Photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, preparation method and photocuring additive manufacturing method

Abstract

The invention provides photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, a preparation method and a photocuring additive manufacturing method. The photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry comprises photosensitive resin, a dispersing agent, silicon carbide powder, chopped carbon fibers, an adhesion promoter, an anti-settling agent and an oxygen inhibition inhibitor. Wherein the photosensitive resin comprises a first monofunctional monomer, a second monofunctional monomer, a bifunctional monomer, a plasticizer and a photoinitiator. According to the preparation method, the short carbon fibers and the silicon carbide powder can be uniformly dispersed in the photosensitive resin-based Csf / SiC slurry, the photocuring reaction activity and the curing depth of the slurry are improved, the anti-settling performance and the stability of the slurry are improved, and the preparation method is very suitable for photocuring 3D printing; the slurry is used for photocuring 3D printing, degreasing and chemical vapor carburization (CVI-C), and densification, strengthening and toughening and homogenization of a complex and fine Csf / SiC component can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing of ceramic-based composite materials, and specifically relates to a photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, a preparation method and a light-curing additive manufacturing method. Background Art

[0002] Photosensitive resin based short carbon fiber reinforced silicon carbide slurry, can be referred to as photosensitive resin based C sf / SiC slurry is a short carbon fiber reinforced silicon carbide composite material (C sf / SiC) basic raw materials for light-curing additive manufacturing process, slurry viscosity, light-curing depth and anti-settling performance are important for C sf / SiC blank strength, precision and structural uniformity play an important role, short carbon fiber (C sf ) has a high aspect ratio and absorbance value, is difficult to disperse in photosensitive resin and easily absorbs light, short-cut carbon fiber C sf The introduction of will significantly increase the slurry viscosity and reduce the light curing depth of the slurry. How to achieve the chopped carbon fiber in the photosensitive resin based C sf The uniform dispersion of SiC slurry, the improvement of the photocuring reaction activity of the slurry and the anti-settling performance of the slurry are the main factors affecting the performance of the C sf / Problems that need to be solved in SiC photocuring additive manufacturing process. Summary of the Invention

[0003] In response to the defects of the existing technology, the present invention provides a photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, a preparation method and a photocuring additive manufacturing method, which can effectively solve the above problems.

[0004] The first object of the present invention is to provide a photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, comprising the following raw material components: a photosensitive resin, a dispersant, silicon carbide powder, chopped carbon fibers, an adhesion promoter, an anti-settling agent, and an oxygen inhibition inhibitor; wherein the photosensitive resin comprises a first monofunctional monomer, a second monofunctional monomer, a difunctional monomer, a plasticizer, and a photoinitiator.

[0005] Preferably, the ratio of each raw material component is:

[0006] By volume, the photosensitive resin is 45 to 60 parts by volume; the chopped carbon fiber is 10 to 25 parts by volume; and the silicon carbide powder is 30 to 45 parts by volume.

[0007] The mass of the dispersant is 3-7% of the sum of the mass of the silicon carbide powder and the chopped carbon fibers;

[0008] The mass of the adhesion promoter is 1 to 5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber;

[0009] The mass of the anti-settling agent is 1 to 5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber;

[0010] The mass of the oxygen inhibition inhibitor is 0.1 to 0.5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber;

[0011] Wherein: for 45 to 60 parts by volume of the photosensitive resin, calculated by mass, it contains the following components: 10 to 30 parts by mass of the first monofunctional monomer, 10 to 30 parts by mass of the second monofunctional monomer, 40 to 50 parts by mass of the difunctional monomer, 10 to 30 parts by mass of the plasticizer, and the photoinitiator is 2 to 7% of the sum of the mass of the first monofunctional monomer, the second monofunctional monomer, the difunctional monomer and the plasticizer.

[0012] Preferably, the combination of the first monofunctional monomer and the second monofunctional monomer is a combination of any two of lauryl acrylate LA, hydroxyethyl acrylate HEA, hydroxyethyl methacrylate HEMA, isobornyl methacrylate IBOMA, tetrahydrofuranyl methyl acrylate THFA, 2-phenoxyethyl acrylate 2-PHEA, cyclotrimethylolpropane formal acrylate CTFA, and acryloylmorpholine ACMO.

