Method for constructing multiphase multi-material through DLP3D printing and SLS laser selective sintering

Abstract

The invention provides a method for constructing a multi-phase multi-material structure through DLP3D printing and SLS laser selective sintering. The method comprises the steps that 1, materials are prepared; photosensitive resin is used as a matrix, a ceramic precursor, a metal particle precursor and a functional resin mixed material suitable for photocuring 3D printing are prepared, and it is ensured that the viscosity, rheological property and stability of all materials meet the photocuring printing requirement. And 2, carrying out photocuring 3D printing. Step 2, the multiple kinds of slurry in the step 1 are sequentially loaded into an independent special material groove of 3D printing equipment, layer-by-layer curing printing is conducted through the digital light processing technology according to preset three-dimensional model geometric information, and in the printing process, different materials are deposited to a designated area according to the design layout by adjusting the printing sequence and the light source position. The invention provides a new possibility for manufacturing a complex and multifunctional composite structure.

Description

Technical Field

[0001] The present invention belongs to the field of material technology, and particularly relates to a method for constructing multi-phase and multi-materials by DLP 3D printing and SLS laser selective sintering. Background Art

[0002] Additive Manufacturing (AM), commonly known as three-dimensional (3D) printing, is an advanced manufacturing method for fabricating three-dimensional objects by successively adding materials layer by layer. With the continuous progress of this technology, 3D printing has gradually evolved from single-material printing to multi-material printing, especially the 3D printing technology of multi-heterogeneous materials, which has brought profound impacts to fields such as industrial manufacturing, biomedicine, and aerospace. Multi-heterogeneous materials refer to a material system composed of two or more materials with different properties. By combining different materials, comprehensive properties that are not possessed by single materials can be achieved, such as enhancing strength, improving heat resistance, enhancing electrical conductivity, or improving biocompatibility.

[0003] A multi-phase and multi-materials composite structure refers to a composite material composed of two or more materials with different phases, and these materials are different in physical, chemical, and mechanical properties. Each phase maintains its unique characteristics in the structure and is combined together by physical or chemical methods to achieve more superior comprehensive properties than single materials. The development of the 3D printing technology for multi-phase and multi-materials composite structures has undergone a gradual evolution process. The initial 3D printing technology mainly used single materials, such as plastics (PLA, ABS) and metals (titanium alloys, stainless steels). With the increasing demand for complex functions, multi-material 3D printing technology emerged. From the concept proposed in the 1990s, to the exploration in the early 2000s, and then to the rapid development in the 2010s, the multi-heterogeneous materials printing technology has achieved efficient mixing and precise printing of heterogeneous materials through improving nozzle design, material supply systems, and printing algorithms. The multi-nozzle printing technology and the hybrid printing technology are the cores of multi-heterogeneous materials 3D printing, and can print complex objects with different properties and functions through precise control of materials and optimization of printing paths.

[0004] However, most of the above-mentioned technologies are of the same-phase heterogeneous structure rather than a truly multi-phase and multi-materials composite structure.

[0005] Although the 3D printing technology of multiphase and multimaterial composite structures has broad application prospects, it still faces many challenges. The bonding strength between materials, the control of printing accuracy, the improvement of printing speed, and the reduction of costs are all problems that need to be solved urgently, mainly manifested in material compatibility and interface bonding, process control, material supply and handling, etc. Different materials (such as metals and resins) have different coefficients of thermal expansion during heating and cooling, which may lead to interfacial stress and warping, affecting the overall performance of the part. In a multiphase composite structure, the bonding strength between different materials is crucial. A weak interface may lead to delamination, debonding, and a decrease in overall strength. Different materials require different printing parameters (such as temperature, speed, layer thickness, etc.). In the same printing process, how to optimize these parameters to meet the needs of all materials is a challenge. Multiphase composite structures require dedicated multimaterial nozzles that need to be able to precisely control the ejection and switching of different materials to ensure that the materials are deposited as needed. During the printing process, it is necessary to precisely control the supply amount and rate of multiple materials. The material supply system needs to be highly integrated and synchronized to ensure the stability and continuity of the printing process. Different materials may have different requirements during storage and handling, such as humidity control, temperature control, etc., and a suitable handling and storage system needs to be established. During the printing process, different materials react differently to heat, and an effective thermal management system is required to control the cooling rate and temperature distribution of the materials to avoid thermal stress and deformation.

[0006] Technical solution of the prior art I The invention title is a galvanometer nozzle multimaterial 3D printing device and printing method, application number: 202310058613.X. It realizes an additive manufacturing technology that combines the laser sintering of metal powder with the jet curing of glue or polymer materials through the integration of a laser galvanometer printing module and a nozzle printing module. The device uses a layer-by-layer printing strategy to enable laser sintering and jet curing to work together in the same part to manufacture multimaterial parts with complex structures and multifunctional integration. The laser galvanometer module is responsible for printing the metal skeleton part with high precision, providing strength and dimensional stability; the nozzle module is used to print the support structure or the functional non-metal material part, which can be easily removed by dissolution or heating.

[0007] This technology is suitable for the manufacture of parts with complex geometries and cavities, and can also reduce the manual operation during the support removal process. However, the complexity of the device and process poses higher requirements for material compatibility, dimensional accuracy, printing efficiency, and large-scale application, and further optimization is needed to improve industrial adaptability.

[0008] Disadvantages of the prior art I Material Compatibility Limitations: Laser sintering is mainly applicable to metal powders. However, the thermal expansion coefficients of the nozzle-cured materials (such as glue or polymer materials) and metals differ significantly, which may lead to a decline in interfacial bonding performance or structural stress concentration. The nozzle module has high requirements for the fluidity and curing characteristics of the used binder and polymer materials, restricting the variety of selectable materials.

[0009] Limitations in Support Removal Methods: Although the support materials printed by the nozzle can be removed by dissolution or heating, the treatment process still requires additional time and resources, which may have a certain impact on the overall efficiency.

[0010] Challenges in Dimension Accuracy and Consistency: Although the laser sintering part has high precision, the nozzle-cured part may cause dimensional deviations due to material curing shrinkage or the dissolution removal process, requiring further dimensional compensation and simulation optimization. Hybrid material printing may result in uneven thermal expansion and dimensional changes during post-processing (such as sintering or debinding), affecting the consistency of the final parts.

[0011] Technical Solution of the Second Prior Art The invention title is a preparation method for multi-material photocuring 3D printing integration of a titanium nitride-silicon carbide endothermic heat storage heterogeneous ceramic skeleton, and the application number is CN202311856540.5. This patent records that first, by configuring photocurable resin, dispersant, photoinitiator, and sintering aids, TiN and SiC ceramic slurries are respectively prepared, and high-speed ball milling is used to ensure the uniform dispersion and stability of the slurries. In the photocuring 3D printing stage, the slurries are respectively loaded into the printing equipment, and materials are deposited layer by layer through selective photocuring. By precisely controlling the laser power, layer thickness, and slurry extrusion rate, the forming of the multi-material integrated ceramic skeleton is completed. During the post-processing, slow heating is used for debinding to 600°C to remove organic components, and then high-temperature sintering is carried out at 1800°C in an inert gas environment to achieve the densification and strength optimization of the ceramic structure. The finally formed heterogeneous ceramic skeleton is designed such that the outer layer of TiN provides high light absorption and photothermal conversion functions, and the inner layer of SiC has thermal conductivity and heat storage capacity, and can effectively encapsulate the molten salt phase change material to achieve the energy storage function.

