A method for preparing a spacecraft device based on 3D printing, the spacecraft device and application

Abstract

The application discloses a method for preparing a spacecraft device based on 3D printing, the spacecraft device and application, and relates to the technical field of spacecraft devices, and in particular to a method for preparing a spacecraft device based on 3D printing. The method comprises the following steps: selecting CuCrNb pre-alloy powder and controlling the composition, particle size and oxygen content of the CuCrNb pre-alloy powder; adopting integrated modeling design to construct a three-dimensional model of the spacecraft device; importing data of the three-dimensional model into a 3D printing device, adopting a green laser selective melting process, and performing parameter matching; preheating a substrate of the 3D printing device, printing in an inert gas protection atmosphere by adopting a layer-by-layer scanning superposition and partition temperature control mode, and obtaining a preform of the spacecraft device; and performing hot isostatic pressing treatment on the preform to obtain the spacecraft device. Through full-process collaborative improvement, the traditional process bottleneck is completely broken through, the spacecraft device prepared has excellent compactness, size precision, heat conduction performance and high-temperature stability, and can meet the service requirement of a spacecraft combustion chamber under extreme working conditions.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing technology, specifically to a method for preparing aerospace devices based on 3D printing, and the aerospace devices and applications thereof. Background Technology

[0002] Liquid rocket engine combustion chambers, thrust chambers, and other aerospace components are core high-temperature load-bearing components of aerospace propulsion systems. Their working environment is characterized by extremely high temperatures, intense heat flux, and complex alternating loads. Complex cooling channels need to be arranged inside to achieve efficient heat dissipation and cooling, ensuring the safety and service life of the components during high-temperature operation.

[0003] Metal 3D printing (additive manufacturing), as a core technology in high-end aerospace manufacturing, has completely broken through the process constraints of traditional subtractive manufacturing and is highly compatible with the development of aerospace components. Copper alloys have excellent high-temperature strength, resistance to softening, and thermal conductivity, making them ideal materials for aerospace components such as engine combustion chambers and thrust chambers.

[0004] Currently, when using conventional infrared laser 3D printing to prepare copper alloy components, the copper alloy has an extremely low absorption rate of infrared laser, and defects such as spheroidization, porosity and cracking are prone to occur during the printing process, making it difficult to meet the stringent requirements of aerospace devices; moreover, there is a lack of matching post-processing technology, which cannot eliminate internal micro-defects, resulting in poor performance stability in batch production. Summary of the Invention

[0005] This application provides a method for fabricating aerospace devices based on 3D printing, as well as aerospace devices and applications, with the aim of solving problems in the prior art such as the extremely low absorption rate of copper alloys to infrared lasers and the easy occurrence of spheroidization, porosity, and cracking during the printing process.

[0006] The technical solution provided in this application is as follows: To achieve the above objectives, this application provides a method for fabricating aerospace devices based on 3D printing, comprising the following steps: CuCrNb pre-alloyed powder was selected as the 3D printing material, and the powder particle size and oxygen content were controlled to meet the printing requirements. A three-dimensional model of an aerospace device is constructed, which includes an inner wall cooling channel, an outer wall load-bearing structure, a liquid collection cavity, and a flow guide groove. The data of the three-dimensional model is imported into the 3D printing equipment, and the parameters are matched using the green laser selective melting process. The substrate of the 3D printing equipment is preheated, and printing is carried out in an inert gas protective atmosphere by layer-by-layer scanning and stacking and zoned temperature control to obtain prefabricated parts of aerospace devices. The preform is subjected to hot isostatic pressing to obtain the aerospace device.

[0007] Optionally, the CuCrNb pre-alloyed powder, by mass percentage, contains 0.8%-1.2% Cr, 0.15%-0.35% Nb, and the balance is Cu. The CuCrNb pre-alloyed powder has a particle size of 15μm-53μm and an oxygen content of ≤300ppm.

[0008] Optionally, the inner wall cooling channel adopts a spiral, grid, or porous gradient structure, and the minimum wall thickness of the inner wall cooling channel is controlled to be 0.4mm-0.8mm.

[0009] Optionally, the parameter matching is specifically as follows: setting the laser power to 300W-700W, the scanning speed to 800mm / s-1200mm / s, the printing layer thickness to 0.03mm-0.06mm, the single-scan width to 0.08mm-0.12mm, and the overlap rate to 30%-50%.

[0010] Optionally, the preheating temperature of the substrate is controlled at 200℃-300℃, and the partition size of the zone temperature control is 2mm-4mm.

[0011] Optionally, during the printing process, the oxygen content is controlled to be ≤50ppm. When performing interlayer scanning by layer-by-layer scanning and stacking, a rotation scanning strategy is adopted, and the interlayer scanning rotation angle is set to 15°-30°.

[0012] Optionally, the parameters for the hot isostatic pressing treatment are: temperature of 920℃-980℃, pressure of 120MPa-150MPa, and holding time of 2h-3h.

[0013] Optionally, the aerospace device has a density ≥99.5%, a material utilization rate ≥95%, a forming dimensional accuracy of ±0.05mm, an elongation ≥15%, a high-temperature strength retention rate of 600℃ ≥85%, and a thermal conductivity ≥320W / (m²). K).