[0013] Preferably, the bifunctional monomer is 1,6-hexanediol diacrylate HDDA; the plasticizer is polyethylene glycol 200, i.e., PEG-200; the photoinitiator is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide BAPO; the dispersant is a polymer dispersant, including one of SP710, 4200, BYK-9076, Lubrizol 17000 and Lubrizol 20000; the adhesion promoter is 2-hydroxyethyl methacrylate phosphate HEMAP; the anti-settling agent is BYK-410; the oxygen inhibition inhibitor is triphenylphosphine; the silicon carbide powder is shaped silicon carbide powder with a median diameter of 10-45 μm; and the chopped carbon fiber is PAN-based carbon fiber with a length of 100 μm-2 mm.

[0014] Preferably, the viscosity of the photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry is in the range of 2000-50000 mPa.s.

[0015] Preferably, when the exposure intensity is 50-120 mw / cm 2 When the exposure time is 3-10 seconds, the curing depth of the photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry is 80-200 μm.

[0016] The second object of the present invention is to provide a method for preparing a photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, comprising the following steps:

[0017] Step 1: mixing a first monofunctional monomer, a second monofunctional monomer, a difunctional monomer, a plasticizer, and a photoinitiator in a prescribed amount, and obtaining a photosensitive resin by ultrasonic dispersion;

[0018] Step 2: taking a formulated amount of photosensitive resin, adding a formulated amount of dispersant to the formulated amount of photosensitive resin, and dispersing by ultrasonication to obtain a mixed liquid phase;

[0019] Step 3, adding the formulated amount of silicon carbide powder to the mixed liquid phase obtained in step 2 and stirring to obtain a photosensitive resin-based silicon carbide slurry;

[0020] Step 4: adding the formulated amount of chopped carbon fibers to the photosensitive resin-based silicon carbide slurry obtained in Step 3 and stirring and mixing to obtain a mixed slurry;

[0021] Step 5: Add the formulated amount of adhesion promoter, anti-settling agent and oxygen inhibition inhibitor to the mixed slurry, mix them evenly with a homogenizer and vacuum degas to obtain photosensitive resin-based short carbon fiber reinforced silicon carbide C for light-curing 3D printing. sf / SiC slurry.

[0022] The third object of the present invention is to provide a method for light-curing additive manufacturing using a photosensitive resin-based short carbon fiber reinforced silicon carbide slurry, wherein the photosensitive resin-based short carbon fiber reinforced silicon carbide slurry is the photosensitive resin-based short carbon fiber reinforced silicon carbide C prepared by the above method. sf / SiC slurry; the method for light-curing additive manufacturing using photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry comprises the following steps:

[0023] Step 1: the photosensitive resin-based chopped carbon fiber reinforced silicon carbide C sf The / SiC slurry is transferred to the ceramic light-curing additive manufacturing equipment, and the exposure intensity, exposure time and slice thickness process parameters are set. The C sf / SiC body; among them, C sf / SiC stands for photosensitive resin-based chopped carbon fiber reinforced silicon carbide;

[0024] Step 2: C sf The / SiC blank was transferred to an atmosphere degreasing furnace and heated at the set temperature. sf / SiC body degreasing treatment, porous C sf / SiC degreased body;

[0025] Step 3, for porous C sf / SiC degreased blank is treated with chemical vapor carburizing process to achieve porous C sfThe densification, toughening and homogenization of the SiC / SiC degreased blank were carried out to prepare a photosensitive resin-based chopped carbon fiber reinforced silicon carbide composite material.

[0026] Preferably, in step 1, the exposure intensity is 50-120 mw / cm 2 , exposure time is 3-10 seconds, slice thickness is 50-150μm;

[0027] In step 2, the degreasing temperature is 1000-1200°C, the heating rate is 0.1-3.0°C / min, the holding time is 0.5-2 hours, the degreasing atmosphere is vacuum or inert gas protection, and the inert gas is high-purity nitrogen or high-purity argon.