[0012] Disadvantages of the Second Prior Art High equipment complexity and lack of universality: Special multi-material photocuring 3D printing equipment is required, and high-precision control of printing parameters is needed, increasing the equipment cost and operation difficulty. There are technical barriers when promoting to other material systems.

[0013] Low process stability and reliability: The preparation and printing of different slurries require high-precision control. Otherwise, poor interfacial bonding or layer separation may occur. The photocuring and sintering processes require strict control of the heating and holding rates. Otherwise, cracks or structural deformation may be caused. Summary of the Invention

[0014] The object of the present invention is to solve the defects existing in the above-mentioned prior art, and provide a method for constructing multi-phase and multi-materials by DLP 3D printing and SLS laser selective sintering.

[0015] The object of the present invention is to solve the problems existing in the prior art, such as insufficient bonding strength between materials, difficulty in controlling printing accuracy and resolution, slow printing speed, and high production cost. By researching new composite materials and optimizing interface treatment technology, the bonding strength between materials is enhanced; the printing equipment and process are improved to improve printing accuracy and resolution, and promote the wide application of multi-phase and multi-materials 3D printing technology in the fields of industrial manufacturing, biomedicine, aerospace, etc.

[0016] The present invention has the following improvements: 1. Material compatibility and interface bonding Coefficient of thermal expansion of different materials: Different materials (such as metals and resins) have different coefficients of thermal expansion during heating and cooling, which may cause interface stress and warping, affecting the overall performance of the part.

[0017] Interface bonding strength: In a multi-phase composite structure, the bonding strength between different materials is crucial. A weak interface may lead to delamination, debonding, and a decrease in overall strength.

[0018] 2. Process control Printing Parameter Optimization: Different materials require different printing parameters (such as temperature, speed, layer thickness, etc.). In the same printing process, how to optimize these parameters to meet the requirements of all materials is a challenge. The present invention adopts a process control method of setting partition parameters and real-time dynamic regulation according to the physical and chemical property differences of different materials, which specifically includes the following measures: 1. Establishment of a multi-material parameter database. According to the curing characteristics, sintering temperature, and thermal expansion coefficient of different materials (such as photosensitive resin, metal powder, etc.), a multi-material process parameter database is established in advance, covering key parameters such as exposure time, scanning speed, laser power, layer thickness, and preheating temperature. 2. Adaptive parameter adjustment model. An intelligent algorithm (such as a process optimization model based on machine learning) is used to monitor the process response (such as curing degree, sintering density, and interfacial bonding strength) of each material area in real time during the printing process, and dynamically adjust the printing parameters to ensure that each material reaches the best processing state. 3. Partitioned multi-level process path planning. The printing area is partitioned according to the material properties, and independent photocuring or sintering paths are set for different materials respectively. By optimizing the scanning order and energy distribution, the thermal influence and stress concentration between materials are reduced, and the multi-material bonding quality is improved; 4. Multi-material collaborative temperature control system. Independent heating or cooling control is set for each partition in combination with the characteristics of multiple materials to ensure that each material is within its optimal processing temperature range, avoid warping and cracking caused by the difference in thermal expansion of materials, and improve the printing accuracy and stability of multi-materials.

[0019] Multi-material Switching Design: The multi-phase composite structure (precursor) needs to go through corresponding material switching processes to avoid contamination between materials, the internal stress during switching, and the impact on the interface quality.

[0020] Specifically, the following methods are adopted: 1. Evaluation of material compatibility parameters. Based on the physical and chemical properties of different materials (such as curing shrinkage rate, coefficient of thermal expansion, sintering temperature, adhesion performance, etc.), a multi-material compatibility evaluation model is established to calculate the matching degree of materials at the interface, and material combinations with good interface bonding performance are screened to ensure no defects such as delamination and cracks during the switching process. 2. Optimized design of the delamination interface. A gradient transition layer or mixed material layer is introduced at the material switching interface, and the thickness and composition ratio of this layer are adjusted according to the material properties to reduce interface stress concentration, enhance the bonding force between materials, and ensure the structural continuity and stability of the material switching area. 3. Dynamic parameter adjustment mechanism. During the material switching process, key process parameters (such as exposure energy, scanning speed, laser power, ambient temperature, etc.) are adjusted in real time. According to the curing or sintering characteristics of different materials, a partition-independent control strategy is adopted to achieve seamless connection of each material switching and avoid defects at the material interface. 4. Switching path and process planning. Combining the multi-material layout and structural requirements, a method combining path priority and area allocation is adopted to pre-plan the spatial position and switching sequence of material switching in advance to ensure uniform distribution of materials in complex structures and reduce deformation and residual stress caused by material alternation. 5. Process verification and feedback optimization. Through a real-time monitoring system during the multi-material switching process, data such as interface forming quality, bonding strength, and material diffusion range are obtained. Combining a closed-loop feedback control strategy, the switching process parameters are continuously adjusted and optimized to ensure the stability and consistency of multi-material switching.

[0021] 3. Material supply and handling Material supply system: During the printing process, it is necessary to precisely control the supply amount and rate of multiple materials. The material supply system needs to be highly integrated and synchronized to ensure the stability and continuity of the printing process.

[0022] Material handling and storage: Different materials may have different requirements during storage and handling, such as humidity control, temperature control, etc., and a suitable handling and storage system needs to be established.

[0023] Through closed-loop feedback control, independent channel design, digital micro-control, dynamic parameter calibration, and step-by-step supply strategy, precise regulation of the supply amount and rate of multiple materials can be achieved, ensuring the forming accuracy, interface quality, and process stability of multi-material structures. Specifically as follows:

[0024] The closed-loop control system based on real-time monitoring integrates high-precision sensors (such as mass flow meters, laser displacement sensors) in the material supply device to real-time monitor the supply amount and flow rate of each material. Combining with the PID closed-loop control algorithm, the drive parameters of the supply system are dynamically adjusted according to the feedback data to ensure the accuracy and stability of material output.

[0025] The independent multi-channel supply system adopts a multi-channel independent control design, with separate supply paths and drive units set for different materials to ensure the independence and non-interference of each material during the supply process. According to the rheological characteristics of the materials, the diameters of the supply channels, the pushing pressures, and the flow rates are adjusted to ensure the precise switching and uniform output of synchronous or asynchronous supply of multiple materials.

[0026] Humidity control method Hermetic storage and dry environment Hermetic storage containers are used to encapsulate hygroscopic materials, combined with desiccants (such as molecular sieves, silica gel) or inert gas protection (such as nitrogen, argon) to maintain a low-humidity environment and prevent the materials from being affected by moisture and deteriorating.

[0027] Dynamic humidity monitoring and regulation Humidity sensors are integrated into the material storage and supply system to monitor the environmental humidity changes in real time. Combined with dynamic dehumidification devices (such as condensation dehumidifiers or adsorption dryers), the humidity is automatically adjusted to ensure that the materials are stored and supplied within a specific humidity range.

[0028] Local drying treatment For highly hygroscopic materials that need to be used temporarily, local drying pretreatment is carried out before supply. Through a hot air circulation system or a vacuum oven, the humidity on the surface and inside of the materials is quickly reduced to ensure the stability of the material properties.

[0029] Temperature control method Constant temperature storage system Constant temperature storage devices are used for heat-sensitive materials. Through temperature sensors, real-time monitoring is carried out, and combined with thermoelectric coolers (TEC) or constant temperature heaters, precise temperature control is achieved to ensure that the materials are always within the set temperature range, avoiding heat deformation or low-temperature condensation.