[0014] In addition, to achieve the above objectives, this application also provides a space device, which is prepared using the above-described method for preparing space devices based on 3D printing.

[0015] This application also provides an application of the above-mentioned method for fabricating aerospace devices based on 3D printing in combustion chamber cooling channel components.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This application provides a method for fabricating aerospace devices based on 3D printing, as well as the aerospace devices and their applications. This method reduces inclusions and porosity defects from the source by strictly controlling the composition, particle size, and oxygen content of the CuCrNb pre-alloyed powder, thereby improving the material's crack resistance and formability. It employs integrated modeling design to avoid the structural defects and stress concentration problems of traditional split-piece welding, enabling the fabrication of complex thin-walled cooling channel structures. Green laser technology is used with specific parameters to significantly improve the laser absorption rate of the copper alloy, stabilize the molten pool, and suppress spheroidization and incomplete fusion defects. Through substrate preheating, zoned temperature control, interlayer rotation scanning, and inert atmosphere protection, temperature and stress fields are balanced, effectively solving the problems of deformation and cracking in thin-walled components. Hot isostatic pressing (HIP) treatment closes microscopic defects, homogenizes the microstructure, and releases residual stress. This application, through collaborative improvements across the entire process, completely breaks through the bottlenecks of traditional processes. The fabricated aerospace devices exhibit excellent density, dimensional accuracy, thermal conductivity, and high-temperature stability, meeting the extreme operating conditions required for aerospace combustion chambers. Attached Figure Description

[0017] Figure 1 This is a flowchart of a method for fabricating aerospace devices based on 3D printing in the embodiments of this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] See Figure 1 This application provides a method for fabricating aerospace devices based on 3D printing, comprising the following steps: S1. Select CuCrNb pre-alloyed powder as 3D printing material, and control the powder particle size and oxygen content to meet the printing requirements.

[0020] S2. Construct a three-dimensional model of the aerospace device, which includes an inner wall cooling channel, an outer wall load-bearing structure, a liquid collection cavity, and a guide channel.

[0021] S3. Import the data of the 3D model into the 3D printing equipment and use the green laser selective melting process to match parameters.

[0022] S4. Preheat the substrate of the 3D printing equipment, and print it in an inert gas protective atmosphere by layer-by-layer scanning and stacking and zoned temperature control to obtain the preform of the aerospace device.

[0023] S5. The preform is subjected to hot isostatic pressing to obtain aerospace components.

[0024] Specifically, step S1 is a preliminary step in the preparation method of this application. By selectively using CuCrNb pre-alloyed powder as the 3D printing material and limiting and controlling key physical properties such as powder particle size and oxygen content, the compatibility and compositional stability of the printing material can be effectively guaranteed. A reasonable powder particle size ensures uniform powder spreading and continuous forming, avoiding problems such as powder spreading defects and uneven melting during the printing process. A lower oxygen content effectively suppresses the generation of oxidation inclusion defects during the printing process, providing a fundamental guarantee for the high-precision and high-density forming of subsequent devices from the raw material end, thus meeting the high reliability requirements of aerospace device fabrication.

[0025] Step S2 involves constructing an integrated 3D model of the aerospace device, integrating multiple functional structures such as the inner wall cooling channels, outer wall load-bearing structure, liquid collection cavity, and flow guide groove into a single integrated design, overcoming the limitations of traditional split-structure design and manufacturing. This integrated modeling approach ensures the spatial continuity and structural integrity of the device's cooling, load-bearing, and flow guide structures, avoiding structural defects and precision errors caused by subsequent assembly and welding during split-form molding. It can adapt to the integrated molding requirements of complex functional aerospace devices, effectively improving the overall structural integrity and service adaptability of the device.

[0026] Step S3 involves importing the completed 3D model data into the 3D printing equipment to achieve precise matching between digital slicing and the forming path. Simultaneously, a green laser selective melting process is employed, with corresponding process parameters adapted and adjusted. Compared to conventional laser printing, the green laser selective melting process is better suited to the melting and forming characteristics of the CuCrNb pre-alloyed powder in this application. Through targeted parameter matching, the molten pool state can be stabilized, the melting and solidification process optimized, and printing defects effectively reduced. This provides a reliable process foundation for high-precision and stable additive manufacturing of complex aerospace device structures.

[0027] Step S4, conducted in an inert gas-protected forming environment, involves prefabrication of the preform through a composite printing method combining substrate preheating, layer-by-layer scanning and stacking, and zoned temperature control. This is a core process ensuring the quality of the formed device. Substrate preheating effectively reduces the temperature gradient during printing, alleviating the problem of thermal stress accumulation; the inert gas atmosphere prevents material oxidation failure during high-temperature forming; the layer-by-layer scanning and stacking method enables precise layer-by-layer forming of complex structures, ensuring dimensional accuracy and structural uniformity of the components; and zoned temperature control achieves uniform temperature field in different structural regions, suppressing forming defects such as deformation and cracking, ultimately resulting in aerospace device preforms with complete structures and excellent forming quality.

