A composite additive manufacturing device and preparation method for ceramic-based multi-component materials

Abstract

The present invention discloses a composite additive manufacturing device and preparation method of ceramic-based multi-component materials, the device includes a direct writing molding head, etc.; the laser head is installed at the center of a follower platform, the direct writing molding head is installed on the adjacent side of the laser head, the follower platform is rotated by a rotating shaft to change the position of the direct writing molding head, and the follower platform is connected to a horizontal motion mechanism through a hanger; the direct writing molding head and the laser head are located above a printing substrate, the printing substrate is connected to a lifting mechanism, and the resin tank is located below the printing substrate; the composite additive manufacturing device adopted in this method is formed from top to bottom, and the followable direct writing molding head and the laser head are both point-line-surface forming, which simplifies the forming steps, effectively improves the forming efficiency, and expands the further application of additive manufacturing technology.

Description

Technical Field

[0001] The present invention belongs to the field of rapid prototyping, and in particular relates to a composite additive manufacturing device and a preparation method of a ceramic-based multi-component material. Background Art

[0002] Ceramic composite materials offer advantages such as high hardness, low density, high thermal conductivity, stable chemical properties, and excellent high-temperature strength and corrosion resistance. They are widely used in aerospace, semiconductors, nuclear energy, electronic packaging, and other fields. The rapid development of various industries is driving higher demands on the structure, performance, and precision of ceramic composite components. Traditional molding methods such as slip casting, gel casting, and isostatic pressing, however, suffer from long manufacturing cycles and low dimensional accuracy, making them unable to meet the rapid prototyping requirements of the next generation of high-performance, complex-structure ceramic composite components.

[0003] In recent years, the emerging additive manufacturing technology has the characteristics of one-piece molding, flexible structural design, and no restrictions on the complexity of the model structure. It can quickly form complex structural parts in a layer-by-layer stacking manner without any molds. At present, stereolithography is widely used in the field of ceramic manufacturing due to its high molding precision and fast printing speed. The research on the photolithography molding process of oxide ceramics at home and abroad is quite mature. However, non-oxide gray ceramics such as silicon carbide have high refractive index and absorbance of the printing material powder, which makes the SiC photolithography slurry difficult to penetrate ultraviolet light, insufficient photocuring reaction, and low curing layer thickness. It cannot meet the requirements of stereolithography printing. Direct writing molding based on material extrusion has the characteristics of simple equipment and high ceramic solid phase content. However, in the molding process of large-scale components, its precision is seriously affected by gravity and the molding speed is relatively slow. Summary of the Invention

[0004] To overcome the shortcomings of the prior art and meet the requirements for both ceramic solid content and molding accuracy during additive manufacturing, the present invention provides a composite additive manufacturing device and preparation method for ceramic-based multi-component materials. This composite additive manufacturing device performs top-down molding, with both the movable direct-write molding head and the laser head performing point-line-surface molding. This simplifies the molding process, effectively improves molding efficiency, and expands the application of additive manufacturing technology.

[0005] The present invention is achieved by adopting the following technical solutions:

[0006] A composite additive manufacturing device for ceramic-based multi-component materials includes a direct writing head, a laser head, a follower platform, a horizontal motion mechanism, a printing substrate, a lifting mechanism and a resin tank; the laser head is installed at the center of the follower platform, the direct writing head is installed on the adjacent side of the laser head, the follower platform is rotated by a rotating shaft to change the position of the direct writing head, and the follower platform is connected to the horizontal motion mechanism via a hanger; the direct writing head and the laser head are located above the printing substrate, the printing substrate is connected to the lifting mechanism, and the resin tank is located below the printing substrate.

[0007] A further improvement of the present invention is that the follower platform includes a direct writing connecting frame, a laser connecting frame, a rotary bearing, a bearing fixing frame, a rotating shaft, a rotating motor and a hanger; the direct writing forming head is connected to the inner ring of the rotating bearing through the direct writing connecting frame, and the laser head is connected to the center of the inner ring of the rotating bearing through the laser connecting frame; the bearing fixing frame is connected to the outer ring of the rotating bearing, and the hanger is installed on the top to realize the connection with the horizontal motion mechanism; the upper end of the rotating shaft is connected to the rotating motor, and the lower end is installed at the center of the inner ring of the rotating bearing. The rotating motor drives the inner ring of the rotating bearing to rotate, thereby realizing the change of the position of the direct writing forming head.

