An ultrasonic-assisted continuous fiber-reinforced ceramic matrix composite 3D printing method

Abstract

An ultrasonic-assisted continuous fiber-reinforced ceramic matrix composite 3D printing method, which mixes photosensitive resin for photocuring with ceramic powder in proportion, configures different photocured ceramic slurries with different ceramic powders, respectively fills different storage barrels, and under the action of air pressure, the photocured ceramic slurry enters the feeding port from the screw extrusion, the photocured ceramic slurry is fully combined with the continuous fiber at the nozzle and is extruded by the screw, and after ultrasonic vibration mixing, it is extruded on the printing platform and is rapidly cured by the annular array ultraviolet light, so as to realize the preparation of the continuous fiber-reinforced ceramic matrix composite; the mixing uniformity of the photocured ceramic slurry is realized by adjusting the intensity of the ultrasonic wave, the curing depth is controlled by adjusting the intensity of the annular array ultraviolet light, and the printing precision and the printing quality are improved; the printing quality and the structural strength are effectively improved, and the high-performance integrated rapid forming manufacturing of complex structure ceramics can be realized.

Description

Technical Field

[0001] This invention belongs to the field of rapid prototyping technology, specifically relating to an ultrasonic-assisted 3D printing method for continuous fiber-reinforced ceramic matrix composites. Background Technology

[0002] Continuous fiber ceramic matrix composites have good wave transmission and heat resistance, and have great application prospects in aerospace and other fields. Existing preparation processes mainly use hand lay-up molding and compression molding, but these methods cannot meet the needs of complex parts and small-batch production.

[0003] 3D printing methods for continuous fiber reinforced ceramic matrix composites can adapt to the printing of complex parts, reduce production costs, and provide a new approach to the manufacturing of continuous fiber ceramic matrix composites. For example, the patent application titled "3D Printing Method for Continuous Fiber Reinforced Ceramic Matrix Composites Based on Photocurable Ceramic Slurry and Fiber Co-extrusion" (Publication No.: CN118721363A) uses a screw extrusion of ceramic slurry and ultraviolet light for curing to achieve the molding of continuous fiber ceramic composite structures. However, this method produces ceramic slurry with problems such as air bubbles leading to discontinuous extrusion, high porosity of the sample, uneven slurry dispersion, and untimely curing, resulting in low mechanical properties of the formed structure that cannot meet the needs of practical applications. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide an ultrasonic-assisted 3D printing method for continuous fiber reinforced ceramic matrix composites, thereby achieving the preparation of high-performance continuous fiber reinforced ceramic matrix composites and effectively improving printing quality and structural strength. The use of a ring array of ultraviolet light can achieve rapid and uniform curing of ceramic slurry, and combined with structural design, it can realize high-performance integrated rapid prototyping manufacturing of complex ceramic structures.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An ultrasonic-assisted 3D printing method for continuous fiber reinforced ceramic matrix composites involves mixing photosensitive resin for photocuring with ceramic powder in a specific ratio, preparing different photocurable ceramic slurries using different ceramic powders and loading them into different storage cylinders, extruding the photocurable ceramic slurries through the feed inlet under air pressure, fully combining the photocurable ceramic slurries with continuous fibers at the nozzle, extruding them through the screw, mixing them with ultrasonic vibration, and then extruding them together onto the printing platform where they are rapidly cured by a ring array of ultraviolet light, thus realizing the preparation of continuous fiber reinforced ceramic matrix composites.

[0007] The uniformity of mixing of photocurable ceramic slurry is achieved by adjusting the intensity of ultrasonic waves, and the curing depth is controlled by adjusting the intensity of the ring array ultraviolet light, thereby improving printing accuracy and printing quality.

[0008] An ultrasound-assisted 3D printing method for continuous fiber-reinforced ceramic matrix composites includes the following steps:

[0009] 1) Draw a 3D model of the printed part, import the model into slicing software to export the path G-code file, use a Python program to convert the path G-code file into a robotic arm control program, and install the 3D printing device on the robotic arm.