[0028] Step S5 involves hot isostatic pressing (HIP) post-processing of the printed preform to optimize its microstructure and repair defects. HIP eliminates microscopic defects such as internal micropores and microcracks generated during additive manufacturing under high temperature and high pressure coupling, optimizes the internal structure of the component, improves its overall density and mechanical stability, eliminates residual printing stress, effectively improves the overall service performance of aerospace devices, and ultimately obtains finished aerospace devices that meet the requirements of high precision, high strength, and high reliability.

[0029] In other embodiments, the CuCrNb pre-alloyed powder contains 0.8%-1.2% Cr and 0.15%-0.35% Nb by mass percentage, with the balance being Cu. The CuCrNb pre-alloyed powder has a particle size of 15μm-53μm and an oxygen content of ≤300ppm.

[0030] Specifically, this embodiment precisely defines the elemental ratio, particle size range, and oxygen content of the CuCrNb pre-alloyed powder, representing a material optimization design suitable for additive manufacturing of aerospace devices. By limiting the mass percentage range of Cr and Nb elements, a stable strengthening phase can be formed in the copper matrix, effectively refining the alloy grain structure and synergistically improving the alloy's high-temperature softening resistance and mechanical stability, while preserving the intrinsic high thermal conductivity of copper alloys to the greatest extent, achieving a balance between thermal conductivity and structural strength. The powder particle size range of 15μm-53μm ensures the uniformity and flowability of powder during the 3D printing process, adapting to thin-layer high-precision forming processes and avoiding forming defects caused by powder agglomeration and uneven powder distribution. Controlling the oxygen content of the CuCrNb pre-alloyed powder to below 300ppm can significantly reduce the content of internal oxide inclusions in the raw material, inhibit the formation of porosity and embrittlement during the printing process, ensure the purity and performance consistency of the printed aerospace devices, and meet the high reliability and long service life requirements of aerospace devices.

[0031] In other embodiments, the inner wall cooling channels may adopt a spiral, grid-like, or porous gradient structure, and the minimum wall thickness of the inner wall cooling channels is controlled to be 0.4mm-0.8mm.

[0032] Specifically, this embodiment limits the internal wall cooling channels to a spiral, grid-like, or porous gradient structure, and controls the minimum wall thickness to 0.4mm-0.8mm. This is an optimized design for the high heat flux heat dissipation requirements and thin-walled structure forming characteristics of aerospace devices. Various irregular and complex channel structures can effectively increase the heat exchange area of ​​the cooling medium, optimize the flow field distribution, and significantly improve the overall heat dissipation efficiency of aerospace devices, adapting to extreme service conditions of high temperature and high heat flux. Limiting a reasonable minimum wall thickness range satisfies the functional requirements of thin-walled lightweighting and rapid heat dissipation, avoiding problems such as delayed heat dissipation and severe heat accumulation caused by excessive wall thickness. It also effectively ensures the overall rigidity and forming integrity of the thin-walled structure, preventing defects such as puncture, wall breakage, and deformation during the printing process, thus balancing the device's heat dissipation performance and structural load-bearing capacity.

[0033] In other embodiments, parameter matching is performed, specifically: the laser power is set to 300W-700W, the scanning speed to 800mm / s-1200mm / s, the printing layer thickness to 0.03mm-0.06mm, the single-scan width to 0.08mm-0.12mm, and the overlap rate to 30%-50%.

[0034] Specifically, this embodiment limits the laser power, scanning speed, printing layer thickness, single-pass scanning width, and overlap rate to create a dedicated process window suitable for high-precision forming of CuCrNb alloys. A reasonable match between laser power and scanning speed stabilizes the molten pool morphology, ensuring the CuCrNb pre-alloy powder melts fully and uniformly, avoiding incomplete fusion and porosity defects caused by insufficient energy, and molten pool collapse and coarse grains caused by excessive energy. Thin-layer printing of 0.03mm-0.06mm effectively improves the dimensional accuracy and interlayer bonding quality of aerospace devices, meeting the forming requirements of thin-walled complex flow channel structures. By limiting the single-pass scanning width and the overlap rate to 30%-50%, it ensures tight bonding between adjacent molten passes without gaps, improving the compactness of single-layer forming, effectively suppressing forming defects such as spheroidization and grooves, and ensuring the uniformity and structural continuity of aerospace devices.

[0035] In other embodiments, the preheating temperature of the substrate is controlled at 200°C-300°C, and the partition size of the zone temperature control is 2mm-4mm.

[0036] Specifically, this embodiment limits the substrate preheating temperature to 200℃-300℃ and the zoned temperature control size to 2mm-4mm. This is a key optimization method to solve the problems of excessive temperature gradient, thermal stress concentration, and thin-wall deformation and cracking in CuCrNb alloy printing. Appropriate substrate preheating can effectively reduce the temperature difference between the molten pool and the substrate, and between the printed layer and the formed layer, significantly reducing the overall temperature gradient, alleviating the accumulated thermal residual stress layer by layer, and suppressing warping, interlayer delamination, and the initiation of microcracks in aerospace devices. The small-size zoned temperature control mode of 2mm-4mm enables precise temperature control of the forming area, solving the problem of uneven local temperature caused by alternating thick and thin structures and numerous flow channel corners in aerospace devices. This makes the temperature field of each forming area more uniform, avoiding forming defects caused by local heat accumulation or excessively rapid cooling, and significantly improving the forming stability and dimensional accuracy of complex irregular-shaped aerospace devices.

