Direct writing forming equipment and method for continuous fiber reinforced ceramic matrix composite

Abstract

The invention discloses direct writing forming equipment and method for a continuous fiber reinforced ceramic matrix composite, the direct writing forming equipment comprises an XYZ-axis motion platform, an extrusion nozzle, an ultrasonic transducer, a screw propeller, a wire feeder, a forming table and a curing mechanism, the extrusion nozzle is mounted on the XYZ-axis motion platform, and an outlet is formed in the bottom of the extrusion nozzle; the screw propeller comprises a motor and a screw, the motor is mounted on the extrusion nozzle and connected with the screw to drive the screw to rotate, so that the screw shears ceramic slurry in the extrusion nozzle and extrudes the ceramic slurry from an outlet of the extrusion nozzle, and a through hole is formed in the screw. Continuous fibers sent out by the wire feeder penetrate through the screw rod and then are discharged from an outlet of the extrusion nozzle; and the curing mechanism is used for curing the ceramic slurry on the forming table. The viscosity of the ceramic slurry is reduced through the shearing effect of the screw rod, blockage is prevented, and the extrusion nozzle can disperse nano-particle aggregates in the ceramic slurry through the vibration effect of ultrasonic waves.

Description

Technical Field

[0001] The present invention belongs to the field of advanced manufacturing technology, and more specifically, relates to direct writing forming equipment and methods for continuous fiber reinforced ceramic matrix composite materials. Background Art

[0002] Direct Ink Writing (DIW) is an additive manufacturing technology based on extrusion 3D printing. By precisely controlling the extrusion and deposition of ceramic slurries, it breaks through the limitations of traditional continuous fiber reinforced ceramic matrix composites in the design of complex structures, costs, and performance. DIW's significant advantages over traditional processes are: (1) mold-free molding, which allows for direct printing of complex topological structures; (2) fiber orientation control, which controls fiber orientation through extrusion nozzle design and path planning; (3) near-net shape, with material deposition on demand and utilization exceeding 95%; and (4) rapid prototyping, with complex structures printed in just a few hours, and suitable for customized production. Therefore, DIW has great application potential in aerospace, energy, biomedicine, and other fields, and has become the core technology direction for the manufacturing of next-generation high-performance continuous fiber reinforced ceramic matrix composites.

[0003] The ideal DIW ceramic slurry needs to have the characteristics of high solid content, easy sintering, low additive content and not easy to cause defects, low viscosity when sheared and extruded so as not to clog the extrusion nozzle, and high viscosity and not easy to collapse when deposited. However, a major challenge of current DIW technology is that high-solid content ceramic slurry (high-solid content ceramic slurry refers to slurry with a relatively large solid content, usually with a solid content greater than 60% or higher) is prone to clogging the extrusion nozzle and often requires the addition of dispersants for optimization, which increases the experimental time cost and process complexity. At the same time, the addition of more additives can easily cause deformation, cracking and other post-processing defects due to degreasing / sintering shrinkage during the post-processing of the molded parts.

[0004] Patent application number 202310388238.5 discloses a thermally assisted extrusion direct writing molding 3D printing method for continuous fiber reinforced ceramics. This method injects a thermoplastic ceramic ink with a melting temperature of 75°C-90°C into a heatable direct writing molding barrel. The heatable direct writing molding barrel is heated to a specified temperature, and the ceramic ink is supplied to a coaxial extrusion nozzle. The ceramic ink is fully combined with the continuous fiber and then co-extruded into filaments, which are stacked layer by layer to form a continuous fiber reinforced ceramic matrix composite material preform, effectively improving the bonding strength between the fiber and the ceramic. The direct writing molding equipment has a simple structure, low cost, and environmentally friendly. Although the thermoplastic ceramic ink has a low viscosity after high temperature heating, ensuring that the continuous fiber can be fully impregnated, if the ink deposited on the printing plate cannot be cooled in time, its strong fluidity will easily cause the molded body to collapse.

[0005] Patent application number 202410815191.0 discloses a method for preparing degreasing-free photocurable 3D-printed alumina ceramics. This method involves mixing a reactive diluent monomer, a photoinitiator, and one or more silane coupling agents or organosilicon precursors containing photocurable groups, adding a dispersant and alumina ceramic powder to obtain an alumina ceramic slurry. The slurry is then printed into a green body using a photocurable 3D printing device. After drying and sintering, the degreasing-free photocurable 3D-printed alumina ceramics are obtained. This simplifies the degreasing process while maintaining a low viscosity of the slurry and increasing its solid content. However, the preparation of this ceramic ink requires a certain experimental cycle to determine the appropriate amount and ratio of photocurable organic fillers, dispersants, and ceramic powders, which increases time and material costs for actual production applications. Summary of the Invention

[0006] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides a direct writing forming equipment and method for continuous fiber reinforced ceramic matrix composite materials. The equipment and method utilize the principle of ultrasonic dispersion of nanoparticle agglomerates in an extrusion nozzle to efficiently reduce the viscosity of the ceramic slurry and prevent the deposition and blockage of the ceramic slurry at the outlet of the extrusion nozzle. When the ceramic slurry is deposited onto the forming table, the ceramic slurry is solidified by a curing mechanism, so that the ceramic slurry with higher fluidity is deposited on the substrate and then quickly formed, preventing the deposit from collapsing due to insufficient drying.

