Cold field 3D printing device and cold field 3D printing method for ceramic nanofiber aerogel

Abstract

The invention relates to a cold field 3D printing device for ceramic nanofiber aerogel and a cold field 3D printing method. The cold field 3D printing device comprises a closable 3D printing rack, an X-Y-Z-axis movement mechanism is arranged on the rack, an ultralow-temperature printing platform is integrated, and the cold field 3D printing device is arranged on the Z-axis movement mechanism, so that ceramic nanofiber ink is instantly frozen and solidified when being extruded from a printing nozzle. The continuous directional ink supply module comprises a screw type ink supply device connected with the X-Y axis movement mechanism and a built-in vortex stirring type material storage assembly, and can unwind nanofibers and form directional flow. The printing nozzle is connected with an outlet of the ink supply module and used for receiving ink and conducting extrusion forming. The laser distance measuring sensor is arranged on the printing nozzle and monitors the height between the nozzle and the ultralow-temperature platform in real time. Compared with the prior art, instant freezing and curing of ink are achieved through the ultralow-temperature printing platform, the continuous directional ink supply module is matched, it is ensured that fiber ink is evenly and stably extruded, and the printing precision and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing technology, and in particular to a cold-field 3D printing device and a cold-field 3D printing method for ceramic nanofiber aerogel. Background Art

[0002] With the advancement and development of science and technology, high-tech fields such as aerospace, medical devices, and energy development are demanding customized topological structures. Traditional manufacturing methods, such as uniform material manufacturing or subtractive manufacturing, achieve specific structures through molds or cutting. However, these methods suffer from low precision and efficiency, and are unable to meet the current demand for precision structures. Furthermore, the inherent brittleness of ceramic materials makes it difficult to achieve complex and delicate structures using traditional manufacturing methods.

[0003] Additive manufacturing technology provides a new way to overcome the above limitations. Among them, 3D printing technology realizes the moldless forming of three-dimensional solid structures through digital modeling. It has outstanding advantages such as short manufacturing cycle and simple manufacturing process. It is especially used for rapid prototyping of complex and special-shaped structural parts. At present, 3D printing molding technology can be divided into two categories. One is the molding based on laser technology, including selective laser sintering (SLS), selective laser melting (SLM), two-photon stereolithography (SLA), etc.; the other is the molding based on non-laser technology, such as fused deposition modeling (FDM), chemical reaction deposition (CRM), mapping-acoustic molding technology (DIP), etc. From the current development point of view, laser technology is gradually being replaced by non-laser technology because it relies on expensive special laser systems and corresponding special photoinitiators. However, existing non-laser technologies simply convert the dependence on photoinitiators or complex chemical composition materials into dependence on thermosensitive / chemical triggers. For example, melt deposition requires the addition of thermoplastic polymers to the printing ink (CN109955480A), chemical reaction deposition relies on chemical reaction gelation and solidification between raw materials (CN114213142A), and mapping-acoustic forming technology uses hydrogel as printing ink to solidify under the action of acoustic waves (Nature 2024,634,1096). The above method has a slow single-layer curing speed, which causes easy fusion between layers, resulting in low printing resolution and poor fidelity. Cold field printing uses the instantaneous freezing crystallization of the liquid in the ink at ultra-low temperature to solidify. It is versatile, universal, and efficient, is not limited by printing materials, and is expected to replace the existing 3D printing curing system.

[0004] Furthermore, existing ink extrusion methods, including pneumatic, screw, plunger, or a combination of the two, can achieve fiber-based ink extrusion through high-pressure, large-aperture nozzles. However, this can easily lead to uneven fiber distribution, reducing printing uniformity and limiting printing accuracy to the centimeter level. Using low-pressure, small-aperture nozzles, however, can prevent uniform and continuous extrusion of fiber-based inks due to the inherent entanglement of fibers, which can lead to nozzle clogging.

[0005] Moreover, existing 3D printing devices lack continuity. After the ink is completely squeezed out, the device needs to be stopped to add ink (CN110787320A) or switched to add ink (CN116423819A), which greatly reduces printing efficiency. In addition, the offset of the position after restarting the device reduces the printing accuracy.

[0006] Therefore, existing 3D printing devices still need to achieve uniform and stable extrusion, high-precision printing, and high-efficiency molding. Specifically, they face the following problems: 1) Traditional light / heat / chemical curing methods have a slow response speed, resulting in excessive interlayer fusion and low feature resolution; 2) Existing storage extrusion devices cannot meet the requirements of uniform, stable, and high-precision extrusion of fiber inks. Summary of the Invention

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a cold field 3D printing device and a cold field 3D printing method for ceramic nanofiber aerogels. The ultra-low temperature printing platform is used to achieve instantaneous freezing and solidification of the ink, and a continuous directional ink supply module is used to ensure uniform and stable extrusion of the fiber ink, thereby improving printing accuracy and efficiency.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A first aspect of the present invention provides a cold-field 3D printing device for ceramic nanofiber aerogels, comprising a sealable 3D printer frame for forming a closed printing environment, wherein the sealable frame is provided with an XYZ-axis motion mechanism, wherein the XYZ-axis motion mechanism includes a Z-axis motion mechanism and an XY-axis motion mechanism, and the cold-field 3D printing device further comprises:

[0010] An ultra-low temperature printing platform is provided on the Z-axis motion mechanism. The ultra-low temperature printing platform is used to control the printing working temperature at -50°C to -5°C, so that the ceramic nanofiber ink extruded from the printing nozzle is instantly frozen and solidified;

[0011] A continuous directional ink supply module, comprising a screw-type ink supply device connected to the XY-axis motion mechanism, and a vortex stirring storage assembly provided in the screw-type ink supply device, wherein the vortex stirring storage assembly is used to disentangle the nanofibers in the ceramic nanofiber ink and form a directional flow;

[0012] A printing nozzle connected to the outlet of the continuous directional ink supply module, used for receiving the directional ceramic nanofiber ink and extruding it into shape;

[0013] The laser ranging sensor is installed on the printing nozzle to monitor the height between the printing nozzle and the ultra-low temperature printing platform in real time, and to provide feedback to the XYZ axis moving mechanism to dynamically compensate for the inter-layer fusion error generated during the printing process.

[0014] Furthermore, the cold field 3D printing device further includes a controller, which is communicatively connected to the laser ranging sensor and the XYZ axis moving mechanism;

[0015] The controller is a single chip microcomputer or a processor of x86 architecture, ARM architecture, or RISC-V architecture.

[0016] Furthermore, the ultra-low temperature printing platform includes a cold plate made of a high thermal conductivity metal material, a semiconductor refrigeration plate arranged on the cold plate, an isolation plate arranged under the cold plate, a temperature probe inserted between the cold plate and the isolation plate and communicatively connected to the controller, and a thermometer electrically connected to the temperature probe. The thermometer is used to monitor the temperature signal of the cold plate in real time, and the controller adjusts the cooling power of the semiconductor refrigeration plate based on the temperature signal.

