Energetic slurry toughening and photocuring 3D printing method

Abstract

The invention discloses an energetic slurry toughening and photocuring 3D printing method, relates to a preparation method of energetic slurry, and aims to solve the problems that an existing energetic material is poor in mechanical property, poor in toughness and easy to crack; the particles are fast to settle in the light-cured resin, the stability is poor, and the printing precision is poor. The invention develops a photocuring high-energy resin for photopolymerization additive manufacturing. The composition contains a high-energy filler, an acrylate adhesive, whiskers and an inert plasticizer. The material has the characteristics of compatibility, printability and mechanical property, and the possibility of printing increasingly complicated high-energy articles is proved through experiments. The preparation method of the light-cured resin comprises the following steps: adding the low polymer bisphenol A epoxy acrylate and the six-functionality polyurethane acrylate; diluting monomers including 1, 6-hexanediol diacrylate and trimethylolpropane triacrylate; uniformly mixing an auxiliary agent, a thickening agent and a dispersing agent, and magnetically stirring for 30 minutes to obtain the light-cured resin. A preparation method of the energetic slurry comprises the following steps: mixing light-cured resin, whiskers, an inert plasticizer, energetic particles, a photoinitiator and a light absorber, and uniformly stirring to obtain the energetic slurry; after the energetic slurry is used for 3D printing, a sample piece is obtained, the yield reaches 95%-100%, the cost is low, preparation is easy, and the method can be applied to the field of energetic slurry 3D printing.

Description

Technical Field

[0001] A method for toughening energetic slurries and photocuring 3D printing belongs to the technical field of 3D printing materials. Background Art

[0002] Physical toughening is one of the toughening methods for traditional energetic materials. Physical toughening methods improve the toughness of materials by introducing different types of fillers or fibers, such as fiber reinforcement, nanoparticle toughening, whisker or fiber toughening, etc. These methods usually absorb energy by increasing the stress concentration points or crack propagation paths inside the materials, thereby improving the toughness of the materials. However, physical toughening methods have some limitations. For example, the distribution of fillers is uneven and the compatibility with the matrix is poor, which may lead to local stress concentration and affect the overall performance of the materials.

[0003] At present, there is little research on the manufacture of energetic materials by photocuring 3D printing. The mechanical properties of the samples printed by 3D printing are poor. The effect of using whiskers to toughen the photocurable 3D printable energetic slurries is not ideal, and the compatibility between the whiskers and the photocurable resin is poor. This severely limits the application of 3D printing in the field of energetic materials. Summary of the Invention

[0004] The present invention aims to solve the problems of poor mechanical properties and low strength of the splines printed by 3D printing of energetic slurries, and provides a preparation method, a toughening method and a 3D printing method for energetic materials. The present invention has developed a tough photocurable energetic slurry for photopolymerization additive manufacturing. The composition contains high-energy fillers (such as TATB, RDX, HMX, CL-20, etc.), photocurable resin, modified whiskers and inert plasticizers. By adding whiskers and modifying the surface of the whiskers to change the functional groups on the surface of the whiskers, the compatibility between the photocurable resin and the whiskers in 3D printing is improved, the filler content of the whiskers in the slurry is increased, and the toughening treatment of the energetic slurry is realized. The problems of decreased 3D printing accuracy and low solid content caused by the poor compatibility between the whiskers and the photocurable resin are solved. The solid content can reach up to 70% (60% energetic particles + 10% modified whiskers), and the printed samples still maintain good mechanical properties under the condition of high solid content.

[0005] The preparation method of the energetic resin slurry for 3D printing and the energetic resin toughening treatment technology of the present invention are carried out according to the following steps:

[0006] 1. Weigh 20 - 70 parts by weight of resin oligomer; 5 - 50 parts of resin monomer diluent; 0.5 - 2 parts of thickener; 0.5 - 4 parts of dispersant. Stir for 30 min under the condition that the stirring speed is 400 - 600 r / min to make the photosensitive resin evenly mixed, and obtain a photocurable resin mixed solution;

[0007] II. Weigh 10 - 25 parts of inert plasticizer and 100 - 185 parts of energetic particles by weight ratio, add them to the prepared photocurable resin, and stir until the particles are evenly dispersed in the photocurable resin to obtain an energetic slurry.