[0037] In other embodiments, during the printing process, the oxygen content is controlled to be ≤50ppm. When performing interlayer scanning by layer-by-layer scanning and stacking, a rotation scanning strategy is adopted, and the interlayer scanning rotation angle is set to 15°-30°.

[0038] Specifically, in this embodiment, the oxygen content is controlled below 50 ppm during the printing process, and a 15°-30° interlayer rotation scanning strategy is adopted to further optimize the forming environment and scanning path. The low-oxygen inert atmosphere can completely isolate the high-temperature molten pool from oxygen contact throughout the process, thoroughly suppressing high-temperature oxidation, surface peeling, and inclusion defects of CuCrNb alloy, and ensuring the surface quality and internal structure purity of aerospace devices.

[0039] In conventional fixed-direction scanning mode, the laser scanning path remains consistent for each layer, resulting in a highly uniform solidification direction of the molten pool and grain growth direction. This leads to preferential grain growth along a single direction, causing significant directional differences in the internal structure of the component and consequently, anisotropy in mechanical properties. Simultaneously, the fixed path causes thermal and shrinkage stresses to accumulate continuously in the same direction, easily leading to defects such as microcracks, warping, and interlayer cracking in stress concentration areas like thin-walled cooling channels and structural corners, severely impacting the dimensional accuracy and operational reliability of aerospace devices. This embodiment addresses this by setting an angular rotation of 15°-30° between adjacent printed layers, causing the laser scanning trajectory of each layer to shift relative to the previous layer. This continuously disrupts the directional growth trend of the grains, breaking the continuous growth path of columnar crystals, promoting grain refinement, disordered and uniform distribution within the alloy, significantly weakening the mechanical anisotropy of aerospace devices, making the lateral and longitudinal mechanical properties of aerospace devices more consistent, and improving the overall structural stability. Meanwhile, interlayer rotation scanning can change the heat input path and stress distribution direction of each layer, avoiding the accumulation of residual stress along a fixed path, achieving uniform dispersion and layer-by-layer release of thermal stress, and significantly reducing the risk of deformation and cracking of thin-walled complex cooling channel structures. If the rotation angle is too small, the stress dispersion effect is limited and cannot effectively solve the anisotropy problem; if the rotation angle is too large, it will cause scanning path disorder, decreased melt channel overlap stability, and easily lead to forming defects such as local incomplete fusion and scanning blind zones. Therefore, an interlayer rotation angle of 15°-30° is the optimal range for printing CuCrNb alloy thin-walled complex structures. It can maximize the optimization of internal structure, balance stress distribution, and improve the dimensional accuracy and comprehensive mechanical properties of aerospace devices while ensuring stable melt pool formation and reliable melt channel overlap, thus meeting the high-precision, high-reliability, and long-life manufacturing requirements of aerospace combustion chambers.

[0040] In other embodiments, the parameters for hot isostatic pressing are: temperature of 920℃-980℃, pressure of 120MPa-150MPa, and holding time of 2h-3h.

[0041] Specifically, this embodiment defines the temperature, pressure, and holding time range for hot isostatic pressing, representing the optimal post-processing regime for defect repair and performance enhancement of CuCrNb alloy-printed aerospace devices. The specific high-temperature and high-pressure coupling effectively closes microscopic defects such as residual micropores and microcracks within the aerospace device, eliminating interlayer bonding voids and significantly improving the device's density. Prolonged holding time promotes full recrystallization of the alloy microstructure, refines grains, homogenizes the internal microstructure, releases residual printing stress, and optimizes the second-phase distribution. Without compromising the high-precision shape and complex flow channel structure of the aerospace device, it simultaneously improves the room-temperature toughness and high-temperature resistance to degradation, achieving an overall improvement in the comprehensive mechanical properties and high-temperature service stability of the printed aerospace device.

[0042] In other embodiments, the aerospace device has a density ≥99.5%, a material utilization rate ≥95%, a forming dimensional accuracy of ±0.05mm, an elongation ≥15%, a high-temperature strength retention rate of 600℃ ≥85%, and a thermal conductivity ≥320W / (m²). K).

[0043] Specifically, this embodiment comprehensively defines the density, material utilization rate, dimensional accuracy, mechanical properties, and thermal properties of aerospace components, providing a quantitative representation of the fabrication process effects of this application. A density of ≥99.5% ensures the absence of internal interconnections and excellent structural integrity; a forming accuracy of ±0.05mm meets the assembly and usage requirements of aerospace components; and a material utilization rate of ≥95% is significantly superior to traditional subtractive manufacturing, greatly saving high-end alloy raw materials and shortening the manufacturing cycle. Simultaneously, the aerospace components possess high elongation, excellent high-temperature strength retention, and high thermal conductivity, enabling efficient heat dissipation and cooling while ensuring structural toughness and high-temperature load-bearing stability. This perfectly adapts to the extreme service conditions of aerospace components under high temperature, high heat flux, and alternating loads, ensuring long-term reliable service.

