieve a high density of ≥99% aluminum-copper alloy components. Specifically, Dv(10) = 30~40μm ensures that fine powder is sufficient to fill the gaps between coarse powder, Dv(50) = 60~70μm ensures that the main powder has good flowability, and Dv(90) = 110~130μm avoids excessively coarse particles from causing incomplete fusion. However, if the particle size is not within the range of the present invention, and the proportion of coarse particles is too high, the gaps formed between coarse powder particles are difficult to be completely filled by the molten pool, resulting in a significant increase in incomplete fusion defects between layers or passes. If the proportion of fine powder is too high, severe powder blowing will occur. In addition, an excessively wide particle size distribution will lead to a decrease in powder flowability and uneven density of the powder layer.

[0021] In a preferred embodiment, during the electron beam additive manufacturing process, the substrate preheating temperature is controlled to be 300~450℃, the powder thickness is 30~70μm, the electron beam current is 5~8mA, and the electron beam scanning speed is 3~5m / s.

[0022] In this invention, by controlling the process parameters of electron beam additive manufacturing within the aforementioned range, a uniform and fine equiaxed crystal structure of aluminum-copper alloy with isotropic mechanical properties can be obtained. If the preheating substrate temperature is too low, significant thermal stress will occur during printing, easily leading to part cracking; if the temperature is too high, aluminum alloy powder is prone to agglomeration at high temperatures, causing over-melting and bulging of the parts. Furthermore, excessively high preheating temperatures will also lead to coarsening of grains and precipitates, altering the expected microstructure of the alloy. In addition, controlling the powder thickness to 30~70μm, the electron beam current to 5~8mA, and the electron beam scanning speed to 3~5m / s ensures sufficient powder melting and provides suitable supercooling and compositional supercooling conditions for the molten pool, promoting equiaxed crystal nucleation. If the scanning speed is too fast, an excessively large temperature gradient will form, leading to the formation of columnar crystals, and excessive energy input will cause defects.

[0023] In a preferred embodiment, the scanning strategy during electron beam additive manufacturing is a 90° orthogonal scan. By rotating the scan by 90° layer by layer, the heat input direction of each layer can be changed, avoiding the continuous accumulation of heat and stress in a single direction, which helps to reduce warping and deformation of the part. Secondly, changing the scanning direction by 90° forces the heat dissipation direction of the molten pool to change, which helps to make the material properties more uniform in different directions, thereby reducing the anisotropy of mechanical properties.

[0024] A significant difference between electron beam additive manufacturing and laser additive manufacturing lies in the higher temperature field, which reduces the temperature gradient during molten pool solidification, thus significantly reducing the tendency for hot cracking. However, the uniformity of the temperature field still has a significant impact on forming and hot cracking behavior. For small-sized, regularly shaped samples, heat transfer is fast and heat dissipation is uniform, making it easy to ensure a uniform temperature field. Therefore, when the cross-sectional width of aluminum-copper alloy components is less than 50 mm, zonal scanning is unnecessary, and a uniform and fine equiaxed grain structure can be obtained under the process parameters of this invention. However, for large-sized, complex-shaped components, the heat transfer rate is slow, and the degree of heat dissipation varies in different parts due to uneven wall thickness. Using a printing process for small-sized, regularly shaped samples makes it difficult to achieve uniform microstructure in different parts, and may even lead to localized hot cracking.

[0025] In a preferred embodiment, when the cross-sectional width of the aluminum-copper alloy component is ≥50mm, during electron beam additive manufacturing, partition scanning is adopted, the width of the partition is controlled to be 5~9mm, and the overlap of the partition is 0.03~0.08mm; and the substrate preheating adopts gradient preheating, the gradient preheating process is as follows: the initial preheating temperature of the substrate is set to 300℃~350℃, and the substrate preheating temperature is increased by 5℃~20℃ for every 8~10% increase in the printing height direction.

