Double-coil micro-nano soft magnetic and hard magnetic particle composite magnetic control enhanced 3D printing device and method

Abstract

The invention relates to a double-coil micro-nano soft magnetic and hard magnetic particle composite magnetic control enhanced 3D printing device and method. The device comprises a magnetic composite consumable, a driving wheel, a pulse magnetizing coil, a constant field magnetizing coil, a ceramic heating ring, a nozzle and a hot bed. According to the method, an innovative double-stage cooperative regulation and control strategy is adopted, namely, the technical means of combining solid pre-magnetizing and melting constant field orientation is adopted, and accurate control is conducted according to different magnetic characteristics of soft magnetic particles and hard magnetic neodymium iron boron particles. In the printing process, directional arrangement of soft magnetic particles and hard magnetic particles is achieved by regulating and controlling the magnetic field intensity of the pulse magnetizing coil and the constant field magnetizing coil, and then efficient arrangement of reinforcing materials such as carbon fibers is driven. The mechanical property of the printing structure in the particle arrangement direction is remarkably improved. By accurately matching the dynamic magnetic field intensity with the hot bed temperature, high-precision arrangement of the magnetic composite material in the whole process of conveying, extruding and the like is ensured, so that complex parts with excellent mechanical properties are printed.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device and method. Background Art

[0002] In traditional 3D printing technology of magnetic responsive materials, a single magnetizing coil is often used to perform magnetic field-induced directional arrangement of magnetic particles. The typical process is: in the process of the print head heating and extruding the molten material, an instantaneous or pulsed magnetic field is generated by the coil, so that the magnetic particles are preliminarily arranged along the direction of the magnetic field in the liquid or semi-solid state. However, this type of single-coil magnetizing scheme has significant defects: first, due to the internal space of the print head and the thermal management requirements, the coil magnetic field has a short action time and limited intensity, resulting in insufficient particle pre-arrangement effect, especially during the cooling and solidification process of the material, the decrease in fluidity will further destroy the formed orientation structure; secondly, the single magnetic field action stage is usually only applied during extrusion, and it is impossible to take into account the dynamic regulation of the entire process from solid to molten state of the material, resulting in the particles not fully activating the magnetic response characteristics in the solid pre-filling stage, and after melting, it is difficult to achieve high-precision arrangement by relying only on a short-term magnetic field. In order to solve this problem, the present invention proposes a dual-coil magnetizing print head. It is able to apply differentiated magnetic fields in stages throughout the entire process of material delivery, phase change and extrusion. Through the dual effects of solid-state pre-magnetization and precise orientation in the molten state, it breaks through the limitations of the magnetic field effect of the single-coil solution and solves the problem of coordinated control of the split system, thereby improving the orientation accuracy and functional consistency of magnetic composite material printing. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of insufficient orientation accuracy of magnetic particles and short magnetic field action time caused by a single magnetizing coil in traditional 3D printing, and to improve the consistency of particle arrangement of magnetic composite consumables during printing and further improve the mechanical properties. A dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device was fabricated.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A dual-coil micro-nano soft magnetic hard magnetic particle composite magnetron enhanced 3D printing device, characterized in that it includes a magnetic composite consumable, a throat, a driving wheel, a pulse magnetization module, a heat sink, a constant field magnetization module, a ceramic heating ring, a nozzle and a hot bed. The magnetic composite consumable is rotated and transported into the throat by the driving wheel, the pulse magnetization module is installed above the heat sink and close to the throat entrance, the constant field magnetization module is installed below the radiator and located outside the ceramic heating ring, the ceramic heating ring is installed near the throat and located inside the constant field magnetization module, and the nozzle is installed below the throat.

[0006] The magnetic composite consumables are made of 300-500 mesh hard magnetic particles, soft magnetic particles, 300 mesh TPU, 300 mesh carbon fiber, and 300 mesh PLA polylactic acid particles mixed in proportion, and prepared into 1.75mm diameter wire through a melt mixing process. Magnetic particles can provide magnetic properties and structural strength for printed samples, TPU can make the materials tightly bonded together, carbon fiber can improve the toughness of the material, and PLA polylactic acid particles can melt at high temperature and quickly solidify at low temperature.

[0007] The driving wheel consists of two 15mm diameter synchronous wheels with an inner hole diameter of 3mm, mounted on a connecting plate and controlled by a 42 stepper motor.

[0008] The pulse magnetization module is wound with 0.8-1.2mm diameter thick copper enameled wire, with 30-50 turns. A pulse current of 300A is applied to generate a pulse magnetic field with a magnetic field strength of 3-4T.

[0009] The constant field magnetization module is wound with 0.4mm diameter fine copper wire, with 800-1000 turns. A constant current of 1-2A is applied to generate a stable magnetic field of 2-8T.