[0017] Furthermore, the cold field 3D printing device further comprises a constant humidity component provided in the sealable 3D printing frame, wherein the constant humidity component comprises a hygrometer, a small dehumidifier, and an atomizer all fixed inside the frame;

[0018] The controller obtains humidity information output from the hygrometer and controls the operation of a small dehumidifier or atomizer, thereby stabilizing the humidity of the printing environment at 10-30 RH%.

[0019] Furthermore, the screw-type ink supply device includes a screw motor, a screw connected to the screw motor, a pushing platform driven by the screw, a first stopper and a second stopper sequentially arranged along the ink supply direction, and drive motors respectively connected to the controller in communication;

[0020] When the pushing platform triggers the second limiter, the controller instructs the screw to reset and replenish ink through the self-priming pump until the first limiter is triggered and normal ink supply is restored, achieving continuous, uniform and directional ceramic nanofiber ink supply.

[0021] Furthermore, the pushing platform is provided with three through holes, wherein the through holes on both sides are smooth holes, both smooth holes are sleeved on the positioning rod, and the middle through hole is a screw hole, and the screw hole is threadedly connected to the screw rod;

[0022] The screw housing is a cylindrical sealed cavity, the screw housing encapsulates the screw and the pushing platform, and the lower end of the screw housing is fixedly connected to the storage component fixing frame, the clamping inner diameter of the storage component fixing frame is adjustable, and the storage component fixing frame is used to clamp the vortex stirring type storage component;

[0023] The lower surface of the pushing platform can abut against the upper end of the stirring motor body of the vortex stirring storage assembly to convert the rotational motion of the screw into a linear propulsion force on the storage assembly, thereby achieving quantitative extrusion of the ceramic nanofiber ink;

[0024] The side wall of the screw housing is fixedly connected to the motion connection block, and the motion connection block is fixed on the Y-axis ball screw nut in the XY-axis motion mechanism, thereby driving the screw-type ink supply device to move in the XY plane.

[0025] Furthermore, the vortex stirring storage assembly includes a storage cavity tube, a stirring motor, an I-shaped push rod, and a wedge-shaped discharge port;

[0026] The outer edge of the lower push plate of the I-shaped push rod is covered with a rubber ring and is in sealing and sliding cooperation with the inner wall of the storage cavity tube. The wedge-shaped discharge port is a conical structure with a pointed bottom and a thick top and a smooth inner wall. The outlet end of the wedge-shaped discharge port is connected to the printing nozzle. A second solenoid valve is provided at the wedge-shaped discharge port.

[0027] A feed port is provided on the lower push plate of the I-shaped push rod, and the feed port is connected to an external barrel through a pipeline, and the external barrel is filled with ceramic nanofiber ink;

[0028] A first electromagnetic valve is provided at the feed inlet.

[0029] Furthermore, the bottom surface of the cold plate is provided with rectangular unit mounting positions arranged in an array, and a semiconductor refrigeration plate is embedded in each rectangular unit mounting position;

[0030] The isolation plate is made of low thermal conductivity plastic. The four corners of the isolation plate are fixed to the ball nuts of the Z-axis motion mechanism. The upper surface of the isolation plate is provided with mounting grooves corresponding to the semiconductor cooling fins. The mounting grooves are embedded with water-cooled radiators. The heat-conducting metal base of the water-cooled radiator is tightly fitted with the hot end surface of the semiconductor cooling fin.

[0031] The cold end of the semiconductor refrigeration plate is in contact with the lower surface of the cold plate, and the hot end is in contact with the water-cooled radiator on the isolation plate. The water-cooled radiator forms a closed-loop water circuit with the water cooling circulation system through the water inlet and the water outlet. The thermometer arranged in series in the closed-loop water circuit feeds back the cold plate temperature to the controller in real time. The controller adjusts the power supply to the semiconductor refrigeration plate to achieve refrigeration temperature regulation.

[0032] A second aspect of the present invention provides a cold-field 3D printing method for ceramic nanofiber aerogel using the cold-field 3D printing device described above, comprising the following steps:

[0033] Obtaining a three-dimensional model to be printed and slicing it to obtain a sliced ​​model, and importing the sliced ​​model into the controller;

[0034] Setting printing parameters on the cold field 3D printing device, including printing speed, ink supply speed, cold plate temperature, and ambient humidity;

[0035] The ceramic nanofiber ink is loaded into the external barrel, and the self-priming pump is started and the first solenoid valve is opened through the controller command to fill the ink from the external barrel into the vortex stirring storage assembly;

[0036] The printing program is started, and the printing process is controlled by the controller so that the printing nozzle prints layer by layer on the ultra-low temperature printing platform based on the slice model. The height between the printing nozzle and the ultra-low temperature printing platform is monitored in real time using a laser ranging sensor and the error is dynamically compensated to form a ceramic nanofiber / ice crystal complex.

[0037] Furthermore, when the pushing platform of the screw-type ink supply device reaches the second limiter, the second limiter feeds back a signal to the controller, and the controller controls the screw motor to drive the screw, so that the pushing platform is reset;

[0038] While pushing the platform to reset, the controller opens the first solenoid valve and closes the second solenoid valve, and simultaneously starts the self-priming pump and replenishes the printing ink from the barrel into the storage assembly through the self-priming conduit;

[0039] When the pushing platform triggers the first limiter, the controller controls the screw motor to drive the screw to reset the pushing platform and stop, and then starts to advance;

[0040] While pushing the platform forward, the controller closes the first solenoid valve and opens the second solenoid valve, thereby achieving continuous supply of printing ink to the printing nozzle and uniform and stable ink discharge.

[0041] The present invention provides a cold-field 3D printing device and method for ceramic nanofiber aerogels, which have outstanding technical advantages:

[0042] First, the ultra-low-temperature printing platform utilizes a highly thermally conductive metal cold plate and semiconductor refrigeration chips, dissipating heat through a water-cooled circulation system. This provides rapid cooling and precise temperature control. During printing, ceramic nanofiber ink is extruded from the nozzle and contacts the ultra-low-temperature platform surface, freezing and solidifying in an extremely short period of time. Compared to traditional light, heat, or chemical curing methods, this cold-field curing significantly reduces the problem of excessive interlayer fusion, effectively improving print resolution and fidelity.

[0043] Secondly, the continuous directional ink supply module utilizes a screw-type ink supply device and an integrated vortex stirring reservoir assembly. The screw's rotational motion is converted into a linear propulsion force on the reservoir assembly, while the stirring motor drives the stirring blades to evenly mix the ink. First and second stoppers monitor the ink level. When the ink level falls below a set value, the controller resets the screw and activates the self-priming pump to replenish ink until the first stopper is triggered to resume normal ink supply. This design eliminates the discontinuity of traditional ink supply devices, ensuring a uniform and stable ink supply during printing, thereby achieving high-precision, high-efficiency continuous printing.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] (1) The cold field 3D printing device for precise molding of ceramic nanofiber aerogels provided by this technical solution is provided with an ultra-low temperature platform. By monitoring the temperature and humidity of the printing field, the temperature and humidity of the cold field are automatically adjusted, so that the printing ink is instantly frozen and solidified on the platform without the nozzle freezing, thereby greatly reducing the 3D printing curing time and improving the 3D printing efficiency.

