Semi-solid 3D printing device capable of achieving synchronous degreasing and real-time solvent recovery

Abstract

The utility model belongs to the field of additive manufacturing equipment, and discloses a semi-solid 3D printing device capable of achieving synchronous degreasing and real-time solvent recovery. A 3D printing module; the liquid supplementing module comprises a liquid supplementing spray head and a solvent pre-storage cabin which is arranged outside the forming cabin and is connected with the liquid supplementing spray head through a solvent pipeline; and the solution self-circulation module comprises a solution recovery cabin which forms a closed loop with the forming cabin through a circulating pipeline. The liquid supplementing module and the solution self-circulation module are integrated, a degreasing solvent is injected into the forming cabin through the liquid supplementing module, synchronous degreasing in the printing process of a green body part is achieved, online recovery and cyclic utilization of the degreasing solvent are achieved through the solution self-circulation module, and the material forming efficiency and forming quality can be remarkably improved.

Description

A semi-solid 3D printing device that achieves simultaneous degreasing and real-time solvent recovery Technical Field

[0001] This utility model belongs to the technical field of additive manufacturing equipment, and more specifically, relates to a semi-solid 3D printing device that realizes simultaneous degreasing and real-time solvent recovery. Background Technology

[0002] Semi-solid indirect additive manufacturing is an advanced manufacturing technology based on the principle of stepwise forming. This technology uses semi-solid extrusion to build a green part layer by layer from a composite slurry composed of powdered raw materials and binders. After debinding and sintering, a dense component is prepared. It has significant advantages such as wide material compatibility, low manufacturing cost, and low residual stress, providing a new solution for high-performance, low-cost additive manufacturing. It has already been applied on a large scale in fields such as mold manufacturing and the automotive industry.

[0003] In this technology's process flow, the degreasing step is a critical quality control point, directly affecting the product's density and dimensional accuracy. Different degreasing methods can be employed depending on the binder system, such as solvent degreasing, thermal degreasing, and catalytic degreasing. Among these, solvent degreasing, with its advantages of low energy consumption, low equipment complexity, and high production capacity, has become the mainstream degreasing solution for industrial production.

[0004] Existing solvent degreasing technologies for semi-solid 3D printed green parts typically employ a static immersion method, where the green part is completely immersed in a degreasing solvent and left to stand. However, this method has the following drawbacks: First, the degreasing process relies on the natural penetration of the solvent, requiring a long immersion time, often tens of hours, resulting in low production efficiency. Second, for green parts with complex internal cavity structures, the solvent's penetration path is limited, easily leading to incomplete degreasing in localized areas and excessively high levels of binder residue. Furthermore, as the immersion time increases, the concentration of dissolved binder in the solvent gradually rises, severely slowing down the binder removal rate and reducing the removal efficiency. These disadvantages collectively limit the practical application of this technology in mass production. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this utility model provides a semi-solid 3D printing device that achieves simultaneous degreasing and real-time solvent recovery. By integrating a liquid replenishment module and a solution self-circulation module, it realizes simultaneous degreasing during the green part printing process and online recovery and recycling of degreasing solvent, thereby solving the problems of excessively long degreasing time, difficulty in degreasing complex structures, and efficiency reduction due to concentration accumulation during the degreasing process in semi-solid additive manufacturing.

[0006] To achieve the above objectives, in a first aspect of this invention, a semi-solid 3D printing apparatus is provided that enables simultaneous degreasing and real-time solvent recovery, comprising:

[0007] The forming chamber has an opening at the top;

[0008] A 3D printing module includes: a printing substrate disposed at the bottom of the forming chamber; and a print head disposed above the printing substrate;

[0009] The liquid replenishment module includes: a liquid replenishment nozzle disposed above the printing substrate; and a solvent pre-storage chamber disposed outside the forming chamber and connected to the liquid replenishment nozzle via a solvent pipe;

[0010] The solution self-circulation module includes: a solution recovery chamber located outside the forming chamber, which forms a closed loop with the forming chamber through a circulation pipe.

