Preparation method of continuous fiber reinforced SiC ceramic composite material for 3D printing

Abstract

The invention provides a preparation method of a continuous fiber reinforced SiC ceramic composite material for 3D printing, and aims to solve the problems of difficulty in forming of a complex structure, high mold cost, long manufacturing period, high material brittleness, low fracture toughness and the like in the prior art. The method comprises the following steps that S1, a continuous fiber printing wire is prepared, thermoplastic resin is dried, continuous fibers are subjected to high-temperature glue removal, coupling agent modification and impregnation operation, and extrusion molding is conducted in combination with ultrasonic-assisted equipment; s2, preparing a silicon carbide wire, mixing silicon carbide powder and a sintering aid through wet ball milling, and performing twin-screw extrusion granulation and single-screw melt extrusion molding; and S3, printing a fiber reinforced / SiC / polymer blank by using an FDM 3D printer, and performing degreasing and high-temperature sintering processes to obtain the final material. The method effectively improves the mechanical property and fracture toughness of the material, can efficiently prepare the ceramic composite material with a complex structure at low cost, and is suitable for the fields of aerospace, national defense industry and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing technology, and in particular to a method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material. Background Art

[0002] With the development of high-tech fields such as aerospace, national defense, nuclear energy and electronic information, higher and higher requirements are placed on material performance. SiC ceramics have gradually become a highly regarded structural material due to their high hardness, high stiffness, excellent wear resistance, strong thermal stability and high chemical inertness. However, as a typical covalent bond compound, SiC ceramics also have problems such as high brittleness, low fracture toughness and difficulty in sintering, which seriously restricts its wide application in complex structural parts.

[0003] Traditional SiC ceramic manufacturing processes, including dry pressing, isostatic pressing and slip casting, rely on molds to complete the molding of materials. Although these methods can produce SiC ceramics of a certain size and shape, they have the disadvantages of high mold development costs, long processing cycles, and difficulty in molding large-scale complex structures. In addition, the subsequent processing steps of SiC ceramics are also restricted by their high hardness and brittleness, resulting in low processing efficiency and low yield.

[0004] In recent years, 3D printing technology has attracted widespread attention due to its unique advantages in the manufacture of complex structural parts. Among them, fused deposition modeling (FDM) has become one of the research hotspots of ceramic 3D printing due to its low cost and easy operation of equipment. By mixing ceramic powder with thermoplastic polymers for extrusion molding, FDM technology provides a new idea for the manufacture of complex structural ceramics. However, the existing FDM printing ceramic technology still faces the following challenges:

[0005] Insufficient density and mechanical properties of molded parts: During the FDM molding process, the material is extruded and stacked layer by layer to form a green body. Due to the weak bonding force between the layers, micropores and cracks often exist inside the molded parts, resulting in the density and mechanical properties of the material being lower than those of ceramics manufactured by traditional molding methods.

[0006] Low fracture toughness: The inherent brittleness of ceramic materials and the limitations of existing FDM processes result in low fracture toughness of 3D printed ceramics, limiting their promotion in high-demand applications.

[0007] Deficiencies of fiber-reinforced impregnation technology: Currently, 3D printing methods for SiC ceramics are mostly limited to the molding of single SiC powders. When using continuous fiber reinforcement, the degree of impregnation between the fiber and the matrix is ​​often insufficient due to limitations of process equipment, resulting in unsatisfactory fiber reinforcement effects.

[0008] Insufficient adaptability to complex structures: Although 3D printing technology has a certain degree of free design capabilities, when printing large-scale and complex-shaped ceramic parts, existing technologies are often unable to achieve high-precision molding due to material and equipment limitations.

[0009] In this context, existing technologies have made some improvements, but still fail to completely solve the above problems. For example:

[0010] A Chinese patent application with publication number CN113651605A proposes a method for preparing filaments for FDM printing of ceramics. Although the uniformity and printing stability of the filaments are improved, the final formed ceramic product still exhibits low density and mechanical properties due to insufficient interlayer bonding.

[0011] The Chinese patent application with publication number CN118745115A introduces a melt deposition method for continuous fiber reinforced ceramic matrix composites, which improves the toughness of the material by introducing continuous fibers. However, the process control of this method is complex during the fiber impregnation process, and the degree of bonding between the fiber and the matrix is ​​insufficient, resulting in limited reinforcement effect. In addition, the technology has poor adaptability to complex-shaped parts.

[0012] A Chinese patent application with publication number CN118146002A proposes a method for layered ceramic manufacturing by combining FDM with a filling process, attempting to improve the density and strength of the material. However, this method relies on a precise vacuum filling process, which increases manufacturing costs and process complexity, limiting its actual industrial application.

[0013] In summary, the existing SiC ceramic 3D printing technology still has many shortcomings in terms of molding process, material properties, equipment design and complex structure manufacturing. There is an urgent need for an innovative method with simple process, low equipment cost and the ability to manufacture high-density, high-strength complex-shaped SiC ceramic structural parts to break through the limitations of traditional technology. Summary of the invention

[0014] The technical problem to be solved by the present invention is to provide a preparation method of 3D printed continuous fiber reinforced SiC ceramic composites, so as to solve the problems of complex structure difficulties, high mold cost, long cycle, high material brittleness and low fracture toughness in the conventional preparation methods in the prior art, while improving the mechanical properties and fracture toughness of the material, and providing an efficient and low-cost preparation method for ceramic composites with complex structures and high performance requirements.