[0046] (2) The cold field 3D printing device for precise molding of ceramic nanofiber aerogels provided by this technical solution is provided with a first and a second limiter. The limiter determines the content of ink in the storage component and automatically controls the opening and closing of the solenoid valve, the screw movement mode and the self-priming pump switch to deliver the ink in the external barrel to the storage component, thereby realizing a continuous supply of ink and achieving continuous 3D printing.

[0047] (3) The cold field 3D printing device for precise molding of ceramic nanofiber aerogels provided by this technical solution is provided with a vortex stirring storage component and connected to a wedge-shaped discharge port. The fiber ink in the storage component is stirred by vortex to achieve directional arrangement of the fibers, and then flows into the printing nozzle from the wedge-shaped discharge port to achieve continuous and uniform ink discharge, thereby avoiding blockage of the printing nozzle and discontinuous and uneven ink discharge caused by fiber entanglement, and improving the accuracy of 3D printing.

[0048] (4) The cold field 3D printing device for precise molding of ceramic nanofiber aerogels provided by this technical solution is equipped with a laser ranging sensor. By monitoring the distance between the needle and the printing plane and adjusting it in real time, it can avoid excessive fusion defects between layers, improve the fidelity of 3D printing, and achieve precise molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 : A schematic structural diagram of a cold field 3D printing device for precise molding of ceramic nanofiber aerogels in an embodiment;

[0050] Figure 2: A schematic structural diagram of a screw-type ink supply device of a cold-field 3D printing device for precise molding of ceramic nanofiber aerogels in an embodiment;

[0051] Figure 3 : A schematic structural diagram of a vortex stirring type material storage assembly of a cold field 3D printing device for precise molding of ceramic nanofiber aerogels in an embodiment;

[0052] Figure 4 : A schematic structural diagram of an external barrel of a cold field 3D printing device for precise molding of ceramic nanofiber aerogels in an embodiment;

[0053] Figure 5 : Schematic diagram of the structure of the ultra-low temperature printing component of a cold field 3D printing device for precise molding of ceramic nanofiber aerogels in an embodiment.

[0054] The numbers in the figure show:

[0055] 1. Enclosed 3D printer frame, 2. Screw ink supply device, 3. Vortex stirring storage assembly, 4. Self-priming pump, 5. External barrel, 6. Print nozzle, 7. Laser ranging sensor, 8. Ultra-low temperature printing platform, 9. Water cooling circulation system, 10. Constant humidity assembly, 2-1. Screw motor, 2-2. Screw, 2-3 Push platform, 2-4 Storage assembly fixing frame, 2-5. Screw housing, 2-6. Motion connection block, 2-7. First limiter, 2-8. Second limiter, 3- 1. Stirring motor, 3-2. I-shaped push rod, 3-3. Feed port, 3-4. Stirring blade, 3-5. Wedge-shaped discharge port, 3-6. First solenoid valve, 3-7. Second solenoid valve, 4-1. Self-priming catheter, 6-1. Print needle, 8-1. Cold plate, 8-2. Isolation plate, 8-3. Thermometer, 8-4. DC power supply, 8-5. Water inlet, 8-6. Water outlet, 8-7. Temperature probe, 9-1. Power supply, 9-2. Cooling fan, 9-3. Bucket, 9-4. Self-priming pump. DETAILED DESCRIPTION

[0056] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, circuit structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0057] Example 1

[0058] like Figures 1 to 5As shown, the embodiment provides a cold field 3D printing device for precise forming of ceramic nanofiber aerogel, which comprises a sealable 3D printer frame 1, an X-Y-Z axis moving mechanism arranged in the sealable 3D printer frame 1, a screw type ink supply device 2 arranged on the X-Y axis moving mechanism, a vortex stirring type storage assembly 3 placed in the screw type ink supply device, a self-suction pump 4 connected with the storage assembly, an external cartridge 5 placed in the self-suction pump, a printing nozzle 6 connected with the storage assembly, a laser ranging sensor 7 connected with the printing nozzle, an ultralow-temperature printing platform 8 arranged on the Z axis moving mechanism, a water-cooling circulation system 9 connected with the ultralow-temperature printing platform, and a constant humidity assembly 10 arranged in the sealable 3D printer frame 1.

[0059] The sealable 3D printer frame 1 comprises a frame crossbeam, a frame column, a frame, a sealed plastic box body, a magnetic switch door, an X-Y-Z axis moving mechanism comprising a plurality of motors, ball screws and lifting rods, which specifically comprises an X axis ball screw, a Y axis ball screw and a Z axis ball screw arranged orthogonally.

[0060] The Z axis ball screw is perpendicular to the four corners in the sealable 3D printer frame 1, as shown in the vertical direction in Figure 1 The ultralow-temperature printing platform is connected with the ball nuts of the four Z axis ball screws, so as to realize the vertical lifting of the ultralow-temperature printing platform.

[0061] The X axis ball screw, the Y axis ball screw and the Z axis ball screw are arranged vertically with respect to each other; in operation, the sealable printer frame 1 is in a closed state through the magnetic switch door, so as to ensure the stability of the internal environment.

[0062] In specific implementation, the frame crossbeam, the frame column and the base in the embodiment can be selected from aluminum alloy, carbon fiber or plastic material, the sealed plastic box body is selected from acrylic plate, and the motor is selected from a servo motor.

[0063] In specific implementation, the X axis ball screw and the Y axis ball screw constitute the X-Y axis moving mechanism. One end of the X axis ball screw is rotatably connected to the frame column through a bearing, and the other end of the X axis ball screw is connected with the output shaft of the first servo motor, and the main body of the first servo motor is connected with the frame column.

[0064] During specific implementation, a first carrier block is fixedly connected to the ball nut of the X-axis ball screw on one side, and the carrier block is provided with a second servo motor. The output shaft of the second servo motor is connected to one end of the Y-axis ball screw, and a second carrier block is fixedly connected to the ball nut on the other side. The second carrier block is connected to a bearing, and the other end of the Y-axis ball screw is connected to the bearing, that is, when the first servo motors on both sides rotate synchronously, the first carrier block and the second carrier block move synchronously, causing the Y-axis ball screw to displace. When the Y-axis ball screw is driven to rotate by the second servo motor, the motion connecting block 2-6 connected to the ball nut on the Y-axis ball screw is displaced, thereby driving the screw-type ink supply device 2 and the vortex stirring storage assembly 3 to displace.

[0065] In a specific implementation, the sealed plastic box body is connected to the rack beam, rack column, and base. In addition, the magnetic switch door is hinged to the rack column and is opened by the magnetic switch door. The sealed plastic box body and the magnetic switch door cooperate to achieve communication or sealing between the internal space and the external space.

[0066] The screw-type ink supply device 2 is fixed on the XY-axis motion mechanism in the enclosed 3D printer frame 1, and includes a positioning rod, a screw motor 2-1, a screw 2-2, a pushing platform 2-3, a storage component fixing frame 2-4, a screw housing 2-5, a motion connecting block 2-6, a first limiter 2-7, and a second limiter 2-8, which is used to programmatically advance the storage component 3 to achieve uniform extrusion of ink.