[0011] Preferably, the 3D printing module further includes a multi-axis motion control module, with the plane parallel to the bottom surface of the forming chamber as the XY two-dimensional plane;

[0012] The multi-axis motion control module includes a sliding table, a Y-axis stepper motor, a cross slide fixed position, an X-axis stepper motor, and a nozzle assembly. The sliding table is connected to the cross slide fixed position, and both the X-axis and Y-axis stepper motors are connected to the sliding table to drive it to move in the XY two-dimensional plane. The nozzle assembly is rigidly fixed to the sliding table and can move with it in the XY two-dimensional plane.

[0013] Preferably, the Z-axis direction is perpendicular to the bottom surface of the forming chamber;

[0014] The multi-axis motion control module also includes a Z-axis stepper motor, which is connected to the slide plate and is used to drive the slide plate to move along the Z-axis direction.

[0015] Alternatively, the multi-axis motion control module may further include a lifting mechanism connected to the base of the printing substrate for driving the printing substrate to move along the Z-axis.

[0016] Preferably,

[0017] The number of nozzle assemblies is 2, each independently fixed to the sliding plate, and the print head and the liquid replenishment nozzle are respectively built into the two nozzle assemblies;

[0018] Alternatively, the nozzle assembly may be a dual-channel coaxial structure, with the printhead and the replenishment nozzle respectively built into it.

[0019] Preferably, the solution self-circulation module is provided with a multi-layer filtration system, and the multi-layer filtration system is provided with a coarse filter layer, a fine filter layer and an adsorption layer in sequence along the solution flow direction.

[0020] Preferably, the material used for the coarse filter layer includes stainless steel filter screen, multi-layer nylon filter cloth, or ceramic honeycomb filter element;

[0021] The materials used in the fine filtration layer include ultrafiltration membranes or microfiltration membranes;

[0022] The materials used in the adsorption layer include molecular sieves or activated carbon.

[0023] Preferably, the semi-solid 3D printing device further includes sensing elements.

[0024] They are distributed inside the forming chamber, inside the solvent pre-storage chamber, on the solvent pipeline, and on the circulation pipeline.

[0025] Preferably, the semi-solid 3D printing device further includes an electrically adjustable valve distributed on the solvent pipeline and the circulation pipeline.

[0026] Preferably, the semi-solid 3D printing device further includes a check valve distributed on the solvent pipeline and the circulation pipeline.

[0027] Preferably, the forming chamber is equipped with one or more of a heating device, a stirring device, or an ultrasonic device.

[0028] In summary, compared with the prior art, the above-described technical solution conceived by this utility model has the following main technical advantages:

[0029] 1. This utility model integrates a forming chamber, a 3D printing module, a liquid replenishment module, and a solution self-circulation module. Through the combined action of these modules, the device based on this utility model can improve material forming efficiency and forming quality. During the semi-solid 3D printing process, by injecting degreasing solvent layer by layer into the forming chamber, simultaneous degreasing of the green part during printing can be achieved. As the green part is stacked layer by layer, the liquid replenishment module can replenish the degreasing solvent into the forming chamber, effectively eliminating the penetration blind spots of the degreasing solvent in the complex structure of the green part, ensuring the complete dissolution and removal of the binder within the green part, and optimizing the traditional process, effectively shortening the forming cycle and reducing manufacturing costs, significantly improving production efficiency. Simultaneously, the solution self-circulation module connects the forming chamber and the solution recovery chamber in a closed loop through a circulation pipeline, further improving degreasing efficiency and quality during the forming process, as well as the online recovery and recycling of the degreasing solvent.

[0030] 2. In the semi-solid 3D printing process, the waste liquid rich in binder can be effectively recovered and recycled in real time through a multi-layer filtration system and a self-circulating pipeline system. This not only saves solvent raw materials, but also effectively avoids the pollution of the environment caused by the discharge of waste liquid.