[0015] In order to overcome the above defects of the prior art, the present invention provides a method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material, comprising the following steps:

[0016] S1: Preparation of continuous fiber printing filament:

[0017] S11: Select a thermoplastic resin and dry it for later use;

[0018] S12: selecting continuous fibers and performing a degumming treatment, performing a primary drying on the degummed continuous fibers, and immersing the fibers in a water solvent prepared with a coupling agent for immersion treatment, and drying the fibers again after the immersion is completed;

[0019] S13: preheating the continuous fiber treated in step S12, pouring a thermoplastic resin into the continuous fiber for impregnation, then extruding, cooling and winding to obtain a 3D printing continuous fiber wire;

[0020] S2: Preparation of silicon carbide wire:

[0021] S21: selecting a thermoplastic resin and silicon carbide powder, and drying them respectively;

[0022] S22: the silicon carbide powder of step S21 is mixed with a sintering aid and a coupling agent, and then dried to obtain a mixture, and then the mixture is mixed with the thermoplastic resin of step S21, and then granulated by twin-screw extrusion to obtain a mixed granular material;

[0023] S23: melt-extrude the mixed granular material obtained in step S22 through a single screw to obtain silicon carbide wire;

[0024] S3: Preparation of continuous fiber reinforced SiC ceramic composites:

[0025] S31: Printing is performed using an FDM printer, wherein the two inlets of the printer are the continuous fiber printing wire obtained in step S1 and the silicon carbide wire obtained in step S2, respectively, and the FDM printer is used to print in a layered solidification and layer-by-layer stacking manner to obtain a fiber-reinforced / SiC / polymer blank;

[0026] S32: Degreasing the green body obtained in step S31 to obtain a preform;

[0027] S33: Sintering the preform obtained in step S32 to obtain a continuous fiber reinforced SiC ceramic composite material.

[0028] Compared with the prior art, the preparation method of a 3D-printed continuous fiber-reinforced SiC ceramic composite material of the present invention has the following advantages: the core principle of the preparation method of a 3D-printed continuous fiber-reinforced SiC ceramic composite material proposed by the present invention is to combine additive manufacturing technology (3D printing) with the fiber reinforcement mechanism of the composite material, and at the same time realize the densification and performance optimization of the ceramic composite material through process design, and by introducing FDM 3D printing technology, the limitations of complex structure manufacturing in traditional mold forming methods are avoided, and the mold cost and production cycle are greatly reduced; the fracture toughness and overall mechanical properties of the SiC ceramic composite material are effectively improved by the reinforcement effect of continuous fibers, and the problem of high brittleness of traditional ceramic materials is overcome; the fiber surface modification technology is used to enhance the interface bonding force between the fiber and the matrix, and the optimization of stress transfer is realized; the hardness and high temperature resistance of the composite material are significantly improved by reaction sintering and densification process; in addition, the process conditions of the present invention are flexible and controllable, and have strong adaptability, which can not only meet the requirements of products with complex shapes and high performance requirements, but also have the characteristics of low cost and high efficiency, and provide extensive technical support for aerospace, national defense industry and other high-performance application fields.

[0029] In a possible implementation, in step S11, step S21 and step S22, the drying conditions are: temperature: 50-80°C, time: 4-8h.

[0030] Compared with the prior art, by adopting the above-mentioned technical scheme, the drying of the thermoplastic resin (steps S11 and S21) can effectively reduce the problem of residual moisture caused by its internal and surface hygroscopicity, and avoid bubbles, stratification or poor interface bonding caused by water volatilization in the subsequent melt extrusion process; and the drying of the silicon carbide powder (step S22) can ensure the dispersibility of the powder, avoid uneven mixing caused by agglomeration, and provide a stable raw material basis for subsequent twin-screw granulation and wire forming. The above-mentioned embodiment of the present invention can avoid the problem of material instability during the extrusion process caused by moisture by further clarifying the drying temperature and time.

[0031] In a possible implementation, in step S11 and step S21, the thermoplastic resin is one or more of polylactic acid, ABS plastic, polycarbonate, nylon, polyethylene, paraffin and stearic acid, and the ABS plastic is a ternary mixture of three monomers consisting of acrylonitrile, butadiene and styrene; in step S12, the continuous fiber is one or more of carbon fiber, silicon carbide fiber and alumina fiber; in step S12 and step S22, the coupling agent is one or more of KH550, KH560, KH570 and KH792.

[0032] Compared with the prior art, the above technical solution provides a wide range of performance control space through a variety of choices of thermoplastic resins (including polylactic acid, ABS plastics, polycarbonate, etc.), among which polylactic acid has biodegradability and good processing performance, and is suitable for applications requiring environmental protection; ABS plastic provides good toughness and impact resistance through the optimized combination of acrylonitrile, butadiene and styrene; polycarbonate and nylon have high strength and high heat resistance, and can meet the mechanical requirements in harsh environments. The diversity of resins enables the present invention to adapt to different application scenarios and performance requirements; and the selection of continuous fibers (including The invention relates to a 3D printed ceramic composite material which is a composite material of the present invention. The invention relates to a 3D printed ceramic composite material which is a composite material of the present invention. The 3D printed ceramic composite material comprises a plurality of continuous fibers (including carbon fiber, silicon carbide fiber and alumina fiber), wherein the carbon fiber provides excellent strength and fracture toughness, the silicon carbide fiber has high temperature stability, and the alumina fiber has outstanding thermal shock resistance. Different selections of coupling agents can form stable chemical bonds between the above-mentioned continuous fibers and the thermoplastic resin matrix, thereby improving the interfacial bonding strength between the fibers and the matrix. Through the preferred combination of the above-mentioned thermoplastic resin, continuous fibers and coupling agents, the problems of the deficiencies of the existing 3D printed ceramic composite materials in terms of mechanical properties, processing stability and interfacial bonding properties are solved.

[0033] In a possible implementation, in step S12, the degumming treatment includes: subjecting the continuous fibers to a high-temperature degumming treatment at a temperature of 600-1000° C.; and the conditions for the immersion treatment are: ultrasonically cleaning the continuous fibers with anhydrous ethanol.

[0034] Compared with the prior art, the above technical solution adopts a high temperature degumming treatment of 600-1000°C to completely remove impurities, resin coatings and other organic matter on the fiber surface, making the fiber surface purer. Meanwhile, ultrasonic cleaning in anhydrous ethanol medium can further remove tiny particles and adsorbents on the fiber surface. The above treatment of the present invention combines high temperature degumming with ultrasonic cleaning, removes impurities on the fiber surface by physical and chemical cleaning means, and increases the active sites of the fiber. Subsequently, a coupling agent is impregnated to form a chemically bonded interface layer on the fiber surface. The synergistic effect of the two further improves the interface bonding strength between the fiber and the matrix material.