[0007] To achieve the above objectives, according to one aspect of the present invention, there is provided a direct writing molding equipment for continuous fiber reinforced ceramic matrix composites, characterized in that it includes an XYZ axis motion platform, an extrusion nozzle, an ultrasonic transducer, a screw propeller, a wire feeder, a molding table and a curing mechanism, wherein:

[0008] The vertical extrusion nozzle is installed on the XYZ axis motion platform to drive the extrusion nozzle to move, and an outlet is provided at the bottom of the extrusion nozzle;

[0009] The forming station is arranged corresponding to the outlet of the extrusion nozzle;

[0010] The ultrasonic transducer is mounted on the outer side wall of the extrusion nozzle to drive the extrusion nozzle to vibrate;

[0011] The screw propeller includes a motor and a screw, the screw is located inside the extrusion nozzle and is coaxially arranged with the extrusion nozzle, the motor is mounted on the extrusion nozzle and the output shaft of the motor is connected to the screw, so as to drive the screw to rotate, thereby allowing the screw to shear the ceramic slurry in the extrusion nozzle and extrude the ceramic slurry from the outlet of the extrusion nozzle, and a vertical through hole is provided on the screw so that the continuous fiber fed by the wire feeder passes through the screw and then exits from the outlet of the extrusion nozzle, so that the continuous fiber and the ceramic slurry wrapping the continuous fiber are deposited on the forming table together;

[0012] The curing mechanism is used to cure the ceramic slurry on the forming table, so that the continuous fibers are combined with the ceramic slurry and cured to form a continuous fiber reinforced ceramic matrix composite rough blank.

[0013] Preferably, the forming table includes a forming base plate and a gypsum board placed on the forming base plate.

[0014] Preferably, the ceramic slurry contains a photosensitizer, and the curing mechanism is an ultraviolet LED light source.

[0015] Preferably, the apparatus further comprises a moving platform, on which the curing mechanism is mounted, so as to allow the curing mechanism to follow and adapt to the position of the extrusion nozzle to cure the slurry coming out of the extrusion nozzle.

[0016] According to another aspect of the present invention, there is also provided a method for forming a continuous fiber reinforced ceramic matrix composite material, characterized in that it comprises the following steps:

[0017] 1) The end of the continuous fiber is fed by the wire feeder and passes through the screw and enters the outlet of the extrusion nozzle;

[0018] 2) The wire feeder stops feeding continuous fiber;

[0019] 3) Start the ultrasonic transducer on the extrusion nozzle to make the extrusion nozzle vibrate;

[0020] 4) Pre-prepared ceramic slurry is injected into the extrusion nozzle. While the screw of the screw propeller rotates, the wire feeder continues to feed the continuous fiber. The ceramic slurry wrapped around the continuous fiber is extruded from the outlet of the extrusion nozzle and deposited on the forming table.

[0021] 5) While the XYZ-axis motion platform drives the extrusion nozzle to move along a pre-planned path, the curing mechanism solidifies the ceramic slurry on the forming table, allowing the ceramic slurry to be deposited and solidified layer by layer on the forming table. In this way, the continuous fiber and the ceramic slurry are combined and solidified to form a continuous fiber reinforced ceramic matrix composite rough blank.

[0022] Preferably, in step 1), the lower end surface of the end of the continuous fiber is flush with the bottom end of the outlet of the extrusion nozzle.

[0023] Preferably, in step 4), the ceramic slurry comprises the following raw materials in parts by mass:

[0024] 100 parts of nano-alumina ceramic powder;

[0025] 25 to 33 parts of solvent;

[0026] 18.8 to 21 parts of photosensitive resin;

[0027] 1.9 to 2.2 parts of photoinitiator;

[0028] The solvent is deionized water or an oily organic solvent.

[0029] Preferably, the photosensitive resin comprises polyurethane acrylate, tripropylene glycol diacrylate and 1,6-hexanediol diacrylate;

[0030] or,

[0031] The photosensitive resin includes polyacrylate, 1,6-hexanediol diacrylate and trimethylolpropane trimethacrylate.

[0032] Preferably, the photoinitiator is ethyl 4-dimethylaminobenzoate.

[0033] Preferably, the photoinitiator comprises camphorquinone and ethyl 4-dimethylaminobenzoate.

[0034] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0035] 1) The direct writing forming equipment of a continuous fiber reinforced ceramic matrix composite material of the present invention realizes efficient compounding and forming of continuous fiber and ceramic slurry by combining key components such as an XYZ axis motion platform, an extrusion nozzle, a screw propeller, a wire feeder, a forming table and a curing mechanism. The XYZ axis motion platform provides the extrusion nozzle with precise spatial motion trajectory control capability, and can move according to a pre-set complex path, thereby meeting the forming requirements of continuous fiber reinforced ceramic matrix composite materials of different shapes and structures, which greatly expands the application range and flexibility of the device. The screw propeller arranged inside the extrusion nozzle is driven by a motor, which can not only reduce the viscosity of the ceramic slurry through the shearing action of the screw to prevent blockage, but also can smoothly extrude the ceramic slurry. At the same time, the vertical through hole on the screw allows the continuous fiber sent out by the wire feeder to pass through the screw and be fully wrapped by the ceramic slurry in the extrusion nozzle, ultimately forming a continuous fiber reinforced ceramic matrix composite material rough blank in which the reinforcement phase and the matrix phase are tightly combined.