[0030] Temperature control of the supply path Local heating or cooling modules are set in the material supply path to dynamically adjust the temperature during the material transmission process, preventing problems such as uneven rheology and poor deposition due to temperature changes of the materials, and ensuring consistent output material performance.

[0031] Zone temperature control strategy According to the material characteristics and process requirements, a zone temperature control method is adopted to independently control the temperature of the storage area, supply area, and forming area of different materials, ensuring that the environmental temperature in each stage is precisely adapted, and improving the processing accuracy of multiple materials and the interface bonding quality.

[0032] The present invention adopts the following technical solutions: A method for constructing a multi-phase and multi-material structure by DLP 3D printing and SLS laser selective sintering, comprising: Step 1. Material preparation: Using photosensitive resin as the matrix, prepare any two or more of the ceramic precursor, metal particle precursor, and functional resin composite materials suitable for photocuring 3D printing. The ceramic precursor is used to provide enhanced mechanical strength and high-temperature resistance. The metal particle precursor is used to achieve electrical conductivity or strength improvement of the material. The functional resin is used to provide the required chemical, physical, or optical properties, ensuring that the viscosity, rheology, and stability of all materials meet the requirements of the photocuring printing process.

[0033] Step 2. Photocuring 3D printing: Load the various slurries in Step 1 into the independent dedicated material tanks of the 3D printing device one by one. According to the preset model geometric information, use digital light processing technology (DLP) to establish a corresponding printing database and cure and print layer by layer. During the printing process, by adjusting the printing order and the position of the light source, different materials are deposited onto the designated areas according to the designed layout.

[0034] The content of the database includes: Viscosity control: Ceramic precursor: 700 cP, ensuring good fluidity and deposition uniformity at a high solid content.

[0035] Metal precursor: 850 cP, maintaining the stable suspension of metal particles, preventing sedimentation, and ensuring electrical conductivity and structural strength.

[0036] Functional resin composite material: 500 cP, ensuring the photocuring response speed and uniform deposition of the material, and adapting to the curing requirements of fine areas.

[0037] Temperature control: Ceramic precursor: 25 ± 2 °C, maintaining the dispersibility of ceramic particles and preventing material sedimentation caused by temperature fluctuations.

[0038] Metal precursor: 22 ± 2 °C, reducing the oxidation risk of metal particles and ensuring that the rheological properties are adapted to the photocuring process.

[0039] Functional resin composite material: 24 ± 2 °C, maintaining the reaction activity of the photosensitive resin and ensuring curing uniformity.

[0040] Humidity control: During the preparation and batching process of all materials, the environmental humidity is maintained at 50 ± 5%, preventing viscosity changes in hygroscopic materials and ensuring material stability and curing accuracy.

[0041] Printing temperature: The ambient temperature is set to 30 ± 2 °C to ensure the fluidity and curing efficiency of the photosensitive resin, and to prevent incomplete curing of the material at low temperatures or decomposition of the material at high temperatures.

[0042] Printing speed: The printing speed is designed in grades according to the material properties: Ceramic precursor: 30 mm / s, ensuring sufficient deposition and curing of ceramic particles, and avoiding uneven deposition caused by excessive speed.

[0043] Metal precursor: 30 mm / s, balancing printing efficiency and material bonding strength, and preventing accumulation or dispersion of metal particles due to speed fluctuations.

[0044] Functional resin composite material: 30 mm / s, ensuring sufficient photocuring, strong interlayer bonding force, and complete functional layer structure.

[0045] Layer thickness setting: The layer thickness is uniformly set to 0.1 mm, ensuring the printing accuracy of the fine structures of multi-materials and avoiding weakening of the interfacial bonding force caused by thickness differences.

[0046] Printing humidity: The environmental humidity is controlled at 45 ± 5%, preventing excessive humidity from causing material moisture absorption and insufficient curing, or too low humidity from causing rapid curing of photocuring materials and resulting in interlayer bonding defects.

[0047] Nozzle pressure: Set the precise injection pressure according to the rheology of the material, ensuring uniform and stable material supply, and avoiding excessive or insufficient deposition: Ceramic precursor: 2.5 Bar, maintaining stable output of ceramic particles and preventing blockage.

[0048] Metal precursor: 3.0 Bar, enhancing the uniform ejection of metal particles and avoiding uneven deposition.

[0049] Functional resin composite material: 2.0 Bar, ensuring smooth output of photosensitive resin and preventing abnormal deposition caused by pressure fluctuations.

[0050] The printing sequence is planned through a partitioned multi-level process path, ensuring that different materials are deposited into the designated areas according to the design requirements, while reducing interfacial stress and improving bonding strength. Specifically, it includes: Partition control based on material properties: The area is divided according to the physical and chemical properties of the materials (such as curing rate, thermal expansion coefficient, rheology), ensuring that each material is in the optimal processing area. Separate photocuring paths are set for ceramics, metals, and functional resins to avoid cross-contamination and improve interfacial bonding quality.

[0051] Dynamic path adjustment and optimization: An intelligent path optimization algorithm is adopted to dynamically adjust the printing sequence according to the material distribution data, reducing stress concentration between materials and avoiding interlayer debonding or warping caused by temperature changes. Combining with the design of the transition layer, a buffer area is generated at the junction of heterogeneous materials, and through small-angle staggered printing, the influence of thermal stress is reduced.

[0052] Layered stacking process design: Adopt a layer-by-layer optimization strategy to ensure that high-melting-point materials (such as ceramics and metals) are deposited and cured first, and then low-temperature-curing materials (such as functional resins) are filled later, reducing the interfacial stress in the heat-affected area. When printing each layer, adjust the light-curing exposure time and layer thickness settings according to the material properties to ensure uniform deposition of different materials and form a stable interface.

[0053] Multi-material collaborative temperature control. During the printing and sintering processes, adopt a multi-material collaborative temperature control strategy according to the temperature requirements of different materials to ensure the printing accuracy, interfacial bonding strength, and overall stability of multi-materials. Specifically, it includes: Zone-independent temperature control: During the printing process, set independent temperature control zones for each material. For example: Ceramic precursor: 25 ± 2°C, to prevent sedimentation and ensure uniformity. Metal precursor: 22 ± 2°C, to reduce the oxidation risk and maintain good rheology. Functional resin: 24 ± 2°C, to maintain the stability of the photocuring reaction. Adopt an intelligent temperature control system to monitor the temperature changes in the material areas in real time and ensure that each material is always within the optimal forming temperature range.

[0054] Local temperature control strategy Adopt local heating or cooling methods to set a temperature buffer zone in the multi-material junction area, reduce the interfacial stress between materials with different thermal expansion coefficients, and ensure the stability of the transition layer. Through low-power pre-sintering technology (such as a slow heating strategy with a 700W laser power in the ceramic-metal interface area), optimize the interfacial bonding strength and improve the interfacial stability.

[0055] Real-time dynamic temperature control adjustment During the printing and sintering processes, use thermocouple sensors and infrared temperature measurement systems to monitor the material temperature in real time and dynamically adjust the heating or cooling strategy to ensure temperature balance of different materials and prevent local overheating or uneven cooling.

[0056] Step 3. Cleaning and drying Use ultrasonic vibration to clean the printed composite structure to remove uncured residual materials. Dry it in a negative pressure environment to ensure the uniformity and pore stability of the structure.