[0035] In a possible embodiment, in step S13, the weight ratio of the thermoplastic resin to the continuous fiber is (80-20): (20-80), and the impregnation further includes the operation of adding an auxiliary agent, and the auxiliary agent is paraffin or stearic acid; the preheating temperature is 0-300°C, the impregnation temperature is 100-300°C, the extrusion port temperature is 100-300°C, and the extrusion port diameter is 1-3mm.

[0036] Compared with the prior art, the above technical scheme is adopted to adjust the weight ratio of thermoplastic resin to continuous fiber to (80-20): (20-80), so as to achieve the synergistic effect of matrix and reinforcing fiber, which not only ensures that the continuous fiber can play a reinforcing role on the composite material, but also ensures that the thermoplastic resin provides sufficient fluidity to achieve a good impregnation effect; by adding auxiliary agents, the processing performance and printing quality of the continuous fiber wire are significantly improved; and by preheating the fiber, residual moisture and stress can be removed, the adhesion with the resin can be improved, and at the same time, thermal damage to the fiber caused by excessive temperature can be avoided. The control of the impregnation temperature heats the thermoplastic resin within the temperature range of 100-300°C, improves the fluidity, ensures that the resin fully penetrates the fiber bundle, avoids the formation of bubbles or voids, and further ensures the shape stability of the wire during the extrusion process by precisely controlling the extrusion port temperature, avoiding decomposition caused by high temperature or incomplete extrusion caused by low temperature; the diameter control of the extrusion port can ensure that the wire meets the specification requirements of the subsequent FDM printing equipment, and has good flexibility and mechanical strength.

[0037] In one possible embodiment, in the step S21, the particle size of the silicon carbide powder is 200-400 mesh; in the step S22, the silicon carbide powder is mixed with the sintering aid and the coupling agent by wet ball milling, and the conditions of the wet ball milling are: the ball mill speed is 200-500r / min, the ball-to-material mass ratio is 1:(1-3), and the ball milling time is 10-20h; the mixture is mixed with the thermoplastic resin by dry mixing, and the conditions of the dry mixing are: the ball mill speed is 50-100r / min, the ball-to-material mass ratio is 1:(1-3), and the ball milling time is 3-5h; the conditions of the twin-screw extrusion granulation are: preheating zone 100-300℃, melting zone 100-300℃, and molding mold 100-300℃.

[0038] Compared with the prior art, the above technical solution is adopted. In step S21, the particle size of silicon carbide powder is controlled so that the particles have a small enough size to improve the sintering activity, and at the same time, the surface area of ​​the particles is moderate within the particle size range, and agglomeration will not occur; in step S22, wet ball milling mixes silicon carbide powder, sintering aid and coupling agent evenly through the interaction between the grinding balls and the materials, and at the same time breaks up possible particle agglomerations, and by further controlling its conditions, the effect is further optimized, and dry mixing avoids excessive crushing of the material by setting a lower speed ball milling, while ensuring that the uniformity of the particles after wet ball milling is maintained when mixed with the thermoplastic resin; further, by controlling the twin-screw extrusion granulation conditions, the mixture is heated in the preheating zone to reach a suitable molten state, the molten zone further ensures uniform extrusion, and the temperature of the molding mold controls the size and shape stability of the granules.

[0039] In a possible implementation, in step S23, the diameter of the silicon carbide wire is 1.75-2.85 mm, and the conditions for the single screw melt extrusion are: preheating zone 100-300°C, melting zone 100-300°C, molding die 100-300°C, and pressure 15-35N.

[0040] Compared with the existing technology, the above technical solution is used to control the diameter of the silicon carbide wire. The wire diameter range of 1.75-2.85mm not only meets the feed specification requirements of common FDM 3D printing equipment, but also ensures that the wire has high flexibility and suitable mechanical strength during the printing process; and the further optimization of the single-screw extrusion conditions, through the precise control of temperature and pressure, avoids material degradation, pore generation or size inconsistency during the melting process, and significantly improves the qualified rate of the wire.

[0041] In a possible implementation, in step S31, the printing conditions of the FDM printer are: the melting zone temperature is 100-300°C, the nozzle temperature is controlled at 100-300°C, the stage temperature is controlled at 20-150°C, the printing speed is 10-50mm / s, and the single layer thickness is 0.1-1mm.

[0042] Compared with the prior art, the above technical solution ensures that the material is completely melted in the nozzle by controlling the temperature of the melting zone and the nozzle at 100-300°C, while avoiding material degradation caused by excessively high temperature or insufficient melting caused by too low temperature; by controlling the stage temperature at 20-150°C, warping or cracking of the printed part due to uneven cooling or excessive temperature difference can be avoided; secondly, the range of 10-50mm / s can ensure that the deposited material flows fully in the melting zone of the nozzle, and can avoid insufficient interlayer bonding caused by excessively high speed or decreased efficiency caused by too low speed. A smaller single layer thickness (such as 0.1mm) is suitable for printing high-precision complex structures, which optimizes the printing molding effect.

[0043] In a possible implementation, in step S32, the debinding condition is: heating the green body to 800° C. at a heating rate of 0.2-1° C. / min in a debinding furnace, and keeping the temperature at this temperature for 1-3 hours.

[0044] Compared with the prior art, the above technical scheme is adopted to control the slow heating rate of 0.2-1°C / min. The low heating rate ensures that the organic matter in the green blank can be decomposed and gradually released during the heating process, thereby avoiding porosity, cracking or stratification problems caused by too fast volatilization rate. The decomposition reaction of organic degreasing is usually carried out between 300-800°C. The above implementation scheme selects 800°C as the upper limit of the degreasing temperature, which can ensure that the thermoplastic resin in the green blank is completely decomposed and volatilized, while avoiding excessive sintering or crystal growth of materials caused by high temperature. Appropriate insulation at 800°C for 1-3h can ensure complete decomposition of organic matter and provide sufficient discharge time for residual volatile substances.

[0045] In a possible implementation, in step S33, the sintering conditions are: sintering the preform in a high-temperature sintering furnace, the furnace temperature is 1400-1900° C., the insulation time is 0.5-5 hours, and the sintering atmosphere is a combination of vacuum or inert atmosphere.