[0028] Preferably, in step 3, the porous C sf / The SiC degreased body is subjected to chemical vapor carburizing process, specifically:

[0029] Natural gas and high-purity nitrogen are used as raw materials, the chemical vapor carburizing temperature is 1000-1100℃, the holding time is 50-200h, and the heating rate is 0.5-1.0℃ / min.

[0030] The photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, preparation method, and light-curing additive manufacturing method provided by the present invention have the following advantages:

[0031] The present invention provides a photosensitive resin-based short carbon fiber reinforced silicon carbide slurry, a preparation method and a light-curing additive manufacturing method. The introduction of a dispersant can achieve C sf The SiC powder is evenly dispersed in the photosensitive resin, and the introduction of anti-settling agent can increase the C content of the photosensitive resin. sf / SiC slurry anti-settling performance, improve the stability of the slurry, introduce adhesion promoter and oxygen inhibition inhibitor can improve the photocuring reaction activity of the slurry, increase the curing depth of the slurry, and improve the photocuring 3D printing C sf / SiC body interlayer bonding state, improve C sf / SiC green body strength, precision and structural uniformity; after the introduction of dispersants, anti-settling agents, adhesion promoters, oxygen inhibition inhibitors, short-cut carbon fiber C sf and silicon carbide powder in photosensitive resin based C sf The uniform dispersion of SiC slurry improves the photocuring reaction activity and curing depth of the slurry, as well as the anti-settling performance and stability of the slurry, making it very suitable for photocuring 3D printing. Using this photosensitive resin-based short carbon fiber reinforced silicon carbide slurry for photocuring 3D printing can obtain C sf / SiC body, C sf / SiC blank is degreased under high temperature vacuum or inert atmosphere to obtain porous Csf / SiC body, porous C sf / SiC blank is subjected to chemical vapor carburizing (CVI-C), which can achieve complex and fine C sf The densification, toughening and homogenization of SiC components have resulted in C with excellent mechanical properties and high temperature ablation resistance. sf / SiC components. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart of the method for preparing the photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry provided by the present invention;

[0033] Figure 2 A three-dimensional model diagram of a complex and irregular structure used in an embodiment of the present invention;

[0034] Figure 3 This is a structural diagram of a carbon fiber reinforced silicon carbide blank printed in an embodiment of the present invention;

[0035] Figure 4 This is a temperature curve diagram of the degreasing process used in an embodiment of the present invention;

[0036] Figure 5 This is a temperature curve diagram of the CVI-C carburizing process used in an embodiment of the present invention;

[0037] Figure 6 The porous C obtained after degreasing in step 8 of the embodiment of the present invention sf / Microstructure of SiC degreased body (500×);

[0038] Figure 7 The porous C obtained after degreasing in step 8 of the embodiment of the present invention sf / Microstructure of SiC degreased body (1000×);

[0039] Figure 8 C in the embodiment of the present invention sf / Microstructure of the sample surface after chemical vapor carburizing of SiC components (500×);

[0040] Figure 9 C in the embodiment of the present invention sf Microstructure of the cross section of the SiC component after chemical vapor carburizing (2000×). DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] The present invention provides a photosensitive resin-based short carbon fiber reinforced silicon carbide C sf / SiC slurry, preparation method and photocuring additive manufacturing method to solve the problems of high carbon fiber content, high photocuring activity and high stability C sf / SiC slurry preparation is difficult, to achieve C sf / High-precision, high-structural uniformity light-curing additive manufacturing of SiC components.

[0043] The present invention provides a photosensitive resin-based short-cut carbon fiber reinforced silicon carbide slurry, which includes the following raw material components: photosensitive resin, dispersant, silicon carbide (SiC) powder, short-cut carbon fiber (C sf ), adhesion promoter, anti-settling agent and oxygen inhibition inhibitor; wherein the photosensitive resin includes a first monofunctional monomer, a second monofunctional monomer, a difunctional monomer, a plasticizer and a photoinitiator.

[0044] The proportions of the raw material components are as follows: by volume, the photosensitive resin is 45 to 60 parts by volume; the chopped carbon fiber is 10 to 25 parts by volume; and the silicon carbide powder is 30 to 45 parts by volume.