[0044] This application provides a space device that is prepared using the above-described method for preparing space devices based on 3D printing.

[0045] Specifically, the aerospace device defined in this application is integrally formed using the aforementioned 3D printing method. This gives the aerospace device significant structural and performance advantages compared to aerospace components obtained through traditional machining, modular welding, and conventional additive manufacturing. It fundamentally solves the technical drawbacks of traditional aerospace devices (such as aerospace combustion chamber devices), including poor structural integrity, low forming accuracy, numerous internal defects, rapid high-temperature performance degradation, and difficulty in balancing thermal conductivity and strength. This aerospace device leverages the specific proportions and property control advantages of CuCrNb pre-alloyed powder to ensure the intrinsic characteristics of high thermal conductivity, high-temperature softening resistance, and creep resistance from the material source. Simultaneously, combined with integrated modeling design, it achieves integral forming of the inner wall cooling channels, outer wall load-bearing structure, liquid collection cavity, and guide groove, eliminating modular assembly and welding structures. This completely eliminates inherent structural defects such as assembly gaps, welding cracks, and stress concentration, significantly improving the overall structural continuity and load-bearing reliability of the aerospace device. By employing a composite forming strategy involving green laser selective melting with customized process parameters, substrate preheating, zoned temperature control, and interlayer rotational scanning, defects such as porosity, spheroidization, incomplete fusion, and deformation cracking during the printing process are effectively suppressed. This results in aerospace devices with uniform and dense internal structure, high dimensional accuracy, and excellent anisotropic performance consistency. Combined with a dedicated hot isostatic pressing post-processing technique, internal micropores are further closed, microcracks are repaired, and residual stress is released, significantly improving the density, mechanical strength, toughness, and high-temperature service stability of the aerospace devices. Therefore, aerospace devices prepared using this method simultaneously possess high density, high dimensional accuracy, high material utilization, excellent room-temperature mechanical properties, high-temperature strength retention, and ultra-high thermal conductivity. They can withstand the extreme and complex service conditions of high temperature, high heat flux, and alternating loads in liquid rocket engine combustion chambers for extended periods. They exhibit high structural reliability, excellent heat dissipation, and longer service life, fully meeting the engineering application and batch stable fabrication requirements of high-end aerospace propulsion core components.

[0046] This application provides an application of the above-mentioned method for fabricating aerospace devices based on 3D printing in combustion chamber cooling channel components.

[0047] Specifically, this application also provides a specific application of the aforementioned 3D printing method for preparing aerospace components in combustion chamber cooling channel components. This represents an adaptation and engineering application scenario of the technical solution presented in this application. It fully utilizes the core technological advantages of the additive manufacturing method of this application, namely integrated forming, high precision, low defects, and controllable performance, and specifically addresses many industry bottlenecks in the traditional manufacturing process of combustion chamber cooling channel components. Liquid rocket engine combustion chamber cooling channel components are core hot-end components of aerospace propulsion systems. They operate under extreme service environments characterized by ultra-high temperatures, extremely high heat flux densities, drastic temperature fluctuations, and complex mechanical loads. This requires components to possess excellent high-temperature structural strength, creep resistance, and thermal shock resistance, while also demanding extremely high heat exchange efficiency to quickly remove combustion heat and prevent component ablation failure. Traditional combustion chamber cooling channel components are constrained by forging, machining, and separate welding processes, making it impossible to achieve integral forming of complex topological cooling channels. They generally suffer from poor structural integrity, insufficient cooling uniformity, numerous welding defects, severe high-temperature performance degradation, and poor manufacturing consistency, making it difficult to meet the heat dissipation and load-bearing requirements of next-generation high-thrust, high thrust-to-weight ratio aerospace engines. This application employs a CuCrNb pre-alloyed powder-matched green laser selective melting process, combined with integrated structural design, zoned temperature-controlled forming, interlayer rotational scanning, and a dedicated hot isostatic pressing (HIP) strengthening system. This allows for the direct, integrated forming of integral combustion chamber cooling channel components, including complex irregular cooling channels, load-bearing outer walls, liquid collection chambers, and guide grooves, eliminating the need for secondary assembly and welding, thus significantly improving structural integrity. Furthermore, this method can stably produce cooling channel components with high density, high precision, high thermal conductivity, and high high-temperature strength retention, ensuring both the heat dissipation efficiency and lightweight characteristics of the thin-walled cooling structure, as well as the mechanical load-bearing reliability and high-temperature service stability of the overall structure. Compared to traditional manufacturing technologies, this method offers shorter manufacturing cycles, higher material utilization, higher forming accuracy, and smaller component performance dispersion. It enables rapid iterative development and mass production of combustion chamber cooling channels with different specifications and channel structures, effectively improving the service safety and lifespan of hot-end components in aerospace engines, and possesses strong engineering application value and promising prospects for industrialization.

