Photocurable 3D printing fiber-reinforced ceramic matrix composite slurry and preparation method

Abstract

The application provides a photocured 3D printing fiber-reinforced ceramic-based composite slurry and a preparation method thereof, which comprises a ceramic precursor powder, a reinforcing fiber, a photosensitive resin mixture and a polymer dispersant. The application provides a photocured 3D printing fiber-reinforced ceramic-based composite slurry and a preparation method thereof, by introducing a ceramic precursor powder with a lower absorbance into the slurry, the problems of low curing thickness and long forming time of non-oxide ceramic powder with high absorbance in the photocured forming printing process can be solved. The application can improve the slurry curing thickness, shorten the forming time, and thus effectively improve the printing forming efficiency.

Description

Technical Field

[0001] This invention belongs to the field of 3D printing technology, specifically relating to a photocurable 3D printing fiber-reinforced ceramic matrix composite slurry and its preparation method. Background Technology

[0002] Currently, when using photopolymer 3D printing to produce fiber-reinforced ceramic matrix composites, the main method is to mix ceramic powder and reinforcing fibers to prepare the slurry. This method has the following problems: For non-oxide ceramic powders with high light absorption values, such as silicon carbide and silicon nitride, they have relatively high absorption and scattering of ultraviolet light, which makes it difficult for the slurry to cure during the photopolymerization process, resulting in problems such as low curing thickness and long molding time. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a photocurable 3D printing fiber-reinforced ceramic matrix composite slurry and its preparation method, which can effectively solve the above-mentioned problems.

[0004] The technical solution adopted in this invention is as follows:

[0005] This invention provides a photocurable 3D printing fiber-reinforced ceramic matrix composite slurry, comprising ceramic precursor powder, reinforcing fibers, a mixture of photosensitive resin and a polymeric dispersant.

[0006] Preferably, the volume ratio of each component is as follows: the volume of the ceramic precursor powder is 11 to 31 parts; the volume of the reinforcing fiber is 5 to 25 parts; the volume of the photosensitive resin mixture is 44 to 74 parts; and the volume of the polymeric dispersant is 0.01 to 0.03 parts.

[0007] Preferably, it further includes 0 to 30 parts by volume of ceramic powder, wherein the ceramic powder is silicon carbide powder and the particle size of the ceramic powder is 4 to 40 μm.

[0008] Preferably, the ceramic precursor powder is any one of polycarbosilane, polysiloxane, and polysilazane, and the particle size of the ceramic precursor powder is 1 to 100 μm.

[0009] Preferably, the reinforcing fiber is any one or a mixture of several of chopped carbon fibers and silicon carbide fibers; the length of the reinforcing fiber is 50 to 500 μm.

[0010] Preferably, the photosensitive resin mixture is a mixture of acrylate monomers, prepolymers, plasticizers, and photoinitiators.

[0011] Preferably, the acrylate monomer is a mixture of multiple acrylate monomers; the prepolymer is one or a mixture of several of polyurethane acrylate prepolymers and polyester acrylate prepolymers; the plasticizer is polyethylene glycol; and the photoinitiator is phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0012] Preferably, the polymeric dispersant is one or a mixture of several of SP710 polymeric dispersant, BYK111 polymeric dispersant, KOS110 polymeric dispersant, 4200 polymeric dispersant and 20000 polymeric dispersant.

[0013] This invention also provides a method for preparing a photocurable 3D printing fiber-reinforced ceramic matrix composite slurry, comprising the following steps:

[0014] Step S1, Preparation of ceramic precursor powder:

[0015] Step S1.1: Place the liquid ceramic precursor of the formula amount in an oven for heat curing treatment. The heat curing temperature is 120-250℃ and the heat curing time is 2-4h.

[0016] Step S1.2: The ceramic precursor after thermosetting in step S1.1 is placed in a ball mill jar for ball milling. The ball milling speed is 100-400 rpm and the ball milling time is 2-6 h to obtain coarse powder of ceramic precursor.