[0067] In specific implementation, the screw motor 2-1 in this embodiment is a stepper motor, 12V, 3A, which can achieve a push-pull force of 60N; the maximum stroke of the screw 2-2 is 140mm, the speed is 0.01~150mm / min, and the accuracy can reach 0.0003mm; the pushing platform 2-3, the fixing frame 2-4 and the screw housing 2-5 are all made of acrylic material with a thickness of 5cm; the first limiter 2-7 and the second limiter 2-8 are both contact sensors; the storage component fixing frame 2-4 can clamp the storage component barrel with a diameter of 10mm~48mm. The screw housing 2-5 encloses a sealed space, encapsulating the screw 2-2 inside. Figure 3 The diagram in the middle is the internal structure, and the overall schematic diagram after packaging is not shown.

[0068] During specific implementation, the screw motor 2-1 is connected to the screw 2-2; the screw 2-2 passes through the inside of the screw housing 2-5; the pushing platform 2-3 is threadedly connected to the screw 2-2, that is, there are three through holes in the plate structure of the pushing platform 2-3, the holes on both sides are used for the positioning rod to pass through, the holes on both sides are smooth holes, and the middle hole is a screw hole, and the screw 2-2 passes through the screw hole. When the screw 2-2 rotates, the pushing platform 2-3 moves up or down. When moving down, the pushing platform 2-3 can be pressed against the main body of the stirring motor 3-1.

[0069] In a specific implementation, the material storage assembly fixing frame 2-4 is connected to the lowermost end of the screw housing 2-5. A motion connection block 2-6 is fixedly connected to one side of the screw housing 2-5. The motion connection block 2-6 is fixed to the XY axis motion mechanism in the sealable 3D printer frame 1. Specifically, the motion connection block 2-6 is connected to the ball nut on the Y axis ball screw.

[0070] During specific implementation, the first stopper 2-7 is located on a positioning rod above the storage assembly fixing frame 2-4. The distance of the first stopper 2-7 is set according to the maximum height of the clamped storage assembly when it is full, such as 10 cm above the lowest point of the storage assembly fixing frame 2-4, for feedback that the printing ink in the storage assembly is full. The second stopper 2-8 is located on the positioning rod on the storage assembly fixing frame 2-4, 1 cm above the lowest point of the storage assembly fixing frame 2-4, for timely feedback that the printing ink capacity in the storage assembly is too low. The first stopper 2-7 and the second stopper 2-8 are respectively connected to the controller for communication.

[0071] During operation, the enclosed 3D printer frame 1 is in a closed state via a magnetic switch door, providing a stable working environment for the internal components. The XYZ-axis motion mechanism drives the screw-type ink supply device 2 and the vortex stirring storage assembly 3 to move. The X-axis ball screw and the Y-axis ball screw are perpendicular to each other, forming an XY-axis motion mechanism, which can drive the printing nozzle 6 to move in two orthogonal directions (X and Y) on the base plane to achieve precise plane positioning. The Z-axis ball screw is vertically installed at the four corners inside the frame 1, and the ultra-low temperature printing platform 8 is connected to the ball nuts of the four Z-axis ball screws to achieve vertical lifting and meet the requirements of different printing heights. During the printing process, the controller controls the XYZ-axis motion mechanism to move the print nozzle 6 to the specified position according to the set parameters and model data. The screw-type ink supply device 2 evenly squeezes the ceramic nanofiber ink from the storage component 3 and deposits it on the ultra-low temperature printing platform 8 through the print nozzle 6. The temperature of the platform 8 is controlled at -50℃~-5℃, so that the ink is quickly frozen and solidified to form a ceramic nanofiber / ice crystal complex. The laser ranging sensor 7 monitors the height between the print nozzle 6 and the ultra-low temperature printing platform 8 in real time and feeds back to the controller. The controller dynamically compensates for the interlayer fusion error to ensure printing accuracy.

[0072] One end of the X-axis ball screw is rotatably connected to the frame column via a bearing, and the other end is connected to the output shaft of the first servo motor. The main body of the first servo motor is connected to the frame column. The ball nut of the X-axis ball screw on one side is fixedly connected to a first carrier block, which is equipped with a second servo motor. The output shaft of the second servo motor is connected to one end of the Y-axis ball screw. The ball nut on the other side is fixedly connected to a second carrier block, which is connected to a bearing. The other end of the Y-axis ball screw is connected to the bearing. When the first servo motors on both sides rotate synchronously, the first carrier block and the second carrier block move synchronously, causing the Y-axis ball screw to shift. When the Y-axis ball screw is driven to rotate by the second servo motor, the motion connection block 2-6 connected to the ball nut on the Y-axis ball screw shifts, thereby driving the screw-type ink supply device 2 and the vortex stirring storage assembly 3 to move.

[0073] In specific implementation, the storage assembly is a vortex stirring storage assembly 3, which is arranged on the fixing frame 2-4 of the screw type ink supply device 2, and can be specifically fixed by clamping, bolting, or clamping.

[0074] The vortex stirring storage assembly 3 includes a storage cavity tube, a stirring motor 3-1, an I-shaped push rod 3-2, a feed port 3-3, a stirring blade 3-4, and a wedge-shaped discharge port 3-5. The vortex stirring storage assembly 3 is used to evenly stir the printing ink to form a directionally distributed ink, which facilitates continuous and uniform ink discharge.

[0075] In specific implementation, the structure of the wedge-shaped discharge port 3-5 is a structure with a pointed bottom and a rough top, and a multi-plane side. The interior is smooth and has no burrs. The function of the wedge-shaped discharge port 3-5 is to facilitate the directional delivery of fibers to the printing nozzle and avoid fiber accumulation and blockage caused by the right-angle discharge port formed by the storage assembly and the printing nozzle.

[0076] During specific implementation, the storage cavity tube range of the vortex stirring storage assembly 3 in this embodiment can be from 1 to 100 mL. The stirring motor 3-1 uses a DC motor. The I-shaped push rod 3-2 is a plastic rod or a stainless steel rod. The I-shaped push rod 3-2 in the present invention includes a rod body, an upper push plate provided at the upper end of the rod body, and a lower push plate provided at the lower end of the rod body. The stirring blade 3-4 is made of stainless steel and can be fan-type, propulsion-type, spiral-belt-type or folding-blade-paddle-type. The rod body of the I-shaped push rod 3-2 is a hollow tube, which extends upward and is connected to the housing of the stirring motor 3-1. The output end of the stirring motor 3-1 is connected to a connecting rod. The connecting rod is precisely fitted to the inner wall surface of the hollow tube and the gap is sealed by industrial lubricating oil.

[0077] In specific implementation, the stirring motor 3-1 is located above the I-shaped pushing rod 3-2, and the output shaft of the stirring motor 3-1 is in transmission connection with the stirring blade 3-4 through a connecting rod. The I-shaped pushing rod 3-2 is located in the storage cavity tube of the vortex stirring type storage assembly 3, and the outer edge of the lower pushing plate is wrapped with a rubber ring. The upper pushing plate and the lower pushing plate of the I-shaped pushing rod 3-2 are both arranged inside the storage cavity tube, and are tightly attached to the inner wall of the storage cavity tube. See Figure 2 When the stirring motor 3-1 is pressed down, the pressing force is transmitted to the upper pushing plate and the lower pushing plate through the hollow tube, and the lower pushing plate presses down the lower part of the lower pushing plate and the printing material liquid in the storage cavity tube and pushes out from the wedge-shaped discharge port 3-5. The hollow tube enables the stirring motor 3-1 to be pressed down without affecting the rotation of the output shaft, and enables the torsional force to be transmitted to the stirring blade 3-4 through the connecting rod.