[0031] 3. Furthermore, the device of this utility model connects the computer control module with each module to adjust the parameters of the degreasing solvent in real time, thereby achieving precise degreasing of multiple material systems. Attached Figure Description

[0032] Figure 1 is a schematic diagram of the semi-solid 3D printing device that achieves simultaneous degreasing and real-time solvent recovery in this invention.

[0033] Figure 2 is a schematic diagram illustrating the working principle of the 3D printing module and the liquid replenishment module working together in the device of this utility model.

[0034] Figure 3 is a flowchart of the additive manufacturing process implemented by the device of this utility model.

[0035] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0036] 100. Forming chamber; 101. Forming chamber solution state sensor; 102. Heating device; 103. Green part; 104. Printing substrate; 201. Print head; 202. Slide moving plate; 203. Y-axis stepper motor; 204. Cross slide fixing point; 205. X-axis stepper motor; 206. Semi-solid slurry feed cylinder; 301. Liquid replenishment nozzle; 302. First check valve; 303. First electric regulating valve; 304. Flow meter; 305. 1. Water pump; 306. Solvent pre-storage chamber; 307. Liquid replenishment port; 308. Solvent level sensor in the solvent pre-storage chamber; 401. Second electric regulating valve; 402. Second check valve; 403. Solution inlet; 404. Solution recovery chamber; 405. Coarse filter layer; 406. Fine filter layer; 407. Adsorption layer; 408. Solution outlet; 409. Second water pump; 410. Third electric regulating valve; 411. Third check valve; 500. Computer control module. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be 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 illustrative of the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0040] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0042] According to one aspect of this utility model, as shown in Figure 1, the XY two-dimensional plane in this utility model is a plane parallel to the bottom surface of the forming chamber 100, and the Z-axis direction is a direction perpendicular to the bottom surface of the forming chamber 100. This embodiment provides a semi-solid 3D printing device that achieves simultaneous degreasing and real-time solvent recovery, including a forming chamber device 100, a 3D printing module, a liquid replenishment module, and a solution self-circulation module, specifically including:

[0043] The 3D printing module is used for 3D printing of semi-solid composite slurry on the printing substrate 104 inside the forming chamber 100; the liquid replenishment module is used to add degreasing solvent to the forming chamber 100 in a directional and quantitative manner after each layer of composite slurry is deposited, so as to realize the simultaneous degreasing of the green part; the solution self-circulation module is used for real-time recovery and recycling of binder-rich waste liquid during the semi-solid 3D printing process.

[0044] In practical automation applications, the device of this invention connects to various modules via a computer control module 500 to control parameters such as the level and concentration of the degreasing solvent in real time, achieving precise degreasing of multi-material systems. Furthermore, the methods described in the following embodiments are implemented using the device of this invention, or a combination of the device of this invention and the computer control module 500.

[0045] In this embodiment, the forming chamber 100 provides a working environment for semi-solid 3D printing and solvent degreasing processes. Specifically, the forming chamber 100 is an open container structure at the top, which houses a printing substrate 104, a solution state sensor 101, and other optional auxiliary functional modules. The printing substrate 104 is located at the bottom of the forming chamber 100, and the forming chamber 100 can lift the printing substrate 104 in the Z-axis direction. The top and bottom of the forming chamber 100 are respectively provided with a solvent inlet port and a solvent outlet port, which are connected to the solution recovery chamber 404 in a closed loop through circulation pipes. A one-way third check valve 411 is provided near the inlet section of the forming chamber 100's inlet pipe. The third check valve 411 allows the purified degreasing solvent to flow into the forming chamber in the forward direction and prevents the fluid from flowing back in the reverse direction.

[0046] In this embodiment, the solution state sensor 101 is located on the inner wall of the forming chamber 100 near the bottom. The solution state sensor 101 can sense solution state parameters, including but not limited to liquid level, fluid pressure, solution pH, solute concentration, and solution temperature. Furthermore, the solution state sensor 101 integrates liquid level, solute concentration, and solution temperature monitoring modules, and synchronizes the detection data to the computer control module 500 in real time via a built-in signal transmission circuit. To optimize the synchronous degreasing process and adapt to the degreasing solvent process requirements of different binders, auxiliary function modules can be integrated or detachably installed inside and around the forming chamber 100. These auxiliary function modules include, but are not limited to, a stirring device, a heating device 102, or an ultrasonic device. Preferably, a heating device 102 is provided below the printing substrate 104 and around the forming chamber 100.