[0048] Example 1 This embodiment provides a method for fabricating aerospace devices based on 3D printing, including the following steps: S1. Raw material selection: CuCrNb pre-alloyed powder is selected. The mass percentage composition of CuCrNb pre-alloyed powder is 0.8% Cr, 0.15% Nb, and the balance is Cu. The particle size of CuCrNb pre-alloyed powder is controlled at 15μm, and the oxygen content of powder is ≤300ppm to ensure powder flowability, powder spreading uniformity and printing purity.

[0049] S2. Model Construction: Establish an integrated three-dimensional model of the combustion chamber cooling channel, including the inner wall cooling channel, the outer wall load-bearing structure, the liquid collection cavity, and the guide groove. The inner wall cooling channel adopts a spiral structure, and the minimum wall thickness of the cooling channel is controlled at 0.4mm.

[0050] S3. Model Import and Process Parameter Matching: The completed integrated 3D model is sliced ​​layer by layer to obtain the layer-by-layer scanning path and process data required for printing. The sliced ​​process data is then imported into the green laser selective melting 3D printing equipment. The printing process parameters are set as follows: laser power is set to 300W, scanning speed is set to 800mm / s, printing layer thickness is set to 0.03mm, single-pass scanning width is set to 0.08mm, and overlap rate is set to 30%.

[0051] S4. Printing and forming: The printing substrate is preheated to 200℃; under the protection of argon inert gas, the oxygen content in the forming chamber is controlled to be ≤50ppm; a zoned temperature control method is adopted, with a zone size of 2mm; at the same time, a layer-by-layer scanning and stacking forming method is adopted, combined with an interlayer rotation scanning strategy, with the interlayer scanning rotation angle set to 15°, and the combustion chamber cooling channel preform is obtained by stacking and printing layer by layer.

[0052] S5. Post-processing of hot isostatic pressing: The printed combustion chamber cooling channel preform is placed in a hot isostatic pressing equipment, and the processing temperature is set to 920℃, the pressure to 120MPa, and the holding time to 2h. After processing, it is cooled with the furnace to finally obtain an integrated combustion chamber cooling channel.

[0053] Testing revealed that the combustion chamber cooling channel prepared in this embodiment has a density of 99.6%, a dimensional accuracy of ±0.05 mm, a room temperature tensile strength of 483 MPa, an elongation of 15.2%, a high-temperature strength retention rate of 85.2% at 600℃, and a thermal conductivity of 322 W / (m·K), fully meeting the high-performance requirements of this application.

[0054] Example 2 This embodiment provides a method for fabricating aerospace devices based on 3D printing, including the following steps: S1. Raw material selection: CuCrNb pre-alloyed powder is selected. The mass percentage composition of CuCrNb pre-alloyed powder is 1.0% Cr, 0.25% Nb, and the balance is Cu. The powder particle size is controlled at 53μm, the powder oxygen content is ≤300ppm, the powder composition is uniform, the impurity content is low, and it is suitable for high-precision additive manufacturing requirements.

[0055] S2. Model Construction: Establish an integrated three-dimensional model of the combustion chamber cooling channel, which includes the inner wall cooling channel, the outer wall load-bearing structure, the liquid collection chamber and the guide groove. The inner wall cooling channel adopts a grid structure, and the minimum wall thickness of the cooling channel is controlled at 0.6mm, taking into account both heat dissipation efficiency and structural load-bearing rigidity.

[0056] S3. Model Import and Process Parameter Matching: The completed integrated 3D model of the combustion chamber is sliced ​​layer by layer to obtain the layer-by-layer scanning path and process data required for printing. The sliced ​​process data is then imported into the green laser selective melting 3D printing equipment. The printing process parameters are set as follows: laser power is set to 500W, scanning speed is set to 1000mm / s, printing layer thickness is set to 0.045mm, single-scan width is set to 0.10mm, and overlap rate is set to 40% to ensure a stable molten pool and dense bonding of the molten channels.

[0057] S4. Printing and Forming: The printing substrate is preheated to 250℃ to eliminate the temperature difference stress during forming; high-purity argon gas is used for protection throughout the process, and the oxygen content in the chamber is controlled within 50ppm to avoid high-temperature oxidation of the alloy; a zoned temperature control forming strategy is adopted, with a single zone size of 3mm, to achieve uniform temperature field in the forming area; a layer-by-layer scanning and stacking method is used for forming, with the inter-layer scanning rotation angle set to 20° to evenly disperse residual stress, weaken the anisotropy of the component, and obtain a prefabricated combustion chamber cooling channel with complete structure and no obvious defects.

[0058] S5. Hot Isostatic Pressing Post-treatment: The prefabricated combustion chamber cooling channel is subjected to high temperature and high pressure densification treatment. The hot isostatic pressing temperature is set to 950℃, the pressure to 135MPa, and the holding time to 2.5h. After the treatment is completed, it is cooled with the furnace to finally obtain an integrated combustion chamber cooling channel.

[0059] Testing revealed that the combustion chamber cooling channel prepared in this embodiment has a density of up to 99.7%, a forming dimensional accuracy of ±0.05 mm, a room temperature tensile strength of 496 MPa, an elongation of 15.3%, a high-temperature strength retention rate of 87.1% at 600℃, and a thermal conductivity of 329 W / (m·K).