[0057] Step 4. Laser sintering: After printing, directly use a laser sintering system to perform area-selective sintering on the composite material structure. The laser system tracks the structure shape and material position in real time, performs high-precision densification on ceramic and metal materials, and ensures effective bonding of the material interfaces.

[0058] Ceramic precursor: The sintering temperature is set at 1500°C. Through high-temperature sintering, the densification of ceramic materials is achieved, enhancing their high-temperature resistance and mechanical strength.

[0059] Metal precursor: The sintering temperature is controlled at 1000 °C to ensure that metal particles are fully melted and form a stable bond with other materials, improving electrical conductivity and structural strength.

[0060] Functional resin composite material: Low-temperature assisted curing at 60 ± 5 °C is used to prevent material decomposition and ensure the integrity and interfacial stability of the special functional layer.

[0061] Step 5. Cleaning and post-treatment: Clean the sintered structural parts to remove residual materials on the surface.

[0062] Furthermore, before step 1, it also includes: constructing a preset 3D model according to requirements, where the 3D model includes the interlayer distribution and nesting relationship of multiple printing materials. Slice the model to generate a material distribution map for each layer, including material boundary information and its corresponding attribute data. The slicing algorithm combines an interface optimization strategy. By adjusting the transition region between different materials, the bonding strength between materials is ensured. The slicing algorithm automatically optimizes the boundaries of each layer of material according to the physical properties and printing order of the materials, making it uniform during the printing process and reducing interfacial stress to improve the stability and functionality of the structure, ensuring a smooth transition at the boundaries of each material region.

[0063] Furthermore, in order to optimize multi-material switching and interface quality control, a dynamic adjustment mechanism needs to be introduced on the basis of fixed database parameters. By real-time monitoring of the material supply rate, ambient temperature and humidity, photocuring response characteristics, and energy distribution during the sintering process, combined with an adaptive control algorithm, the process parameters are dynamically adjusted according to the actual working conditions. For example, when the ambient humidity increases, the system can automatically adjust the material supply pressure to maintain viscosity stability; when the temperature deviation during the sintering process exceeds the set range, the laser power or scanning path can be adjusted to optimize the heat distribution. Based on sensor feedback and historical data optimization model, precise matching and stable deposition of different materials under complex process conditions are achieved, ensuring the overall forming quality and interfacial bonding strength of multi-material 3D printing.

[0064] Furthermore, step 2 includes the selection of different material tanks based on system control for multi-material switching. By designing the switching process, material contamination is avoided, and the properties of heterogeneous materials are stable and the interface quality is controllable.

[0065] Furthermore, step 4 also includes: after one layer of nested precursor printing and sintering is completed, the printing device automatically reads the slice data of the next layer, and repeats digital light processing (DLP) printing and selective laser sintering (SLS). Through the nesting and stacking between layers, a complex multi-phase and multi-material product structure is gradually constructed, realizing the orderly distribution of multi-materials in three dimensions.

[0066] Furthermore, step 5 also includes chemical polishing, electrolytic polishing, and heat treatment processes to optimize the surface finish and mechanical properties of the metal, and reduce residual stress to enhance the reliability of the structure.

[0067] Furthermore, it also includes repeating the above steps to achieve 3D printing of products with arbitrary complexity.

[0068] Advantages of the present invention: 1. Enhanced material versatility Function integration: By combining powders of different materials with photosensitive resin, the characteristics of multiple materials can be simultaneously achieved in a thin plate. For example, mixing metal powder or ceramic powder into the resin, so as to form a structure with composite material properties during the SLS sintering process. This method can integrate the advantages of different materials to achieve the manufacture of multifunctional components.

[0069] 2. Improved sintering efficiency and accuracy Uniform sintering: Pre-mixing the powder into the photosensitive resin and curing it into a thin plate can ensure uniform powder distribution, reduce material separation and non-uniform sintering problems during the SLS process, thereby improving the overall quality and accuracy of the component.

[0070] Reduced powder diffusion: During the SLS printing process, the cured layer of photosensitive resin provides a stable substrate, which helps to reduce powder diffusion and mixing, and improve the controllability of the sintering process.

[0071] 3. Improved material processing performance Simplified post-processing: By curing the photosensitive resin to form a thin plate, preliminary processing and shaping of the material can be carried out before SLS printing, which can reduce the complexity of post-processing during the sintering process, thereby improving production efficiency.

[0072] Increased stability: The cured photosensitive resin layer can provide additional stability, prevent powder displacement or deformation during the sintering process, and ensure the accuracy of the size and shape of the final component.

[0073] 4. Enhanced mechanical properties of the material Improved material characteristics: Mixing specific powders (such as metals, ceramics) with photosensitive resin can form a composite structure during the sintering process, enhancing the strength, hardness, and wear resistance of the material. The uniform distribution of powder and good interfacial bonding during the sintering process contribute to improving the mechanical properties of the final product.

[0074] 5. Expanded material selection and application scope Flexible material combinations: This method allows the use of various powder materials (such as metal powders, ceramic powders) in combination with photosensitive resins, thus expanding the material selection range of SLS technology and enabling more functional materials to be applied in 3D printing. Innovative applications: It can achieve complex material structures that are difficult to manufacture with traditional SLS technology. For example, by mixing powders and resins, multi-material composites with unique properties can be created for specific industrial applications or scientific research experiments.

[0075] 6. Improving surface quality Smooth surface: The cured photosensitive resin layer can provide a relatively smooth surface before printing, thereby reducing surface defects during SLS printing and improving the surface finish of the final part.

[0076] In the present invention, the powder of the target material is mixed into the photosensitive resin and cured into a thin plate, and then selective sintering is carried out using SLS technology, which can improve the versatility, sintering efficiency, processing performance and mechanical properties of the material, expand the material selection range, and improve the surface quality. This method not only enhances the material properties of SLS printing, but also provides new possibilities for manufacturing complex and multifunctional composite structures.

[0077] 7. Through the optimization of photocuring temperature control, sintering temperature grading, material deposition sequence, and local temperature control of the transition layer, the present invention realizes the organic combination of material compatibility, interfacial bonding force, and thermal management during the multi-material 3D printing process, ensuring that complex multi-phase material structures have high precision, high density, and stable performance.

[0078] 7.1 Optimal design of photocuring printing temperature Determination of temperature range: By experimentally measuring the viscosity-temperature response curves of different materials, ensure that each material has appropriate rheological properties and curing characteristics at a specific temperature.

[0079] Specific parameters: The ambient temperature during the photocuring printing process is controlled at 30 ± 2 °C to maintain the fluidity of ceramics, metals, and functional resins, ensure uniform deposition, and avoid incomplete curing of materials or poor interlayer bonding caused by temperature fluctuations.

[0080] Achieve stable deposition and uniform curing of multi-materials during the photocuring stage, improve printing accuracy, and avoid defects such as delamination and material dispersion.

[0081] 8. Precise regulation of laser sintering temperature 8.1 Determination of temperature range: According to the thermal expansion coefficient matching and interfacial bonding experiments, set the optimal sintering temperatures for ceramics, metals, functional resins, and other functional materials respectively.

[0082] 8.2 Specific parameters: Ceramic precursor: At 1500 °C, ensure high-density forming, enhance high-temperature resistance and mechanical strength.

[0083] Metal precursor: At 1000 °C, ensure sufficient melting and form a stable bond with the ceramic layer.

[0084] Functional resin: At 60 ± 5 °C, use low-temperature assisted curing to prevent thermal decomposition of the material and maintain the stability of the special functional layer.