[0047] In this embodiment, the 3D printing module includes an extruder head 201, a multi-axis motion control module, and a semi-solid slurry feed cylinder 206. The extruder head 201 is located above the forming chamber 100 and is connected to the semi-solid slurry feed cylinder 206 through a feeding pipe. The extruder head integrates a basic extrusion unit and a temperature control unit, which are conventional in the art. All of the above components are electrically connected to the computer control module 500. The former controls and adjusts the extrusion volume, while the latter performs slurry heating as needed to ensure accurate printing of semi-solid materials.

[0048] In this embodiment, the multi-axis motion control module includes a sliding table 202, a Y-axis stepper motor 203, a cross slide fixing point 204, an X-axis stepper motor 205, and a nozzle assembly. The sliding table 202, together with the Y-axis stepper motor 203 and the X-axis stepper motor 205, forms a planar motion mechanism via the cross slide fixing point 204. The X-axis stepper motor 205 drives the sliding table 202 to move along the X-axis, and the Y-axis stepper motor 203 drives the sliding table 202 to move along the Y-axis via an orthogonal transmission mechanism. The forming chamber 100 is equipped with a Z-axis lifting mechanism, which drives the printing substrate 104 to move vertically. The nozzle assembly containing the extrusion head 201 is rigidly connected to the sliding table 202. The computer control module 500 controls the XY-axis movement of the extrusion head 201 and the Z-axis lifting of the printing substrate 104 to achieve precise extrusion forming of semi-solid materials in three-dimensional space.

[0049] In some embodiments, there are two nozzle assemblies, each independently fixed on the sliding plate 202, and each nozzle assembly has a built-in print head 201 and a replenishing nozzle 301, which move independently in the XY plane; or, the nozzle assembly is a dual-channel coaxial structure, with a built-in print head 201 and a replenishing nozzle 301.

[0050] In this embodiment, the liquid replenishment module consists of a liquid replenishment nozzle 301, a liquid supply pipeline, and a solvent pre-storage chamber 306. The liquid replenishment nozzle 301 is integrated with the extrusion head 201 in the 3D printing module onto the same nozzle assembly, sharing a three-axis motion system. The nozzle assembly adopts a dual-channel coaxial structure. The first channel connects to the semi-solid slurry delivery pipeline of the 3D printing module, and the second channel connects to the solvent pre-storage chamber 306 via a pipeline. After the deposition of one layer of composite slurry is completed, the nozzle assembly closes the first channel and activates the second channel, driving the nozzle to move to the non-green part area to perform a precise and quantitative addition of solvent, ensuring uniform distribution of the degreasing solution.

[0051] Referring to the coordinate positioning in Figure 1, the motion coordinate systems of the print head 201 of the 3D printing module and the liquid replenishment nozzle 301 of the liquid replenishment module can both be configured to one of the following operating modes:

[0052] 1) XY axis planar positioning mode: The print head 201 and the liquid replenishment nozzle 301 perform two-dimensional trajectory movement along the substrate plane, and the substrate is lifted in the Z-axis direction;

[0053] 2) XYZ three-axis spatial positioning mode: the print head 201 and the liquid replenishment nozzle 301 perform three-dimensional spatial trajectory movement, while the substrate remains statically positioned.

[0054] Furthermore, the liquid replenishment module uses a motion coordinate system to drive the nozzle to apply solvent at precise points in non-green areas. For complex internal structures, it can directly and accurately apply solvent from internal coordinate points, shortening the penetration path. The liquid level sensor monitors the liquid level in real time and transmits the signal to the computer control system, dynamically adjusting the amount of liquid replenished each time to ensure that the liquid level is always lower than the top surface of the current green part, preventing the soaking of the deposited slurry layer and affecting subsequent printing.