[0026] Experiments have shown that, for large-sized components with complex shapes in electron beam additive manufacturing, the above-mentioned partitioned scanning strategy and substrate gradient preheating can effectively ensure the uniformity of the microstructure in each part. Partial scanning avoids the increased heat dissipation caused by the long cycle time when printing large-sized components, and substrate gradient preheating can ensure that the temperature drop of the already formed part is compensated by the higher substrate temperature after the height of the printed component increases.

[0027] Experiments revealed that by controlling the partitioned scanning strategy and substrate gradient preheating parameters within the range of this invention, the resulting aluminum-copper alloy components exhibit optimal mechanical properties and isotropy. Excessive or insufficient overlap can create weak areas. If the substrate preheating temperature is fixed or the rate of increase is too low, thermal cracking may occur in the later stages of printing. Conversely, excessively high preheating temperatures or excessively rapid rate of increase can cause aluminum alloy powder to agglomerate at high temperatures, leading to over-melting and bulging of the parts, and even coarse grains in the printed components.

[0028] Further preferred, the partition width of the partition scanning is 7~8mm, and the overlap of the partitions is 0.04~0.06mm; and the substrate preheating adopts gradient preheating, the gradient preheating process is as follows: the initial preheating temperature of the substrate is set to 320℃~350℃, and the substrate preheating temperature is increased by 10℃~15℃ for every 9~10% increase in the printing height direction.

[0029] In a preferred embodiment, the heat treatment process is as follows: first, the aluminum-copper alloy component blank is subjected to solution treatment; then, the solution-treated blank is quenched; subsequently, it is immediately subjected to aging treatment; and finally, it is air-cooled.

[0030] The electron beam additive manufacturing process of this invention can obtain aluminum-copper alloy component blanks with uniform and fine equiaxed crystal structures. Due to the high temperature field and low temperature gradient during the printing process, the second phase in the microstructure is uniformly distributed, but its size is on the micrometer scale. This invention further utilizes heat treatment to further control the size of the precipitated phase, thereby achieving strengthening effects at both room temperature and high temperature.

[0031] In a further preferred embodiment, the solution treatment temperature is 530~550℃, the heating method is furnace heating, and the solution treatment time is 2~4h.

[0032] Further optimization involves using room temperature water as the quenching medium and a quenching transfer time of ≤5s.

[0033] In a further preferred embodiment, the aging treatment is performed at a temperature of 160~175℃ for a time of 6~14h.

[0034] Experiments have shown that the aluminum-copper alloy billet obtained by electron beam additive manufacturing of this invention does not require the two-stage solution treatment process of low temperature followed by high temperature required for other high-copper-content aluminum-copper alloys. It can be directly heated to a relatively higher solution temperature for processing. This is due to the design of the composition and the control of the temperature field and temperature gradient during the printing process. Under the action of the temperature field and temperature gradient, the second phase in the component exhibits near-equilibrium solidification, resulting in a near-spherical precipitate, avoiding the dendritic second phase formed in conventional aluminum-copper alloys. The near-spherical second phase has a larger specific surface area than the dendritic second phase, and therefore it is easier to dissolve back into the matrix during the solution treatment process. Even at higher solution temperatures, overheating and grain growth will not occur. The low Mg content in the alloy composition avoids the formation of a low-melting-point Mg-containing second phase in the alloy, so there is no need to eliminate the low-melting-point phase at a lower temperature first. The extremely low Mg content also results in a strong natural aging effect of the alloy. Therefore, it is necessary to strictly control the quenching transfer time and perform aging treatment immediately after solution treatment to avoid the pre-precipitation of strengthening phases and ensure the supersaturation state of the solid solution. Experiments revealed that the precipitation of the strengthening phase can be achieved over a wider range of aging temperatures. However, the alloy exhibits optimal mechanical properties only when the aging temperature is between 160 and 175°C and the aging time is between 6 and 14 hours. If the aging temperature is too high, the precipitation rate is too fast, and the θ′ phase rapidly nucleates and coarsens, resulting in poor strengthening of the alloy. Conversely, if the aging temperature is too low, the precipitation rate is extremely slow, and the peak aging effect cannot be achieved even after 100 hours.