[0046] Compared with the prior art, the above technical solution requires high temperature conditions for the sintering of SiC ceramics to promote the formation of dense sintering necks through diffusion and rearrangement between particles, while avoiding excessive grain growth or material decomposition caused by excessive temperature. Therefore, the temperature range of 1400-1900°C not only meets the sintering activation requirements of SiC, but also avoids the side effects of high temperature. The control of the holding time can make the microstructure of the material reach a uniform and dense state, avoiding insufficient sintering due to too short a time or grain coarsening due to too long a time. In the sintering atmosphere, the vacuum environment helps to reduce the influence of harmful gases (such as oxygen) during the sintering process, avoid material oxidation, and maintain the chemical stability of SiC and reinforcing fibers. Inert atmosphere (such as argon) can prevent the material from chemically degrading due to reaction with the environment at high temperature, while increasing the diffusion rate between particles. The above implementation method significantly improves the performance and preparation efficiency of continuous fiber reinforced SiC ceramic composites by optimizing the sintering process conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of 3D printing continuous fiber wire in the present invention, wherein: 1. fiber bundle; 2. yarn unrolling frame; 3. heating device; 4. ultrasonic vibration device; 5. resin feeding device; 6. impregnation device; 7. extrusion device; 8. cooling device; 9. traction equipment; 10. speed control device; 11. winding device. DETAILED DESCRIPTION

[0048] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present invention, and are not intended to limit the protection scope of the embodiments of the present invention. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0049] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0050] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] The present invention provides a method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material, comprising the following steps:

[0052] S1: Preparation of continuous fiber printing filament:

[0053] S11: Select a thermoplastic resin and dry it for later use;

[0054] S12: selecting continuous fibers and performing a degumming treatment, performing a primary drying on the degummed continuous fibers, and immersing the fibers in a water solvent prepared with a coupling agent for immersion treatment, and drying the fibers again after the immersion is completed;

[0055] S13: preheating the continuous fiber treated in step S12, pouring a thermoplastic resin into the continuous fiber for impregnation, then extruding, cooling and winding to obtain a 3D printing continuous fiber wire;

[0056] S2: Preparation of silicon carbide wire:

[0057] S21: selecting a thermoplastic resin and silicon carbide powder, and drying them respectively;

[0058] S22: the silicon carbide powder of step S21 is mixed with a sintering aid and a coupling agent, and then dried to obtain a mixture, and then the mixture is mixed with the thermoplastic resin of step S21, and then granulated by twin-screw extrusion to obtain a mixed granular material;

[0059] S23: melt-extrude the mixed granular material obtained in step S22 through a single screw to obtain silicon carbide wire;

[0060] S3: Preparation of continuous fiber reinforced SiC ceramic composites:

[0061] S31: Printing is performed using an FDM printer, wherein the two inlets of the printer are the continuous fiber printing wire obtained in step S1 and the silicon carbide wire obtained in step S2, respectively, and the FDM printer is used to print in a layered solidification and layer-by-layer stacking manner to obtain a fiber-reinforced / SiC / polymer blank;

[0062] S32: Degreasing the green body obtained in step S31 to obtain a preform;

[0063] S33: Sintering the preform obtained in step S32 to obtain a continuous fiber reinforced SiC ceramic composite material.

[0064] like Figure 1 As shown, Figure 1 It is the fiber preimpregnation device in the present invention. The fiber preimpregnation device is formulated for the above-mentioned step S1 (including step S12 / S13), wherein the fiber bundle 1 is moved to the heating device 3 for preheating through the yarn unrolling frame 2, the traction device 9 and the constant speed device 10. After the preheating, it continues to be pulled to the impregnation device 6 through the traction device 9 and the constant speed device 10, and then the thermoplastic resin is passed into the impregnation device 6 through the resin feeding device 5. Various auxiliary agents such as paraffin and stearic acid can be further added according to needs. The ultrasonic vibration device 4 at the bottom of the impregnation device 6 can further improve the impregnation effect. After the impregnation is completed, it is extruded, then cooled by the cooling device 8, and then enters the winding device 11 for winding to obtain a 3D printing continuous fiber wire.

[0065] The step S1 is implemented by a fiber pre-impregnation device, which includes a yarn unrolling frame 2, a heating device 3, an impregnation device 6, an extrusion device 7, a cooling device 8, a traction device 9, a speed control device 10 and a winding device 11 connected in sequence. The upper end of the impregnation device 6 is provided with a resin feeding device 5 connected to the inside of the impregnation device 6, and the lower section of the impregnation device 6 is provided with an ultrasonic vibration device 4.

[0066] The yarn unrolling frame 2 is used to pull the fiber out of the reel and flatten it, and the heating device 3 is used to preheat the continuous fiber;

[0067] The working process of the fiber prepreg equipment combined with step S1 is as follows:

[0068] S1: Preparation of continuous fiber printing filament:

[0069] S11: Select a thermoplastic resin and dry it for later use;

[0070] S12: Select continuous fibers and perform degumming treatment through the heating device 3. After the degumming continuous fibers are cleaned with anhydrous ethanol (or ultrasonically cleaned in the impregnation device 6), they are initially dried through the heating device 3 and immersed in a water solvent prepared with a coupling agent for impregnation treatment in the impregnation device 6. After the impregnation, they are dried again in the heating device 3. The continuous fibers are moved by the driving of the traction device 9 and the constant speed device 10.

[0071] S13: The continuous fiber treated in step S12 is then driven by the traction device 9 and the speed control device 10, unfolded by the yarn unrolling frame 2, and then further passed into the heating device 3 for preheating. After preheating by the heating device 3, the thermoplastic resin is poured into the impregnation device 6 through the resin feeding device 5 and impregnated with the continuous fiber, and the impregnation is strengthened by the ultrasonic vibration device 4, and then extruded by the extrusion device 7, further passed into the cooling device 8 for cooling, and then passed into the winding device 11 for winding to obtain the 3D printing continuous fiber wire;

[0072] As a preferred solution, in step S11, step S21 and step S22, the drying conditions are: temperature: 50-80°C, time: 4-8h.