[0055] In some embodiments, the solvent pipeline connected to the solvent pre-storage chamber 306 is equipped with a first check valve 302, a first electrically adjustable valve 303, a flow meter 304, and a first water pump 305. Specifically, after the degreasing solvent is drawn from the solvent pre-storage chamber 306 by the first water pump 305, it first flows through the flow meter 304 for real-time flow monitoring, then enters the first electrically adjustable valve 303 for opening adjustment, and finally is delivered to the replenishment nozzle 301 through the first check valve 302 to complete the replenishment operation. The flow meter 304 and the first electrically adjustable valve 303 are respectively connected to the computer control module 500 via signal signals, and the solution flow rate is dynamically adjusted through a closed-loop control algorithm; the first check valve 302 is provided to ensure the unidirectionality and stability of the replenishment process. In addition, a replenishment port 307 is provided on the upper part of the solvent pre-storage chamber 306. When the solvent level sensor 308 of the solvent storage chamber detects that the liquid level in the solvent storage chamber 306 is lower than the normal value, the degreasing solvent will be added from the replenishment port 307 to ensure that the pre-storage amount of degreasing solvent meets the needs of the entire experiment.

[0056] In practice, the collaborative working principle of the 3D printing module and the liquid replenishment module is shown in Figure 2. During the 3D printing process, the liquid replenishment module quickly moves the liquid replenishment nozzle 301 to a designated position for point-to-point liquid addition based on the distribution of non-green areas in the slice data through path planning. For complex internal cavity structures, solvent can be precisely added from the inside, and the liquid level is monitored in real time by the solution state sensor 101 in the forming chamber. First, the 3D printing module deposits the first layer of semi-solid composite slurry. Then, the liquid replenishment module moves the liquid replenishment nozzle 301 to a suitable position for point-to-point and quantitative liquid addition, ensuring that the amount of liquid added each time is less than the thickness of the deposited layer. Starting from the second layer, after each layer is printed, the liquid replenishment nozzle 301 adds solvent equal to the thickness of that layer, and monitors the liquid level through the solution state sensor 101 in the forming chamber. Liquid replenishment stops when the set height is reached. After the last layer is deposited, the liquid replenishment module replenishes a sufficient amount of solvent at once, ensuring that the liquid level is higher than the top surface of the green part, so that it is completely immersed in the degreasing solvent.

[0057] In this embodiment, the solvent self-circulation module consists of a solution recovery chamber 404 and a recovery pipe and a supply pipe connected to the forming chamber 100. The solution recovery chamber 404 includes a solution inlet 403, a coarse filter layer 405, a fine filter layer 406, an adsorption layer 407, and a solution outlet 408. An electric regulating valve 401 and a check valve 402 are respectively provided along the flow direction of the recovery pipe. A second water pump 409, a third electric regulating valve 410, and a third check valve 411 are respectively provided along the flow direction of the supply pipe. Specifically, as simultaneous degreasing continues, the binder-rich waste liquid is discharged from the forming chamber 100 and returned to the solution recovery chamber 404 via a recovery pipeline. Along the flow direction, the recovery pipeline is equipped with a third electric regulating valve 401 to dynamically control the return flow and a second check valve 402 to prevent backflow. The waste liquid then flows through a three-stage filtration system: first, a coarse filter layer 405 intercepts large solid particles; then, a fine filter layer 406 retains small molecule pollutants; and finally, an adsorption layer 407 adsorbs and removes oils and organic pollutants. The purified solution is then transported to the forming chamber for recycling via a supply pipeline through a solution outlet 408. Along the flow direction, the supply pipeline is equipped with a second water pump 409, a third electric regulating valve 410, and a third check valve 411, which respectively provide power, precisely control the flow rate, and prevent backflow. The supply pipeline and the recovery pipeline are linked and regulated by a computer control module, which matches the flow rates at both ends in real time to ensure that no residue remains when the solution circulates between the solution recovery chamber 404 and the forming chamber 100.