[0045] The mass of the dispersant is 3-7% of the sum of the mass of the silicon carbide powder and the chopped carbon fibers;

[0046] The mass of the adhesion promoter is 1 to 5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber;

[0047] The mass of the anti-settling agent is 1 to 5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber;

[0048] The mass of the oxygen inhibition inhibitor is 0.1 to 0.5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber;

[0049] Wherein: for 45 to 60 parts by volume of the photosensitive resin, calculated by mass, it contains the following components: 10 to 30 parts by mass of the first monofunctional monomer, 10 to 30 parts by mass of the second monofunctional monomer, 40 to 50 parts by mass of the difunctional monomer, 10 to 30 parts by mass of the plasticizer, and the photoinitiator is 2 to 7% of the sum of the mass of the first monofunctional monomer, the second monofunctional monomer, the difunctional monomer and the plasticizer.

[0050] The following substances are specifically used in each component:

[0051] The combination of the first monofunctional monomer and the second monofunctional monomer is a combination of any two of lauryl acrylate LA, hydroxyethyl acrylate HEA, hydroxyethyl methacrylate HEMA, isobornyl methacrylate IBOMA, tetrahydrofuranyl methyl acrylate THFA, 2-phenoxyethyl acrylate 2-PHEA, cyclotrimethylolpropane formal acrylate CTFA, and acryloylmorpholine ACMO.

[0052] The bifunctional monomer is 1,6-hexanediol diacrylate HDDA; the plasticizer is polyethylene glycol 200, i.e., PEG-200; the photoinitiator is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide BAPO; the dispersant is a polymer dispersant, including one of SP710, 4200, BYK-9076, Lubrizol 17000 and Lubrizol 20000; the adhesion promoter is 2-hydroxyethyl methacrylate phosphate HEMAP; the anti-settling agent is BYK-410; the oxygen inhibition inhibitor is triphenylphosphine; the silicon carbide powder is shaped silicon carbide powder with a median diameter of 10-45 μm; the chopped carbon fiber is PAN-based carbon fiber with a length of 100 μm-2 mm.

[0053] The photosensitive resin-based short carbon fiber reinforced silicon carbide slurry provided by the present invention has a viscosity range of 2000-50000 mPa.s. When the exposure intensity is 50-120 mw / cm 2 When the exposure time is 3-10 seconds, the curing depth of the photosensitive resin-based short carbon fiber reinforced silicon carbide slurry is 80-200 μm. Therefore, the photosensitive resin-based short carbon fiber reinforced silicon carbide slurry provided by the present invention, when the short carbon fiber C is introduced sf After the slurry is cured, the viscosity range is 2000-50000mPa.s and the curing depth is 80-200μm. It does not significantly increase the slurry viscosity and reduce the light curing depth of the slurry as in the prior art. The viscosity range and light curing depth of the slurry of the present invention are still very suitable for light curing 3D printing, which can realize the chopped carbon fiber on the photosensitive resin base C sf / The uniform dispersion of SiC slurry improves the photocuring reaction activity and curing depth of the slurry, as well as the anti-settling performance and stability of the slurry.

[0054] The present invention provides a method for preparing a photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, comprising the following steps:

[0055] Step 1: mixing a first monofunctional monomer, a second monofunctional monomer, a difunctional monomer, a plasticizer, and a photoinitiator in a prescribed amount, and obtaining a photosensitive resin by ultrasonic dispersion;

[0056] Step 2: taking a formulated amount of photosensitive resin, adding a formulated amount of dispersant to the formulated amount of photosensitive resin, and dispersing by ultrasonication to obtain a mixed liquid phase;

[0057] Step 3, adding the formulated amount of silicon carbide powder to the mixed liquid phase obtained in step 2 and stirring to obtain a photosensitive resin-based silicon carbide slurry;

[0058] Step 4: adding the formulated amount of chopped carbon fibers to the photosensitive resin-based silicon carbide slurry obtained in Step 3 and stirring and mixing to obtain a mixed slurry;

[0059] Step 5: Add the formulated amount of adhesion promoter, anti-settling agent and oxygen inhibition inhibitor to the mixed slurry, mix them evenly with a homogenizer and vacuum degas to obtain photosensitive resin-based short carbon fiber reinforced silicon carbide C for light-curing 3D printing. sf / SiC slurry.