[0036] 2) In view of the problem that high-solid-content ceramic slurry in the existing direct writing molding technology is easy to clog the extrusion nozzle, the direct writing molding equipment of a continuous fiber reinforced ceramic-based composite material of the present invention adopts an extrusion nozzle, which utilizes the vibration effect of ultrasound to efficiently disperse the nanoparticle agglomerates in the ceramic slurry. This dispersion effect not only reduces the viscosity of the ceramic slurry, making it smoother during the extrusion process and avoiding the risk of clogging the extrusion nozzle, but also reduces the dependence on additives such as dispersants, thereby simplifying the preparation process of the ceramic slurry and reducing production costs. Moreover, when the ceramic slurry is deposited on the molding table, the curing mechanism promptly performs a curing treatment on it, so that the ceramic slurry with greater fluidity can be quickly formed, effectively preventing the problem of sediment collapse caused by insufficient drying, and ensuring the integrity and quality stability of the continuous fiber reinforced ceramic-based composite material.

[0037] 3) The present invention relates to a direct-write molding device for continuous fiber-reinforced ceramic-based composite materials. The continuous fibers are accurately introduced into the ceramic slurry by a wire feeder, and a continuous reinforcement phase is formed under the wrapping of the ceramic slurry. This helps to fully utilize the fiber reinforcement effect and improve the composite material's key performance indicators, such as strength, toughness, and crack propagation resistance. At the same time, the coordinated work of the curing mechanism allows the ceramic slurry to be deposited layer by layer on the forming table and rapidly cured, greatly shortening the molding cycle and achieving rapid manufacturing of continuous fiber-reinforced ceramic-based composite materials. This meets the demand for efficient manufacturing technology in modern industrial production and is particularly suitable for customized production requirements for high-performance, complex-structure composite materials in fields such as aerospace, energy, and biomedicine.

[0038] In summary, the direct writing molding equipment for continuous fiber reinforced ceramic matrix composite materials of the present invention, through the organic synergy of various components, on the basis of solving the defects of the existing technology, provides an efficient, stable and low-cost innovative solution for the molding of continuous fiber reinforced ceramic matrix composite materials, which helps to promote the development and application of high-performance continuous fiber reinforced ceramic matrix composite material manufacturing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the present invention;

[0040] Figure 2 Schematic diagram of continuous fiber passing through the screw and extrusion nozzle;

[0041] Figure 3 Flowchart of the molding method of the present invention.

[0042] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0043] 1. Extrusion nozzle; 2. Gypsum board; 3. Forming substrate; 4. Curing mechanism; 5. Moving platform; 6. Z-axis motion slide; 7. Motion slide bracket; 8. Y-axis motion slide; 9. Forming table; 10. X-axis motion slide; 11. Ultrasonic transducer; 12. Outer wall of the extrusion nozzle; 13. Through hole; 14. Slurry dispersion chamber; 15. Continuous fiber; 16. Continuous fiber reinforced ceramic matrix composite rough blank; 17. Screw. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0045] Reference Figure 1 、 Figure 2 A direct writing molding device for continuous fiber reinforced ceramic matrix composite materials includes an XYZ axis motion platform, an extrusion nozzle 1, an ultrasonic transducer 11, a screw propeller, a wire feeder (not shown in the figure), a molding table 9 and a curing mechanism 4, wherein:

[0046] The vertical extrusion nozzle 1 is mounted on the XYZ axis motion platform to drive the movement of the extrusion nozzle 1. An outlet is provided at the bottom of the extrusion nozzle 1. The XYZ axis motion platform includes an X-axis motion slide 10, a Y-axis motion slide 8, a Z-axis motion slide 6, and a motion slide bracket 7. The motion slide bracket 7 is fixed to support the Y-axis motion slide 8. The extrusion nozzle 1 can be lifted and lowered perpendicular to the forming table 9 with the assistance of the Z-axis motion slide 6 along the Z axis (perpendicular to the table surface of the forming table 9). The extrusion nozzle 1 can be assisted by the movement of the Z-axis motion slide 6 along the X-axis motion slide 10 to achieve X-axis motion parallel to the substrate direction. The extrusion nozzle 1 can be assisted by the movement of the Y-axis motion slide 8 along the Y axis to achieve Y-axis motion parallel to the substrate direction, thereby achieving movement along the X, Y, and Z axes.

[0047] The forming station 9 is arranged corresponding to the outlet of the extrusion nozzle 1 .

[0048] The ultrasonic transducer 11 is mounted on the outer side wall 12 of the extrusion nozzle 1 to drive the extrusion nozzle 1 to vibrate.

[0049] The screw propeller includes a motor and a screw 17. The screw 17 is located within the extrusion nozzle 1 and is coaxially arranged with the extrusion nozzle 1. The motor is mounted on the extrusion nozzle 1, and the motor's output shaft is connected to the screw 17, which is used to drive the screw 17 to rotate, thereby allowing the screw 17 to shear the ceramic slurry within the extrusion nozzle 1 and extrude the ceramic slurry from the outlet of the extrusion nozzle 1. The screw 17 is provided with a vertical through-hole 13, so that the continuous fiber 15 fed by the wire feeder passes through the screw 17 and then exits the outlet of the extrusion nozzle 1, thereby allowing the continuous fiber 15 coated with ceramic slurry to be deposited on the forming table 9. The motor can drive the screw 17 to rotate via a transmission mechanism. The position of the motor and transmission mechanism does not affect the continuous fiber 15 entering the through-hole of the screw 17. The continuous fiber 15 and the ceramic slurry are both fed from top to bottom, entering the screw 17 and the extrusion nozzle 1, respectively.

[0050] The curing mechanism 4 is used to cure the ceramic slurry on the forming table 9 , thereby combining the continuous fibers 15 with the ceramic slurry and curing the continuous fiber reinforced ceramic matrix composite rough blank 16 .