[0017] Step S1.3: The coarse powder of ceramic precursor is sieved using a sieve to obtain ceramic precursor powder of the required particle size.

[0018] Step S2, preparing fiber-reinforced ceramic matrix composite slurry:

[0019] The ceramic precursor powder, reinforcing fiber, photosensitive resin mixture and polymeric dispersant of the specified amount are added sequentially into the material tank and stirred with a homogenizing mixer to obtain a uniformly mixed fiber-reinforced ceramic matrix composite slurry.

[0020] The photopolymerizable 3D printing fiber-reinforced ceramic matrix composite slurry and its preparation method provided by this invention have the following advantages:

[0021] This invention provides a photopolymerizable 3D printing fiber-reinforced ceramic matrix composite slurry and its preparation method. By introducing ceramic precursor powder with lower absorbance into the slurry, the problems of low curing thickness and long molding time of high-absorbance non-oxide ceramic powders in the photopolymerization process can be solved. This invention can increase the curing thickness of the slurry and shorten the molding time, thereby effectively improving the printing efficiency. Attached Figure Description

[0022] Figure 1A schematic flowchart illustrating a method for preparing a photopolymerizable 3D printing fiber-reinforced ceramic matrix composite slurry provided by this invention;

[0023] Figure 2 Photographs of the printed blank samples from experimental examples of this invention;

[0024] Figure 3 Interlayer electron micrograph of the printed green blank sample in the experimental example of this invention;

[0025] Figure 4 The absorbance diagrams are for silicon carbide powder and polycarbosilane powder. Detailed Implementation

[0026] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention 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 and are not intended to limit the invention.

[0027] This invention provides a photopolymerizable 3D printing fiber-reinforced ceramic matrix composite slurry and its preparation method. By introducing ceramic precursor powder with lower absorbance into the slurry, the problems of low curing thickness and long molding time of high-absorbance non-oxide ceramic powders in the photopolymerization process can be solved. This invention can increase the curing thickness of the slurry and shorten the molding time, thereby effectively improving the printing efficiency.

[0028] refer to Figure 1 This invention provides a photocurable 3D printing fiber-reinforced ceramic matrix composite slurry, comprising ceramic precursor powder, reinforcing fibers, a photosensitive resin mixture, and a polymeric dispersant. The volume ratios of the components are as follows: the ceramic precursor powder is 11-31 parts; the reinforcing fibers are 5-25 parts; the photosensitive resin mixture is 44-74 parts; and the polymeric dispersant is 0.01-0.03 parts.

[0029] The ceramic precursor powder is any one of polycarbosilane, polysiloxane, and polysilazane, and the particle size of the ceramic precursor powder is 1–100 μm. The ceramic precursor powder is prepared by thermosetting a liquid ceramic precursor, which is any one of silicon-based ceramic precursor polymers such as polycarbosilane, polysiloxane, and polysilazane.

[0030] The reinforcing fiber is any one or a mixture of several reinforcing fibers such as chopped carbon fiber and silicon carbide fiber; the length of the reinforcing fiber is 50 to 500 μm.

[0031] The photosensitive resin mixture is a mixture of acrylate monomers, prepolymers, plasticizers, and photoinitiators.

[0032] The acrylate monomer is a mixture of various acrylate monomers; the prepolymer is one or a mixture of several acrylate prepolymers such as polyurethane acrylate prepolymer and polyester acrylate prepolymer; the plasticizer is polyethylene glycol (PEG-200); and the photoinitiator is phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO).

[0033] The polymeric dispersant is one or a mixture of several of the following: SP710 polymeric dispersant, BYK111 polymeric dispersant, KOS110 polymeric dispersant, 4200 polymeric dispersant, and 20000 polymeric dispersant.

[0034] The photopolymerizable 3D printing fiber-reinforced ceramic matrix composite slurry provided by this invention comprises ceramic precursor powder, reinforcing fibers, a photosensitive resin mixture, and a polymeric dispersant. Depending on actual needs, 0-30 parts by volume of ceramic powder, wherein the ceramic powder is silicon carbide powder with a particle size of 4-40 μm, can also be added to the composite slurry.