[0078] In specific implementation, the wedge-shaped discharge port 3-5 is arranged at the lower part of the storage cavity tube, the first electromagnetic valve 3-6 is mounted on the wedge-shaped discharge port 3-5, and the self-suction guide pipe 4-1 is connected to the wedge-shaped discharge port 3-5. The stirring blade 3-4 is arranged at the lower part of the lower pushing plate of the pushing rod 3-2, the paddle on the stirring blade 3-4 can be designed according to specific needs, and the stirring blade 3-4 is driven to rotate by the stirring motor 3-1.

[0079] The lower pushing plate of the I-shaped pushing rod 3-2 is provided with the feeding port 3-3, the first electromagnetic valve 3-6 is arranged on the feeding port 3-3, and the feeding port 3-3 is used to receive the material liquid from the barrel 5 through the self-suction guide pipe 4-1 and the corresponding self-suction pump 4.

[0080] The wedge-shaped discharge port 3-5 is located at the bottom end of the storage assembly 3 and is provided with the second electromagnetic valve 3-7. In this embodiment, the first electromagnetic valve 3-6 and the second electromagnetic valve 3-7 are both in communication connection with the controller, and the controller controls the first electromagnetic valve 3-6 and the second electromagnetic valve 3-7 based on the signals fed back by the first limit stop 2-7 and the second limit stop 2-8.

[0081] In the cold field 3D printing device of the present invention, the eddy current stirring storage assembly 3 is a key component for achieving uniform ink supply. The storage assembly 3 is installed on the fixed frame 2-4 of the screw-type ink supply device 2 and can be fixed by clamping, bolts or clamps. Component 3 includes a storage cavity tube, a stirring motor 3-1, an I-shaped push rod 3-2, a feed port 3-3, a stirring plate 3-4 and a wedge-shaped discharge port 3-5. During the printing process, the stirring motor 3-1 drives the stirring plate 3-4 to rotate, uniformly stirring the ceramic nanofiber ink in the storage cavity tube to form a directionally distributed ink, ensuring stable ink performance. Driven by the screw-type ink supply device 2, the I-shaped push rod 3-2 pushes the stirred ink toward the wedge-shaped discharge port 3-5 to achieve continuous and uniform ink supply. The wedge-shaped discharge port 3-5 is designed as a multi-plane structure with a pointed bottom and a thick top. The interior is smooth and burr-free, which is conducive to the directional delivery of fiber ink to the printing nozzle 6, effectively avoiding the fiber accumulation and clogging problems easily caused by traditional right-angle discharge ports, and improving the stability and accuracy of printing.

[0082] The storage cavity of the storage component 3 has a measuring range of 1-100mL, which can adapt to the requirements of different printing tasks. The stirring motor 3-1 uses a DC motor, and the I-shaped push rod 3-2 can be made of plastic or stainless steel. Its rod body is a hollow tube, the upper end of which is connected to the stirring motor 3-1 shell, and the outer edge of the lower push plate at the lower end is wrapped with a rubber ring, which fits tightly with the inner wall of the storage cavity to ensure sealing. When the stirring motor 3-1 is subjected to downward pressure, it is transmitted to the upper push plate and lower push plate of the I-shaped push rod 3-2 through the hollow rod. The lower push plate presses down the ink in the storage cavity, forcing the ink to be squeezed out from the wedge-shaped discharge port 3-5. The hollow rod design ensures that the rotation of the output shaft of the stirring motor 3-1 is not affected, and at the same time, the torsional force is transmitted to the stirring plate 3-4 through the connecting rod to realize the stirring function. The feed port 3-3 is arranged on the lower push plate of the I-shaped push rod 3-2, connected to the self-priming conduit 4-1 and the self-priming pump 4, which is used to replenish ink from the barrel 5. A second solenoid valve 3-7 is installed at the wedge-shaped discharge port 3-5, and a first solenoid valve 3-6 is installed at the feed port 3-3. Both are connected to the controller. The controller controls the opening and closing of the solenoid valves based on signals from the first and second limiters 2-7 and 2-8, achieving automatic replenishment and precise control of ink.

[0083] During specific implementation, the solenoid valve is a direct-acting solenoid valve with a response time of 10ms.

[0084] In practice, a self-priming pump 4 is connected to the feed port 3-3 of the ink reservoir 3 via a self-priming conduit 4-1. The pump 4 is housed in a cartridge 5 located outside the sealable 3D printer frame 1 and supplies ink to the ink reservoir. In this embodiment, the pump 4 utilizes a 12V DC unit with a flow rate of 1.2 to 1.5 L / min. The conduit 4-1 is a silicone tube, resistant to acid and alkali corrosion. The cartridge 5 can be located on the left, back, or right side of the sealable 3D printer frame 1 and has a capacity of 5 to 20 L.

[0085] In practice, the print nozzle 6 is connected to the wedge-shaped outlet 3-5 of the ink reservoir 3. The print nozzle 6 includes a standard series of print needles 6-1. In this embodiment, the print needles 6-1 are stainless steel needles, ranging in size from 11G to 30G, with inner diameters ranging from 2.55mm to 0.16mm. Any needle can be selected based on the solid content and viscosity of the ink.

[0086] In practice, a laser distance sensor 7 is positioned in the middle of the print nozzle 6 to measure the distance between the print nozzle and the printing surface. In this embodiment, the laser distance sensor 7 utilizes a Class II laser with an RS232 output, achieving a resolution of up to 1 mm. The laser distance sensor 7 is communicatively connected to the controller.

[0087] During specific implementation, the ultra-low temperature printing platform 8 is arranged on the Z-axis motion mechanism of the 3D printing device 1. The ultra-low temperature printing platform 8 includes a cold plate 8-1, an isolation plate 8-2, a thermometer 8-3, a DC power supply 8-4, a water inlet 8-5, a water outlet 8-6, and a temperature probe 8-7. The ultra-low temperature printing platform 8 is used to accurately control and adjust the temperature of the printing platform.

[0088] In this embodiment, the temperature range of the ultra-low temperature printing platform 8 is -50°C to room temperature, and the cooling speed is 15°C / min; the display resolution of the thermometer 8-3 is 0.01°C, and the DC power supply is 6V and 12V.

[0089] During specific implementation, the isolation plate 8-2 is arranged below the cold plate 8-1, and the four corners of the isolation plate 8-2 are connected to the ball nuts on the Z-axis ball screws in the four Z-axis motion mechanisms. The servo motor in the Z-axis motion mechanism is synchronously driven to realize the Z-direction lifting and lowering of the isolation plate 8-2, that is, the Z-direction lifting and lowering adjustment of the ultra-low temperature printing platform 8.