[0008] III. Weigh 1 - 10 parts of surface-treated silicon carbide whiskers and 10 - 20 parts of surface-modified calcium sulfate whiskers by weight ratio, add them to the energetic slurry, and stir magnetically for 30 min to make them evenly mixed.

[0009] IV. Weigh 100 parts of energetic slurry resin, 1 - 5 parts of photoinitiator, and 0.01 - 0.1 part of light absorber by weight ratio, and stir until the powder is completely dissolved to obtain a photocurable high-energy tough resin.

[0010] V. Pour the photosensitive resin into the material tank of the 3D printer, ensure that the bottom layer of the material tank can be completely covered with a layer of resin after the squeegee passes, adjust the light exposure time to 2 - 13 s, and the exposure intensity is 10 - 100 mw / cm 2 , and the layer thickness of printing is 40 - 150 μm, and complete 3D printing layer by layer to obtain a sample.

[0011] VI. Rinse the sample printed by DLP 3D printing with absolute ethanol to remove the uncured resin in the sample. For some large printed samples, post-treatment such as removing supports and polishing is required. After treatment, an energetic material component is obtained. [[ID=1�]]

[0012] Furthermore, the oligomer in step I can be bisphenol A epoxy acrylate (EA), hexafunctional polyurethane acrylate (PUA), polyacrylate, or vinyl ether resin.

[0013] Furthermore, the diluent in step I can be 1,6 - hexanediol diacrylate (HDDA), hydroxypropyl acrylate (HPA), hydroxyethyl acrylate (HEA), isobornyl acrylate (IBOA), 2 - hydroxyethyl methacrylate (HEMA), or trimethylolpropane triacrylate (TMPTA).

[0014] Furthermore, the thickener in step I can be hydroxypropyl cellulose or hydroxymethylpropyl cellulose.

[0015] Furthermore, the dispersant in step I can be BYK111, BYK180, or BYK333.

[0016] Furthermore, additives such as hydroxypropyl cellulose, BYK111, and BYK333 added in step I help the energetic slurry maintain stability at high solid content and ensure the progress of photocurable 3D printing.

[0017] Further, the inert diluent in step two can be dioctyl adipate (DOA), dioctyl sebacate (DOS), dioctyl phthalate (DOP), or glyceryl triacetate (TA).

[0018] Further, the energetic particles in step two can be RDX, HMX, or CL-20.

[0019] Further, the modification of the whiskers in step three is mainly because the polarity difference between the whiskers and the photocurable resin is large, resulting in poor compatibility between the whiskers and the resin, which affects the mechanical properties of the printed samples.

[0020] Further, the surface treatment method of silicon carbide whiskers in step three is as follows: 1. Put the SiC whiskers into an ammonium fluoride solution with a mass fraction of 10%, and clean them with an ultrasonic oscillator. Determine the cleaning time according to the amount of whiskers. After the whiskers are evenly dispersed, take out the whiskers and bake them at 80°C for 5 hours; 2. Dissolve the silane coupling agent KH550 in a mixed solvent composed of 3 parts of absolute ethanol and 1 part of distilled water with a mass fraction of 2%. Dropwise add acetic acid to adjust the pH value of the solution to about 4-5. Put the cleaned SiC fibers into an ultrasonic oscillator and oscillate, while slowly dropping the pre-hydrolyzed silane solution, stir evenly with a magnetic stirrer, pour it into a petri dish and leave it at room temperature for 2 hours, then dry it in a vacuum drying oven at 80°C for 8 hours to obtain the treated whiskers, and store them in a dry and airtight manner.

[0021] Further, the modification principle of silicon carbide whiskers in step three is as follows: The alkoxy group of the silane coupling agent is the main group that reacts with -Si-OH on the surface of SiC. According to the thermodynamics of the reaction between SiC and O2, SiC can undergo an oxidation reaction with O2 in the air at room temperature to form a SiO2 film on the surface of the whiskers. The SiO2 film grown on the surface reacts with water vapor in the air to form silanol (-Si-OH). These hydroxyl groups (-OH) have high activity and are easily dissociated, making the surface of SiC negatively charged.