[0035] This invention also provides a method for preparing a photocurable 3D printing fiber-reinforced ceramic matrix composite slurry, comprising the following steps:

[0036] Step S1, Preparation of ceramic precursor powder:

[0037] Step S1.1: Place the liquid ceramic precursor of the formula amount in an oven for heat curing treatment. The heat curing temperature is 120-250℃ and the heat curing time is 2-4h.

[0038] Step S1.2: The ceramic precursor after thermosetting in step S1.1 is placed in a ball mill jar for ball milling. The ball milling speed is 100-400 rpm and the ball milling time is 2-6 h to obtain coarse powder of ceramic precursor.

[0039] Step S1.3: The coarse powder of ceramic precursor is sieved using a sieve to obtain ceramic precursor powder of the required particle size.

[0040] Step S2, preparing fiber-reinforced ceramic matrix composite slurry:

[0041] The ceramic precursor powder, reinforcing fiber, photosensitive resin mixture and polymeric dispersant of the specified amount are added sequentially into the material tank and stirred with a homogenizing mixer to obtain a uniformly mixed fiber-reinforced ceramic matrix composite slurry.

[0042] To ensure the slurry is mixed evenly, each component should be added separately, and after each addition, it should be stirred with a homogenizer before adding and stirring the next component.

[0043] This invention provides a photopolymerizable 3D printing fiber-reinforced ceramic matrix composite slurry and its preparation method. By introducing ceramic precursor powder with lower absorbance into the slurry, the problems of low curing thickness and long molding time of high-absorbance non-oxide ceramic powders in the photopolymerization process can be solved. This invention can increase the curing thickness of the slurry and shorten the molding time, thereby effectively improving the printing efficiency.

[0044] The following experimental and control examples verify that the fiber-reinforced ceramic matrix composite slurry prepared in this invention can improve the slurry curing thickness.

[0045] Experimental example:

[0046] The slurry used in this embodiment for photopolymerizing 3D printing fiber-reinforced ceramic matrix composites includes polycarbosilane powder, chopped carbon fibers, acrylate monomers, prepolymer, plasticizer, photoinitiator, and polymeric dispersant. The specific slurry preparation process is as follows:

[0047] Preparation of polycarbosilane powder: Liquid polycarbosilane was thermally cured at 150℃ for 4 hours, and then ball-milled at a speed of 300 r / min for 4 hours. After ball milling, polycarbosilane powder with a particle size of 1-10 μm was obtained.

[0048] Preparation of the photosensitive resin mixture: Ethoxytrimethylolpropane triacrylate (TMPEO3TA), polyurethane acrylate (PUA), PGE-200, and BAPO were added sequentially to a container in a certain mass ratio. The container was then placed on a magnetic stirrer and mixed uniformly at a speed of 800 r / min for 1 h to prepare a uniformly mixed photosensitive resin mixture. The mass ratio of PUA to TMPEO3TA was 0.143:1; the mass ratio of PEG-200 to PUA+TMPEO3TA was 0.25:1; and BAPO accounted for 3% of the total mass of TMPEO3TA, PUA, and PEG-200.

[0049] Preparation of fiber-reinforced ceramic matrix composite slurry: A photosensitive resin mixture, polycarbosilane powder, and a polymeric dispersant were mixed and stirred in a homogenizer at 1500 r / min for 1 min. Short-cut carbon fibers were then added, and the mixture was stirred again at 1500 r / min for 2 min. Finally, a uniformly mixed fiber-reinforced ceramic matrix composite slurry was obtained. The slurry contained the following components: photosensitive resin mixture volume content 63.99%; polycarbosilane powder volume content 11%; short-cut carbon fibers volume content 25%; and dispersant 4200 with a volume content of 0.01%.