[0090] In a specific implementation, temperature probe 8-7 of thermometer 8-3 is inserted between cold plate 8-1 and isolation plate 8-2, and thermometer 8-3 is electrically connected to a controller. A DC power supply 8-4 is connected to cold plate 8-1, and DC power supply 8-4 is electrically connected to the controller. The controller controls the output power of DC power supply 8-4 based on a preset temperature program and the temperature signal obtained by thermometer 8-3, thereby achieving cooling control of the semiconductor refrigeration chip. The plug-in side of cold plate 8-1 can be located on the left, right, or rear of cold plate 8-1 to provide power to cold plate 8-1. Isolation plate 8-2 is provided with multiple mounting slots, each of which is equipped with a water-cooled radiator corresponding to a semiconductor refrigeration chip (the water-cooled radiator is based on the same principle as the water-cooled radiator in a PC chassis). The contact surface of the water-cooled radiator contacts the hot end of the semiconductor refrigeration chip. Heat from the hot end of the semiconductor refrigeration chip is transferred through the heat-conducting metal on the water-cooled radiator. The heat from the heat-conducting metal is further transferred to the water-cooling circulation system 9 outside the sealable 3D printer frame 1 through water flow.

[0091] Water inlet 8-5 and outlet 8-6 are both located on isolation plate 8-2. Water pipes are installed within isolation plate 8-2 to connect the radiators in series. These inlet and outlet 8-6 are used to bring in and out water for heat exchange. The cold plate 8-1 consists of a cold plate body made of a highly thermally conductive metal material. The underside of the cold plate body features a plurality of evenly distributed rectangular unit mounting areas. Each pair of units houses a semiconductor cooling chip. A DC power supply 8-4 is connected to the positive and negative terminals of the semiconductor cooling chip. Water inlet 8-5 and outlet 8-6 are both connected to a U-shaped pipe inside isolation plate 8-2.

[0092] In practice, water-cooled radiators corresponding to the semiconductor refrigeration chips are arranged in series, with a water inlet 8-5 and a water outlet 8-6 provided at the beginning and end, respectively. The water inlet 8-5 and the water outlet 8-6 are connected to a water cooling circulation system 9. In this embodiment, cold plate 8-1 is made of a high-thermal-conductivity electronic material, such as one or more of aluminum, aluminum nitride, or silicon nitride. The cold end of each semiconductor refrigeration chip is fixedly attached to the lower surface of cold plate 8-1, and isolation plate 8-2 is made of a low-thermal-conductivity plastic.

[0093] The water cooling system 9 is located on either the left or right side of the printer frame 1 and includes a power supply 9-1, a cooling fan 9-2, a water bucket 9-3, and a water supply pump 9-4, which cools the heat exchange water. In this embodiment, the self-priming pump 4 is a 12V DC unit with a flow rate of 1.2-1.5 L / min. The self-priming conduit 4-1 is a silicone tube that is resistant to acid and alkali corrosion. The barrel 5 can be located on the left, back, or right side of the frame 1.

[0094] The power supply 9-1 is connected to the cooling fan 9-2 and the water supply pump 9-4; the cooling fan 9-2 is placed on one side of the water bucket 9-3; the water supply pump 9-4 is placed in the water bucket 9-3. In this embodiment, the water bucket has a capacity of 5 to 10L.

[0095] The constant humidity component 10 is placed inside the sealable 3D printer frame 1 and includes a hygrometer, a small dehumidifier, an atomizer, and a circulating water tank. It is used to monitor and control the humidity of the printing field. In this embodiment, the hygrometer has an accuracy of 0.1 RH%.

[0096] The hygrometer is placed above the interior of the enclosed 3D printer frame 1. The hygrometer is electrically connected to the controller, and the controller is connected to the small dehumidifier and the atomizer to achieve power control of the small dehumidifier and the atomizer. The small dehumidifier and the atomizer are both connected to the circulating water tank. The small dehumidifier injects the water produced into the circulating water tank. The atomizer can directly use the water in the circulating water tank for humidification and is placed in the middle of the enclosed 3D printer frame 1 to adjust the humidity of the printing environment.

[0097] In the cold field 3D printing device, the ultra-low temperature printing platform 8 is a key component for achieving instantaneous freezing and solidification of the ink. The temperature probe 8-7 of the thermometer 8-3 is inserted between the cold plate 8-1 and the isolation plate 8-2. The thermometer 8-3 is electrically connected to the controller and feeds back the temperature signal to the controller in real time. The DC power supply 8-4 is connected to the cold plate 8-1 and is also electrically connected to the controller. The controller accurately regulates the output power of the DC power supply 8-4 based on the preset temperature program and the temperature signal sent back by the thermometer 8-3, thereby achieving precise control of the cooling effect of the semiconductor refrigeration plate. The plug-in side of the cold plate 8-1 can be flexibly set to the left, right or rear of the cold plate 8-1 according to the actual layout requirements. Isolation plate 8-2 is provided with multiple mounting slots, each housing a water-cooled radiator corresponding to a semiconductor refrigeration chip. The contact surface of the water-cooled radiator closely aligns with the hot end of the semiconductor refrigeration chip. Heat generated by the semiconductor refrigeration chip is transferred through the heat-conducting metal on the water-cooled radiator. Through the action of water flow, the heat is further conducted to the water-cooling circulation system 9 outside the sealable 3D printer frame 1, achieving efficient heat dissipation. Both water inlet 8-5 and water outlet 8-6 are located on isolation plate 8-2. Water pipes within isolation plate 8-2 connect the radiators in series. Water inlet 8-5 is used to introduce heat exchange water, while water outlet 8-6 is used to discharge the heat exchanged water. Cold plate 8-1 is made of a highly thermally conductive metal material. Its bottom surface is equipped with a uniformly distributed array of rectangular unit mounting points. Each pair of unit mounting points houses a semiconductor refrigeration chip. A DC power supply 8-4 is connected to the positive and negative terminals of the semiconductor refrigeration chip to ensure proper operation of the chip. The water inlet 8-5 and the water outlet 8-6 are respectively connected to the U-shaped tube inside the isolation plate 8-2, forming a complete water circuit.

[0098] The water cooling circulation system 9 is installed on the left or right side of the printer frame 1. It primarily consists of a power supply 9-1, a cooling fan 9-2, a water bucket 9-3, and a water supply pump 9-4. It is used to cool the heat exchange water. Power supply 9-1 provides power to both the cooling fan 9-2 and the water supply pump 9-4. The cooling fan 9-2 is placed on one side of the water bucket 9-3 to enhance the heat dissipation of the water within. The water supply pump 9-4 is installed within the water bucket 9-3 and is responsible for transporting the cooled water to the water inlet 8-5 on the isolation plate 8-2. The water bucket 9-3 has a capacity of between 5 and 10 liters, which is sufficient for heat exchange during the printing process. The constant humidity assembly 10 is installed within the sealable 3D printer frame 1 and includes a hygrometer, a small dehumidifier, an atomizer, and a circulating water tank. It is used to monitor and control the humidity of the printing environment in real time. The hygrometer is installed above the interior of the frame 1 and has an accuracy of 0.1 RH%. It is electrically connected to the controller and transmits humidity information to the controller in real time. Based on the hygrometer data, the controller controls the power of the small dehumidifier and atomizer to precisely adjust the humidity in the printing environment. Both the small dehumidifier and atomizer are connected to a circulating water tank. The small dehumidifier discharges absorbed moisture into the circulating water tank, while the atomizer uses the water in the circulating water tank for humidification.