[0008] A method for composite additive manufacturing of ceramic-based multi-component materials, based on the aforementioned device for composite additive manufacturing of ceramic-based multi-component materials, comprises the following steps:

[0009] Step 1: Use computer 3D modeling software to create the designed 3D model and convert it into a layered path file. The path file is divided into zones according to the design of different materials, and different areas adopt different additive manufacturing methods. The layered path file is then imported into the composite additive manufacturing device;

[0010] Step 2: Prepare ceramic direct writing ink and inject it into the direct writing head;

[0011] Step 3: Prepare short fiber light-curing slurry and inject it into the resin tank;

[0012] Step 4: The direct writing head and the laser head work simultaneously or separately to perform synchronous printing or separate printing;

[0013] Step 5: Based on the cross-sectional data of the current layer model, the program controls the horizontal motion mechanism 7 to drive the follower platform 6 to move along the designed path to form the cross-sectional shape;

[0014] Step 6: After printing the current layer of cross-section, the lifting mechanism drives the printing substrate to descend by one layer thickness;

[0015] Step 7: Repeat steps 4 to 6 until the ceramic preform is printed;

[0016] Step eight: remove the liquid in the preform by freeze drying to obtain a ceramic prototype.

[0017] A further improvement of the present invention is that, in step 2, the preparation method of the ceramic direct writing ink is as follows:

[0018] In the first step, three types of ceramic powders with medium particle sizes of 200 nm-500 nm, 10 μm-20 μm, and 40 μm-80 μm are selected and mixed in a mass ratio of (0.2-0.3): (0.3-0.4): (0.4-0.6) to obtain graded ceramic powders;

[0019] In the second step, the graded ceramic powder is mixed with polyacrylic acid, polyethyleneimine, and deionized water to prepare a high-solid phase ceramic ink with appropriate viscosity, wherein polyacrylic acid and polyethyleneimine are weighed according to the stoichiometric ratio of 1: (0.1-5).

[0020] A further improvement of the present invention is that the ceramic powder is selected from one of silicon carbide, silicon nitride, barium titanate and aluminum oxide.

[0021] A further improvement of the present invention is that in step 3, the preparation method of the short fiber light-curing slurry is as follows:

[0022] In the first step, short fibers with a length of 10 μm-50 μm are selected;

[0023] The second step is to mix hexanediol diacrylate, trimethylolpropane triacrylate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, PEG, and isopropyl alcohol according to the mass percentage of (30wt.%-60wt.%): (30wt.%-60wt.%): (4wt.%-8wt.%): (4wt.%-8wt.%): (5wt.%-10wt.%) to obtain a photosensitive resin;

[0024] The third step is to mix the selected short fibers with the photosensitive resin in a mass ratio of 1:(4-7) to obtain a short fiber photocurable slurry.

[0025] A further improvement of the present invention is that the short fibers are selected from one of short carbon fibers, short silicon carbide fibers, and short silica fibers.

[0026] A further improvement of the present invention is that, in step 4, the synchronous printing method is as follows:

[0027] In the first step, the direct writing head and the laser head are started simultaneously;

[0028] The second step is to rotate the follower platform according to the path data, ensuring that the direct writing head is always behind the laser head in the printing direction.

[0029] In the third step, composite additive manufacturing begins. The laser head polymerizes the ceramic photocurable resin to form a photocurable layer. The direct writing extruded filament is deposited on the photocurable layer to perform a single double-layer printing to achieve material alternation along the Z direction.

[0030] A further improvement of the present invention is that, in step 4, the printing methods are as follows:

[0031] In the first step, the direct writing head 1 and the laser head 5 are started alternately according to the path data;

[0032] In the second step, composite additive manufacturing is started according to the path data. During the molding process, only one of the direct writing molding head 1 and the laser head 5 works, performing a single-layer printing to achieve material alternation in the XY plane.

[0033] The present invention has at least the following beneficial technical effects:

[0034] This invention combines the advantages of direct writing and stereolithography technologies, leveraging stereolithography to ensure material forming accuracy while effectively increasing the solid content of ceramics. Furthermore, a follower platform 6 enables tracking of the direct writing head 1 and laser head 5 during the printing process, enabling the formation of two layers of material in a single print pass. This effectively improves forming efficiency and further expands the application of additive manufacturing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0036] Figure 2 Schematic diagram of the follower platform structure.