[0085] Through hierarchical sintering and local temperature control, prevent interfacial thermal stress, cracks and deformation, and ensure the densification and bonding strength of the multi-material composite structure.

[0086] 9. Multi-material printing sequence and thermal management 9.1 Sequence design: According to the thermal stability and curing characteristics of each material, design the deposition sequence of ceramic-metal-functional resin, form the high-melting-point material first, and then deposit the low-temperature assisted curing material to ensure the interfacial bonding strength.

[0087] 9.2. By a reasonable material deposition sequence and layer-by-layer temperature control, reduce the temperature difference stress, and improve the thermal stability and multi-material compatibility of the composite structure.

[0088] 10. Transition layer and interface temperature control 10.1 Temperature range determination: Introduce a gradient transition layer at the multi-material interface and set the local pre-sintering temperature (such as 700W laser power at the ceramic-metal interface) to ensure a smooth transition at the interface.

[0089] 10.2 The transition layer design combines low-power pre-sintering technology to effectively eliminate interfacial stress concentration, improve the bonding strength of the heterogeneous material interface, and enhance the overall performance of the multi-phase multi-material structure. Description of the drawings

[0090] Figure 1 It is the schematic diagram of the 3D printing process of the photosensitive resin composite material of the present invention; Figure 2 It is the 3D printed three-dimensional sample of the ceramic spherical precursor based on PEEK and Al2O3; Figure 3 It is the 3D printed three-dimensional sample of the hexahedron lattice precursor based on PEEK and Al2O3; Figure 4 It is the 3D printed three-dimensional sample of the double-triangle stacked precursor based on PEEK and Al2O3; Figure 5 It is the 3D printed three-dimensional sample of the ceramic strip lattice precursor of Al2O3 and the strip lattice precursor based on PEEK; Figure 6A 3D printed solid sample of an Al2O3-based ceramic cubic precursor and a PEEK-based cubic precursor; Figure 7 A 3D printed solid sample of a PEEK-based precursor and an Al2O3-based precursor. Detailed implementation manners

[0091] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0092] The improvements of the present invention in terms of technology are as follows: 1). Interface bonding optimization In the photocuring stage, by precisely controlling the printing sequence and deposition position of different materials, the stress concentration caused by material property differences is reduced. In the laser sintering stage, the interface bonding strength is further enhanced by local high-temperature heating.

[0093] 2). Dynamic parameter optimization During the photocuring process, the exposure time, layer thickness and printing speed are dynamically adjusted to ensure the printing accuracy of different materials. In the laser sintering stage, the laser power, scanning speed and focal point size are optimized to adapt to the sintering requirements of multiple materials.

[0094] 3). Integrated manufacturing equipment The equipment integrates photocuring printing and laser sintering functions, eliminating the need for transfer or multiple clamping, and improving manufacturing efficiency and accuracy. A single device can achieve multi-material distribution design, interface strengthening and densification treatment.

[0095] 4). Quality monitoring and thermal management A real-time monitoring system is adopted to record the temperature distribution and structural morphology during the printing and sintering stages. This prevents problems such as cracks, pores and warping caused by overheating or uneven sintering.

[0096] The preparation processes of Examples 1 - 3 are as Figure 1 shown.

[0097] Example 1 This example combines multi-material digital light processing (DLP) printing and selective laser sintering (SLS) technologies. By precisely controlling the printing parameters (such as temperature, speed, layer thickness, humidity, etc.) of different materials and the material supply amount, the interlayer nesting and stacking manufacturing of multi-phase and multi-material structures are realized, thereby constructing any complex 3D topological structure.

[0098] This embodiment provides a method for manufacturing a composite turbine blade based on multi-phase and multi-material nesting and stacking, specifically including the following steps: First step. Establish a CAD model of the multi-phase and multi-material composite structure of the turbine blade in 3D modeling software, and clarify the nesting distribution and topological relationship of ceramics, metals, and functional resins.

[0099] For example, ceramic materials are used to construct the core framework of the blade, metal materials are nested between ceramic layers to enhance structural strength and conductivity, and functional resins are used in specific areas to achieve conductivity or other functions. The specific distribution and nesting position of each material are optimized according to design requirements to ensure that the performance requirements of the functional areas are met.

[0100] The model is sliced along the z-axis direction through the calculus principle to generate the sliced data of the multi-material nested structure for each layer, including material boundary information and its corresponding attribute data. A slicing algorithm is used to process the 3D model into layers to generate a material distribution map for each layer. During the slicing process, combined with the interface optimization strategy, by adjusting the transition area between different materials, the bonding strength between materials is ensured. The algorithm automatically optimizes the boundaries of each layer of material according to the physical properties and printing order of the materials, making them uniform during the printing process and reducing interface stress, so as to improve the stability and functionality of the structure, ensure the smooth transition of the boundaries of each material area, and lay a foundation for subsequent nesting and stacking printing.

[0101] Second step. According to the model design, load the ceramic precursor slurry (viscosity 700 cP, temperature controlled at 25 ± 2 °C), metal precursor slurry (viscosity 850 cP, temperature controlled at 22 ± 2 °C), and functional resin (viscosity 500 cP, temperature controlled at 24 ± 2 °C) into the corresponding material tanks of the equipment respectively. During the entire slurry preparation process, ensure that the humidity of the slurry is controlled at 50 ± 5% to ensure the fluidity and stability of the materials. These materials are processed through high-efficiency dispersion and vacuum degassing to ensure that their viscosity, stability, and photocuring performance meet the requirements of DLP printing, while maintaining uniform distribution.

[0102] Third step. Load the ceramic, metal, and functional resin precursor slurries into the corresponding material tanks of the equipment respectively. The ceramic precursor is used to construct the blade framework, the metal precursor is used to enhance the strength and conductivity of the structure, and the functional resin is used to provide the required functional areas at the designed positions. Through the multi-material DLP printing technology, print the precursors of the nested structure layer by layer according to the sliced data.

[0103] Based on the sliced data, the precursor of the nested structure is printed layer by layer through the multi-material DLP printing technology. During the printing process, the temperature is controlled at 30 ± 2 °C, the printing speed is controlled at 30 mm / s, and the layer thickness is set to 0.1 mm. The supply amount of each material is precisely controlled according to the sliced data to ensure uniform distribution of the materials and avoid differences in material properties caused by fluctuations in printing parameters. To ensure good bonding between different materials, the environmental humidity during printing is maintained at 45 ± 5% to avoid a decrease in the printing quality of the materials due to excessive humidity.

[0104] The specific operations are as follows: 1). The ceramic precursor is first printed and formed to construct the framework of the blade; 2). The metal precursor is then deposited and photocured to fill the nested area and strengthen the overall structure; 3). The functional resin material is subsequently deposited at the target position according to the design requirements to achieve the printing of the conductive layer or functional area.