[0060] Furthermore, based on the above prepared photosensitive resin-based chopped carbon fiber reinforced silicon carbide C for photocurable 3D printing sf / SiC slurry, the present invention also provides a method for light-curing additive manufacturing using photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, comprising the following steps:

[0061] Step 1: the photosensitive resin-based chopped carbon fiber reinforced silicon carbide C sf The / SiC slurry is transferred to the ceramic light-curing additive manufacturing equipment, and the exposure intensity, exposure time and slice thickness process parameters are set. The C sf / SiC body;

[0062] In this step, the exposure intensity is 50-120 mw / cm 2 , exposure time is 3-10 seconds, slice thickness is 50-150μm;

[0063] Step 2: C sf The / SiC blank was transferred to an atmosphere degreasing furnace and heated at the set temperature. sf / SiC body degreasing treatment, porous C sf / SiC degreasing blank; wherein: the degreasing temperature is 1000-1200°C, the heating rate is 0.1-3.0°C / min, the holding time is 0.5-2 hours, the degreasing atmosphere is vacuum or inert gas protection, and the inert gas is high-purity nitrogen or high-purity argon.

[0064] Step 3, for porous C sf / SiC degreased blank is treated with chemical vapor carburizing (CVI-C) process to achieve porous C sfThe densification, toughening and homogenization of the SiC / SiC degreased blank were carried out to prepare a photosensitive resin-based chopped carbon fiber reinforced silicon carbide composite material.

[0065] In this step, the porous C sf / The SiC degreased body is subjected to chemical vapor carburizing (CVI-C) process, specifically:

[0066] Natural gas and high-purity nitrogen are used as raw materials, the chemical vapor carburizing temperature is 1000-1100℃, the holding time is 50-200h, and the heating rate is 0.5-1.0℃ / min.

[0067] The present invention provides a photosensitive resin-based short carbon fiber reinforced silicon carbide slurry, a preparation method and a light-curing additive manufacturing method. Compared with the traditional manufacturing process, it does not require molds and a large amount of mechanical processing, shortens the manufacturing cycle, improves the manufacturing accuracy, and can achieve complex and fine structure C sf Rapid and high-precision manufacturing of SiC components; Compared with other additive manufacturing processes, the C sf / SiC green body has higher strength, precision and better structural uniformity. By optimizing the type and content of polymer dispersant, the volume fraction of short-cut carbon fiber is increased. By optimizing the monomer composition and introducing adhesion promoter and oxygen inhibition inhibitor, the photocuring reaction activity of the slurry is improved, overcoming the problem of low slurry curing depth caused by silicon carbide powder and carbon fiber absorption and oxygen inhibition, and improving the performance of photocuring 3D printing C sf / SiC body interlayer bonding state, improves the C sf / SiC body strength, precision and structural uniformity, for large size, complex fine structure C sf The rapid, low-cost and high-precision manufacturing of SiC / SiC components is of great significance.

[0068] An embodiment is described below:

[0069] Step 1: Prepare photosensitive resin:

[0070] In this embodiment, the first monofunctional monomer is 2-phenoxyethyl acrylate 2-PHEA; the second monofunctional monomer is cyclotrimethylolpropane formal acrylate CTFA; the difunctional monomer is 1,6-hexanediol diacrylate HDDA; the plasticizer is polyethylene glycol 200, i.e., PEG-200; the photoinitiator is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide BAPO;

[0071] Calculated by mass, weigh 25 parts by mass of the first monofunctional monomer, 15 parts by mass of the second monofunctional monomer, 40 parts by mass of the difunctional monomer, and 20 parts by mass of the plasticizer. The photoinitiator is 5% of the sum of the mass of the first monofunctional monomer, the second monofunctional monomer, the difunctional monomer, and the plasticizer;

[0072] The first monofunctional monomer, the second monofunctional monomer, the difunctional monomer, the plasticizer and the photoinitiator are mixed in the above-mentioned formula amount, and ultrasonically dispersed at room temperature for 15 minutes to obtain a photosensitive resin;