[0037] Description of reference numerals:

[0038] 1. Direct writing molding head, 2. Lifting mechanism, 3. Resin tank, 4. Printing substrate, 5. Laser head, 6. Follow-up platform, 7. Horizontal motion mechanism, 8. Hanger, 9. Rotating axis, 10. Rotating bearing, 11. Laser connecting frame, 13. Bearing fixing frame, 12. Rotating motor, 14. Direct writing connecting frame. DETAILED DESCRIPTION

[0039] The present invention is further described below with reference to specific embodiments and accompanying drawings:

[0040] like Figure 1As shown, the present invention provides a ceramic-based multi-material composite additive manufacturing device, including a direct writing molding head 1, a laser head 5, a follower platform 6, a horizontal motion mechanism 7, a hanger 8, a printing substrate 4, a lifting mechanism 2 and a resin tank 3; the laser head 5 is installed at the center of the follower platform 6, the direct writing molding head 1 is installed on the adjacent side of the laser head 5, the follower platform 6 is rotated by the rotating shaft 9 to change the direct writing molding head 1, and the hanger 8 connects the follower platform 6 with the horizontal motion mechanism 7; the printing substrate 4 is located below the direct writing molding head 1 and the laser head 5, the lifting mechanism 2 drives the printing substrate 4 to move up and down along the Z direction, and the resin tank 3 is located at the bottom of the device.

[0041] like Figure 2 As shown, the follower platform 6 includes a direct writing connecting frame 14, a laser connecting frame 11, a rotary bearing 10, a bearing fixing frame 13, a rotating shaft 9 and a rotating motor 12; the direct writing forming head 1 is connected to the inner ring of the rotary bearing 10 through the direct writing connecting frame 14, and the laser head 5 is installed at the center of the inner ring of the rotary bearing 10 through the laser connecting frame 11; the bearing fixing frame 13 is connected to the outer ring of the rotary bearing 10, so that the outer ring of the rotary bearing 10 is relatively fixed; a hanger 8 is installed on the top of the bearing fixing frame 13, and the hanger 8 connects the bearing fixing frame 13 with the horizontal motion mechanism 7; the upper end of the rotating shaft 9 is connected to the rotating motor 12, and the lower end is installed at the center of the inner ring of the rotary bearing 10. The rotating motor 12 drives the inner ring of the rotary bearing 10 to rotate, thereby realizing the change of the position of the direct writing forming head 1 and the laser head 5.

[0042] A composite additive manufacturing method using the above device has the following specific embodiments:

[0043] Example 1

[0044] Preparation of ceramic direct writing ink and short fiber photocurable slurry

[0045] Ceramic direct writing ink:

[0046] In the first step, silicon carbide ceramic powders having a medium particle size of 200 nm, 10 μm, and 40 μm are weighed in a mass ratio of 0.2:0.3:0.5, and are fully mechanically stirred to obtain graded silicon carbide ceramic powders;

[0047] In the second step, 50g of graded silicon carbide ceramic powder was mixed with 10g of deionized water, 0.2g of polyacrylic acid, and 0.0005g of polyethyleneimine, where the stoichiometric ratio of polyacrylic acid to polyethyleneimine was 1:0.1. After sufficient mechanical stirring, a high-solid-phase ceramic ink with shear-thinning rheological properties was prepared.

[0048] The third step is to inject high solid ceramic ink into the direct writing head;

[0049] Short fiber light-curing paste:

[0050] In the first step, hexanediol diacrylate, trimethylolpropane triacrylate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, PEG, and isopropyl alcohol are mixed in a mass percentage of 30 wt. %: 50 wt. %: 4 wt. %: 8 wt. %: 8 wt. %, and the mixture is fully homogenized to obtain a photosensitive resin;

[0051] In the second step, 10 μm long silicon carbide fibers were mixed with photosensitive resin in a mass ratio of 1:4 and fully homogenized to obtain a short silicon carbide fiber photocurable slurry;

[0052] The third step is to inject the short silicon carbide fiber light-curing slurry into the resin tank at 2 / 3 of the liquid level.