[0035] The present invention also provides an aluminum-copper alloy component prepared by the above preparation method.

[0036] In a preferred embodiment, the aluminum-copper alloy component has a room temperature tensile strength ≥430MPa, a yield strength ≥300MPa, and an elongation ≥10%. At 200℃, the tensile strength ≥270MPa, the yield strength ≥230MPa, and the elongation ≥12%, and the mechanical properties are isotropic.

[0037] The present invention also provides an application of an aluminum-copper alloy component prepared by the above preparation method, wherein the aluminum-copper alloy component is used as a load-bearing component of a commercial satellite.

[0038] Principles and advantages

[0039] This invention uses aluminum-copper alloy powder as raw material; employs electron beam additive manufacturing technology, and obtains aluminum-copper alloy component blanks with uniform and fine equiaxed crystal structure by controlling process parameters and scanning strategies. After heat treatment, aluminum-copper alloy components with excellent mechanical properties and isotropy are obtained. After precision machining, these aluminum-copper alloy components can be directly used as load-bearing components for commercial satellites.

[0040] This invention addresses the additive manufacturing of high-strength, heat-resistant aluminum alloy load-bearing components for commercial satellites in the aerospace field. It overcomes the forming problem of aluminum-copper alloys with high thermal cracking sensitivity. The resulting components possess mechanical properties such as high strength, high toughness, and low anisotropy, meeting the stringent requirements of commercial satellites. The manufacturing method provided by this invention has extremely important economic and engineering significance. Attached Figure Description

[0041] Figure 1 The aluminum-copper alloy component prepared in Example 1 of this invention.

[0042] Figure 2 The image shows a metallographic photograph of the aluminum-copper alloy component prepared in Example 1 of this invention.

[0043] Figure 3 This is an EBSD-IPF image of the aluminum-copper alloy component prepared in Example 1 of the present invention.

[0044] Figure 4 The figures show the room temperature engineering stress-strain curves of the aluminum-copper alloy component prepared in Example 1 of this invention before and after heat treatment.

[0045] Figure 5 The figure shows the engineering stress-strain curve of the aluminum-copper alloy component prepared in Example 1 of this invention at 200°C after heat treatment.

[0046] Figure 6 The microstructure of the aluminum-copper alloy prepared in Comparative Example 1 is shown.

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0048] Example 1

[0049] Using aluminum-copper alloy powder with a particle size range of 30~150μm and a particle size distribution of Dv(10)=33μm, Dv(50)=65μm, and Dv(90)=120μm as raw material, its composition by mass percentage is as follows: Cu: 5.63wt%; Mn: 0.58wt%; Ti: 0.19wt%; Zr: 0.11wt%; V: 0.17wt%; B: 0.006%; Mg: 0.0037wt.%; Fe: 0.033wt.%; Si: 0.022wt.%, with the balance being Al and unavoidable impurities.

[0050] Electron beam additive manufacturing technology was used to form a load-bearing component (target product) for commercial satellites. The component is 146 mm long and has a maximum printing height of 55 mm. Before forming, the substrate preheating temperature was set to 350℃, the powder thickness was 50 μm, and a 90° orthogonal scanning strategy was adopted. The scanning was divided into sections based on the component's cross-sectional characteristics, with a section width of 7.5 mm and a section overlap of 0.05 mm. The melting process parameters were: electron beam current 8 mA and scanning speed 3 m / s. When the printed component height reached 10 mm, the substrate temperature was adjusted to 360℃; when it reached 20 mm, the temperature was adjusted to 370℃; when it reached 30 mm, the temperature was adjusted to 380℃; when it reached 40 mm, the temperature was adjusted to 390℃; and when it reached 50 mm, the temperature was adjusted to 400℃.

[0051] After forming, the resulting aluminum-copper alloy billet is placed in a heating furnace and heated in the furnace for solution treatment. The solution treatment temperature is controlled at 540℃ and the time is 2h. Then, the solution billet is placed in room temperature water for quenching. The quenching transfer time is controlled at less than 5s. Finally, aging treatment is performed. The aging treatment temperature is controlled at 170℃ and the time is 12h.