[0073] Step 2: The components and proportions of this embodiment are specifically as follows:

[0074] In this embodiment, the silicon carbide powder is shaped silicon carbide powder, and the median diameter D 50 =28μm; PAN-based carbon fiber is used for the chopped carbon fiber with a length of 150μm; polymer dispersant 4200 is used as the dispersant; 2-hydroxyethyl methacrylate phosphate HEMAP is used as the adhesion promoter; BYK-410 is used as the anti-settling agent; and triphenylphosphine is used as the oxygen inhibition inhibitor;

[0075] In this embodiment, the proportions of the components are:

[0076] By volume, 50 parts by volume of photosensitive resin, 10 parts by volume of chopped carbon fibers, and 40 parts by volume of silicon carbide powder were measured.

[0077] Weighing out 5% of the total mass of the silicon carbide powder and the chopped carbon fibers in a dispersant, 2.5% of the total mass of the silicon carbide powder and the chopped carbon fibers in an adhesion promoter, 3.0% of the total mass of the silicon carbide powder and the chopped carbon fibers in an anti-settling agent, and 0.2% of the total mass of the silicon carbide powder and the chopped carbon fibers in an oxygen inhibition inhibitor;

[0078] Step 3: Based on the components and proportions of step 2, add a formulated amount of dispersant to the formulated amount of photosensitive resin, and disperse by ultrasonication for 15 minutes to obtain a mixed liquid phase;

[0079] Step 4: Add the formulated amount of silicon carbide powder to the mixed liquid phase and stir and mix manually to obtain a photosensitive resin-based silicon carbide slurry;

[0080] Step 5: Add the formulated amount of chopped carbon fibers to the photosensitive resin-based silicon carbide slurry, and manually stir and mix to obtain a mixed slurry;

[0081] Step 6: Add the formulated amount of adhesion promoter, anti-settling agent and oxygen inhibition inhibitor to the mixed slurry and stir it manually;

[0082] The manually stirred slurry was transferred to a homogenizer and degassed for 60 seconds at 1000 rpm and 100 Pa vacuum conditions to obtain photosensitive resin-based chopped carbon fiber reinforced silicon carbide C for photocurable 3D printing. sf / SiC slurry, slurry viscosity 13950mPa.s (shear rate 52s -1 );

[0083] Step 7: Stereolithography

[0084] The photosensitive resin-based chopped carbon fiber reinforced silicon carbide C sf The / SiC slurry is transferred to the ceramic light-curing additive manufacturing equipment, and C is obtained by 3D printing according to the three-dimensional model. sf / SiC blank, where the light source wavelength is 405nm, the exposure time is 10s, and the exposure power is 90mW / cm 2 , set the slice thickness to 75μm, the slurry curing depth to 140μm, and obtain the carbon fiber reinforced silicon carbide blank; Figure 2 As shown in the figure, it is a three-dimensional model of a complex special-shaped structure; Figure 3 As shown, this is the structural diagram of the carbon fiber reinforced silicon carbide blank obtained by printing in this step.

[0085] Step 8, C sf / Degreasing of SiC body:

[0086] C sf / SiC blank is transferred to atmosphere degreasing furnace, high purity nitrogen inert gas (purity ≥ 99.9999%) is introduced, and C sf / SiC body degreasing treatment, porous C sf / SiC debinding body; wherein: debinding temperature is 1055℃, holding time is 1 hour, of which it takes 21 hours to heat from room temperature to 1055℃, with a heating rate of about 0.8℃ / min; it takes 24 hours to cool from 1055℃ to room temperature, with a cooling rate of about -0.7℃ / min. Figure 4 As shown, this is the degreasing process temperature curve used in this step.