[0060] Example 3 This embodiment provides a method for fabricating aerospace devices based on 3D printing, including the following steps: S1. Raw material selection: CuCrNb pre-alloyed powder is selected. The mass percentage composition of CuCrNb pre-alloyed powder is 1.2% Cr, 0.35% Nb, and the balance is Cu. The particle size of CuCrNb pre-alloyed powder is maintained at 35μm, and the oxygen content of the powder is ≤300ppm. The high alloy element content effectively improves the high-temperature softening resistance and creep resistance of the alloy.

[0061] S2. Model Construction: Establish an integrated three-dimensional model of the combustion chamber cooling channel, including the inner wall cooling channel, the outer wall load-bearing structure, the liquid collection cavity, and the guide groove. The inner wall cooling channel adopts a spiral structure, and the minimum wall thickness of the cooling channel is controlled at 0.8mm to meet the service requirements of high heat flux extreme conditions.

[0062] S3. Model Import and Process Parameter Matching: The completed integrated 3D model is sliced ​​layer by layer to obtain the layer-by-layer scanning path and process data required for printing. The sliced ​​process data is then imported into the green laser selective melting 3D printing equipment. The printing process parameters are set as follows: laser power is set to 700W, scanning speed is set to 1200mm / s, printing layer thickness is set to 0.06mm, single-pass scanning width is set to 0.12mm, and overlap rate is set to 50% to ensure sufficient fusion of thick layers and tight interlayer bonding.

[0063] S4. Printing and forming: The substrate preheating temperature is set to 300℃ to minimize the forming temperature gradient; argon gas protection is maintained throughout the process and the oxygen content in the chamber is ≤50ppm; a zoned temperature control strategy is adopted, with a zone size of 4mm, to adapt to uniform temperature control in large areas; layer-by-layer scanning and stacking is used for forming, with the interlayer scanning rotation angle set to 30°, and the combustion chamber cooling channel preform is obtained by stacking and printing layer by layer.

[0064] S5. Post-processing of hot isostatic pressing: The printed combustion chamber cooling channel preform is placed in a hot isostatic pressing equipment, and the processing temperature is set to 980℃, the pressure to 150MPa, and the holding time to heat and pressure to 3h. After processing, it is cooled with the furnace to finally obtain an integrated combustion chamber cooling channel.

[0065] Testing revealed that the combustion chamber cooling channel prepared in this embodiment has a density of 99.8%, a forming dimensional accuracy of ±0.05mm, a room temperature tensile strength of 512MPa, an elongation of 15.9%, a high-temperature strength retention rate of 88.3% at 600℃, and a thermal conductivity of 337W / (m·K). It exhibits excellent high-temperature load-bearing capacity and thermal conductivity, making it suitable for the demanding service scenarios of high-end aerospace hot-end components.

[0066] Compare with Example 1 The overall process is the same as in Example 3, except that the laser power is set to 850W, the scanning speed is set to 1400mm / s, the interlayer rotation angle is set to 40°, the hot isostatic pressing temperature is set to 1050℃, and the pressure is set to 180MPa. The other raw materials, modeling, and forming conditions remain unchanged.

[0067] Compare with Example 2 The overall process is the same as in Example 3, except that the laser power is 150W, the scanning speed is 600mm / s, the interlayer rotation angle is 5°, the hot isostatic pressing temperature is 850℃, and the pressure is 100MPa. The other raw materials, modeling, and forming conditions remain unchanged.

[0068] Compare with Example 3 The same specifications of CuCrNb alloy combustion chamber cooling channel components were prepared using existing mainstream manufacturing processes. The overall forming approach was based on separate forging, separate machining, and welding assembly. 3D printing, green laser processing, and hot isostatic pressing were not used throughout the process. The specific preparation steps are as follows: The first step is billet preparation and split forging. CuCrNb alloy ingots that meet the composition standards are selected as raw materials. Based on the structural characteristics of the combustion chamber, the billets are separated into inner wall cooling structure billets and outer wall load-bearing structure billets. The two types of split billets are heated and forged respectively. Through pressure forging, the billets are made to initially approach the outline of the inner wall cooling matrix and the outer wall load-bearing matrix, eliminating casting porosity defects and obtaining structural split rough billets.

[0069] The second step is precision machining of the two parts. The forged inner and outer wall blanks are precision milled, bored, and ground by CNC. The basic inner wall surface, the outer wall bearing surface, and the simple flow guide structure are machined by mechanical cutting. Due to the characteristics of the machining process, it is not possible to prepare complex spiral, grid, or porous gradient cooling channels. Only conventional straight-through cooling channels can be machined, while ensuring the dimensional accuracy of the assembly reference surface of the two parts.

[0070] The third step is pretreatment and assembly. The processed inner wall components, outer wall components, liquid collection transfer structure, and flow guide accessories are pretreated by surface grinding, degreasing, and descaling to remove machining burrs and surface impurities. They are then assembled in layers according to the assembly position of the combustion chamber and tooling is used to ensure that the assembly gaps of each substructure are uniform and the positions are aligned to form an integral component to be welded.