[0073] As a preferred solution, in step S11 and step S21, the thermoplastic resin is one or more of polylactic acid, ABS plastic, polycarbonate, nylon, polyethylene, paraffin and stearic acid, and the ABS plastic is a ternary mixture of three monomers consisting of acrylonitrile, butadiene and styrene; in step S12, the continuous fiber is one or more of carbon fiber, silicon carbide fiber and alumina fiber; in step S12 and step S22, the coupling agent is one or more of KH550, KH560, KH570 and KH792.

[0074] As a preferred solution, in step S12, the degumming treatment includes: placing the continuous fiber at a temperature of 600-1000° C. for high-temperature degumming treatment; and the conditions for the immersion treatment are: ultrasonically cleaning the continuous fiber with anhydrous ethanol.

[0075] As a preferred embodiment, in step S13, the weight ratio of the thermoplastic resin to the continuous fiber is (80-20): (20-80), and the impregnation also includes the operation of adding an auxiliary agent, and the auxiliary agent is paraffin or stearic acid; the preheating temperature is 0-300°C, the impregnation temperature is 100-300°C, the extrusion port temperature is 100-300°C, and the extrusion port diameter is 1-3mm.

[0076] As a preferred scheme, in the step S21, the particle size of the silicon carbide powder is 200-400 mesh; in the step S22, the silicon carbide powder is mixed with the sintering aid and the coupling agent by wet ball milling, and the conditions of the wet ball milling are: the ball mill speed is 200-500r / min, the ball-to-material mass ratio is 1:(1-3), and the ball milling time is 10-20h; the mixture is mixed with the thermoplastic resin by dry mixing, and the conditions of the dry mixing are: the ball mill speed is 50-100r / min, the ball-to-material mass ratio is 1:(1-3), and the ball milling time is 3-5h; the conditions of the twin-screw extrusion granulation are: preheating zone 100-300℃, melting zone 100-300℃, and molding mold 100-300℃.

[0077] As a preferred solution, in step S23, the diameter of the silicon carbide wire is 1.75-2.85 mm, and the conditions for the single screw melt extrusion are: preheating zone 100-300°C, melting zone 100-300°C, molding die 100-300°C, and pressure 15-35N.

[0078] As a preferred solution, in step S31, the printing conditions of the FDM printer are: the melting zone temperature is 100-300°C, the nozzle temperature is controlled at 100-300°C, the stage temperature is controlled at 20-150°C, the printing speed is 10-50mm / s, and the single layer thickness is 0.1-1mm.

[0079] As a preferred solution, in step S32, the debinding conditions are: heating the green body to 800°C at a heating rate of 0.2-1°C / min in a debinding furnace, and keeping the temperature at this temperature for 1-3h.

[0080] As a preferred solution, in step S33, the sintering conditions are: sintering the preform in a high-temperature sintering furnace, the furnace temperature is 1400-1900°C, the insulation time is 0.5-5 hours, and the sintering atmosphere is a combination of vacuum or inert atmosphere.

[0081] Embodiment 1:

[0082] This embodiment provides a method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material, comprising the following steps:

[0083] S1: Preparation of continuous fiber printing filaments

[0084] S11: Drying of thermoplastic resin

[0085] The thermoplastic resin is placed in an oven for drying under the following conditions: temperature of 65° C. and time of 6 hours. The thermoplastic resin is polylactic acid.

[0086] S12: Surface modification of continuous fibers

[0087] Degumming treatment: The continuous fiber (carbon fiber) is placed in a furnace for high-temperature degumming treatment at a temperature of 800°C.

[0088] Cleaning and drying: The continuous fibers after degumming are ultrasonically cleaned with anhydrous ethanol and then dried.

[0089] Coupling agent impregnation: Use KH550 coupling agent to prepare an aqueous solution, impregnate the cleaned continuous fiber for 5 hours and then dry it to improve the bonding strength between the fiber and the resin.

[0090] S13: Preparation of continuous fiber wire

[0091] Fiber preheating: The continuous fiber treated in step S12 is preheated to a temperature of 150°C.

[0092] Resin impregnation: Pour the preheated continuous fiber into the thermoplastic resin for impregnation, with the mass ratio of fiber to thermoplastic resin being 50:50; during the impregnation process, an auxiliary agent (paraffin) is added to improve the impregnation effect.

[0093] Extrusion and cooling: The impregnated continuous fiber is extruded from the extrusion port through an ultrasonic-assisted device. The extrusion port temperature is 200°C and the extrusion port diameter is 2mm. After extrusion, it is cooled and rolled up to obtain a 3D printing continuous fiber wire with a uniform surface.

[0094] S2: Preparation of silicon carbide wire

[0095] S21: Drying of thermoplastic resin and silicon carbide powder

[0096] The thermoplastic resin and silicon carbide powder with a particle size of 300 meshes are dried separately. The drying conditions are: temperature of 65° C. and time of 6 hours. The thermoplastic resin is polylactic acid.

[0097] S22: Preparation of silicon carbide granules

[0098] Wet ball milling: Silicon carbide powder, sintering aid and coupling agent (KH550) are mixed evenly by wet ball milling. The wet ball milling conditions are as follows: ball mill speed is 350r / min, ball-to-material mass ratio is 1:2, and ball milling time is 15 hours.

[0099] Dry mixing after drying: the mixed material is dried and then dry mixed with the thermoplastic resin. The dry mixing conditions are: the ball mill speed is 75r / min, the ball-to-material mass ratio is 1:2, and the ball milling time is 4 hours.

[0100] Twin-screw extrusion granulation: The mixture is granulated by twin-screw extrusion. The granulation conditions are: preheating zone 200°C, melting zone 200°C, and molding die temperature 200°C to obtain mixed granules with a particle size of 300 μm.

[0101] S23: Forming of silicon carbide wire

[0102] The mixed granular material prepared in step S22 was melt-extruded by a single screw, and the extrusion conditions were: preheating zone 200°C, melting zone 200°C, molding die temperature 200°C, extrusion pressure 25N, to obtain a standard SiC / polymer wire with a smooth surface and uniform wire, and the wire diameter was 2.1 mm.