[0051] The space between the outer wall 12 of the extrusion nozzle and the screw 17 forms a slurry dispersion chamber 14, which is filled with the ceramic slurry to be used to wrap and impregnate the continuous fibers 15. The rotatable screw 17, with composite rectangular threads distributed on its outer wall in contact with the slurry dispersion chamber 14, continues to rotate during the extrusion of the ceramic slurry from the extrusion nozzle 1, shearing and extruding the slurry. The ultrasonic transducer 11 converts electrical energy into mechanical vibrations, which act on the ceramic slurry in the slurry dispersion chamber 14 through the outer wall 12 of the extrusion nozzle, dispersing any deposited and agglomerated ceramic particle aggregates.

[0052] The continuous fiber 15 is transported by the wire feeder through the through hole 13 of the screw 17 and enters the lower half of the slurry dispersion chamber 14 to achieve wrapping and impregnation of the continuous fiber 15 with the ceramic slurry. Finally, it is extruded from the extrusion nozzle 1 and deposited on the forming table 9 as a continuous fiber reinforced ceramic matrix composite rough blank 16.

[0053] Furthermore, the forming table 9 includes a forming substrate 3 and a gypsum board 2 placed on the forming substrate 3 .

[0054] The use of gypsum board 2 significantly improves the drying and curing effects during the molding process. After the ceramic slurry is extruded and deposited onto the molding table 9, the gypsum board 2 has excellent water absorption and can quickly absorb moisture and other solvent components in the ceramic slurry, thereby accelerating the slurry drying process. This not only shortens the molding cycle and improves production efficiency, but also effectively prevents quality problems such as collapse and deformation of the deposit caused by uneven solvent evaporation by timely removing moisture, thereby ensuring the dimensional accuracy and surface quality of the molded part.

[0055] Furthermore, the ceramic slurry contains a photosensitizer, and the curing mechanism 4 is a UV LED light source. The power density of the UV LED light source is preferably 30 mW / cm 2 .

[0056] The application of photocuring technology has greatly improved the molding efficiency. Compared with traditional thermal curing or other physical drying methods, the ultraviolet LED light source can cause the ceramic slurry containing photosensitizer to undergo a curing reaction in a very short time. After the ceramic slurry is extruded and deposited onto the molding table 9, the ultraviolet LED light source immediately irradiates the slurry according to a pre-set path. Under the excitation of ultraviolet light, the photosensitizer triggers the photosensitive components such as the resin in the ceramic slurry to undergo a cross-linking polymerization reaction, quickly converting the slurry with high fluidity into a solid state, so that each layer of deposited material can be quickly shaped and tightly combined with the previous layer. This efficient curing speed allows the entire molding process to be carried out continuously and stably, greatly shortening the manufacturing cycle of the composite material and meeting the high efficiency requirements of industrial production.

[0057] Secondly, photocuring technology can significantly improve the molding quality. Since the curing process is carried out under the precise irradiation of ultraviolet light, each layer of ceramic slurry can be precisely cured, effectively avoiding defects caused by insufficient or excessive curing. Precise curing control ensures good bonding strength between the layers of the molded part, reduces the risk of interlayer delamination, and improves the overall performance of the composite material. At the same time, during the photocuring process, the penetration depth and energy distribution of ultraviolet light can be optimized and adjusted to adapt to ceramic slurries of different formulations and deposition layers of different thicknesses, thereby ensuring the consistency and reliability of the curing effect, further improving the dimensional accuracy and surface finish of the continuous fiber 15 reinforced continuous fiber reinforced ceramic matrix composite rough blank 16, and reducing the workload of subsequent processing.

[0058] Furthermore, the apparatus further includes a mobile platform 5 on which the curing mechanism 4 is mounted, allowing the curing mechanism 4 to follow and adapt to the position of the extrusion nozzle 1 to solidify the ceramic slurry exiting the extrusion nozzle 1. Preferably, there are two curing mechanisms 4, with a forming table 9 located between the two curing mechanisms 4. Each curing mechanism 4 can move parallel to the Y-axis on the mobile platform 5, thereby solidifying the ceramic slurry deposited on the forming table 9 in real time. When the XYZ-axis motion platform drives the extrusion nozzle 1 to move along the X-axis or Z-axis, the curing mechanism 4 can remain stationary.

[0059] By setting up the mobile platform 5, the curing mechanism 4 can follow the motion trajectory of the extrusion nozzle 1 and adjust its own position in real time, accurately aligning with the ceramic slurry extruded from the extrusion nozzle and just deposited on the forming table 9. This closely following curing method ensures that each part of the ceramic slurry can be effectively cured immediately after being deposited, avoiding the problem of slurry flow, deformation or inconsistent curing degree with other parts due to delayed curing. The existence of the mobile platform 5 means that the curing mechanism 4 is no longer fixed to a certain position, but can be flexibly adjusted according to the specific requirements of the molding task and the planned path of the extrusion nozzle 1. For molding operations with different sizes, shapes and path requirements, the mobile platform 5 can quickly and accurately position the curing mechanism 4 to the appropriate position to achieve efficient curing. In addition, the coordinated control of the mobile platform 5 and the extrusion nozzle 1 also helps to improve production efficiency. During the molding process, the extrusion nozzle 1 and the curing mechanism 4 can achieve seamless synchronous operation under the command of the integrated control system. When the extrusion nozzle completes the deposition of a portion of the slurry, the curing mechanism 4 can quickly take position and begin curing.

[0060] The present invention is based on the principle of direct writing molding, and uses light curing to assist the drying and curing process of the deposited material on the deposition substrate after direct writing, which is beneficial to avoid deformation or even collapse of the deposited material, ensuring the flexible structural design of the molded part and the fast molding process without losing good molding quality.