[0010] Hard magnetic particles and soft magnetic particles, for hard magnetic particles with remanent magnetism, the pulsed magnetic field will make them retain their magnetic pole characteristics, for soft magnetic particles, the pulsed magnetic field will make them shake slightly to promote their adhesion with surrounding particles, the constant field magnetization module will enhance the arrangement and rotational force of hard magnetic particles to drive the particles to arrange consistently, and for soft magnetic particles, it will make them adhere to more particles to achieve consistent arrangement.

[0011] The heat sink is installed under the pulse magnetization module and is made of brass. The heat dissipation area is ≥ 200cm 2 , used to ensure that the temperature rise of the throat (6) is ≤15°C.

[0012] The ceramic heating ring is nested under the heat sink, with a heating power of 500-800W, a temperature control accuracy of ±2℃, and a heating temperature range of 160-220℃.

[0013] The nozzle is made of brass, with a diameter of 0.36-0.8mm, an inner wall roughness of ≤0.8μm, and an axial length of 30-40mm.

[0014] The hot bed is installed under the deposition platform and is made of carbon silicon crystal glass. The surface temperature can be adjusted from 0 to 110°C, and the heating uniformity deviation is ≤±3°C, which is conducive to the curing and molding of the printed structure.

[0015] The operation steps of the dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing proposed by the present invention are as follows:

[0016] S1: Prepare magnetic composite consumables. First, mix PLA polylactic acid powder, TPU, carbon fiber, hard magnetic particles, and soft magnetic particles according to the ratio and pour them into a stirrer. Cover and stir at a speed of 500 rpm for 10 minutes. After cooling for 5 minutes, take out and pour into a beaker.

[0017] S2: Start the internal mixer and set the preheating temperature to 160-170 degrees Celsius. After the preheating is completed, pour the mixed powder into the internal mixer and set the wire output speed of the internal mixer;

[0018] S3: Start the winding machine, turn on the cooling device at the end of the internal mixer, set the winding speed of the winding machine to be consistent with the extrusion speed of the internal mixer, and refine the magnetic composite consumables;

[0019] S4: Before printing begins, preheat the printer fuser at a temperature of 200-220 degrees Celsius. After reaching the preset temperature, the magnetic composite consumable is sandwiched between the driving wheels and transported to the fuser;

[0020] S5: Turn on the extrusion mode in the printer tool options to allow filament to extrude from the nozzle;

[0021] S6: Import the printed model slice data into the 3D printer and set the process parameters such as temperature and printing speed;

[0022] S7: The printing interface sets the magnetic domain direction and distribution of the printing model. When printing a single area with the same magnetic domain direction, if the traveling direction is consistent with the magnetic domain direction of the double coil, there is material extrusion, and a pulse magnetic field and a constant field magnetic field with the same magnetic pole direction are applied at the same time. If the traveling direction is opposite to the magnetic domain direction, there is no material extrusion and no magnetic field is applied;

[0023] S8: Repeat S7 until the model is completely printed;

[0024] S9: After the part printing is completed and the hot bed cools down to a safe temperature, remove the part. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The invention discloses a double-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device.

[0026] Figure 2 The invention discloses a nozzle for a double-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device.

[0027] Figure 3 Structural diagram of complex parts printed with dual-coil micro-nano soft magnetic and hard magnetic particles composite magnetron enhanced 3D printing.

[0028] Figure numerals: 1-magnetic composite consumables, 2-driving wheel, 3-connecting plate, 4-pulse magnetizing module throat, 5-heat sink, 6-throat, 7-ceramic heating ring, 8-constant field magnetizing module, 9-nozzle, 10-heat bed DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] like Figure 1 The double-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device described in the figure prints magnetic composite consumables in a certain proportion through the composite magnetron enhanced 3D printing device, and finally obtains a complex structure with excellent mechanical properties, such as Figure 3 As shown. The raw materials of magnetic composite consumables required for the printing process include hard magnetic particles, soft magnetic particles, TPU, carbon fiber, and PLA polylactic acid particles. The preparation process includes the following steps:

[0031] S1: Use a high-precision electronic scale to weigh 60 grams of PLA powder, 25 grams of soft magnetic Fe3O4 particles or 25 grams of hard magnetic NdFeB particles, 5 grams of TPU, and 10 grams of carbon fiber.

[0032] S2: Pour the weighed materials into a beaker, stir at room temperature, set the speed to 300 rpm, and stir for 15 minutes to make them evenly mixed.

[0033] S3: Pour the mixed materials into an internal mixer and set the temperature to 180-200°C.

[0034] S4: The refined consumables are wound by an automatic winding machine.

[0035] The model is printed by using a double-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing method of the present invention, and the operation method thereof comprises the following steps:

[0036] S1: The prepared magnetic composite consumables are transported into the melter through the driving wheel.

[0037] S2: Adjust the stepper motor to drive the synchronous wheel so that material is extruded from the printer nozzle.

[0038] S3: Turn on the printing device for automatic leveling, set the print head temperature to 200℃, the hot bed temperature to 60℃, the nozzle diameter to 0.2mm, and the printing height to 0.2mm. Before printing, turn on the pulse magnetization module and the constant field magnetization module to apply pulses and constant strong magnetic fields to the material inside the throat.