[0010] 2) Prepare photocurable ceramic slurry by mixing photocurable resin and ceramic powder in a certain proportion to prepare a variety of photocurable ceramic slurries. Put different photocurable ceramic slurries into storage cylinders, squeeze them into the feed port under air pressure, and then precisely extrude them by the screw.

[0011] 3) The photocurable ceramic slurry is extruded through a screw to the end of the printing nozzle. Continuous fibers enter the fiber channel from the side inlet of the printing nozzle. After being initially mixed with the photocurable ceramic slurry in the printing nozzle, they are extruded together on the printing platform. Under the vibration of ultrasonic waves, the continuous fibers and the photocurable ceramic slurry are mixed again to defoam.

[0012] 4) After the continuous fiber and the photocurable ceramic slurry are fully combined, the photocurable ceramic slurry is rapidly cured under the irradiation of the ring array of ultraviolet lamps. The photocurable continuous fiber reinforced ceramic matrix composite preform is formed by printing layer by layer. The ring array of ultraviolet lamps is installed on the printing nozzle and moves together with the robotic arm.

[0013] 5) The photocurable continuous fiber reinforced ceramic matrix composite preform is subjected to high-temperature sintering and heat preservation treatment to obtain the final photocurable continuous fiber reinforced ceramic matrix composite.

[0014] In step 2), there is at least one storage cylinder, and each storage cylinder contains a different photocurable ceramic slurry. The specific number of storage cylinders depends on the printing process requirements. The switching of different photocurable ceramic slurries is achieved by controlling the air pressure of each storage cylinder.

[0015] In step 2), the ceramic powder in the photocurable ceramic slurry is one or more of silicon dioxide, silicon nitride, and silicon carbide.

[0016] In step 2), the ceramic powder used is spherical silicon nitride with different particle sizes, specifically silicon nitride powder with particle sizes of 500 nanometers and 45 micrometers.

[0017] In step 3), the ultrasonic vibration occurs in two ways: one is internal ultrasonic assistance, where ultrasonic waves are generated inside the printing nozzle for assistance; the other is external ultrasonic assistance, where ultrasonic waves are generated outside the printing nozzle after the photocurable ceramic slurry and continuous fibers are extruded. The power of the ultrasonic generator can be adjusted.

[0018] In step 4), the ring array UV lamp uses eight 395nm UV lamp beads soldered onto a PCB circuit board, and a constant current circuit is used to control the current passing through the UV lamp.

[0019] A 3D printing device used in an ultrasonic-assisted continuous fiber reinforced ceramic matrix composite material 3D printing method includes a stepper motor 1, which is connected to a screw 2. The screw 2 extends into a feed inlet 4, which is connected to a storage cylinder 3 and a printing nozzle 6. Continuous fibers 5 are introduced into the fiber channel on the side of the printing nozzle 6. An ultrasonic generator 7 is provided on the outside of the printing nozzle 6, and a ring array of ultraviolet lamps 8 is coaxially provided on the outside of the printing nozzle 6.

[0020] The ring array ultraviolet lamp 8 consists of a PCB circuit board 8-1 and ultraviolet lamp beads 8-2 mounted on it. The central through hole 8-3 of the PCB circuit board 8-1 is fitted onto the printing nozzle 6.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention provides an ultrasonic-assisted continuous fiber reinforced ceramic matrix composite material 3D printing method, which can uniformly cure ceramic slurry by using a ring array of ultraviolet lamps, thus improving the problem of insufficient curing in the shadow surface of a single light source.

[0023] 2. The photocurable ceramic slurry of the present invention can achieve rapid and uniform curing by irradiation with a ring array of ultraviolet light, without the need for additional operations such as heating.