[0022] Further, the surface treatment method of calcium sulfate whiskers in step three is as follows: First, add anhydrous calcium sulfate whiskers to a sodium phosphate solution with a concentration of 0.015 mol / L and disperse them ultrasonically for 2 minutes, then continue stirring for 10 minutes, filter by suction, wash, add the filter cake to 100 mL of absolute ethanol, heat it in an oil bath to 90°C, add an absolute ethanol solution containing a stearic acid modifier, with the amount of stearic acid being 6 wt%, carry out the modification treatment for 5 minutes, then filter while it is hot, wash three times with absolute ethanol, and dry at 100°C to obtain the modified product.

[0023] Further, the modification principle of calcium sulfate whiskers in step three is as follows: Phosphate ions and hydrogen phosphate ions can react with the active calcium on the surface of anhydrous calcium sulfate whiskers. Some of the calcium on the surface of anhydrous calcium sulfate whiskers is bonded with phosphate ions and hydrogen phosphate ions and exists on the surface of anhydrous calcium sulfate whiskers. In the organic modification anhydrous ethanol system, stearic acid can ionize CH3(CH2) 16 COO - and H + . Due to hydrogen bond interaction, H + can be partially bonded with the oxygen in phosphate ions and hydrogen phosphate ions, weakening the binding ability of the oxygen on phosphate ions and hydrogen phosphate ions with the calcium on the surface of anhydrous calcium sulfate whiskers. Then, CH3(CH2) 16 COO - is partially bonded with the calcium on the surface of anhydrous calcium sulfate whiskers, and phosphate ions and hydrogen phosphate ions are converted into hydrogen phosphate ions or dihydrogen phosphate ions. Finally, stearic acid can be coated on the surface of anhydrous calcium sulfate whiskers.

[0024] Further, when the amount of silicon carbide whiskers added in step three is 4 g and the amount of calcium sulfate whiskers is 10 g, the toughening effect on the 3D printing sample is the best.

[0025] Further, the photoinitiator in step four can be 184D, TPO, 819, 2595, 1173.

[0026] Further, the light absorber in step four can be Sudan III and methyl orange.

[0027] The present invention improves the performance of the 3D printing energetic resin from the following aspects.

[0028] (1) The present invention selects a resin oligomer with good comprehensive performance, making the sample printed by DLP 3D printing have high hardness and good wear resistance. By adding silicon carbide whiskers for toughening treatment, the mechanical properties of the sample are improved. Silicon carbide has two polytypes, namely hexagonal α-SiC and cubic β-SiC. Compared with α-SiC whiskers, β-SiC whiskers are less likely to break during the pressure processing. Most of the silicon carbide whiskers used industrially are β-SiC whiskers. In this study, β-SiC whiskers with a diameter of 0.1 - 0.6 μm and a length of 10 - 50 μm are selected. For SiC whisker / resin matrix composites, since the polarity of SiC whiskers as the reinforcement is much greater than that of the resin matrix and their surface chemical composition is also very different from that of the matrix resin, the compatibility between the two is poor. If the whiskers are not surface-treated, it will inevitably lead to poor interfacial adhesion of the composite material, uneven distribution of the reinforcing material in the matrix, and adverse effects on the performance of the synthesized composite material. Therefore, surface modification treatment of SiC whiskers is required.

[0029] (2) Acrylate monomers with low viscosity and high polarity were selected, which will help to form a stable dispersion. Different types and dosages of dispersants were tested, and the optimal dosage relative to the filler dosage was selected, which can prevent particle sedimentation and lead to a viscosity reduction. Adding more dispersants will not cause a further viscosity reduction and will deteriorate the mechanical properties of the printing material.