[0087] Step 9, C sf / Chemical vapor carburizing densification of SiC body:

[0088] The porous C sf The degreased SiC blank was transferred to a chemical vapor deposition furnace and heated from room temperature (~25°C) to 1042°C in a vacuum state for 20 hours at a heating rate of about 0.8°C / min. Natural gas (mainly methane CH4) and high-purity nitrogen were then introduced at 1042°C. The natural gas was pyrolyzed to generate carbon atoms that penetrated and deposited on the C sf / SiC is kept at 1042℃ for 200 hours to complete the chemical vapor carburizing process; finally, the temperature is lowered and nitrogen (purity ≥ 99.995%) is introduced during the cooling process. The entire cooling process takes about 90 hours and the cooling rate is about -0.7℃ / min. Figure 5 As shown, this is the temperature curve of the chemical vapor carburizing process used in this step.

[0089] like Figure 6 As shown, the porous C after degreasing obtained in step eight of this embodiment sf / SiC degreased body microstructure picture magnified 500 times. Figure 7 As shown, the porous C after degreasing obtained in step eight of this embodiment sf / Microstructure of SiC degreased body magnified 1000 times.

[0090] like Figure 8 As shown, C in this embodiment sf The microstructure of the surface of the sample after chemical vapor carburization of the SiC component shows that the carbon atoms generated by natural gas pyrolysis are deposited on the C sf In the / SiC sample, a carbon layer of a certain thickness is formed to wrap the carbon fibers and silicon carbide particles. The carbon layer is smooth and dense, making the C sf / SiC samples exhibit metallic luster.

[0091] like Figure 9 As shown, C in this embodiment sf The microstructure of the cross section of the SiC component after chemical vapor carburization shows that the carbon atoms generated by natural gas pyrolysis have penetrated into the porous C sf / SiC body, and deposited on the surface of carbon fiber and silicon carbide particles, forming a deposition layer with a thickness of 4-7μm. The carbon layer fracture layer has fine texture and clear layer structure, just like the annual ring of a tree, and has the typical structural characteristics of smooth layer (SL) pyrolytic carbon. sf / SiC samples play an important role in densification, toughening and homogenization, which can give C sf / SiC samples have excellent mechanical properties and high temperature ablation resistance.

[0092] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, characterized in that: The invention comprises the following raw material components: a photosensitive resin, a dispersant, silicon carbide powder, chopped carbon fiber, an adhesion promoter, an anti-settling agent and an oxygen inhibition inhibitor; wherein the photosensitive resin comprises a first monofunctional monomer, a second monofunctional monomer, a difunctional monomer, a plasticizer and a photoinitiator.

2. The photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry according to claim 1, characterized in that: The proportions of the raw material components are: By volume, the photosensitive resin is 45 to 60 parts by volume; the chopped carbon fiber is 10 to 25 parts by volume; and the silicon carbide powder is 30 to 45 parts by volume; The mass of the dispersant is 3 to 7% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber; The mass of the adhesion promoter is 1 to 5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber; The mass of the anti-settling agent is 1 to 5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber; The mass of the oxygen inhibition inhibitor is 0.1 to 0.5% of the sum of the mass of the silicon carbide powder and the chopped carbon fiber; Wherein: for 45 to 60 parts by volume of the photosensitive resin, calculated by mass, it contains the following components in mass parts: 10 to 30 parts by mass of the first monofunctional monomer, 10 to 30 parts by mass of the second monofunctional monomer, 40 to 50 parts by mass of the difunctional monomer, 10 to 30 parts by mass of the plasticizer, and the photoinitiator is 2 to 7% of the sum of the mass of the first monofunctional monomer, the second monofunctional monomer, the difunctional monomer and the plasticizer.

3. The photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry according to claim 1, characterized in that: The combination of the first monofunctional monomer and the second monofunctional monomer is a combination of any two of lauryl acrylate LA, hydroxyethyl acrylate HEA, hydroxyethyl methacrylate HEMA, isobornyl methacrylate IBOMA, tetrahydrofuran methyl acrylate THFA, 2-phenoxyethyl acrylate 2-PHEA, cyclotrimethylolpropane methyl acrylate CTFA, and acryloyl morpholine ACMO.