[0061] The present invention allows the use of ceramic slurry with a high solid content, directly improving the density of the sediment (continuous fiber reinforced ceramic matrix composite rough blank 16), and indirectly improving the matrix density and comprehensive mechanical properties of the continuous fiber reinforced ceramic matrix composite rough blank 16.

[0062] The present invention can use nano-scale ceramic particles that are easy to sinter subsequently to prepare slurry, and does not require the addition of additional dispersants to assist in the dispersion and stabilization of the ceramic particles. For actual production, it shortens the research and experimental cycle of ceramic slurry preparation, simplifies the process flow, and also improves the matrix density of the continuous fiber reinforced ceramic matrix composite rough blank 16 after sintering.

[0063] The present invention uses ultrasonic principles to avoid mutual attraction and agglomeration of nano-scale particles due to van der Waals forces and electrostatic adsorption forces, and can effectively prevent the slurry from being unable to fully impregnate the fiber bundles due to agglomeration and deposition, as well as the slurry from being deposited and blocked at the extrusion nozzle. The continuous fiber-reinforced ceramic matrix composite rough blank 16 is efficiently formed with a smooth extrusion process, good consistency of deposition shape, and sufficient bonding between the fiber and the matrix.

[0064] The present invention can effectively reduce the addition of organic dispersants and organic / inorganic solvents, making the continuous fiber reinforced ceramic matrix composite material less likely to deform or crack due to shrinkage during subsequent drying, sintering and other heat treatment densification processes, thereby indirectly improving the mechanical properties of the continuous fiber reinforced ceramic matrix composite material rough blank 16.

[0065] Reference Figure 3 According to another aspect of the present invention, there is also provided a method for forming a continuous fiber reinforced ceramic matrix composite material, comprising the following steps:

[0066] 1) The end of the continuous fiber 15 is fed by a wire feeder and passes through the screw 17 before entering the outlet of the extrusion nozzle 1 .

[0067] 2) The wire feeder stops feeding the continuous fiber 15; the continuous fiber 15 is carbon fiber, silicon carbide fiber, aluminum oxide fiber, zirconium dioxide fiber, boron nitride fiber or silicon nitride fiber, and the diameter is preferably 1 mm to 1.5 mm.

[0068] 3) activating the ultrasonic transducer 11 on the extrusion nozzle 1 to vibrate the extrusion nozzle 1;

[0069] 4) The pre-formulated ceramic slurry is injected into the extrusion nozzle 1. While the screw 17 of the screw propeller rotates, the wire feeder continues to feed the continuous fiber 15. The ceramic slurry wrapped around the continuous fiber 15 comes out of the outlet of the extrusion nozzle 1 and is deposited on the forming table 9. It is necessary to ensure the synchronous coordination of the wire feeder and the extrusion nozzle 1, and accurately control the wire feeding speed of the continuous fiber 15 to match the extrusion speed of the ceramic slurry, so as to ensure that the continuous fiber 15 can pass through the screw propeller evenly and be fully wrapped by the ceramic slurry.

[0070] 5) While the XYZ-axis motion platform drives the extrusion nozzle 1 to move along a pre-planned path, the curing mechanism 4 cures the ceramic fibers, thereby allowing the ceramic slurry to be deposited and cured layer by layer on the forming table 9. In this way, the continuous fibers 15 are combined with the ceramic slurry and cured to form a continuous fiber-reinforced ceramic matrix composite rough blank 16.

[0071] After the deposition is completed, the XYZ axis motion platform, the screw propeller, the wire feeder and the curing mechanism 4 are turned off.

[0072] The molding method starts with the initial delivery of the continuous fiber 15 and the vibration preparation of the extrusion nozzle 1, which lays a good foundation for the subsequent molding process. In step 1), the end of the continuous fiber 15 is accurately introduced into the outlet of the extrusion nozzle 1, so as to achieve precise docking of the continuous fiber 15 with the ceramic slurry extrusion path. This step ensures that in the subsequent injection of the ceramic slurry and the delivery of the continuous fiber 15, the continuous fiber 15 can smoothly enter the extrusion nozzle and be fully mixed with the ceramic slurry, thereby avoiding the problem of blockage or misalignment of the continuous fiber 15 at the entrance. At the same time, the ultrasonic transducer 11 is started in advance to make the extrusion nozzle enter a vibrating state, which creates conditions for the smooth extrusion of the ceramic slurry and the uniform wrapping of the continuous fiber 15, and helps to improve the preparation quality of the material. Steps 2) and 3) of the method are closely connected, so as to achieve efficient compounding of the continuous fiber 15 and the ceramic slurry and layer-by-layer deposition and solidification. In step 2), a pre-formulated ceramic slurry is injected into the extrusion nozzle 1 and combined with the continuous fiber 15. The shearing action of the screw propeller and the vibration action of the extrusion nozzle 1 are used to make the ceramic slurry evenly wrap the continuous fiber 15 to form a stable fiber-reinforced composite material rough billet flow. In this process, ultrasonic vibration not only helps to prevent the ceramic slurry from clogging in the extrusion nozzle 1, but also promotes the infiltration between the slurry and the fiber, and enhances the bonding force between the two. In step 3), the XYZ axis motion platform drives the extrusion nozzle 1 to move according to a pre-planned path, so that the composite material rough billet can be deposited layer by layer on the forming table 9 according to the design requirements. At the same time, the curing mechanism 4 synchronously cures the deposited ceramic fibers, ensuring that each layer of material is quickly shaped after deposition, forming a continuous fiber-reinforced ceramic matrix composite material rough billet with a three-dimensional structure. This method effectively avoids the problems of loose interlayer bonding and low molding efficiency that may occur in traditional molding processes, and improves the overall performance and dimensional accuracy of the molded parts.