[0053] Composite Additive Manufacturing

[0054] Using the 3D printing layering software Simplify3D on a computer, the 3D model was converted into a layered path file based on the material composition design and imported into the composite additive manufacturing device of the present invention. The diameter of the direct writing printing head was selected to be 0.6 mm.

[0055] Perform synchronous printing

[0056] In the first step, the laser is activated to generate a laser beam with a spot diameter of 0.6 mm. Air pressure is supplied, and ceramic ink is extruded from the direct writing head at a flow rate of 100 nL / s.

[0057] In the second step, the follower platform rotates according to the path data to ensure that the direct writing head always follows the laser head during the printing process;

[0058] In the third step, according to the cross-sectional pattern of the model, the horizontal motion mechanism moves at a speed of 600 mm / min. The short silicon carbide fiber photocuring slurry is excited by the laser to form a photocuring layer. The direct writing extruded filament is then deposited on the photocuring layer. A double layer is formed in a single printing path, and finally a ceramic preform with alternating Z-direction materials is completed.

[0059] Freeze drying

[0060] The ceramic preform was freeze-dried at -25°C for 48 hours to sublime the solvent and obtain a ceramic prototype.

[0061] Example 2

[0062] Preparation of ceramic direct writing ink and short fiber photocurable slurry

[0063] Ceramic direct writing ink:

[0064] In the first step, barium titanate ceramic powders having a medium particle size of 500 nm, 20 μm, and 80 μm were weighed in a mass ratio of 0.1:0.3:0.6, and after being fully mechanically stirred, graded barium titanate ceramic powders were obtained;

[0065] In the second step, 50g of graded barium titanate ceramic powder was mixed with 10g of deionized water, 0.2g of polyacrylic acid, and 0.025g of polyethyleneimine, where the stoichiometric ratio of polyacrylic acid to polyethyleneimine was 1:5. After sufficient mechanical stirring, a high-solid-phase ceramic ink with shear-thinning rheological properties was prepared.

[0066] The third step is to inject high solid ceramic ink into the direct writing head;

[0067] Short fiber light-curing paste:

[0068] In the first step, hexanediol diacrylate, trimethylolpropane triacrylate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, PEG, and isopropyl alcohol are mixed in a mass percentage of 60 wt. %: 27 wt. %: 4 wt. %: 4 wt. %: 5 wt. %, and the mixture is fully homogenized to obtain a photosensitive resin;

[0069] In the second step, 50 μm long carbon fibers were mixed with photosensitive resin in a mass ratio of 1:7 and fully homogenized to obtain a short carbon fiber photocurable slurry.

[0070] The third step is to inject the short carbon fiber light-curing slurry into the resin tank at 2 / 3 of the liquid level.

[0071] Composite Additive Manufacturing

[0072] Using the 3D printing layering software Simplify3D on a computer, the 3D model was converted into a layered path file based on the material composition design and imported into the composite additive manufacturing device of the present invention. The diameter of the direct writing printing head was selected to be 0.8 mm.

[0073] Print separately

[0074] In the first step, the laser is started to generate a laser beam with a spot diameter of 0.8 mm;

[0075] In the second step, the follower platform remains fixed, and the horizontal motion mechanism moves at a speed of 600 mm / min according to the cross-sectional pattern of the model. The short carbon fiber photocurable slurry is excited by the laser to form a photocured layer.

[0076] In the third step, air pressure is supplied, and the ceramic ink is extruded from the direct writing head at a flow rate of 120nL / s. The direct writing extrusion filament is deposited on the adjacent side of the photocuring layer, forming a single layer in a single printing path, and finally completing a ceramic preform with alternating materials in the XY plane.

[0077] Freeze drying

[0078] The ceramic preform was freeze-dried at -25°C for 48 hours to sublime the solvent and obtain a ceramic prototype.