[0058] In practical implementation, the semi-solid 3D printing device that achieves simultaneous degreasing and real-time solvent recovery also includes a computer control module 500, which is electrically connected to the aforementioned devices to achieve effective control during the semi-solid 3D printing and simultaneous degreasing processes, thereby improving the degree of automation. Specifically, it is connected to the forming chamber 100 and the 3D printing module to achieve full-process control of precise three-dimensional extrusion molding of semi-solid materials; it is connected to the forming chamber solution state sensor 101 in the forming chamber to monitor the various state parameters of the degreasing solvent in real time, and controls the replenishment module to adjust the amount of degreasing solvent added and start / stop the solution self-circulation module based on the monitoring results; it is connected to the solvent level state sensor 308 in the solvent pre-storage chamber of the replenishment module to ensure that the pre-stored amount of degreasing solvent meets the needs of the entire experiment; it is connected to the heating device 106 in the forming chamber 100 to dynamically adjust the temperature parameters during the forming process; and it is connected to the electric regulating valves in each solution pipeline to precisely control the real-time recovery, recycling, and on-demand supply of degreasing solvent.

[0059] In practice, the adhesive system includes, but is not limited to, water-based adhesive systems, wax-based adhesive systems, and composite adhesive systems.

[0060] In practice, the degreasing solvent is a non-flammable and non-explosive liquid, including but not limited to pure water, n-hexane, ethanol, etc.

[0061] In practice, the forming chamber 100 can be integrated into the equipment workbench or detached via a quick-release interface. When detached, it can be removed as a whole along with the internal green part after printing is completed. After reinstallation, the printing reference consistency can be maintained through the positioning structure.

[0062] In practice, to optimize the effect of the synchronous degreasing process and adapt to the degreasing solvent process requirements of different binders, auxiliary functional modules, including but not limited to stirring devices, heating devices or ultrasonic devices, can be integrated or detachably installed inside and around the forming chamber 100.

[0063] This device can achieve rapid printing and simultaneous degreasing of materials such as metals and ceramics.

[0064] Based on the embodiments of this utility model, the additive manufacturing method using the semi-solid 3D printing device that achieves simultaneous degreasing and real-time solvent recovery, as shown in Figure 3, includes the following steps:

[0065] Step S1: Based on the material properties and process requirements of the target component, select appropriate powder raw materials, binders and solvent formulations, and prepare the required semi-solid composite slurry and degreasing solvent.

[0066] Step S2: Determine the semi-solid 3D printing process parameters and other key parameters for device operation, plan the movement paths of the 3D printing module nozzle and the liquid replenishment module nozzle, and write the control program;

[0067] Step S3: Add the semi-solid composite slurry into the feed cylinder, and pre-store the degreasing solvent in the solvent pre-storage chamber of the replenishment module through the replenishment port;

[0068] Step S4: Based on the material properties and process requirements of the target component, selectively activate the heating devices at the bottom and periphery of the forming chamber for preheating;

[0069] Step S5: Run the 3D printing module, execute the printing program, and deposit the first layer of semi-solid composite slurry;

[0070] Step S6: After the first layer of semi-solid composite slurry has been deposited, start the liquid replenishment module and add a small amount of solvent at fixed points and in a fixed quantity to the forming chamber to ensure that the liquid level is lower than the current deposition layer thickness.

[0071] Step S7: Continue running the 3D printing module and print layer by layer. After each layer is deposited, solvent is added dropwise at fixed points and in fixed quantities. The solvent status sensor ensures that the solvent addition height is consistent with the current layer deposition thickness, and the computer control module dynamically adjusts the liquid replenishment amount.

[0072] Step S8: Selectively activate auxiliary function modules, such as stirring devices and ultrasonic devices, according to the requirements of the degreasing process;

[0073] Step S9: Detect the solution concentration using a solution state sensor. If the concentration exceeds the set value, activate the solution self-circulation module for real-time recovery and recycling.