[0073] Furthermore, in step 1), the lower end surface of the end of the continuous fiber 15 is flush with the bottom end of the outlet of the extrusion nozzle 1, which ensures precise docking and a smooth transition between the continuous fiber 15 and the ceramic slurry. Before the extrusion nozzle 1 begins to extrude the ceramic slurry, precise control of the position of the end of the continuous fiber 15 ensures that all continuous fibers 15 are in contact with the ceramic slurry and are evenly coated.

[0074] Furthermore, in step 4), the ceramic slurry includes the following raw materials by weight:

[0075] 100 parts of nano-alumina ceramic powder;

[0076] 25 to 33 parts of solvent;

[0077] 18.8 to 21 parts of photosensitive resin;

[0078] 1.9 to 2.2 parts of photoinitiator;

[0079] The solvent is deionized water or an oily organic solvent.

[0080] Nano-scale alumina ceramic powder serves as the main matrix material, with a relatively high content, ensuring the ceramic matrix properties of the composite material, enabling it to withstand high temperatures and possess good hardness and other properties. The addition of solvents allows the ceramic powder and other ingredients to be evenly dispersed and mixed, forming a slurry with a certain fluidity, which facilitates extrusion and flow in the extrusion nozzle. The addition of photosensitive resin gives the ceramic slurry the ability to cure rapidly under light, allowing the slurry extruded onto the forming table to cure and take shape in a short period of time, maintaining the deposited shape and structure. Photoinitiators play a key role in the curing process, initiating the polymerization reaction of the photosensitive resin under ultraviolet light, prompting the ceramic slurry to transform from liquid to solid.

[0081] The ceramic slurry with the above ratio can have appropriate viscosity and fluidity while ensuring a high solid content. It will not clog the extrusion nozzle due to excessive viscosity, nor will it affect the shape stability after deposition due to excessive fluidity. Through the synergistic effect of various components, the molded composite material has good comprehensive properties, such as high strength, hardness and certain toughness, etc., which meet the basic performance requirements of continuous fiber reinforced ceramic matrix composites in different application scenarios. At the same time, this clear formula also provides specific guidance for the preparation of the slurry, which is conducive to the stable production and quality control of the slurry, improves the reliability and repeatability of the molding process, and reduces the risk of molding defects and unstable performance due to fluctuations in the slurry composition.

[0082] Furthermore, the photosensitive resin includes polyurethane acrylate, tripropylene glycol diacrylate and 1,6-hexanediol diacrylate;

[0083] or,

[0084] The photosensitive resin includes polyacrylate, 1,6-hexanediol diacrylate and trimethylolpropane trimethacrylate.

[0085] Polyurethane acrylate has good flexibility and adhesive properties, and can play a role in strengthening the bond between fibers and the ceramic matrix in composite materials, allowing continuous fibers to be better wrapped and fixed by the ceramic matrix, thereby improving the integrity and mechanical properties of the composite material. Tripropylene glycol diacrylate is a common diluent monomer that can reduce the viscosity of the slurry and improve its fluidity. It also participates in the photocuring reaction, helping to increase the curing speed and hardness of the slurry after curing. 1,6-Hexanediol diacrylate can adjust the viscosity and curing properties of the slurry, giving the slurry more suitable rheological properties during extrusion and deposition. It can also participate in the cross-linking reaction, increasing the cross-linking density and thermal stability of the cured material. The polyacrylate in the other group of photosensitive resin components also has good film-forming properties and flexibility. When combined with 1,6-Hexanediol diacrylate and trimethylolpropane trimethacrylate, it can ensure the processability of the slurry while improving the strength and chemical corrosion resistance of the cured material.

[0086] The photoinitiator is ethyl 4-dimethylaminobenzoate (4-DMB), which has high initiation efficiency and good photostability. It rapidly decomposes under ultraviolet light to produce free radicals, initiating polymerization of the photosensitive resin. Its molecular structure contains functional groups capable of absorbing ultraviolet light. Under ultraviolet light of a specific wavelength, it effectively absorbs light energy and converts it into chemical energy, promoting the growth and crosslinking of the photosensitive resin molecular chains, thereby achieving rapid light curing of the ceramic slurry.

[0087] or,

[0088] The photoinitiator includes camphorquinone and ethyl 4-dimethylaminobenzoate. Camphorquinone itself is a commonly used photoinitiator with good initiation efficiency and wide applicability. It can absorb ultraviolet light and initiate polymerization reactions over a wide wavelength range. Combining it with ethyl 4-dimethylaminobenzoate can produce a synergistic effect. This combination absorbs light energy over a wider wavelength range, improving photoinitiation efficiency and ensuring a more complete and uniform curing reaction of the photosensitive resin.