[0103] S3: Preparation of continuous fiber reinforced SiC ceramic composites

[0104] S31: Printing

[0105] STL file import: import the designed STL file into the FDM printer, the printer has a dual-inlet design, one inlet is for continuous fiber filaments, and the other inlet is for silicon carbide filaments.

[0106] Printing process parameters: The printing parameters were set as follows: melting zone temperature 200°C, nozzle temperature 200°C, stage temperature 85°C, printing speed 30 mm / s, and single layer thickness 0.5 mm.

[0107] Printing process: The fiber-reinforced / SiC / polymer green body is printed through layered solidification and layer-by-layer stacking.

[0108] S32: Degreasing

[0109] The green body obtained in step S31 is placed in a degreasing furnace and degreased under the following conditions: the temperature is raised to 800°C at a heating rate of 0.5°C / min and kept at this temperature for 2 hours to obtain a preform after degreasing.

[0110] S33: Sintering

[0111] Reaction sintering: The degreased preform is placed in a high-temperature sintering furnace for reaction sintering.

[0112] Sintering process parameters: The sintering conditions were set as follows: furnace temperature was 1650°C, holding time was 2.5 hours, and sintering atmosphere was vacuum.

[0113] Final product: After sintering, a continuous fiber reinforced SiC ceramic composite material is obtained, which has a dense structure, smooth surface and significantly enhanced mechanical properties.

[0114] Embodiment 2:

[0115] This embodiment provides a method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material, comprising the following steps:

[0116] S1: Preparation of continuous fiber printing filaments

[0117] S11: Drying of thermoplastic resin

[0118] The thermoplastic resin is placed in an oven for drying under the following conditions: temperature of 50° C. and time of 4 hours. The thermoplastic resin is ABS plastic (a ternary mixture of three monomers: acrylonitrile, butadiene and styrene).

[0119] S12: Surface modification of continuous fibers

[0120] Degumming treatment: The continuous fiber (alumina fiber) is placed in a furnace for high-temperature degumming treatment at a temperature of 600°C.

[0121] Cleaning and drying: The continuous fibers after degumming are ultrasonically cleaned with anhydrous ethanol and then dried.

[0122] Coupling agent impregnation: Use KH570 coupling agent to prepare an aqueous solution, impregnate the cleaned continuous fiber for 2 hours and then dry it to improve the bonding strength between the fiber and the resin.

[0123] S13: Preparation of continuous fiber wire

[0124] Fiber preheating: The continuous fiber treated in step S12 is preheated to a temperature of 150°C.

[0125] Resin impregnation: Pour the preheated continuous fiber into the thermoplastic resin for impregnation, and the mass ratio of fiber to thermoplastic resin is 20:80; during the impregnation process, an auxiliary agent (stearic acid) is added to improve the impregnation effect.

[0126] Extrusion and cooling: The impregnated continuous fiber is extruded from the extrusion port through an ultrasonic-assisted device. The extrusion port temperature is 200°C and the extrusion port diameter is 1mm. After extrusion, it is cooled and rolled up to obtain a 3D printing continuous fiber wire with a uniform surface.

[0127] S2: Preparation of silicon carbide wire

[0128] S21: Drying of thermoplastic resin and silicon carbide powder

[0129] Thermoplastic resin and silicon carbide powder with a particle size of 200 meshes were dried separately, and the drying conditions were: temperature of 50° C. and time of 4 hours. The thermoplastic resin was ABS plastic (a ternary mixture of three monomers consisting of acrylonitrile, butadiene and styrene).

[0130] S22: Preparation of silicon carbide granules

[0131] Wet ball milling: Silicon carbide powder, sintering aid and coupling agent (KH570) are mixed evenly by wet ball milling. The wet ball milling conditions are as follows: ball mill speed is 350r / min, ball-to-material mass ratio is 1:3, and ball milling time is 10 hours.

[0132] Dry mixing after drying: the mixed material is dried and then dry mixed with the thermoplastic resin. The dry mixing conditions are: the ball mill speed is 75r / min, the ball-to-material mass ratio is 1:3, and the ball milling time is 3 hours.

[0133] Twin-screw extrusion granulation: The mixture is granulated by twin-screw extrusion. The granulation conditions are: preheating zone 100°C, melting zone 200°C, and molding die temperature 200°C to obtain mixed granules with a particle size of 100 μm.

[0134] S23: Forming of silicon carbide wire

[0135] The mixed granular material prepared in step S22 is melt-extruded by a single screw, and the extrusion conditions are: 100°C in the preheating zone, 200°C in the melting zone, 220°C in the molding die temperature, and 15N in the extrusion pressure, to obtain a standard SiC / polymer wire with a smooth surface and uniform wire, and the wire diameter is 1.75mm.

[0136] S3: Preparation of continuous fiber reinforced SiC ceramic composites

[0137] S31: Printing

[0138] STL file import: import the designed STL file into the FDM printer, the printer has a dual-inlet design, one inlet is for continuous fiber filaments, and the other inlet is for silicon carbide filaments.

[0139] Printing process parameters: The printing parameters were set as follows: melting zone temperature 100°C, nozzle temperature 220°C, stage temperature 20°C, printing speed 10 mm / s, and single layer thickness 0.1 mm.

[0140] Printing process: The fiber-reinforced / SiC / polymer green body is printed through layered solidification and layer-by-layer stacking.

[0141] S32: Degreasing

[0142] The green body obtained in step S31 is placed in a degreasing furnace and degreased under the following conditions: the temperature is raised to 800°C at a heating rate of 0.2°C / min and kept at this temperature for 1 hour to obtain a preform after degreasing.

[0143] S33: Sintering

[0144] Reaction sintering: The degreased preform is placed in a high-temperature sintering furnace for reaction sintering.

[0145] Sintering process parameters: The sintering conditions were set as follows: furnace temperature was 1700°C, holding time was 0.5 hours, and sintering atmosphere was vacuum.