[0030] (3) When adding calcium sulfate whiskers to toughen the photosensitive resin, anhydrous calcium sulfate whiskers have stable properties and are not easily hydrated. As a reinforcing material added to the composite material, it has good reinforcement and toughening effects. However, due to the hydrophilic and oleophobic nature of anhydrous calcium sulfate whiskers and their strongly polar surface, when used as a filler directly compounded with the organic matrix, the compatibility is poor. Therefore, its surface needs to be modified to increase its compatibility with the organic matrix. Fatty acids are a common type of surface modifier in powder surface modification. When using fatty acids as the modifier, the fatty acids need to undergo a chemical bonding reaction with the surface with hydroxyl groups to achieve the purpose of surface modification. However, the surface of anhydrous calcium sulfate whiskers is smooth and has no hydroxyl groups, so it is difficult to directly surface-modify anhydrous calcium sulfate whiskers with fatty acids. Therefore, special process treatment is required to solve the problem of the bonding connection between fatty acids and the surface of anhydrous calcium sulfate whiskers. In this study, an inorganic salt was first used to modify the surface of anhydrous calcium sulfate whiskers, so that a layer of insoluble salt with hydroxyl groups adhered to the whisker surface, activating the whisker surface. Then, fatty acids were used to modify the inorganically coated anhydrous calcium sulfate whiskers, so that a chemical bonding reaction occurred between the surface of the inorganically modified anhydrous calcium sulfate whiskers and the fatty acids, thereby achieving the purpose of surface modification of anhydrous calcium sulfate whiskers.

[0031] (4) The thickener hydroxypropyl cellulose and the dispersant BYK111 added to the photocurable resin solved the problems of sedimentation and agglomeration of energetic particles in the photocurable resin, improved the printing yield, and ensured the stability and uniformity of the slurry.

[0032] The preparation method, toughening method and 3D printing method of the energetic slurry of the present invention can be used in the field of energetic material preparation.

[0033] Patent drawings

[0034] Figure 1 Showing the cross-sectional scanning electron micrograph of the sample after 3D printing and forming;

[0035] Figure 2 Showing the stress-strain curves before and after adding 1wt% silicon carbide whiskers to the energetic slurry;

[0036] Figure 3 Showing the dispersibility of silicon carbide whiskers before and after modification;

[0037] Figure 4 Showing the stress-strain curves of different solid contents.

[0038] Specific implementation cases

[0039] Example 1: The method for toughening energetic slurry and photocuring 3D printing is carried out according to the following steps:

[0040] 1. Bisphenol A epoxy acrylate, hexafunctional polyurethane acrylate, 1,6 - hexanediol diacrylate, trimethylolpropane triacrylate, thickening agent hydroxypropyl cellulose, and dispersant BYK111 are mixed in a beaker according to a mass ratio of 20:10:10:10:1:1.5, and magnetically stirred for 30 min to obtain a photocurable resin.

[0041] 2. 20 parts of inert plasticizer dioctyl sebacate and 100 parts of energetic particles are added to the photocurable resin according to the weight ratio, and 2 g of modified silicon carbide whiskers are added, and magnetically stirred for 30 min to make it evenly mixed, obtaining an energetic resin slurry with a solid content of 50%, which is the photocurable energetic resin slurry for 3D printing.

[0042] 3. The energetic resin slurry, TPO photoinitiator, and Sudan III light absorber are mixed and stirred according to a mass ratio of 100:4:0.1 until the powder is completely dissolved to obtain a photosensitive resin.

[0043] 4. The photosensitive resin is poured into the material tank of the DLP printer, ensuring that the bottom layer of the material tank can be completely covered with a layer of resin after being scraped by the blade. The light exposure time is adjusted to 5 s, the exposure intensity is 60 mw / cm 2 , the printing layer thickness is 50 μm, and 3D printing is completed layer by layer to obtain a sample.

[0044] 5. The sample printed by DLP 3D printing is rinsed with anhydrous ethanol to remove the uncured resin in the sample. Some large printed samples need to be post - processed, such as removing supports, grinding and polishing, and an energetic material component is obtained after processing.

[0045] The tensile strength of this material at a solid content of 50% is 13.92 MPa, and the elongation at break is 3.98%. When 2 g of silicon carbide whiskers are added to potassium sulfate powder at a solid content of 50%, without modification, the tensile strength is 8.61 MPa, and the elongation at break is 3.49%, and the effect is worse than that without adding silicon carbide whiskers. After modification, the strength and toughness are significantly improved, the tensile strength is 18.9 MPa, and the elongation at break is 5.78%, and the effect is better than that without adding silicon carbide whiskers. The curing thickness of the photocuring printing slurry is 128 μm, the viscosity is 1690 MPa·s, and the sedimentation height of the obtained energetic resin slurry in 24 h is 4.3%.