[0024] 3. This invention uses a printing nozzle to completely encapsulate continuous fibers with photocurable ceramic slurry. Ultrasonic waves enhance the interfacial bonding between the continuous fibers and the ceramic slurry, reducing the porosity of the ceramic matrix composite. The combination of continuous fibers and the ceramic matrix forms a continuous fiber ceramic matrix composite, which significantly enhances the mechanical properties of the matrix and enables the molding and manufacturing of high-performance ceramic matrix composites. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the 3D printing device used in Embodiment 1 of the present invention.

[0026] Figure 2 This is a schematic diagram of the ring array ultraviolet lamp structure in Embodiment 1 of the present invention.

[0027] Figure 3 This is a schematic diagram of internal and external ultrasonic assistance in Embodiment 1 of the present invention. Detailed Implementation

[0028] To further understand the present invention, a more comprehensive description of the invention will be given below in conjunction with embodiments and accompanying drawings. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the invention and not for limiting the scope of the claims of the invention.

[0029] Example 1: As Figure 1 As shown, a 3D printing device used in an ultrasonic-assisted continuous fiber reinforced ceramic matrix composite 3D printing method includes a stepper motor 1, a screw 2, a storage cylinder 3, a feed inlet 4, continuous fibers 5, a printing nozzle 6, an ultrasonic generator 7, and a ring array of ultraviolet lamps 8. The stepper motor 1 is connected to the screw 2 via a coupling. The screw 2 extends into the feed inlet 4, which is connected to the storage cylinder 3. Photocurable ceramic slurry enters the printing device from the storage cylinder 3 through the feed inlet 4 under air pressure. Controlling the air pressure of each storage cylinder 3 allows for switching between different photocurable ceramic slurries. The feed port 4 is connected to the printing nozzle 6. The stepper motor 1 drives the screw 2 to rotate and extrude the photocurable ceramic slurry into the printing nozzle 6. The fiber channel on the side of the printing nozzle 6 is filled with continuous fiber 5. The continuous fiber 5 enters the printing nozzle 6 and mixes with the photocurable ceramic slurry before being extruded together. An ultrasonic generator 7 is provided on the outside of the printing nozzle 6. A ring array of ultraviolet lamps 8 is coaxially provided on the outside of the printing nozzle 6. The mixture extruded together is then vibrated by the ultrasonic generator 7 to mix and defoam again, and then rapidly cured by the ring array of ultraviolet lamps 8 to form a continuous fiber photocurable ceramic matrix composite material.

[0030] like Figure 2 As shown, the ring array ultraviolet lamp 8 consists of a PCB circuit board 8-1 and ultraviolet lamp beads 8-2 mounted on it. The central through hole 8-3 of the PCB circuit board 8-1 is fitted onto the printing nozzle 6, generating ring ultraviolet light to uniformly cure the photocurable ceramic slurry in all directions.

[0031] An ultrasound-assisted 3D printing method for continuous fiber-reinforced ceramic matrix composites includes the following steps:

[0032] 1) Draw a 3D model of the printed part, import the model into slicing software to export the path G-code file, use a Python program to convert the path G-code file into a robotic arm control program, and install the 3D printing device on the robotic arm.

[0033] This implementation example prints a cuboid specimen with a length of 50mm, a width of 5mm, and a height of 3mm;

[0034] 2) Prepare photocurable ceramic slurry by mixing photocurable resin and ceramic powder in a certain proportion to prepare a variety of photocurable ceramic slurries. Put different photocurable ceramic slurries into storage cylinders, squeeze them into the feed port under air pressure, and then precisely extrude them by the screw.

[0035] In this embodiment, the photocurable resin is pentaerythritol tetraacrylate and tripropylene glycol diacrylate (containing the stabilizer hydroquinone). The photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone. 5g each of pentaerythritol tetraacrylate and tripropylene glycol diacrylate (containing the stabilizer hydroquinone), and 3g of 2-hydroxy-2-methyl-1-phenyl-1-propanone are poured into a light-shielded beaker. Then, 56.4g of 500nm β-phase silicon nitride and 10.6g of 45µm β-phase silicon nitride are uniformly mixed and placed into the light-shielded beaker. The mixture is then stirred for 5 minutes at room temperature using a mixer to obtain a uniform silicon nitride photocurable ceramic slurry. The ceramic powder uses spherical silicon nitride with different particle sizes, which can play a role in fine grain strengthening to improve mechanical properties.