[0074] Step S10: After all layers are printed, the liquid replenishment module adds additional solvent to ensure that the green part is completely immersed in the degreasing solvent.

[0075] Step S11: After the degreasing process is completed, close the liquid inlet pipe of the forming chamber, open the liquid outlet pipe, and discharge the solution to remove the solution environment.

[0076] Step S12: Remove the green blank from the printing substrate inside the forming chamber;

[0077] Step S13: Place the degreased green parts in a drying device and dry them according to the set time and temperature conditions to remove residual solvent;

[0078] Step S14: The dried green blank is sintered at high temperature to promote densification of the green blank and finally obtain a dense component.

[0079] It should be understood that this method is applicable to additive manufacturing of materials such as metals and ceramics. An improved additive manufacturing method is provided below. This method is based on a semi-solid 3D printing device with simultaneous debinding and real-time solvent recovery. Taking a high-precision Ti6Al4V titanium alloy component additive manufacturing method as an example, the specific implementation process includes the following steps:

[0080] Step S1: Based on the material characteristics and process requirements of Ti6Al4V titanium alloy, a wax-based binder system is selected as the binder, including paraffin wax, low-density polyethylene and stearic acid, etc. Hexane with a purity of ≥97% is selected as the degreasing solvent formula, and the required semi-solid composite slurry and degreasing solvent are prepared.

[0081] Step S2: Determine the semi-solid 3D printing process parameters and other key parameters for device operation: nozzle diameter is 0.6mm, nozzle heating temperature is 200℃, printing speed is 20mm / s, printing spacing is 0.6mm, preset line width is 0.6mm, printing layer thickness is 0.3mm, initial phase angle is 45°, relative phase angle is 90°, plan the movement paths of the 3D printing module nozzle and the liquid replenishment module nozzle, and write the control program;

[0082] Step S3: Load the semi-solid composite slurry into the semi-solid slurry feed cylinder, and at the same time, inject sufficient degreasing solvent into the solvent pre-storage chamber through the liquid replenishment port to ensure that the amount of degreasing solvent pre-stored in the liquid replenishment module meets the requirements of the entire experiment.

[0083] Step S4: Based on the material properties of Ti6Al4V titanium alloy and the requirements of the degreasing process, the solution temperature is maintained at 45°C by controlling the bottom and outer ring heating devices of the forming chamber. The two devices are started, stopped and their power is adjusted based on real-time temperature feedback.

[0084] Step S5: Run the 3D printing module, execute the printing program, and deposit the first layer of semi-solid composite slurry;

[0085] Step S6: After the first layer of semi-solid composite slurry is deposited, control the three-axis motion mechanism to move the nozzle to the non-green part area, start the liquid replenishment module to link the water pump, and inject degreasing solvent into the forming chamber at fixed points and in a quantitative manner through the coordinated control of the flow meter and electric regulating valve until the solution state sensor measures that the solution layer thickness reaches 0.1mm, ensuring that the liquid level is lower than the current layer deposition thickness.

[0086] Step S7: Continue running the 3D printing module to print layer by layer. After each layer is deposited, start the liquid replenishment module to add solvent drop by drop. The solvent status sensor 101 monitors and ensures that the liquid level increases by 0.3 mm after each layer is added.

[0087] Step S8: Detect the solution concentration using a solution state sensor. If the concentration exceeds the set value, open the electric regulating valve and start the solution self-circulation module for real-time recovery and recycling.

[0088] Step S9: After all layers are printed, the liquid replenishment module adds an appropriate amount of degreasing solvent to ensure that the green part is completely immersed in the degreasing solvent.

[0089] Step S10: After the degreasing process is completed, close the liquid inlet pipe of the forming chamber, open the liquid outlet pipe, and discharge the solution to remove the solution environment.

[0090] Step S11: Remove the green blank from the printing substrate inside the forming chamber;

[0091] Step S12: Place the degreased green parts in a forced-air drying oven and dry them. Set the drying temperature to 50℃ and the drying time to 2 hours.