[0105] Through the multi-material switching technology, layer-by-layer printing is carried out and combined with the specific properties of each layer. During the switching process, ensure the stability of the supply amount and rate of the materials. The supply rate of the metal material is 0.05 mL per second, the supply rate of the ceramic material is 0.03 mL per second, and the supply rate of the functional resin material is 0.02 mL per second. The ejection temperature of each material is maintained at 22 ± 2 °C to ensure that the viscosity and fluidity of the materials are adapted to the printing requirements during printing. During the switching process, the printing equipment automatically adjusts the output pressure of the nozzle to keep the pressure of the nozzle controlled between 2 - 3 Bar, avoiding uneven printing quality caused by excessive or insufficient ejection of materials. The equipment avoids cross-contamination through an automatic cleaning system and adjusts the light source power in combination with an intelligent control algorithm. The intelligent control algorithm adjusts the light source power in real time according to the photosensitivity, layer thickness, and printing speed of each layer of material. For the ceramic precursor, the light source power is set to 700 mW / cm² to ensure uniform curing; the power of the metal precursor is adjusted to 450 mW / cm² to avoid over-sintering; the light source power of the functional resin material is set to 300 mW / cm² to optimize the curing effect and prevent overheating of the materials. Through dynamic adjustment, ensure uniform deposition and smooth interface transition within the nested area of each material. After each layer of printing is completed, a multi-phase and multi-material nested precursor structure is formed, providing a basis for subsequent sintering.

[0106] Step 4. After one layer of printing is completed, the SLS system selectively sinters the nested precursor of this layer. The laser equipment precisely sinters in a variable power mode according to the characteristics of different materials:

[0107] 1) The ceramic part is sintered at a high temperature of 1500 °C with a laser power of 700 W; 2) The metal part is sintered at a temperature of 1000 °C with a laser power of 450 W; 3) The functional resin area ensures stable performance through low-temperature (60±5°C) assisted curing.

[0108] The SLS system incorporates real-time monitoring and intelligent adjustment functions. By monitoring the material temperature and laser power feedback during the sintering process in real time, it automatically adjusts the laser scanning speed and power output. For ceramic materials, the system adjusts the laser power to 700W according to the real-time temperature to ensure precise sintering; for metal materials, the laser power is adjusted to 450W based on real-time monitoring to avoid overburning; the functional resin area is sintered with low power (200W) to ensure material stability and interlayer bonding strength. This intelligent adjustment function ensures the compatibility of different materials and the interface quality during the sintering process, ensuring a pure sintering effect for different materials within the nested area and avoiding cross-influence between materials. A stable micro-melting transition layer is formed at the ceramic-metal interface through low-power pre-sintering technology, significantly enhancing the bonding strength.

[0109] Step 5. After the printing and sintering of one layer of the nested precursor are completed, the device automatically reads the slice data of the next layer and repeats the DLP printing and SLS sintering steps. Through the nesting and stacking between layers, a complex multi-phase material turbine blade structure is gradually constructed, realizing the orderly distribution of multi-materials in three dimensions. The sintering densification and interface optimization of each layer of material ensure the accuracy and performance of the overall structure, and the sintering densification and interface optimization of each layer of material are achieved by controlling the laser power, scanning speed, and temperature distribution. The laser power is precisely adjusted. According to different material types, it is 700W for the ceramic part, 450W for the metal part, and 200W for the functional resin part. The scanning speed is maintained at 5mm / s to ensure uniform sintering of the material. At the same time, the temperature distribution is controlled within the range of ±5°C to avoid overheating or uneven cooling, ensuring a smooth interface transition between materials, enhancing the bonding force between materials, optimizing the mechanical properties of the structure, and achieving a balance between printing speed and quality.

[0110] Step 6. After completing the printing of all layer stacks, the turbine blade is ultrasonically cleaned and vacuum dried to remove uncured residual materials. The turbine blade is ultrasonically cleaned using an ultrasonic cleaner with a frequency of 40 kHz and cleaned in warm water for 15 minutes to ensure the removal of uncured residual resin and impurities. After cleaning, the blade is processed using a vacuum drying device with a set vacuum of 0.1 bar, a drying temperature controlled at 50 ± 2 °C, and a duration of 4 hours to ensure complete removal of moisture and solvents, avoid material expansion or deformation, and ensure the purity of the multi-phase material interface. Subsequently, through chemical polishing, electrolytic polishing, and heat treatment processes, the turbine blade is electrolytically polished using a mixed solution of phosphoric acid and sulfuric acid as the electrolyte, with a current density set at 2 A / dm² and a polishing time controlled at 10 minutes to ensure a smooth surface, removal of oxides, and improvement of surface brightness. Subsequently, a heat treatment process is carried out by heating the blade to 800 ± 10 °C and holding for 2 hours, and annealing is carried out in an inert gas environment to eliminate internal stress and optimize the mechanical properties of the material, optimize the surface finish and thermodynamic properties of the metal, and reduce residual stress to enhance the reliability of the structure.

[0111] Through the above cycle, 3D printing of parts (multi-phase and multi-material structures) with arbitrarily complex 3D structures and multi-phase material topological relationships is achieved.

[0112] Example 2 In this example, by combining multi-material digital light processing (DLP) 3D printing and selective laser sintering (SLS) technology, precise control and distribution of multiple functional materials within the battery electrode are achieved. This method not only breaks through the technical bottlenecks of traditional battery manufacturing but also significantly improves battery performance, especially showing significant advantages in conductivity, energy storage capacity, and long-term stability. The key to the entire manufacturing process lies in constructing the composite material structure of the battery electrode layer by layer through nesting and stacking methods, enabling precise deposition of functional materials in each layer.

[0113] This example proposes a method for manufacturing a multi-functional composite material battery electrode, and the specific steps are as follows: Step 1. In computer-aided design (CAD) software, first construct a three-dimensional model of the battery electrode with different functional material distributions. This model includes the interlayer distribution and nesting relationship of conductive materials, energy storage materials, and protective coating materials. By slicing the model, a material distribution map for each layer is generated. This slice not only provides geometric information but also refines the functional requirements of each material to ensure its accurate positioning in the battery electrode, especially in the transition regions between materials, to avoid any interface defects. This step ensures the accuracy in subsequent printing and sintering processes.

[0114] Step 2. According to the design requirements of the battery electrodes, prepare a suitable composite material slurry. The viscosity of the conductive materials (such as carbon-based nanomaterials and conductive polymers) is controlled at 800 cP to ensure its excellent electrical conductivity; the viscosity of the energy storage materials (such as the positive and negative electrode materials of lithium batteries) is 700 cP to optimize its ionic conductivity and energy storage capacity; the viscosity of the protective coating material is 600 cP, which is used to enhance the corrosion resistance and long-term stability of the electrodes. Each material undergoes fine degassing and dispersion treatment during the preparation process to ensure its excellent uniformity and stability during the photocuring and sintering processes. The material ratio and concentration are optimized and adjusted to provide the best performance output during the printing process.

[0115] Step 3. In the device, load the conductive material, the reservoir material, and the protective coating slurry into separate troughs respectively. Use DLP technology to print the multi-material nested structure of the battery electrodes layer by layer, specifically including:

[0116] S1. Print the conductive material to construct the basic conductive layer of the electrode; S2. Deposit the energy storage material to construct the energy storage core part of the electrode to achieve high energy density; S3. Finally, print the protective coating material to form a protective layer on the surface of the electrode to prevent the electrode from being corroded or damaged by external forces.

[0117] During the multi-material printing process, the device precisely controls the deposition sequence and layer thickness of each material through the sliced data and the preset 3D model. During each layer printing process, the conductive material is deposited first to ensure the basic conductivity of the electrode, and the layer thickness is set to 0.1 mm. Subsequently, the energy storage material is deposited, and the layer thickness is controlled at 0.12 mm to ensure the structural stability of the core energy storage functional area. Finally, the protective coating material is deposited according to the design requirements, and the layer thickness is 0.05 mm to form a uniform protective layer. The deposition sequence and layer thickness are dynamically adjusted by the intelligent control system to ensure the precise deposition of each material and the distribution of the functional areas. By adjusting the light source power and printing speed, ensure the uniform distribution of each layer of material and avoid problems such as cross-contamination or poor interlayer contact.