[0036] 3) The silicon nitride photocurable ceramic slurry is extruded through the screw 2 to the end of the printing nozzle 6. The silicon nitride continuous fiber enters the fiber channel from the side entrance of the printing nozzle 6. After being initially mixed with the silicon nitride photocurable ceramic slurry in the printing nozzle 6, it is extruded together on the printing platform. Under the vibration of ultrasound, the silicon nitride continuous fiber and the silicon nitride photocurable ceramic slurry are mixed again to defoam.

[0037] The ultrasonic vibration in step 3) occurs in two ways, such as... Figure 3 As shown, one type is internal ultrasonic assistance, which involves generating ultrasonic waves inside the printing nozzle for assistance; the other type is external ultrasonic assistance, which involves ultrasonic waves outside the printing nozzle after the photocurable ceramic slurry and continuous fibers are extruded. The power of the ultrasonic generator can be adjusted, and the bonding performance between the photocurable ceramic slurry and continuous fibers can be adjusted by controlling the power of the ultrasonic waves, thereby controlling the porosity.

[0038] In this embodiment, three sets of samples were printed under conditions of no ultrasonic assistance, internal ultrasonic assistance, and external ultrasonic assistance, respectively.

[0039] 4) After the silicon nitride continuous fiber and silicon nitride photocurable ceramic slurry are fully combined, the silicon nitride photocurable ceramic slurry is rapidly cured under the irradiation of the ring array UV lamp 8. The photocurable continuous fiber reinforced ceramic matrix composite preform is formed by printing layer by layer. In order to improve the curing effect of the UV lamp and achieve uniform curing, a ring array UV lamp is designed for curing. The ring array UV lamp is installed on the printing nozzle 6 and moves together with the robotic arm.

[0040] 5) The photocurable continuous fiber reinforced ceramic matrix composite preform is subjected to high-temperature sintering and heat preservation treatment to obtain the final photocurable continuous fiber reinforced ceramic matrix composite.

[0041] In this embodiment, a photocurable continuous fiber reinforced ceramic matrix composite preform was heated to 1100℃ at a heating rate of 1℃ / min, held at that temperature for 3 hours, and then naturally cooled to obtain Si3N. 4f / Si3N4 composite material. This embodiment uses Si3N... 4f The porosity and flexural strength of the Si3N4 composite material are shown in Table 1.

[0042] Table 1

[0043]

[0044] Table 1 shows that, compared with the unassisted ultrasonic process, the porosity of the silicon nitride ceramic matrix composite material is significantly improved after ultrasonic assistance, and the flexural strength is also significantly improved. This is because the high-frequency vibration of the ultrasonic wave can agitate and mix the ceramic slurry, eliminate micro-bubbles in the slurry and reduce porosity. At the same time, the local flow mixes with the fiber, improving the bonding performance between the fiber and the ceramic matrix, thereby improving the flexural strength.

[0045] Example 2 differs from Example 1 in that: step 2) involves taking 52.1g of 500nm silicon carbide and 14.9g of 45µm silicon carbide; step 3) uses external ultrasonic assistance. This example yields Si3N. 4f The porosity and flexural strength of the / SiC composite material are shown in Table 2.

[0046] Table 2

[0047]

[0048] Example 3 differs from Example 1 in that continuous alumina fibers are used in step 3). This example yields Al3O4. 2f The porosity and flexural strength of the / Si3N4 composite material are shown in Table 3.