[0052] Finally, an aluminum-copper alloy component with good mechanical properties was obtained, with a tensile strength of 440 MPa, a yield strength of 302 MPa, and an elongation of 13.9% in the transverse direction; and a tensile strength of 443 MPa, a yield strength of 310 MPa, and an elongation of 11.5% in the longitudinal direction.

[0053] Figure 1 The aluminum-copper alloy component prepared in Example 1 of the present invention can be seen from the figure. The component has good overall forming quality, complete structure, clear outline, and no defects such as macroscopic cracks.

[0054] Figure 2 The image shows a metallographic photograph of the aluminum-copper alloy component prepared in Example 1 of the present invention. It can be seen that the microstructure of the aluminum-copper alloy component consists of fine equiaxed crystals with a size of about 10~40μm.

[0055] Figure 3 The figure shows the EBSD-IPF image of the aluminum-copper alloy component prepared in Example 1 of the present invention. As shown in the figure, the grain orientation is random and there is no obvious texture.

[0056] Figure 4 The table shows the room temperature engineering stress-strain curves of the aluminum-copper alloy component prepared in Example 1 of this invention before and after heat treatment. It can be seen that the component has good isotropic mechanical properties, and its strength is significantly improved after heat treatment.

[0057] Figure 5The figure shows the engineering stress-strain curve of the aluminum-copper alloy component prepared in Example 1 of this invention after heat treatment at 200°C. It can be seen that the component still has good mechanical properties.

[0058] Example 2

[0059] Using aluminum-copper alloy powder with a particle size range of 30~150μm and a particle size distribution of Dv(10)=33μm, Dv(50)=65μm, and Dv(90)=120μm as raw material, its composition by mass percentage is as follows: Cu: 5.52wt%; Mn: 0.51wt%; Ti: 0.21wt%; Zr: 0.15wt%; V: 0.20wt%; B: 0.02%; Mg: 0.0035wt.%; Fe: 0.033wt.%; Si: 0.023wt.%, with the balance being Al and unavoidable impurities.

[0060] Electron beam additive manufacturing technology was used to form a load-bearing component (target product) for commercial satellites. The component is 146 mm long and has a maximum printing height of 55 mm. Before forming, the substrate preheating temperature was set to 320℃, the powder thickness was 30 μm, and a 90° orthogonal scanning strategy was adopted. The scanning was divided into sections based on the component's cross-sectional characteristics, with a section width of 8 mm and a section overlap of 0.06 mm. The melting process parameters were: electron beam current 5 mA and scanning speed 5 m / s. When the printed component height reached 10 mm, the substrate temperature was adjusted to 335℃; when it reached 20 mm, the temperature was adjusted to 350℃; when it reached 30 mm, the temperature was adjusted to 365℃; when it reached 40 mm, the temperature was adjusted to 380℃; and when it reached 50 mm, the temperature was adjusted to 395℃.

[0061] After forming, the resulting aluminum-copper alloy billet is placed in a heating furnace and heated in the furnace for solution treatment. The solution treatment temperature is controlled at 550℃ and the time is 3h. Then, the solution billet is placed in room temperature water for quenching. The quenching transfer time is controlled at less than 5s. Finally, aging treatment is performed. The aging treatment temperature is controlled at 160℃ and the time is 14h.

[0062] Finally, an aluminum-copper alloy component with good mechanical properties was obtained, with a tensile strength of 439 MPa, a yield strength of 296 MPa, and an elongation of 12.4% in the transverse direction; and a tensile strength of 440 MPa, a yield strength of 302 MPa, and an elongation of 11.4% in the longitudinal direction.

[0063] Example 3

[0064] Using aluminum-copper alloy powder with a particle size range of 30~150μm and a particle size distribution of Dv(10)=33μm, Dv(50)=65μm, and Dv(90)=120μm as raw material, its composition by mass percentage is as follows: Cu: 5.0wt%; Mn: 0.60wt%; Ti: 0.25wt%; Zr: 0.10wt%; V: 0.30wt%; B: 0.04%; Mg: 0.0039wt.%; Fe: 0.037wt.%; Si: 0.024wt.%, with the balance being Al and unavoidable impurities.