[0089] Example 1

[0090] 1) Prepare an alumina ceramic slurry by thoroughly grinding and mixing 100 g of nano-alumina ceramic powder, 25 g of deionized water, 18.8 g of a photosensitive resin (preferably comprising polyurethane acrylate, tripropylene glycol diacrylate, and 1,6-hexanediol diacrylate, with a mass ratio of polyurethane acrylate: tripropylene glycol diacrylate: 1,6-hexanediol diacrylate = 2:1:1), and 1.9 g of a photoinitiator (the photoinitiator is ethyl 4-dimethylaminobenzoate) for 15 minutes;

[0091] 2) Using 3M Nextel 720 with a diameter of 1.3mm TM Alumina continuous fiber bundle is fed by a wire feeder through the through hole 13 of the screw 17 and into the lower half of the slurry dispersion chamber 14, so that the fiber head is flush with the lower end of the extrusion nozzle 1, the continuous fiber feeding 15 is stopped, and the ultrasonic transducer 11 is started;

[0092] 3) Apply gypsum board on the forming substrate 3 in advance, inject pre-prepared alumina ceramic slurry into the slurry dispersion chamber 14, and turn on the feeding switch of the wire feeder;

[0093] 4) Turning on the motion switch wire feeder of the extrusion nozzle 1 and the switches of the two ultraviolet LED light sources 4 in sequence, so that they are deposited and cured layer by layer on the gypsum board 2 according to the pre-planned path;

[0094] 5) After the deposition is completed, the extrusion nozzle 1, the wire feeder, and the two UV LED light sources 4 are closed in sequence to obtain a solidified continuous alumina fiber reinforced alumina continuous fiber reinforced ceramic matrix composite rough blank.

[0095] Example 2

[0096] 1) 100 g of nano-alumina ceramic powder, 33 g of deionized water, 21 g of a photosensitive resin (preferably comprising polyacrylate, 1,6-hexanediol diacrylate, and trimethylolpropane trimethacrylate, with a mass ratio of polyacrylate:1,6-hexanediol diacrylate:trimethylolpropane trimethacrylate = 5:4:1), and 2.2 g of a photoinitiator (the photoinitiator comprises camphorquinone and ethyl 4-dimethylaminobenzoate, with a mass ratio of camphorquinone:ethyl 4-dimethylaminobenzoate = 4:1) were thoroughly ground and mixed for 12 minutes to prepare an alumina ceramic slurry;

[0097] 2) A 1.5 mm diameter mullite continuous fiber bundle is fed by a wire feeder through the through hole 13 of the screw 17 and into the lower half of the slurry dispersion chamber 14, so that the fiber head is flush with the lower end of the extrusion nozzle 1. The continuous fiber feeding 15 is stopped and the ultrasonic transducer 11 is started;

[0098] 3) Apply the gypsum board 2 on the forming substrate 3 in advance, inject the pre-formulated alumina ceramic slurry into the slurry dispersion chamber 14, and turn on the feeding switch of the continuous fiber 15 wire feeder;

[0099] 4) Turn on the motion switch of the extrusion nozzle 1 and the switches of the two UV LED light sources of the wire feeder in sequence, so that they are deposited and cured layer by layer on the gypsum board according to the pre-planned path;

[0100] 5) After the deposition is completed, the extrusion nozzle 1, the wire feeder, and the two UV LED light sources are sequentially closed to obtain a solidified continuous mullite fiber reinforced alumina continuous fiber reinforced ceramic matrix composite rough blank.

[0101] Example 3

[0102] 1) 100 g of nano-alumina ceramic powder, 30 g of deionized water, 20 g of photosensitive resin (the photosensitive resin preferably includes polyurethane acrylate, tripropylene glycol diacrylate, and 1,6-hexanediol diacrylate, and the mass ratio of polyurethane acrylate: tripropylene glycol diacrylate: 1,6-hexanediol diacrylate is 2:1:1), and 2.02 g of photoinitiator (the photoinitiator includes camphorquinone and ethyl 4-dimethylaminobenzoate, and the mass ratio of camphorquinone: ethyl 4-dimethylaminobenzoate is 4:1) are fully ground and mixed for 15 minutes to prepare an alumina ceramic slurry;

[0103] 2) Using 3M Nextel 610 with a diameter of 1.5mm TM Alumina continuous fiber bundle is fed by a wire feeder through the through hole 13 of the screw 17 and into the lower half of the slurry dispersion chamber 14, so that the fiber head is flush with the lower end of the extrusion nozzle 1, the continuous fiber feeding 15 is stopped, and the ultrasonic transducer 11 is started;

[0104] 3) Apply the gypsum board 2 on the forming substrate 3 in advance, inject the pre-formulated alumina ceramic slurry into the slurry dispersion chamber 14, and turn on the feeding switch of the continuous fiber 15 wire feeder;

[0105] 4) Turn on the motion switch of the extrusion nozzle 1 and the switches of the two UV LED light sources of the wire feeder in sequence, so that they are deposited and cured layer by layer on the gypsum board according to the pre-planned path;

[0106] 5) After the deposition is completed, the extrusion nozzle 1, the wire feeder, and the two UV LED light sources are closed in sequence to obtain a solidified continuous alumina fiber reinforced alumina continuous fiber reinforced ceramic matrix composite rough blank.