[0071] The fourth step is welding and solidification. Copper alloy-compatible welding technology is used to weld all assembly seams, interlayer interfaces, and transition positions. Through multi-layer welding, the inner wall cooling structure is integrated with the outer wall load-bearing structure, liquid collection cavity, and flow guiding structure. After welding, the weld seams are ground and shaped to obtain the overall blank component of the combustion chamber.

[0072] Step 5: Finishing and shaping of the finished product. The welded components undergo secondary machining to correct welding deformation, adjust outer contour dimensions and assembly standards, and finally undergo conventional stress-relieving annealing and heatless isostatic pressing densification strengthening process to obtain the finished combustion chamber cooling channel component prepared by traditional methods. This process involves separate molding and welding assembly throughout, resulting in poor structural integrity. Weld seams are prone to inclusions, porosity, microcracks, and stress concentration. Furthermore, it cannot achieve integrated molding of complex thin-walled cooling channels, and the component exhibits significant shortcomings in precision, density, high-temperature performance, and thermal conductivity.

[0073] Compare with Example 4 Traditional infrared lasers are used instead of green lasers. No substrate preheating is set, no zoned temperature control is used, and no interlayer rotation scanning strategy is used. No hot isostatic pressing is performed after printing. The remaining powder materials and model structure are consistent with those in Example 3.

[0074] Compare with Example 5 The process fully adopts all the steps of Example 3, including raw materials, modeling, green laser technology, preheating, zoned temperature control, and rotary scanning, except for the hot isostatic pressing post-processing step, and directly uses the printed preform as the finished product.

[0075] Compare with Example 6 The entire process steps of Example 3 are adopted, except that the zoned temperature control process is cancelled and the overall uniform temperature forming is adopted. There is no 4mm zoned temperature control strategy, and the other conditions remain unchanged.

[0076] The combustion chamber cooling channels prepared in the above embodiments and comparative examples were subjected to performance tests on multiple indicators. The test results are shown in Table 1. Table 1

[0077] As shown in Table 1, the combustion chamber cooling channels prepared by the three sets of embodiments provided in this application have better performance indicators than the combustion chamber cooling channels prepared by the control example. The density of each embodiment is ≥99.5%, the dimensional accuracy can reach ±0.05mm, the room temperature tensile strength is ≥480MPa, the elongation is ≥15%, the high temperature strength retention rate at 600℃ is ≥85%, and the thermal conductivity is ≥320W / (m·K). The process stability and performance consistency are excellent.

[0078] The above description is merely the preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for fabricating aerospace devices based on 3D printing, characterized in that, Includes the following steps: CuCrNb pre-alloyed powder was selected as the 3D printing material, and the powder particle size and oxygen content were controlled to meet the printing requirements. A three-dimensional model of an aerospace device is constructed, which includes an inner wall cooling channel, an outer wall load-bearing structure, a liquid collection cavity, and a flow guide groove. The data of the three-dimensional model is imported into the 3D printing equipment, and the parameters are matched using the green laser selective melting process. The substrate of the 3D printing equipment is preheated, and printing is carried out in an inert gas protective atmosphere by layer-by-layer scanning and stacking and zoned temperature control to obtain prefabricated parts of aerospace devices. The preform is subjected to hot isostatic pressing to obtain the aerospace device.

2. The method according to claim 1, characterized in that, The CuCrNb pre-alloyed powder, by mass percentage, contains 0.8%-1.2% Cr, 0.15%-0.35% Nb, and the balance is Cu. The CuCrNb pre-alloyed powder has a particle size of 15μm-53μm and an oxygen content of ≤300ppm.

3. The method according to claim 1, characterized in that, The inner wall cooling channel adopts a spiral, grid, or porous gradient structure, and the minimum wall thickness of the inner wall cooling channel is controlled to be 0.4mm-0.8mm.

4. The method according to claim 1, characterized in that, The parameter matching process specifically involves setting the laser power to 300W-700W, the scanning speed to 800mm / s-1200mm / s, the printing layer thickness to 0.03mm-0.06mm, the single-scan width to 0.08mm-0.12mm, and the overlap rate to 30%-50%.

5. The method according to claim 1, characterized in that, The preheating temperature of the substrate is controlled at 200℃-300℃, and the partition size of the zone temperature control is 2mm-4mm.

6. The method according to any one of claims 1-5, characterized in that, During the printing process, the oxygen content is controlled to be ≤50ppm. When performing interlayer scanning by layer-by-layer scanning and superposition, a rotation scanning strategy is adopted, and the rotation angle of interlayer scanning is set to 15°-30°.

7. The method according to claim 6, characterized in that, The parameters for the hot isostatic pressing treatment are: temperature 920℃-980℃, pressure 120MPa-150MPa, and holding time 2h-3h.

8. The method according to claim 6, characterized in that, The aerospace components have a density ≥99.5%, material utilization ≥95%, dimensional accuracy of ±0.05mm, elongation ≥15%, strength retention at 600℃ ≥85%, and thermal conductivity ≥320W / (m²). K).

9. An aerospace device, characterized in that, The spacecraft device is prepared using the method for preparing spacecraft devices based on 3D printing as described in any one of claims 1-8.

10. The application of a method for fabricating aerospace devices based on 3D printing as described in any one of claims 1-8 in a combustion chamber cooling channel component.

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