[0065] Electron beam additive manufacturing technology was used to form a load-bearing component (target product) for commercial satellites. The component is 146 mm long and has a maximum printing height of 55 mm. Before forming, the substrate preheating temperature was set to 350℃, the powder thickness was 70 μm, and a 90° orthogonal scanning strategy was adopted. The scanning was divided into sections based on the component's cross-sectional characteristics, with a section width of 7 mm and a section overlap of 0.04 mm. The melting process parameters were: electron beam current 6 mA and scanning speed 4 m / s. When the printed component height reached 10 mm, the substrate temperature was adjusted to 360℃; when it reached 20 mm, the temperature was adjusted to 370℃; when it reached 30 mm, the temperature was adjusted to 385℃; when it reached 40 mm, the temperature was adjusted to 400℃; and when it reached 50 mm, the temperature was adjusted to 410℃.

[0066] After forming, the resulting aluminum-copper alloy billet is placed in a heating furnace and heated in the furnace for solution treatment. The solution treatment temperature is controlled at 530℃ and the time is 4h. Then, the solution billet is placed in room temperature water for quenching. The quenching transfer time is controlled at less than 5s. Finally, aging treatment is performed. The aging treatment temperature is controlled at 175℃ and the time is 6h.

[0067] Finally, an aluminum-copper alloy component with good mechanical properties was obtained, with a tensile strength of 435 MPa, a yield strength of 300 MPa, and an elongation of 11.9% in the transverse direction; and a tensile strength of 441 MPa, a yield strength of 306 MPa, and an elongation of 10.5% in the longitudinal direction.

[0068] Comparative Example 1

[0069] Comparative Example 1 is the same as Example 1, except that the preheating temperature of the substrate is set to 500°C. Due to the excessive heat input, the powder bed agglomerates severely, the surface of the resulting component is slightly bulging, and the grains are obviously coarse. When treated with the same heat treatment regime as Example 1, its mechanical properties are significantly inferior to those of Example 1, especially the tensile strength near the preheated substrate is less than 300 MPa and the elongation is less than 5%. Figure 6The microstructure of the aluminum-copper alloy prepared in Comparative Example 1 shows that its grains and precipitates are significantly coarse.

[0070] Comparative Example 2

[0071] Comparative Example 2 is the same as Example 1, except that the preheating temperature of the substrate is set to 250°C. Due to the low overall temperature field of the powder bed, macroscopic cracks visible to the naked eye appear on the surface of the component. During the tensile test, the sample breaks at the defect, making it impossible to obtain accurate mechanical property data.

[0072] Comparative Example 3

[0073] Comparative Example 3 is the same as Example 1, except that the solution temperature is set to 520°C. Due to the low solution temperature, it failed to fully dissolve back into the Al matrix, resulting in insufficient precipitation strengthening effect after aging. Its tensile strength is 389 MPa, which is lower than that of Example 1.

[0074] Comparative Example 4

[0075] Comparative Example 4 is the same as Example 1, except that the aging temperature is 180°C and the holding time is 6 hours. Due to the higher aging temperature, the precipitated phase coarsens or over-aging, resulting in a weakened strengthening effect. Its tensile strength is 378 MPa, which is lower than that of Example 1.

[0076] Comparative Example 5

[0077] Comparative Example 5 is the same as Example 1, except that the quenching transfer time is extended to 15s. Due to the longer transfer time, pre-precipitation occurs before quenching and cooling, which impairs the solid solution strengthening effect. Its tensile strength is 400MPa, which is lower than that of Example 1.

[0078] Comparative Example 6

[0079] Comparative Example 1 is the same as Example 1, except that the component was not scanned in sections, but was scanned continuously. Due to the severe heat accumulation caused by continuous scanning, the shaped component could not be printed in the end.