[0092] Step S13: The green blank is transferred to a tube furnace for high-temperature sintering under the protection of high-purity argon gas. The temperature is increased to 1200°C at a heating rate of 10°C / min and held for 1 hour. Finally, it is cooled to room temperature with the furnace to obtain a high-precision Ti6Al4V titanium alloy component.

[0093] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the protection scope of this utility model and its equivalents, this utility model also intends to include these modifications and variations. The above-described embodiments are merely preferred embodiments given to fully illustrate this utility model, and their protection scope is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this utility model are all within the protection scope of this utility model.

Claims

1. A semi-solid 3D printing device that achieves simultaneous degreasing and real-time solvent recovery, characterized in that, include: The forming chamber (100) has an opening at the top; the 3D printing module includes: a printing substrate (104) located at the bottom of the forming chamber (100); and a print head (201) located above the printing substrate (104); the liquid replenishment module includes: a liquid replenishment nozzle (301) located above the printing substrate (104); and a solvent pre-storage chamber (306) located outside the forming chamber (100) and connected to the liquid replenishment nozzle (301) via a solvent pipe; the solution self-circulation module includes: a solution recovery chamber (404) located outside the forming chamber (100) and forming a closed loop with the forming chamber (100) via a circulation pipe.

2. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 1, characterized in that, The 3D printing module also includes a multi-axis motion control module, with the plane parallel to the bottom surface of the forming chamber (100) as the XY two-dimensional plane; the multi-axis motion control module includes a sliding table (202), a Y-axis stepper motor (203), a cross slide fixed position (204), an X-axis stepper motor (205), and a nozzle assembly; the sliding table (202) is connected to the cross slide fixed position (204), and the X-axis stepper motor (205) and the Y-axis stepper motor (203) are both connected to the sliding table (202) to drive the sliding table (202) to move on the XY two-dimensional plane; and the nozzle assembly is rigidly fixed to the sliding table (202) and can move with the sliding table (202) on the XY two-dimensional plane.

3. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 2, characterized in that, The Z-axis direction is perpendicular to the bottom surface of the forming chamber (100); the multi-axis motion control module also includes a Z-axis stepper motor connected to the slide moving plate (202) for driving the slide moving plate (202) to move along the Z-axis direction; or, the multi-axis motion control module also includes a lifting mechanism connected to the base of the printing substrate (104) for driving the printing substrate (104) to move along the Z-axis direction.

4. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 2, characterized in that, The number of nozzle assemblies is 2, each independently fixed on the sliding table (202), and each of the two nozzle assemblies contains the print head (201) and the replenishing nozzle (301); or, the nozzle assembly is a dual-channel coaxial structure, each containing the print head (201) and the replenishing nozzle (301).

5. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 1, characterized in that, The solution self-circulation module is equipped with a multi-layer filtration system, and the multi-layer filtration system is provided with a coarse filter layer (405), a fine filter layer (406) and an adsorption layer (407) in sequence along the solution flow direction.

6. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 5, characterized in that, The materials used in the coarse filtration layer (405) include stainless steel filter screen, multi-layer nylon filter cloth or ceramic honeycomb filter element; the materials used in the fine filtration layer (406) include ultrafiltration membrane or microfiltration membrane; the materials used in the adsorption layer (407) include molecular sieve or activated carbon.

7. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 1, characterized in that, The semi-solid 3D printing device also includes sensing elements distributed inside the forming chamber (100), inside the solvent pre-storage chamber (306), on the solvent pipeline and the circulation pipeline.

8. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 1, characterized in that, The semi-solid 3D printing device also includes electrically adjustable valves distributed on the solvent pipeline and the circulation pipeline.

9. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 1, characterized in that, The semi-solid 3D printing device also includes check valves distributed on the solvent pipeline and the circulation pipeline.

10. The semi-solid 3D printing device for simultaneous degreasing and real-time solvent recovery according to claim 1, characterized in that, The forming chamber (100) is equipped with one or more of the following: a heating device (105), a stirring device, a heating device, or an ultrasonic device.

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