[0079] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A composite additive manufacturing method for ceramic-based multi-component materials, characterized in that: The method is based on a composite additive manufacturing device for ceramic-based multi-component materials, which includes a direct writing head, a laser head, a follower platform, a horizontal motion mechanism, a printing substrate, a lifting mechanism, and a resin tank. The laser head is mounted at the center of the follower platform, and the direct writing head is mounted on the adjacent side of the laser head. The follower platform rotates via a rotating shaft to change the position of the direct writing head. The follower platform is connected to the horizontal motion mechanism via a hanger. The direct write molding head and laser head are located above the printing substrate, the printing substrate is connected to the lifting mechanism, and the resin tank is located below the printing substrate; The method comprises the following steps: Step 1: Use computer 3D modeling software to create the designed 3D model and convert it into a layered path file. The path file is divided into zones according to the design of different materials, and different areas adopt different additive manufacturing methods. The layered path file is then imported into the composite additive manufacturing device; Step 2: preparing a high-solid-phase ceramic ink for direct writing ceramics and injecting it into a direct writing head; Step 3: Prepare short fiber light-curing slurry and inject it into the resin tank; Step 4: The direct writing head and the laser head work simultaneously to perform synchronous printing; Step 5: Based on the cross-sectional data of the current layer model, the program controls the horizontal motion mechanism to drive the follower platform to move along the designed path to form the cross-sectional shape; Step 6: After printing the current layer of cross-section, the lifting mechanism drives the printing substrate to descend by one layer thickness; Step 7: Repeat steps 4 to 6 until the ceramic preform is printed; Step eight: remove the liquid in the preform by freeze drying to obtain a ceramic prototype.

2. The method for composite additive manufacturing of ceramic-based multi-component materials according to claim 1, characterized in that: In step 2, the preparation method of ceramic direct writing ink is as follows: In the first step, three types of ceramic powders with medium particle sizes of 200 nm-500 nm, 10 μm-20 μm, and 40 μm-80 μm are selected and mixed in a mass ratio of (0.2-0.3): (0.3-0.4): (0.4-0.6) to obtain graded ceramic powders; In the second step, the graded ceramic powder is mixed with polyacrylic acid, polyethyleneimine, and deionized water to prepare a high-solid phase ceramic ink with appropriate viscosity, wherein polyacrylic acid and polyethyleneimine are weighed according to the stoichiometric ratio of 1: (0.1-5).

3. The method for composite additive manufacturing of ceramic-based multi-component materials according to claim 2, characterized in that: The ceramic powder is selected from one of silicon carbide, silicon nitride, barium titanate and aluminum oxide.

4. The method for composite additive manufacturing of ceramic-based multi-component materials according to claim 1, characterized in that: In step 3, the preparation method of the short fiber light-curing slurry is as follows: In the first step, short fibers with a length of 10 μm-50 μm are selected; In the second step, hexanediol diacrylate, trimethylolpropane triacrylate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, PEG, and isopropyl alcohol are mixed according to the mass percentage of (30 wt.%-60 wt.%): (30 wt.%-60 wt.%): (4 wt.%-8 wt.%): (4 wt.%-8 wt.%): (5 wt.%-10 wt.%) to obtain a photosensitive resin; In the third step, the selected short fibers are mixed with photosensitive resin in a mass ratio of 1:(4-7) to obtain short fiber photocurable slurry.

5. The method for composite additive manufacturing of ceramic-based multi-component materials according to claim 4, characterized in that: The short fibers are selected from one of short carbon fibers, short silicon carbide fibers, and short silica fibers.

6. The ceramic-based multi-component composite additive manufacturing method according to claim 1, characterized in that: In step 4, the synchronous printing method is as follows: In the first step, the direct writing head and the laser head are started simultaneously; The second step is to rotate the follower platform according to the path data, ensuring that the direct writing head is always behind the laser head in the printing direction. In the third step, composite additive manufacturing begins. The laser head polymerizes the ceramic photocurable resin to form a photocurable layer. The direct writing extruded filament is deposited on the photocurable layer to perform a single double-layer printing to achieve material alternation along the Z direction.

7. The ceramic-based multi-component material composite additive manufacturing method according to claim 1, characterized in that: The follow-up platform includes a direct writing connecting frame, a laser connecting frame, a rotary bearing, a bearing fixing frame, a rotating shaft, a rotating motor and a hanger; the direct writing forming head is connected to the inner ring of the rotary bearing through the direct writing connecting frame, and the laser head is connected to the center of the inner ring of the rotary bearing through the laser connecting frame; the bearing fixing frame is connected to the outer ring of the rotary bearing, and a hanger is installed on the top to realize the connection with the horizontal motion mechanism; the upper end of the rotating shaft is connected to the rotary motor, and the lower end is installed at the center of the inner ring of the rotary bearing. The rotating motor drives the inner ring of the rotary bearing to rotate, thereby realizing the change of the position of the direct writing forming head.

Images