[0146] Final product: After sintering, a continuous fiber reinforced SiC ceramic composite material is obtained, which has a dense structure, smooth surface and significantly enhanced mechanical properties.

[0147] Embodiment 3:

[0148] This embodiment provides a method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material, comprising the following steps:

[0149] S1: Preparation of continuous fiber printing filaments

[0150] S11: Drying of thermoplastic resin

[0151] The thermoplastic resin is placed in an oven for drying under the following conditions: temperature of 80° C. and time of 8 hours. The thermoplastic resin is a mixture of polylactic acid, ABS plastic (a ternary mixture of three monomers consisting of acrylonitrile, butadiene and styrene), polycarbonate, nylon, polyethylene, paraffin and stearic acid.

[0152] S12: Surface modification of continuous fibers

[0153] Degumming treatment: The continuous fiber (a mixture of carbon fiber, silicon carbide fiber, and alumina fiber) is placed in a furnace for high-temperature degumming treatment at a temperature of 1000°C.

[0154] Cleaning and drying: The continuous fibers after degumming are ultrasonically cleaned with anhydrous ethanol and then dried.

[0155] Coupling agent impregnation: Use KH792 coupling agent to prepare an aqueous solution, impregnate the cleaned continuous fiber for 5 hours and then dry it to improve the bonding strength between the fiber and the resin.

[0156] S13: Preparation of continuous fiber wire

[0157] Fiber preheating: preheat the continuous fiber after the treatment in step S12 to a temperature of 300°C.

[0158] Resin impregnation: Pour the preheated continuous fiber into the thermoplastic resin for impregnation, and the mass ratio of fiber to thermoplastic resin is 80:20; during the impregnation process, an auxiliary agent (stearic acid) is added to improve the impregnation effect.

[0159] Extrusion and cooling: The impregnated continuous fiber is extruded from the extrusion port through an ultrasonic-assisted device. The extrusion port temperature is 300°C and the extrusion port diameter is 3mm. After extrusion, it is cooled and rolled up to obtain a 3D printing continuous fiber wire with a uniform surface.

[0160] S2: Preparation of silicon carbide wire

[0161] S21: Drying of thermoplastic resin and silicon carbide powder

[0162] Thermoplastic resin and silicon carbide powder with a particle size of 400 mesh are dried separately, and the drying conditions are: temperature 80°C and time 8 hours. The thermoplastic resin is a mixture of polylactic acid, ABS plastic (a ternary mixture of three monomers consisting of acrylonitrile, butadiene and styrene), polycarbonate, nylon, polyethylene, paraffin and stearic acid.

[0163] S22: Preparation of silicon carbide granules

[0164] Wet ball milling: Silicon carbide powder, sintering aid and coupling agent (KH792) are mixed evenly by wet ball milling. The wet ball milling conditions are as follows: ball mill speed is 350r / min, ball-to-material mass ratio is 1:1, and ball milling time is 20 hours.

[0165] Dry mixing after drying: the mixed material is dried and then dry mixed with the thermoplastic resin. The dry mixing conditions are: the ball mill speed is 75r / min, the ball-to-material mass ratio is 1:1, and the ball milling time is 5 hours.

[0166] Twin-screw extrusion granulation: The mixture is granulated by twin-screw extrusion. The granulation conditions are: preheating zone 300°C, melting zone 300°C, and molding die temperature 300°C to obtain mixed granules with a particle size of 500 μm.

[0167] S23: Forming of silicon carbide wire

[0168] The mixed granular material prepared in step S22 was melt-extruded by a single screw, and the extrusion conditions were: preheating zone 300°C, melting zone 300°C, molding die temperature 300°C, extrusion pressure 35N, to obtain a standard SiC / polymer wire with a smooth surface and uniform wire, and the wire diameter was 2.85mm.

[0169] S3: Preparation of continuous fiber reinforced SiC ceramic composites

[0170] S31: Printing

[0171] STL file import: import the designed STL file into the FDM printer, the printer has a dual-inlet design, one inlet is for continuous fiber filaments, and the other inlet is for silicon carbide filaments.

[0172] Printing process parameters: The printing parameters were set as follows: melting zone temperature 300°C, nozzle temperature 300°C, stage temperature 150°C, printing speed 50 mm / s, and single layer thickness 1 mm.

[0173] Printing process: The fiber-reinforced / SiC / polymer green body is printed through layered solidification and layer-by-layer stacking.

[0174] S32: Degreasing

[0175] The green body obtained in step S31 is placed in a degreasing furnace and degreased under the following conditions: the temperature is raised to 800°C at a heating rate of 1°C / min and kept at this temperature for 3 hours to obtain a preform after degreasing.

[0176] S33: Sintering

[0177] Reaction sintering: The degreased preform is placed in a high-temperature sintering furnace for reaction sintering.

[0178] Sintering process parameters: The sintering conditions were set as follows: furnace temperature was 1650°C, holding time was 3 hours, and sintering atmosphere was vacuum.

[0179] Final product: After sintering, a continuous fiber reinforced SiC ceramic composite material is obtained, which has a dense structure, smooth surface and significantly enhanced mechanical properties.

[0180] The mechanical properties of the continuous fiber reinforced SiC ceramic composites prepared in the above examples 1-3 of the present invention were tested: the preparation method of the present invention was optimized by data, and the maximum fracture toughness of the continuous fiber reinforced SiC ceramic composites prepared in examples 1-3 can reach 6.8 MPa·m 1 / 2 The bending strength is 280Mpa. Compared with the SiC ceramics printed and prepared by the same preparation method of the above-mentioned embodiments 1-3 of the present invention, the maximum fracture toughness is 3.7MPa·m 1 / 2 The bending strength is 210Mpa, which further proves that the present invention solves the technical problems existing in the background technology.

[0181] Through the above examples, it is further proved that the present invention provides a method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material, which combines the continuous fiber reinforcement mechanism and FDM 3D printing technology, utilizes the high strength of continuous fibers and the high hardness characteristics of SiC ceramic matrix, and solves the technical problems of difficult molding of complex structures, high mold cost, long processing cycle, high material brittleness, and low fracture toughness in traditional methods by accurately controlling key steps such as wire preparation, printing molding, degreasing, and high temperature sintering. The technical principle of the present invention is to significantly improve the mechanical properties, density, and printing quality of the material by optimizing fiber interface modification, material distribution uniformity, and process control.