[0039] S4: Click to start printing and continue until printing is completed.

[0040] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications without departing from the present invention and its spirit. Such modifications are all within the scope defined by the appended claims.

Claims

1. A dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device, characterized in that: The invention comprises the following components: a magnetic composite consumable (1), a throat (6), a driving wheel (2), a connecting plate (3), a pulse magnetization module (4), a heat sink (5), a constant field magnetization module (8), a ceramic heating ring (7), a nozzle (9) and a hot bed (10); the magnetic composite consumable (1) is clamped and rotated by a driving wheel (2) installed on the connecting plate (3) and transported to the throat (6); the pulse magnetization module (4) is installed above the heat sink (5) and close to the entrance of the throat (6); the constant field magnetization module (8) is installed below the heat sink (5) and is located outside the ceramic heating ring (7); the ceramic heating ring (7) is installed near the extrusion outlet of the throat (6) and is located inside the constant field magnetization module (8); and the nozzle (9) is installed below the throat (6).

2. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that: The magnetic composite consumable (1) is prepared by compounding 300-mesh PLA powder, soft magnetic particles or hard magnetic particles, 300-mesh TPU, and 300-mesh carbon fiber according to a ratio, and the magnetic powder particle size is selected to be 300-500 mesh, and is prepared into a wire material with a diameter of 1.75 mm through a melt mixing process.

3. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that: The driving wheel (2) is composed of two synchronous wheels with a diameter of 15 mm, an inner hole diameter of 3 mm, and is controlled by a 42 stepping motor.

4. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that: The pulse magnetization module (4) is wound with a thick copper enameled wire with a diameter of 0.8-1.2 mm, with 30-50 turns, and a pulse current of 300A is applied to generate a pulse magnetic field with a magnetic field strength of 3-4T. The constant field magnetization module (8) is surrounded by the outside of the ceramic heating ring (7), and is wound with a thin copper wire with a diameter of 0.4 mm, with 800-1000 turns, and a constant current is applied to generate a stable magnetic field with a strength of 2-8T.

5. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that The hard magnetic particles and soft magnetic particles in the magnetic composite consumable (1) have the property of residual magnetism for the hard magnetic particles. The pulsed magnetic field will make them retain their magnetic pole characteristics. The pulsed magnetic field for the soft magnetic particles will make them shake slightly to promote their adhesion with surrounding particles. The constant field magnetization module (8) enhances the arrangement and rotational force of the hard magnetic particles to drive the particles to be arranged consistently, and makes the soft magnetic particles adhere to more particles to achieve consistent arrangement.

6. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that: The heat sink (5) is installed below the pulse magnetization module (4) and is made of brass with a heat dissipation area of ​​≥200cm 2 , used to ensure that the temperature rise of the throat (6) is ≤15°C.

7. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that: The ceramic heating ring (7) is nested under the heat sink (5), has a heating power of 500-800W, a temperature control accuracy of ±2°C, and a heating temperature range of 160-220°C.

8. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that: The nozzle (9) is made of brass, has a diameter of 0.36-0.8 mm, an inner wall roughness of ≤0.8 μm, and an axial length of 30-40 mm.

9. The dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing device according to claim 1, characterized in that: The hot bed (10) is made of carbon silicon crystal glass, the surface temperature can be adjusted in the range of 0-110°C, and the heating uniformity deviation is ≤±3°C.

10. A method for realizing dual-coil micro-nano soft magnetic and hard magnetic particle composite magnetron enhanced 3D printing using the device of claim 1, characterized in that: The specific steps are as follows: S1: PLA polylactic acid powder, TPU, carbon fiber, hard magnetic particles and soft magnetic particles are mixed according to the proportion and stirred evenly; S2: Start the internal mixer. After preheating, pour the mixed powder into the internal mixer and set the wire output speed of the internal mixer. S3: Start the winding machine, set the winding speed of the winding machine to be consistent with the extrusion speed of the internal mixer, and refine the magnetic composite consumables; S4: Before printing begins, the printer fuser is preheated. After reaching the preset temperature, the magnetic composite consumable is sandwiched between the driving wheels and transported to the fuser; S5: Turn on the extrusion mode in the printer tool options to allow filament to extrude from the nozzle; S6: Import the printed model slice data into the 3D printer and set the process parameters such as temperature and printing speed; S7: Set the distribution of the magnetic domain direction of the model. When printing a single area with the same magnetic domain direction, if the traveling direction is consistent with the magnetic domain direction of the double coils, there will be material extrusion, and a pulse magnetic field and a constant magnetic field will be applied at the same time. If the traveling direction is opposite to the magnetic domain direction, there will be no material extrusion and no magnetic field will be applied. S8: Repeat S7 until the model is completely printed; S9: After the part is printed and the hot bed cools down to a safe temperature, remove the part.

Images