[0049] Table 3

[0050]

Claims

1. A method for 3D printing ultrasonically assisted continuous fiber reinforced ceramic matrix composites, characterized in that, Includes the following steps: 1) Draw a 3D model of the printed part, import the model into slicing software to export the path G-code file, use a Python program to convert the path G-code file into a robotic arm control program, and install the 3D printing device on the robotic arm. 2) Prepare photocurable ceramic slurry by mixing photocurable resin and ceramic powder in a certain proportion to prepare a variety of photocurable ceramic slurries. Put different photocurable ceramic slurries into storage cylinders, squeeze them into the feed port under air pressure, and then precisely extrude them by the screw. The number of storage cylinders is at least one, and each storage cylinder contains a different photocurable ceramic slurry. The specific number of storage cylinders depends on the printing process requirements. The switching of different photocurable ceramic slurries is achieved by controlling the air pressure of each storage cylinder. 3) The photocurable ceramic slurry is extruded through a screw to the end of the printing nozzle. Continuous fibers enter the fiber channel from the side inlet of the printing nozzle. After being initially mixed with the photocurable ceramic slurry in the printing nozzle, they are extruded together on the printing platform. Under the vibration of ultrasonic waves, the continuous fibers and the photocurable ceramic slurry are mixed again to defoam. The ultrasonic vibration has two modes: one is internal ultrasonic assistance, which is to generate ultrasonic waves inside the printing nozzle for assistance; the other is external ultrasonic assistance, which is to generate ultrasonic waves outside the printing nozzle after the photocurable ceramic slurry and continuous fibers are extruded. The power of the ultrasonic generator can be adjusted. The uniformity of mixing of the photocurable ceramic slurry can be achieved by adjusting the intensity of the ultrasonic waves. 4) After the continuous fiber and the photocurable ceramic slurry are fully combined, the photocurable ceramic slurry is rapidly cured under the irradiation of the ring array of ultraviolet lamps. The photocurable continuous fiber reinforced ceramic matrix composite preform is formed by printing layer by layer. The ring array of ultraviolet lamps is installed on the printing nozzle and moves together with the robotic arm. By adjusting the intensity of the ultraviolet light from the ring array, the curing depth can be controlled, thereby improving printing accuracy and quality. 5) The photocurable continuous fiber reinforced ceramic matrix composite preform is subjected to high-temperature sintering and heat preservation treatment to obtain the final photocurable continuous fiber reinforced ceramic matrix composite.

2. The method according to claim 1, characterized in that, In step 2), the ceramic powder in the photocurable ceramic slurry is one or more of silicon dioxide, silicon nitride, and silicon carbide.

3. The method according to claim 1, characterized in that, In step 2), the ceramic powder used is spherical silicon nitride with different particle sizes, specifically silicon nitride powder with particle sizes of 500 nanometers and 45 micrometers.

4. The method according to claim 1, characterized in that, In step 4), the ring array UV lamp uses eight 395nm UV lamp beads soldered onto a PCB circuit board, and a constant current circuit is used to control the current passing through the UV lamp.

5. A 3D printing apparatus for implementing the ultrasonic-assisted continuous fiber reinforced ceramic matrix composite 3D printing method according to any one of claims 1-4, characterized in that: It includes a stepper motor (1), the stepper motor (1) and the screw (2) are connected, the screw (2) extends into the feed port (4), the feed port (4) and the storage cylinder (3) are connected, the feed port (4) and the printing nozzle (6) are connected, the fiber channel on the side of the printing nozzle (6) is through which continuous fiber (5) is introduced, an ultrasonic generator (7) is provided on the outside of the printing nozzle (6), and a ring array of ultraviolet lamps (8) is coaxially provided on the outside of the printing nozzle (6).

6. The apparatus according to claim 5, characterized in that: The ring array ultraviolet lamp (8) consists of a PCB circuit board (8-1) and ultraviolet lamp beads (8-2) mounted on it. The central through hole (8-3) of the PCB circuit board (8-1) is fitted onto the printing nozzle (6).

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