4. The photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry according to claim 1, characterized in that: The bifunctional monomer is 1,6-hexanediol diacrylate HDDA; the plasticizer is polyethylene glycol 200, i.e. PEG-200; the photoinitiator is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide BAPO; the dispersant is a polymer dispersant, including one of SP710, 4200, BYK-9076, Lubrizol 17000 and Lubrizol 20000; the adhesion promoter is 2-hydroxyethyl methacrylate phosphate HEMAP; the anti-settling agent is BYK-410; the oxygen inhibition inhibitor is triphenylphosphine; the silicon carbide powder is shaped silicon carbide powder with a median diameter of 10-45 μm; the chopped carbon fiber is PAN-based carbon fiber with a length of 100 μm-2 mm.

5. The photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry according to claim 1, characterized in that: The viscosity range of the photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry is: 2000-50000mPa.s.

6. The photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry according to claim 1, characterized in that: When the exposure intensity is 50-120mw / cm 2 When the exposure time is 3-10 seconds, the curing depth of the photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry is 80-200 μm.

7. A method for preparing a photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry, characterized in that: The following steps are involved: Step 1, mixing a first monofunctional monomer, a second monofunctional monomer, a difunctional monomer, a plasticizer and a photoinitiator in a prescribed amount, and obtaining a photosensitive resin by ultrasonic dispersion; Step 2, taking a formulated amount of photosensitive resin, adding a formulated amount of dispersant to the formulated amount of photosensitive resin, and obtaining a mixed liquid phase by ultrasonic dispersion; Step 3, adding the formulated amount of silicon carbide powder to the mixed liquid phase obtained in step 2, stirring and mixing, to obtain a photosensitive resin-based silicon carbide slurry; Step 4, adding the formulated amount of chopped carbon fibers to the photosensitive resin-based silicon carbide slurry obtained in step 3, stirring and mixing to obtain a mixed slurry; Step 5: Add the formulated amount of adhesion promoter, anti-settling agent and oxygen inhibition inhibitor to the mixed slurry, mix them evenly with a homogenizer and perform vacuum degassing to obtain a photosensitive resin-based short carbon fiber reinforced silicon carbide C for photocuring 3D printing. sf / SiC slurry.

8. A method for photocuring additive manufacturing using photosensitive resin-based short carbon fiber reinforced silicon carbide slurry, characterized in that: The photosensitive resin-based short carbon fiber reinforced silicon carbide slurry is the photosensitive resin-based short carbon fiber reinforced silicon carbide slurry prepared by the method of claim 7. sf / SiC slurry; the method for photocuring additive manufacturing using photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry comprises the following steps: Step 1: the photosensitive resin-based chopped carbon fiber reinforced silicon carbide C sf The SiC / SiC slurry is transferred to the ceramic light-curing additive manufacturing equipment, and the exposure intensity, exposure time and slice thickness process parameters are set. The C sf / SiC body; among which, C sf / SiC stands for chopped carbon fiber reinforced silicon carbide; Step 2: C sf The SiC blank is transferred to an atmosphere degreasing furnace and heated at a set temperature. sf / SiC body degreasing treatment to obtain porous C sf / SiC degreased body; Step 3: For porous C sf / SiC degreased body is treated by chemical vapor carburizing process to achieve porous C sf The densification, toughening and homogenization of the SiC / SiC degreased blank were carried out to prepare a photosensitive resin-based chopped carbon fiber reinforced silicon carbide composite material.

9. The method for photocuring additive manufacturing using photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry according to claim 8, characterized in that: In step 1, the exposure intensity is 50-120 mw / cm 2 , exposure time is 3-10 seconds, slice thickness is 50-150μm; In step 2, the degreasing temperature is 1000-1200°C, the heating rate is 0.1-3.0°C / min, the insulation time is 0.5-2 hours, the degreasing atmosphere is vacuum or inert gas protection, and the inert gas is high-purity nitrogen or high-purity argon.

10. The method for photocuring additive manufacturing using photosensitive resin-based chopped carbon fiber reinforced silicon carbide slurry according to claim 8, characterized in that: In step 3, the porous C sf / SiC degreased body is treated by chemical vapor carburizing process, specifically: Natural gas and high-purity nitrogen are used as raw materials, the chemical vapor carburizing temperature is 1000-1100℃, the insulation time is 50-200h, and the heating rate is 0.5-1.0℃ / min.

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