[0099] The controller is respectively connected to the XYZ-axis motion mechanism, the screw-type ink supply device 2, the first limiter 2-7, the second limiter 2-8, the vortex stirring storage component 3, the first solenoid valve 3-6, the second solenoid valve 3-7, the laser ranging sensor 7, the ultra-low temperature printing platform 8, the water cooling circulation system 9, and the constant humidity component 10.

[0100] When the pushing platform 2-3 of the screw-type ink supply device 2 reaches the second stopper 2-8, indicating that the ink in the material storage assembly 3 is at an extremely low level, the second stopper 2-8 reacts and feeds back a signal to the controller, causing the screw 2-2 to quickly reset. At the same time, the first solenoid valve 3-6 opens and the second solenoid valve 3-7 closes, and the self-priming pump 4 starts to replenish the printing ink from the barrel 5 to the material storage assembly 3 through the self-priming conduit 4-1. Until the pushing platform 2-3 triggers the first stopper 2-7, indicating that the ink in the material storage assembly 3 is at full scale, the controller sends a control command again, causing the screw 2-2 to reset and stop, and then start advancing. At the same time, the first solenoid valve 3-6 closes and the second solenoid valve 3-7 opens.

[0101] The screw-type ink supply device 2, the first limiter 2-7, the second limiter 2-8, the vortex stirring storage assembly 3, the first solenoid valve 3-6, the second solenoid valve 3-7 and the barrel 5 constitute a continuous and uniform ink supply mechanism to ensure the continuous supply of printing ink to the printing nozzle and the uniform and stable ink discharge.

[0102] The laser distance sensor 7 monitors the distance between the printing nozzle 6 and the printing surface, and adjusts the height of the nozzle 6 based on feedback, thereby accurately adjusting the printing height of each printing surface.

[0103] The laser distance sensor 7 and the XYZ axis motion mechanism form a precise distance control mechanism to ensure the uniformity and accuracy of each layer of printing, and improve the printing fidelity and precision of the final product.

[0104] According to the set freezing printing temperature, the DC power supply 8-4 and the water cooling power supply 9-1 are turned on, and the water supply pump 9-4 draws water from the water bucket 9-3 and transmits it to the isolation plate 8-2. Through water circulation, cooling fan and electric refrigeration, the temperature of the refrigeration plate 8-1 is reduced to the required temperature. During the printing process, the thermometer 8-3 monitors in real time and adjusts the temperature of the cold plate 8-1 by controlling the DC current 8-4 and the water volume in the inlet and outlet 8-5 and 8-6.

[0105] The ultra-low temperature printing platform 8, the temperature measuring instrument 8-3, and the water cooling circulation system 9 constitute a cold field mechanism to ensure the timeliness of freezing and solidification.

[0106] The controller controls the ink supply speed, printing speed, print height, and curing speed according to the set printing parameters and input model parameters. The ink supply speed is greater than the printing speed to ensure printing continuity, while the printing speed is less than the ratio of the printed circumference to the curing speed to ensure printing accuracy. The print height is consistent with the printed model. This printing platform design, combined with the continuous and uniform ink supply mechanism, precise distance control mechanism, and cooling structure, can achieve uniform, stable, continuous, and efficient 3D printing of fibers, improving the fidelity and accuracy of 3D printing. The controller includes a single-chip microcomputer or a processor with an x86 architecture, a RISC-V architecture, or an ARM architecture.

[0107] The cold-field 3D printing device for precise molding of ceramic nanofiber aerogels in this embodiment is used for the three-dimensional construction of ceramic nanofibers, including the following steps: slicing the three-dimensional model to be printed to obtain a sliced ​​model, and importing the model into the 3D printer; setting printing parameters, screw propulsion parameters, cold plate parameters, humidity parameters, installing the storage component, and adjusting the limiter position; loading the printed ceramic nanofiber ink into the vortex stirring storage component and the external barrel; starting the 3D printing program to obtain ceramic nanofiber / ice crystal complex special-shaped parts; and then performing vacuum drying and calcination to obtain high-precision, complex-structured ceramic nanofiber aerogels. Among them, the printing speed is 1 to 100 mm / s, the screw advancement speed is 0.01 to 30 mL / h, the screw reset speed is 30 to 99 mL / h, the vortex stirring speed is 10 to 1000 rpm, the printing nozzle is from 11G to 30G (corresponding to the inner diameter from 2.55 mm to 0.16 mm), the cold plate temperature is -50°C to -5°C, and the humidity is 10 to 30 RH%. The vacuum degree of vacuum drying is -0.1 MPa and the drying time is 24 to 48 hours. Subsequently, the temperature is kept at 200 to 800°C in an aerobic environment for 0.5 to 2 hours.

[0108] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A cold field 3D printing device for ceramic nanofiber aerogels, comprising a sealable 3D printer frame (1) for forming a closed printing environment, wherein the sealable frame (1) is provided with an XYZ axis motion mechanism, wherein the XYZ axis motion mechanism includes a Z axis motion mechanism and an XY axis motion mechanism, and wherein: The cold field 3D printing device further comprises: An ultra-low temperature printing platform (8) is provided on the Z-axis motion mechanism, and the ultra-low temperature printing platform (8) is used to control the printing working temperature at -50°C to -5°C, so that the ceramic nanofiber ink extruded from the printing nozzle (6) is instantly frozen and solidified; A continuous directional ink supply module comprises a screw-type ink supply device (2) connected to the XY-axis motion mechanism, and a vortex stirring type material storage component (3) arranged in the screw-type ink supply device (2), wherein the vortex stirring type material storage component (3) is used to disentangle nanofibers in the ceramic nanofiber ink and form a directional flow; A printing nozzle (6), connected to the outlet of the continuous directional ink supply module, for receiving the directional ceramic nanofiber ink and extruding it into shape; A laser distance sensor (7) is provided on the printing nozzle (6) for real-time monitoring of the height between the printing nozzle (6) and the ultra-low temperature printing platform (8), and for providing feedback to the XYZ axis moving mechanism to dynamically compensate for interlayer fusion errors generated during the printing process.

2. A cold field 3D printing device for ceramic nanofiber aerogel according to claim 1, characterized in that: The cold field 3D printing device further comprises a controller, wherein the controller is communicatively connected with the laser distance sensor (7) and the XYZ axis moving mechanism; The controller is a single chip microcomputer or a processor of x86 architecture, ARM architecture, or RISC-V architecture.

3. A cold field 3D printing device for ceramic nanofiber aerogel according to claim 2, characterized in that: The ultra-low temperature printing platform (8) includes a cold plate (8-1) made of a high thermal conductivity metal material, a semiconductor refrigeration plate arranged on the cold plate (8-1), an isolation plate (8-2) arranged below the cold plate (8-1), a temperature probe (8-7) inserted between the cold plate (8-1) and the isolation plate (8-2) and communicatively connected to the controller, and a thermometer (8-3) electrically connected to the temperature probe (8-7), wherein the thermometer (8-3) is used to monitor the temperature signal of the cold plate (8-1) in real time, and the controller adjusts the cooling power of the semiconductor refrigeration plate based on the temperature signal.