[0182] The advantages of the preparation method of the present invention are embodied in the following aspects:

[0183] Through FDM printing technology, efficient and low-cost manufacturing of complex structural ceramic parts is achieved without relying on traditional molds, which has higher design freedom;

[0184] The use of continuous fiber reinforced SiC ceramics significantly improves the fracture toughness and strength of the material to meet the needs of high-performance applications;

[0185] By precisely controlling process parameters, including drying, impregnation, ball milling, extrusion, printing and sintering, material processing defects (such as cracking, porosity, delamination) are significantly reduced, and production efficiency and yield are improved;

[0186] Optimized debinding and sintering process conditions are adopted to ensure the uniformity and density of the internal structure of the composite material, while improving the thermal stability and corrosion resistance of the material;

[0187] In summary, the present invention not only provides an efficient and stable solution for the manufacture of complex-shaped, high-performance ceramic composite materials, but also achieves a balance between process control and material performance optimization, has significant technical advantages and broad application prospects, and can be widely used in aerospace, defense industry, nuclear energy engineering and other high-end manufacturing fields. In the description of the embodiments of the present invention, it should be noted that in the description of the present invention, the terms "inside", "outside", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of description, and do not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0188] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0189] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing a 3D printed continuous fiber reinforced SiC ceramic composite material, characterized in that: The following steps are involved: S1: Preparation of continuous fiber printing filament: S11: Select a thermoplastic resin and dry it for later use; S12: selecting continuous fibers and performing a degumming treatment, performing a primary drying on the degummed continuous fibers, and immersing the fibers in a water solvent prepared with a coupling agent for immersion treatment, and drying the fibers again after the immersion is completed; S13: preheating the continuous fiber treated in step S12, pouring a thermoplastic resin into the continuous fiber for impregnation, then extruding, cooling and winding to obtain a 3D printing continuous fiber wire; S2: Preparation of silicon carbide wire: S21: selecting a thermoplastic resin and silicon carbide powder, and drying them respectively; S22: the silicon carbide powder of step S21 is mixed with a sintering aid and a coupling agent, and then dried to obtain a mixture, and then the mixture is mixed with the thermoplastic resin of step S21, and then granulated by twin-screw extrusion to obtain a mixed granular material; S23: melt-extrude the mixed granular material obtained in step S22 through a single screw to obtain silicon carbide wire; S3: Preparation of continuous fiber reinforced SiC ceramic composites: S31: Printing is performed using an FDM printer, wherein the two inlets of the printer are the continuous fiber printing wire obtained in step S1 and the silicon carbide wire obtained in step S2, respectively, and the FDM printer is used to print in a layered solidification and layer-by-layer stacking manner to obtain a fiber-reinforced / SiC / polymer blank; S32: Degreasing the green body obtained in step S31 to obtain a preform; S33: Sintering the preform obtained in step S32 to obtain a continuous fiber reinforced SiC ceramic composite material.

2. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In the step S11, step S21 and step S22, the drying conditions are: temperature: 50-80°C, time: 4-8h.

3. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In step S11 and step S21, the thermoplastic resin is one or more of polylactic acid, ABS plastic, polycarbonate, nylon, polyethylene, paraffin and stearic acid, and the ABS plastic is a ternary mixture of three monomers consisting of acrylonitrile, butadiene and styrene; in step S12, the continuous fiber is one or more of carbon fiber, silicon carbide fiber and alumina fiber; in step S12 and step S22, the coupling agent is one or more of KH550, KH560, KH570 and KH792.

4. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In the step S12, the degumming treatment includes: placing the continuous fiber at a temperature of 600-1000° C. for high-temperature degumming treatment; the conditions of the immersion treatment are: ultrasonically cleaning the continuous fiber with anhydrous ethanol.

5. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In the step S13, the weight ratio of the thermoplastic resin to the continuous fiber is (80-20): (20-80), and the impregnation also includes the operation of adding an auxiliary agent, the auxiliary agent is paraffin or stearic acid; the preheating temperature is 0-300°C, the impregnation temperature is 100-300°C, the extrusion port temperature is 100-300°C, and the diameter of the extrusion port is 1-3mm.

6. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In the step S21, the particle size of the silicon carbide powder is 200-400 mesh; in the step S22, the silicon carbide powder is mixed with the sintering aid and the coupling agent by wet ball milling, and the conditions of the wet ball milling are: the ball mill speed is 200-500r / min, the ball-to-material mass ratio is 1:(1-3), and the ball milling time is 10-20h; the mixture is mixed with the thermoplastic resin by dry mixing, and the conditions of the dry mixing are: the ball mill speed is 50-100r / min, the ball-to-material mass ratio is 1:(1-3), and the ball milling time is 3-5h; the conditions of the twin-screw extrusion granulation are: preheating zone 100-300℃, melting zone 100-300℃, and molding mold 100-300℃.

7. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In the step S23, the diameter of the silicon carbide wire is 1.75-2.85 mm, and the conditions of the single screw melt extrusion are: preheating zone 100-300°C, melting zone 100-300°C, molding die 100-300°C, and pressure 15-35N.

8. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In step S31, the printing conditions of the FDM printer are: the melting zone temperature is 100-300°C, the nozzle temperature is controlled at 100-300°C, the stage temperature is controlled at 20-150°C, the printing speed is 10-50mm / s, and the single layer thickness is 0.1-1mm.

9. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In the step S32, the debinding conditions are: heating the green body to 800°C at a heating rate of 0.2-1°C / min in a debinding furnace, and keeping the temperature at this temperature for 1-3 hours.

10. The method for preparing the 3D printed continuous fiber reinforced SiC ceramic composite material according to claim 1, characterized in that: In the step S33, the sintering conditions are as follows: the preform is sintered in a high-temperature sintering furnace at a furnace temperature of 1400-1900° C. for a holding time of 0.5-5 hours, and the sintering atmosphere is a combination of vacuum and inert atmosphere.

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