Claims

1. A method of producing an aluminum-copper alloy member, characterized by: Using aluminum-copper alloy powder as raw material, an aluminum-copper alloy component blank is obtained by electron beam additive manufacturing. The aluminum-copper alloy component blank is then heat-treated to obtain the aluminum-copper alloy component. The aluminum-copper alloy powder has the following composition by mass percentage: Cu: 4.8~5.8wt%; Mn: 0.4~0.6wt%; Ti: 0.1~0.4wt% Zr: 0.1~0.3wt% V: 0.05~0.3wt%; B: 0.005~0.06%; Mg≤0.02wt.%, Fe≤0.1wt.%; Si≤0.03wt.%; balance is Al and unavoidable impurities.

2. A method of producing an aluminum copper alloy member according to claim 1, characterized by: The aluminum-copper alloy powder has the following composition by mass percentage: Cu: 5.0~5.7wt%; Mn: 0.5~0.6wt%; Ti: 0.15~0.25wt%; Zr: 0.1~0.2wt% V: 0.15~0.3wt%; B: 0.005~0.04%; Mg≤0.02wt.%; Fe≤0.1wt.%; Si≤0.03wt.%; the balance is Al and unavoidable impurities, and the total amount of impurities is ≤0.05wt.%.

3. A method of producing an aluminum-copper alloy member according to claim 1, characterized by: The aluminum-copper alloy powder has a particle size of 30~150μm and a particle size distribution of Dv(10)=30~40μm, Dv(50)=60~70μm, and Dv(90)=110~130μm.

4. The method of claim 1 wherein: During the electron beam additive manufacturing process, the powder thickness is 30~70μm, the electron beam current is 5~8mA, and the electron beam scanning speed is 3~5m / s. The scanning strategy used in electron beam additive manufacturing is 90° orthogonal scanning.

5. A method of producing an aluminium copper alloy component according to any one of claims 1 to 4, characterised in that: When the cross-sectional width of the aluminum-copper alloy component is ≥50mm, during electron beam additive manufacturing, partition scanning is adopted, and the width of the partition is controlled to be 5~9mm, and the overlap of the partition is 0.03~0.08mm; and the substrate preheating adopts gradient preheating. The gradient preheating process is as follows: the initial preheating temperature of the substrate is set to 300℃~350℃, and the substrate preheating temperature is increased by 5℃~20℃ for every 8~10% increase in the printing height direction.

6. The method for preparing an aluminum-copper alloy component according to claim 5, characterized in that: The partition width of the partition scanning is 7~8mm, and the overlap of the partitions is 0.04~0.06mm; and the substrate preheating adopts gradient preheating. The gradient preheating process is as follows: the initial preheating temperature of the substrate is set to 320℃~350℃, and the substrate preheating temperature is increased by 10℃~15℃ for every 9~10% increase in the printing height direction.

7. The method for preparing an aluminum-copper alloy component according to claim 1, characterized in that: The heat treatment process is as follows: first, the aluminum-copper alloy component blank is subjected to solution treatment, then the solution-treated blank is quenched, followed by aging treatment, and finally air-cooled.

8. The method for preparing an aluminum-copper alloy component according to claim 7, characterized in that: The solution treatment temperature is 530~550℃, the heating method is furnace heating, and the solution treatment time is 2~4h; the quenching medium is room temperature water, and the quenching transfer time is ≤5s; The aging treatment is performed at a temperature of 160~175℃ for 6~14 hours.

9. An aluminum-copper alloy component prepared by the preparation method according to any one of claims 1-8, characterized in that: The aluminum-copper alloy component has a room temperature tensile strength ≥430MPa, a yield strength ≥300MPa, and an elongation ≥10%. At 200℃, it has a tensile strength ≥270MPa, a yield strength ≥230MPa, and an elongation ≥12%, and its mechanical properties are isotropic.

10. The application of an aluminum-copper alloy component prepared by the preparation method according to any one of claims 1-8, characterized in that: The aluminum-copper alloy components are used as load-bearing components in commercial satellites.

Images