4. A cold field 3D printing device for ceramic nanofiber aerogel according to claim 2, characterized in that: The cold field 3D printing device further comprises a constant humidity component (10) arranged in the sealable 3D printing frame (1), wherein the constant humidity component (10) comprises a hygrometer, a small dehumidifier, and an atomizer, all of which are fixed inside the frame (1); The controller obtains humidity information output from the hygrometer and controls the operation of a small dehumidifier or atomizer, thereby stabilizing the humidity of the printing environment at 10-30 RH%.

5. The cold field 3D printing device for ceramic nanofiber aerogel according to claim 2, characterized in that: The screw-type ink supply device (2) comprises a screw motor (2-1), a screw (2-2) connected to the screw motor (2-1), a pushing platform (2-3) driven by the screw (2-2), a first stopper (2-7) and a second stopper (2-8) arranged in sequence along the ink supply direction, and drive motors respectively connected to the controller for communication; When the pushing platform (2-3) triggers the second limiter (2-8), the controller instructs the screw (2-2) to reset and replenish ink through the self-priming pump (4) until the first limiter (2-7) is triggered and normal ink supply is restored, thereby achieving continuous, uniform and directional ceramic nanofiber ink supply.

6. The cold field 3D printing device for ceramic nanofiber aerogel according to claim 5, characterized in that: The pushing platform (2-3) is provided with three through holes, wherein the through holes on both sides are smooth holes, both smooth holes are sleeved on the positioning rod, and the middle through hole is a screw hole, and the screw hole is threadedly connected to the screw rod (2-2); The screw housing (2-5) is a cylindrical sealed cavity, the screw housing (2-5) encapsulates the screw (2-2) and the pushing platform (2-3), and the lower end of the screw housing (2-5) is fixedly connected to the material storage component fixing frame (2-4), the clamping inner diameter of the material storage component fixing frame (2-4) is adjustable, and the material storage component fixing frame (2-4) is used to clamp the vortex stirring type material storage component (3); The lower surface of the pushing platform (2-3) can abut against the upper end of the stirring motor (3-1) of the vortex stirring storage assembly (3) to convert the rotational motion of the screw (2-2) into a linear propulsion force on the storage assembly (3), thereby achieving quantitative extrusion of the ceramic nanofiber ink; The side wall of the screw housing (2-5) is fixedly connected to the motion connection block (2-6), and the motion connection block (2-6) is fixed on the Y-axis ball screw nut in the XY-axis motion mechanism, thereby driving the screw-type ink supply device (2) to move in the XY plane.

7. The cold field 3D printing device for ceramic nanofiber aerogel according to claim 5, characterized in that: The vortex stirring type storage assembly (3) comprises a storage cavity tube, a stirring motor (3-1), an I-shaped push rod (3-2), and a wedge-shaped discharge port (3-5); The outer edge of the lower push plate of the I-shaped push rod (3-2) is covered with a rubber ring and is in sealing and sliding cooperation with the inner wall of the storage cavity tube; the wedge-shaped discharge port (3-5) is a conical structure with a pointed bottom and a thick top and a smooth inner wall; the outlet end of the wedge-shaped discharge port (3-5) is connected to the printing nozzle (6); and a second solenoid valve (3-7) is provided at the wedge-shaped discharge port (3-5); A feed port (3-3) is provided on the lower push plate of the I-shaped push rod (3-2), and the feed port (3-3) is connected to an external barrel (5) through a pipeline, and ceramic nanofiber ink is installed in the external barrel (5); A first electromagnetic valve (3-6) is provided at the feed port (3-3).

8. The cold field 3D printing device for ceramic nanofiber aerogel according to claim 3, characterized in that: The bottom surface of the cold plate (8-1) is provided with rectangular unit installation positions arranged in an array, and a semiconductor refrigeration plate is embedded in each rectangular unit installation position; The isolation plate (8-2) is made of a low-thermal-conductivity plastic material. The four corners of the isolation plate (8-2) are fixedly connected to the ball nuts of the Z-axis motion mechanism. The upper surface of the isolation plate (8-2) is provided with mounting grooves corresponding to the semiconductor refrigeration sheets. A water-cooled radiator is embedded in the mounting groove. The heat-conducting metal base of the water-cooled radiator is tightly fitted with the hot end surface of the semiconductor refrigeration sheet. The cold end of the semiconductor refrigeration plate is in contact with the lower surface of the cold plate (8-1), and the hot end is in contact with the water-cooled radiator on the isolation plate (8-2). The water-cooled radiator forms a closed-loop water circuit with the water-cooled circulation system (9) through the water inlet (8-5) and the water outlet (8-6). The temperature measuring instrument (8-3) arranged in series in the closed-loop water circuit feeds back the temperature of the cold plate (8-1) to the controller in real time. The controller adjusts the power supplied to the semiconductor refrigeration plate to achieve refrigeration temperature regulation.

9. A cold field 3D printing method for ceramic nanofiber aerogel using the cold field 3D printing device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Obtaining a three-dimensional model to be printed and slicing it to obtain a sliced ​​model, and importing the sliced ​​model into the controller; Setting printing parameters on the cold field 3D printing device, including printing speed, ink supply speed, cold plate temperature, and ambient humidity; The ceramic nanofiber ink is loaded into the external barrel (5), and the self-priming pump (4) is started and the first electromagnetic valve (3-6) is opened through the controller instruction, so as to fill the ink from the external barrel (5) into the vortex stirring storage component (3); The printing program is started, and the printing process is controlled by the controller so that the printing nozzle (6) prints layer by layer on the ultra-low temperature printing platform (8) based on the slice model. The height between the printing nozzle (6) and the ultra-low temperature printing platform (8) is monitored in real time by a laser ranging sensor (7) and the error is dynamically compensated to form a ceramic nanofiber / ice crystal complex.

10. The cold field 3D printing method for ceramic nanofiber aerogel according to claim 9, characterized in that: When the pushing platform (2-3) of the screw-type ink supply device (2) reaches the second limiter (2-8), the second limiter (2-8) feeds back a signal to the controller, and the controller controls the screw motor (2-1) to drive the screw (2-2), so that the pushing platform (2-3) is reset; While pushing the platform (2-3) to reset, the controller opens the first solenoid valve (3-6) and closes the second solenoid valve (3-7), and simultaneously starts the self-priming pump (4) and replenishes the printing ink from the barrel (5) into the storage assembly (3) through the self-priming conduit (4-1); When the pushing platform (2-3) triggers the first limiter (2-7), the controller controls the screw motor (2-1) to drive the screw (2-2) so that the pushing platform (2-3) resets and stops, and starts to advance; While the platform (2-3) is being pushed forward, the controller closes the first solenoid valve (3-6) and opens the second solenoid valve (3-7), thereby achieving continuous supply of printing ink to the printing nozzle (6) and uniform and stable ink discharge.

Images