[0118] Step 4. Once the printing of each layer of the multi-material precursor is completed, the SLS system starts the sintering process. According to the properties of each material, the laser system will perform precise sintering at different powers, specifically including:

[0119] S1. For the conductive material, the laser power is set to 450 W, and the sintering temperature is controlled at 600 °C to ensure the good electrical conductivity of the material; S2. For the energy storage material, the power is adjusted to 500 W, and the sintering temperature is 750 °C to optimize its ionic conductivity and energy storage performance; S3. For the protective coating material, sintering is carried out at a lower power. The laser power is set to 150 W, and the sintering temperature is controlled at 400 ± 10 °C to ensure the stability of its protective function.

[0120] The SLS system dynamically adjusts the laser power and scanning path by real-time monitoring the temperature and sintering condition of the material. For the conductive material, the laser power is set to 450 W and the scanning speed is controlled at 5 mm / s to ensure uniform sintering of the material; for the energy storage material, the laser power is adjusted to 500 W and the scanning speed is 4 mm / s to optimize its ionic conductivity. The protective coating material uses a lower power (150 W) and a slower scanning speed (2 mm / s) to ensure uniform curing and functional stability of the coating. The system adjusts the scanning path in real time according to the characteristics of each material to avoid over-sintering or under-sintering, ensuring the best sintering effect for each material and avoiding over-sintering or under-sintering. Especially between the conductive and energy storage materials, the laser function is precisely controlled to ensure good bonding and interface transition between the two materials.

[0121] Step 5. After each layer of material is printed and sintered, the equipment automatically reads the multi-material data of the next layer and starts a new printing and sintering process. Through this way of interlayer nesting and stacking, the functional materials of each layer can be accurately deposited in their designated areas, gradually constructing a battery electrode with a complex three-dimensional topological relationship. This process can achieve precise coordination between different materials, thus maximizing the comprehensive performance of the battery electrode.

[0122] Step 6. After the multi-layer stacking is completed, the battery electrode needs to be cleaned to remove the uncured precursor residues. The battery electrode is ultrasonically cleaned using an ultrasonic cleaner with a frequency of 40 kHz. The cleaning solution is a mixed solution of deionized water and a small amount of surfactant. The cleaning time is set to 20 minutes to ensure the removal of uncured residual materials and impurities. After cleaning, the electrode is placed in a vacuum environment of 0.08 bar using a vacuum drying equipment, and the drying temperature is controlled at 50 ± 2 °C for 4 hours to ensure the removal of moisture and solvents, avoid material deformation and maintain its functional stability, remove residual materials, and ensure a pure and stable material interface. Subsequently, the battery electrode is electro-polished using an electrolyte of a mixed solution of sodium chloride and potassium chloride. The current density is set to 3 A / dm² and the polishing time is 15 minutes to remove the surface oxide layer and improve the surface smoothness. Subsequently, chemical polishing is carried out using a mixed acid solution containing phosphoric acid and sulfuric acid. The soaking time is controlled at 10 minutes to ensure a smooth and scratch-free electrode surface, further improving the surface electrochemical performance. Optimize the smoothness of the electrode surface, reduce the surface resistance, and enhance the electrochemical performance of the electrode. For the energy storage material, heat treatment at 800 °C is also carried out to release internal stress and further improve the cycle stability and energy efficiency of the electrode.

[0123] Example 3 This example is a thermal management composite heat dissipation device for high-performance electronic device heat dissipation. The heat dissipation device includes a composite structure of a thermal conductivity material, a reinforcing material, and a matrix material, aiming to improve the thermal conduction efficiency of the electronic device and effectively reduce the working temperature. By combining multi-material DLP printing and SLS sintering processes, a composite material structural part with excellent thermal conductivity and structural strength is manufactured.

[0124] This example introduces a manufacturing method for a thermal management composite material structural part, including: Step 1. First construct the required three-dimensional thermal management structural part model in CAD. In the model, the spatial distribution and functional areas of the thermal conductivity material, the reinforcing material, and the matrix material are precisely designed. After the model is generated, use slicing software to divide the part layer by layer to generate corresponding sliced diagrams, and clearly mark the deposition areas of different materials. The slicing accuracy is controlled within 0.1 mm to ensure the precise printing and distribution of each layer of material.

[0125] Step 2. According to the design requirements, select three main functional materials for preparation: (1). Preparation of thermal conductivity material Adopt a graphene / metal powder composite material. When preparing, the proportion of graphene is 40%, and the metal powder (copper powder) accounts for 60%. Its viscosity is controlled at 750 cp to meet the requirements of DLP printing. The thermal conductivity of this material can reach 350 W / m·K to ensure the efficient heat dissipation of the structure;

[0126] (2). Preparation of reinforcing material Select a carbon fiber / ceramic particle composite material. The proportion of ceramic particles (such as aluminum oxide) is 50%, and the carbon fiber accounts for 50%. The viscosity is adjusted to 800 cp to ensure its excellent mechanical strength. The tensile strength of the reinforcing material reaches 500 MPa, and the compressive strength exceeds 900 MPa;

[0127] (3). Preparation of matrix material Select a polymer matrix (such as polyimide resin), whose viscosity is 600 cp, to provide sufficient support force and ensure good forming performance.

[0128] Step 3. Load the thermal conductivity material, the reinforcing material, and the matrix material into special material tanks respectively, and print layer by layer through DLP 3D printing technology. The printing process is adjusted according to the functional requirements of each layer of material:

[0129] 1) In the core area of the structural part, first print the thermal conductivity material, and the layer thickness is controlled at 0.1 mm to ensure efficient heat conduction; 2) Print the reinforcing material to form the core part of the reinforcing structure, and the layer thickness is also 0.1 mm to ensure high-strength support; 3) Print the matrix material as the periphery of the support structure to ensure its stability and overall integrity.

[0130] During the printing process of each layer, the light source intensity is set to 800 mW / cm² to ensure uniform curing of the material. For the thermal conductive material, the printing speed is controlled at 8 mm / s to ensure its interlayer bonding force and heat conduction effect; the printing speed of the reinforcing material is set to 6 mm / s to ensure its mechanical strength and structural stability; the printing speed of the matrix material is 10 mm / s to ensure the stability of the formed part and surface quality. All parameters ensure that different materials can be uniformly deposited during the printing process, avoiding cross-contamination and material property differences. The printing accuracy reaches ±0.05 mm to ensure seamless bonding between materials and structural accuracy.

[0131] Step 4. After completing the printing of the precursor of each layer, use selective laser sintering (SLS) technology to sinter it. During the SLS process, the laser power is finely adjusted according to the characteristics of different materials:

[0132] Thermal conductive material Use a laser power of 600 W and sinter in an environment with a temperature of 850 °C to ensure the thermal conductivity of the material and the densification of the microstructure; Reinforcing material Adopt a laser power of 500 W, and control the sintering temperature at 700 °C to ensure the mechanical properties of the reinforcing material, and the tensile strength of the reinforcing material reaches 500 MPa; Matrix material Use a laser power of 400 W and control the sintering temperature at 600 °C to maintain its forming stability and appropriate toughness.

[0133] Step 5. After each layer of printing and sintering is completed, the equipment will automatically read the slice data of the next layer and continue to perform the printing and sintering operations. Through this layer-by-layer stacking and nesting process, each layer stacks the functional materials in an accurate order, and finally forms a heat management structural part with composite functions.