[0107] Example 4

[0108] 1) 100 g of nano-alumina ceramic powder, 25 g of solvent (the solvent includes 22 g of deionized water and 3 g of glycerol), 19.5 g of photosensitive resin (the photosensitive resin preferably includes polyacrylate, 1,6-hexanediol diacrylate, and trimethylolpropane trimethacrylate, and the mass ratio of polyacrylate: 1,6-hexanediol diacrylate: trimethylolpropane trimethacrylate is 5:4:1), and 2 g of photoinitiator (the photoinitiator is ethyl 4-dimethylaminobenzoate) are thoroughly ground and mixed for 18 minutes to prepare an alumina ceramic slurry;

[0109] 2) A zirconia (Y2O3-stabilized) continuous fiber bundle with a diameter of 1.2 mm is fed by a wire feeder through the through hole 13 of the screw and into the lower half of the slurry dispersion chamber 14, so that the fiber head is flush with the lower end of the extrusion nozzle 1. The continuous fiber feeding 15 is stopped and the ultrasonic transducer 11 is started;

[0110] 3) Apply the gypsum board 2 on the forming substrate 3 in advance, inject the pre-formulated alumina ceramic slurry into the slurry dispersion chamber 14, and turn on the feeding switch of the continuous fiber 15 wire feeder;

[0111] 4) Turn on the motion switch of the extrusion nozzle 1 and the switches of the two UV LED light sources of the wire feeder in sequence, so that they are deposited and cured layer by layer on the gypsum board according to the pre-planned path;

[0112] 5) After the deposition is completed, the extrusion nozzle 1, the wire feeder, and the two UV LED light sources are sequentially closed to obtain a solidified continuous zirconia fiber reinforced alumina continuous fiber reinforced ceramic matrix composite rough blank.

[0113] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A direct writing molding equipment for continuous fiber reinforced ceramic matrix composite materials, characterized in that: It includes an XYZ axis motion platform, an extrusion nozzle, an ultrasonic transducer, a screw propeller, a wire feeder, a forming table and a curing mechanism, wherein: The vertical extrusion nozzle is installed on the XYZ axis motion platform to drive the extrusion nozzle to move, and an outlet is provided at the bottom of the extrusion nozzle; The forming station is arranged corresponding to the outlet of the extrusion nozzle; The ultrasonic transducer is mounted on the outer side wall of the extrusion nozzle to drive the extrusion nozzle to vibrate; The screw propeller includes a motor and a screw, the screw is located inside the extrusion nozzle and is coaxially arranged with the extrusion nozzle, the motor is mounted on the extrusion nozzle and the output shaft of the motor is connected to the screw, so as to drive the screw to rotate, thereby allowing the screw to shear the ceramic slurry in the extrusion nozzle and extrude the ceramic slurry from the outlet of the extrusion nozzle, and a vertical through hole is provided on the screw so that the continuous fiber fed by the wire feeder passes through the screw and then exits from the outlet of the extrusion nozzle, so that the continuous fiber and the ceramic slurry wrapping the continuous fiber are deposited on the forming table together; The curing mechanism is used to cure the ceramic slurry on the forming table, so that the continuous fibers are combined with the ceramic slurry and cured to form a continuous fiber reinforced ceramic matrix composite rough blank.

2. The direct writing molding equipment for continuous fiber reinforced ceramic matrix composite materials according to claim 1, characterized in that: The forming table includes a forming base plate and a gypsum board placed on the forming base plate.

3. The direct writing molding equipment for continuous fiber reinforced ceramic matrix composite materials according to claim 1, characterized in that: The ceramic slurry contains a photosensitizer, and the curing mechanism is an ultraviolet LED light source.

4. The direct writing molding equipment for continuous fiber reinforced ceramic matrix composite materials according to claim 1, characterized in that: The device further comprises a moving platform on which the solidification mechanism is installed, so as to allow the solidification mechanism to follow and adapt to the position of the extrusion nozzle to solidify the slurry coming out of the extrusion nozzle.

5. A method for forming a continuous fiber reinforced ceramic matrix composite material, characterized in that: The following steps are involved: 1) The end of the continuous fiber is fed by the wire feeder and passes through the screw and enters the outlet of the extrusion nozzle; 2) The wire feeder stops feeding continuous fiber; 3) Start the ultrasonic transducer on the extrusion nozzle to make the extrusion nozzle vibrate; 4) Pre-prepared ceramic slurry is injected into the extrusion nozzle. While the screw of the screw propeller rotates, the wire feeder continues to feed the continuous fiber. The ceramic slurry wrapped around the continuous fiber is extruded from the outlet of the extrusion nozzle and deposited on the forming table. 5) While the XYZ-axis motion platform drives the extrusion nozzle to move along a pre-planned path, the curing mechanism solidifies the ceramic slurry on the forming table, allowing the ceramic slurry to be deposited and solidified layer by layer on the forming table. In this way, the continuous fiber and the ceramic slurry are combined and solidified to form a continuous fiber reinforced ceramic matrix composite rough blank.

6. The method for forming a continuous fiber reinforced ceramic matrix composite material according to claim 5, characterized in that: In step 1), the lower end surface of the end of the continuous fiber is flush with the bottom end of the outlet of the extrusion nozzle.

7. The method for forming a continuous fiber reinforced ceramic matrix composite material according to claim 5, characterized in that: In step 4), the ceramic slurry includes the following raw materials by mass: 100 parts of nano-alumina ceramic powder; 25 to 33 parts of solvent; 18.8 to 21 parts of photosensitive resin; 1.9 to 2.2 parts of photoinitiator; The solvent is deionized water or an oily organic solvent.

8. The method for forming a continuous fiber reinforced ceramic matrix composite material according to claim 7, characterized in that: The photosensitive resin includes polyurethane acrylate, tripropylene glycol diacrylate and 1,6-hexanediol diacrylate; or, The photosensitive resin includes polyacrylate, 1,6-hexanediol diacrylate and trimethylolpropane trimethacrylate.

9. The method for forming a continuous fiber reinforced ceramic matrix composite material according to claim 7, characterized in that: The photoinitiator is ethyl 4-dimethylaminobenzoate.

10. The method for forming a continuous fiber reinforced ceramic matrix composite material according to claim 7, characterized in that: The photoinitiators include camphorquinone and ethyl 4-dimethylaminobenzoate.

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