[0046] Example 2: The method for toughening energetic slurry and photocuring 3D printing is carried out according to the following steps:

[0047] 1. Mix bisphenol A epoxy acrylate, hexafunctional polyurethane acrylate, 1,6 - hexanediol diacrylate, trimethylolpropane triacrylate, thickener hydroxypropyl cellulose, and dispersant BYK111 in a beaker according to a mass ratio of 20:10:10:10:1:1.5, and stir magnetically for 30 min to obtain a photocurable resin;

[0048] 2. Add 15 parts of inert plasticizer dioctyl sebacate and 150 parts of energetic particles to the photocurable resin according to the weight ratio, add 1 g of modified silicon carbide whiskers, and stir magnetically for 30 min to make it evenly mixed, obtaining an energetic resin slurry, which is the photocurable energetic resin slurry for 3D printing;

[0049] 3. Mix the energetic resin slurry, TPO photoinitiator, and Sudan III light absorber according to a mass ratio of 100:4:0.1 and stir until the powder is completely dissolved to obtain a photosensitive resin;

[0050] 4. Pour the photosensitive resin into the material tank of a DLP printer, ensure that the bottom layer of the material tank can be completely covered with a layer of resin after the squeegee passes, adjust the light exposure time to 5 s, and the exposure intensity is 40 mw / cm 2 , the printing layer thickness is 70 μm, and complete 3D printing layer by layer to obtain a sample;

[0051] 5. Rinse the sample printed by DLP 3D printing with absolute ethanol to remove the uncured resin in the sample. For some large printed samples, post - treatment is required, such as removing supports, grinding and polishing, and an energetic material component is obtained after treatment.

[0052] When adding 1 g of silicon carbide whiskers by mass fraction, without modification, the tensile strength is 8.45 MPa and the elongation at break is 3.23%, and the effect is worse than that without addition; after modification, the tensile strength is 15.1 MPa and the elongation at break is 4.2%. The curing thickness of the photocurable printing slurry is 131 μm, the viscosity is 1610 MPa·s, and the sedimentation height of the obtained energetic resin slurry in 24 h is 4.1%.

[0053] Example 3: The method for toughening the energetic slurry and photocuring 3D printing in this example is carried out according to the following steps:

[0054] 1. Mix bisphenol A epoxy acrylate, hexafunctional polyurethane acrylate, 1,6 - hexanediol diacrylate, trimethylolpropane triacrylate, thickener hydroxypropyl cellulose, and dispersant BYK111 in a beaker according to a mass ratio of 10:20:10:10:1:1.5, and stir magnetically for 30 min to obtain a photocurable resin;

[0055] 2. Add 20 parts of inert plasticizer dioctyl sebacate and 180 parts of energetic particles to the light-curable resin in parts by weight, add 10 g of modified calcium sulfate whiskers, and stir magnetically for 30 minutes to mix them evenly to obtain an energetic resin slurry, which is a light-curable energetic resin slurry for 3D printing;

[0056] 3. Mixing the energetic resin slurry, TPO photoinitiator and Sudan III light absorber in a mass ratio of 100:4:0.1 and stirring until the powder is completely dissolved to obtain a photosensitive resin;

[0057] 4. Pour the photosensitive resin into the material tank of the DLP printer, ensuring that the bottom of the material tank is completely covered with a layer of resin after the scraper passes through. Adjust the lighting time to 6s and the exposure intensity to 80mw / cm 2 , the printed layer thickness is 100μm, and 3D printing is completed layer by layer to obtain the sample;

[0058] 5. The DLP 3D printed samples are rinsed with anhydrous ethanol to remove the uncured resin in the samples. Some large printed samples require post-processing, such as removing supports and grinding and polishing, to obtain energetic material parts.

[0059] The cured thickness of the photocurable printing slurry is 126 μm, and the yield is 95%. At this ratio, the hardness of the pure resin is 78 HA, the viscosity is 1450 MPa·s, and the sedimentation height of the obtained energetic resin slurry after 24 hours is 4.9%.