[0134] During the stacking process, the thermal conductive material continuously expands towards the heat conduction path area to ensure rapid heat dissipation. The reinforcing material is stacked in the stress concentration area to provide the necessary strength support. The matrix material fills other structural areas to maintain the stability of the overall structure. Through precise control, the transition interface between each layer is clear and seamlessly connected, and the functional distribution of the material reaches the best state. The height accuracy of each layer of stacking is controlled within ±0.05 mm, ensuring the precision of the overall structural part.

[0135] Step 6. After completing the entire printing and sintering process, perform necessary post-processing on the structural components. First, use an ultrasonic cleaning device with a frequency of 40 kHz. The cleaning solution is a mixed solution of deionized water and a small amount of surfactant. Set the cleaning time to 20 minutes to ensure thorough removal of uncured residual precursor materials. After cleaning, place the structural components in a vacuum drying device. Set the vacuum degree to 0.1 bar, control the temperature at 50 ± 2 °C, and dry for 4 hours to remove moisture and solvents and prevent material expansion or deformation. Finally, use a phosphoric acid-containing solution through an electrolytic polishing process, with a current density of 2 A / dm² and a polishing time of 10 minutes, to improve the surface finish of the structural components, while enhancing their thermal conductivity and corrosion resistance. The surface roughness (Ra value) is controlled within 0.1 μm, further improving the heat exchange efficiency of the structural components.

[0136] As Figures 2 - 7 shown, according to the above processing method, by adopting a variety of structures, longitudinal comparison of structural strength is carried out, and at the same time, separate printing and combined printing of materials are carried out for transverse comparison of the physical properties of the same structure. Among them Figure 2 the structure adopted is a similar spherical lattice structure, Figure 3 the structure adopted is a similar hexahedron lattice structure, Figure 4 the structure of crossed triangular frames is adopted. The above three groups of models are respectively tested by using PEEK, Al2O3 and mixed printing of the two materials. The heat dissipation effect, structural strength, electrical conductivity and other physical properties are compared.

[0137] Figure 5 adopts a structure similar to a long strip lattice. Figure 6 adopts a cubic lattice structure, Figure 7 adopts a PEEK precursor and an Al2O3-based structure. The above three groups are respectively printed with PEEK and Al2O3 as the base materials for property comparison. Through the combination of multi-material DLP printing and SLS sintering technologies, the present invention successfully realizes the manufacture of a composite thermal management structural component with high thermal conductivity and high strength. By finely adjusting the deposition sequence and sintering parameters of each layer of material, the efficient combination and functional optimization of thermal conduction, reinforcement and matrix materials are ensured, and finally a thermal management component with excellent heat dissipation performance and structural strength is obtained.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a multi-phase and multi-material structure by DLP 3D printing and SLS laser selection and sintering, characterized in that: include: Step 1. Material preparation: using photosensitive resin as the matrix, prepare any two or more of the ceramic precursor, metal particle precursor and functional resin mixed material suitable for photocuring 3D printing, so that the viscosity, rheology and stability of all materials are adapted to the requirements of photocuring printing; Step 2. Photocuring 3D printing: Load the various slurries in step 1 into the independent dedicated material tank of the 3D printing equipment one by one, establish the corresponding printing database by using digital light processing according to the preset 3D model geometry information, and perform curing printing layer by layer. During the printing process, adjust the printing sequence and light source position so that different materials are deposited in the designated area according to the design layout to complete a layer of printing; Step 3. Cleaning and drying: The printing equipment is cleaned through the automatic cleaning system; Step 4. Laser sintering: After all layers are printed, the laser sintering system is used to perform regional selective sintering on the composite structure. The laser system tracks the structure shape and material position in real time, performs high-precision densification on ceramic and metal materials, and ensures effective bonding of the material interface. Step 5. Cleaning and post-processing: Clean the sintered structural parts to remove residual materials on the surface.

2. The method according to claim 1, characterized in that Before step 1, the method also includes: constructing a preset three-dimensional model of the product, wherein the three-dimensional model includes the inter-layer distribution and nesting relationship of multiple printing materials.

3. The method according to claim 2, characterized in that Step 1 also includes slicing the three-dimensional model to generate a material distribution map for each layer, including material boundary information and its corresponding attribute data. The slicing algorithm is combined with the interface optimization method to make the transition of the boundaries of each material area smooth.

4. The method according to claim 1, characterized in that: Step 2 includes multi-material switching, based on the selection of different material troughs controlled by the system, and avoiding material contamination by designing the material switching process, and ensuring the stability of the properties and controllable interface quality between heterogeneous materials.

5. The method according to claim 1, characterized in that The database constructed in step 2 includes: (1) Viscosity control: 700cp for ceramic precursor, 850cp for metal precursor, and 500cp for functional resin mixed material; (2) Temperature control: 25±2℃ for ceramic precursor, 22±2℃ for metal precursor, and 24±2℃ for functional resin mixed material; Humidity control: During the preparation and batching process of all materials, the ambient humidity is maintained at 50±5%; Printing temperature: The ambient temperature is set to 30±2℃; Printing speed: 30mm / s for ceramic precursor, 30mm / s for metal precursor, and 30mm / s for functional resin mixed material; Layer thickness setting: The layer thickness is uniformly set to 0.1mm; Printing humidity: The ambient humidity is controlled at 45±5%; Nozzle pressure: Set according to the rheological properties of the material, 2.5Bar for ceramic precursor, 3.0Bar for metal precursor, and 2.0Bar for functional resin mixed material; 6. The method according to claim 1, characterized in that Step 2 The printing sequence is planned through a multi-level process path based on partitions, including partition control based on material properties: the area is divided according to the physical and chemical properties of the material, and independent light curing paths are set for ceramics, metals, and functional resins; dynamic path adjustment: the intelligent path optimization algorithm is used to dynamically adjust the printing sequence according to the material distribution data, combined with the transition layer design, a buffer area is generated at the interface of heterogeneous materials, and small-angle staggered printing is performed; Layered stacking process: Using a layer-by-layer optimization method, high-melting-point materials are deposited and solidified first, and low-temperature curing materials are subsequently filled. When printing each layer, the light curing exposure time and layer thickness settings are adjusted according to the material characteristics.

7. The method according to claim 1, characterized in that Step 2 also includes coordinated temperature control of multiple materials, which includes: independent temperature control of different zones: during the printing process, an independent temperature control zone is set for each material, and an intelligent temperature control system is used to monitor the temperature changes of the material zone in real time; local temperature control strategy: a local heating or cooling method is used, a temperature buffer zone is set in the interface area of ​​multiple materials, and a low-power pre-burning method is used to optimize the interface bonding strength; real-time dynamic temperature control adjustment: during the printing and sintering process, the material temperature is monitored in real time through thermocouple sensors and infrared temperature measurement systems, and the heating or cooling strategy is dynamically adjusted.

8. The method according to claim 1, characterized in that Step 4 also includes: after a layer of nested precursor printing and sintering is completed, the printing device automatically reads the slice data of the next layer, repeats digital light processing printing and selective laser sintering, and gradually builds a complex multi-phase and multi-material product structure through nesting and stacking between layers, realizing the orderly distribution of multiple materials in the three-dimensional direction.

9. The method according to claim 1, characterized in that: Step 5 also includes chemical polishing, electrolytic polishing and heat treatment processes.

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