[0050] The fiber-reinforced ceramic matrix composite slurry prepared in this embodiment has a viscosity of 2836 mPa·s under a shear rate of 100 1 / s. The cured thickness was tested using a photopolymerization printing device with an ultraviolet wavelength of 405 nm and an exposure power of 30.50 mW / cm². 2 The cured thickness of the slurry at different exposure times is shown in Table 1:

[0051] Table 1:

[0052] Exposure time (s) 4 6 8 10 12 14 Curing thickness (μm) 106 125 134 150 171 182

[0053] The fiber-reinforced ceramic matrix composite slurry prepared in the experimental example was printed using a photopolymerization printing device to produce flexural strength test specimens (36mm×4mm×3mm). The printing parameters were an exposure power of 30.50mw / cm. 2 Exposure time 10s, printing layer thickness 50μm, the printed spline preform is as follows Figure 2 As shown, the surface quality of the sample is good, with no obvious defects. Figure 3 The electron microscope image shows the interlayer bonding of the sample blank, indicating that there are no cracks and that the slurry can be used to form and print the sample.

[0054] Control Example: The polycarbosilane powder in the experimental example was completely replaced with silicon carbide powder of the same particle size, while all other components and proportions remained unchanged. The prepared slurry was then used to test the cured thickness using a UV-curing printer. The UV-curing equipment used had an ultraviolet wavelength of 405nm and an exposure power of 30.50mw / cm². 2 The cured thickness of the slurry at different exposure times is shown in Table 2:

[0055] Table 2:

[0056] Exposure time (s) 4 6 8 10 12 14 Curing thickness (μm) 63 78 81 93 97 110

[0057] Comparing Tables 1 and 2, it was found that under the same exposure power and exposure time, the cured thickness of the slurry prepared in the experimental example of this invention was greater than that of the slurry prepared in the control example. This indicates that the curing ability of the slurry formulated using polycarbosilane powder is superior to that formulated using silicon carbide powder. This is mainly because the absorbance of polycarbosilane powder at a wavelength of 405 nm is only 0.067, which is much smaller than that of silicon carbide powder (0.618). Figure 4 As shown. Therefore, through experimental and control examples, it is verified that the introduction of ceramic precursor powder with lower absorbance in this invention can improve the slurry curing thickness.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a photocurable 3D printing fiber-reinforced ceramic matrix composite slurry, characterized in that, The photocurable 3D printing fiber-reinforced ceramic matrix composite slurry includes polycarbosilane powder, chopped carbon fibers, acrylate monomers, prepolymer, plasticizer, photoinitiator, and polymeric dispersant; the specific slurry preparation process is as follows: Preparation of polycarbosilane powder: Liquid polycarbosilane was thermally cured at 150℃ for 4 hours, and then ball-milled at a speed of 300 r / min for 4 hours. After ball milling, polycarbosilane powder with a particle size of 1-10 μm was obtained. Preparation of the photosensitive resin mixture: Ethoxytrimethylolpropane triacrylate (TMPEO3TA), polyurethane acrylate (PUA), polyethylene glycol (PEG-200), and phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) were added sequentially to a container at a certain mass ratio. The mixture was then placed on a magnetic stirrer and stirred uniformly at a speed of 800 r / min for 1 h to prepare a uniformly mixed photosensitive resin mixture. The mass ratio of PUA to TMPEO3TA was 0.143:1; the mass ratio of PEG-200 to PUA+TMPEO3TA was 0.25:1; and BAPO accounted for 3% of the total mass of TMPEO3TA, PUA, and PEG-200. Preparation of fiber-reinforced ceramic matrix composite slurry: A photosensitive resin mixture, polycarbosilane powder, and a polymeric dispersant were mixed and stirred in a homogenizer at 1500 r / min for 1 min. Short-cut carbon fibers were then added, and the mixture was stirred again at 1500 r / min for 2 min. Finally, a uniformly mixed fiber-reinforced ceramic matrix composite slurry was obtained. The slurry contained: 63.99% photosensitive resin mixture by volume; 11% polycarbosilane powder by volume; 25% short-cut carbon fibers by volume; 0.01% 4200 polymeric dispersant by volume; and an exposure power of 30.50 mw / cm². 2 Exposure time 10 s, printing layer thickness 50 μm.

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