[0060] Example 4: The energetic slurry toughening and light-curing 3D printing method of this embodiment is carried out according to the following steps:

[0061] 1. Bisphenol A epoxy acrylate, hexafunctional polyurethane acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, thickener hydroxypropyl cellulose, and dispersant BYK111 were mixed in a beaker at a mass ratio of 15:15:20:10:1:1.5, and magnetically stirred for 30 minutes to obtain a light-curable resin;

[0062] 2. Add 25 parts of inert plasticizer dioctyl sebacate and 150 parts of energetic particles to the light-curable resin in parts by weight, add 14 g of modified calcium sulfate whiskers, and stir magnetically for 30 minutes to mix them evenly to obtain an energetic resin slurry, which is a light-curable energetic resin slurry for 3D printing;

[0063] 3. Mixing the energetic resin slurry, TPO photoinitiator and Sudan III light absorber in a mass ratio of 100:4:0.1 and stirring until the powder is completely dissolved to obtain a photosensitive resin;

[0064] IV. Pour the photosensitive resin into the material tank of the DLP printer, ensuring that the bottom layer of the material tank is completely covered with a layer of resin after being scraped by the squeegee. Adjust the light exposure time to 4 s and the exposure intensity to 70 mw / cm 2 . The layer thickness of printing is 90 μm, and 3D printing is completed layer by layer to obtain the sample;

[0065] V. Rinse the sample printed by DLP 3D printing with absolute ethanol to remove the uncured resin in the sample. Some large printed samples need to be post-processed, such as removing supports and polishing. After processing, an energetic material component is obtained. The curing thickness of the photocuring printing slurry is 120 μm, the viscosity is 1410 MPa·s, and the sedimentation height of the obtained energetic resin slurry in 24 h is 5.2%.

Claims

1. A method for toughening an energetic slurry and photocuring 3D printing, characterized in that The method is carried out according to the following steps:

1. Weigh 30 - 40 parts by weight of bisphenol A epoxy acrylate (EA), 10 - 20 parts of hexafunctional polyurethane acrylate (PUA) as resin oligomers, 10 - 20 parts of 1,6 - hexanediol diacrylate (HDDA), 10 - 20 parts of trimethylolpropane triacrylate (TMPTA) as resin monomers, 0.5 - 2 parts of thickener, and 0.5 - 4 parts of dispersant. Stir for 30 min under the condition that the stirring speed is 400 - 600 r / min to make the photosensitive resin evenly mixed, and obtain a photocurable resin mixture; 2. Weigh 10 - 25 parts of inert plasticizer and 100 - 185 parts of energetic particles by weight, add them into the prepared photocurable resin, stir until the particles are evenly dispersed in the photocurable resin, then put them into a ball mill and ball - mill for 2 h, and take out to obtain an energetic slurry; 3. Weigh 1 - 5 parts of surface - treated silicon carbide whiskers and 10 - 20 parts of surface - modified calcium sulfate whiskers by weight and add them into the energetic slurry, and stir magnetically for 30 min to make them evenly mixed.

4. Weigh 100 parts of energetic slurry resin, 1 - 4 parts of photoinitiator, and 0.01 - 0.1 parts of light absorber by weight and stir until the powder is completely dissolved to obtain a photosensitive resin; V. Pour the photosensitive resin into the material tank of the 3D printer, ensure that the bottom layer of the material tank can be completely covered with a layer of resin after the squeegee passes, adjust the light exposure time to 2 - 13 s, and the exposure intensity is 10 - 100 mw / cm 2 , the layer thickness of printing is 40 - 150 μm, and complete 3D printing layer by layer to obtain a sample part; 6. The samples printed by DLP 3D printing are rinsed with absolute ethanol to remove the uncured resin in the samples. For some large printed samples, post - treatment is required, such as removing the support, grinding and polishing, and an energetic material component is obtained after treatment.

2. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1, characterized in that Bisphenol A epoxy acrylate and hexafunctional polyurethane acrylate play a key role in determining the properties of the finished product. Bisphenol A epoxy acrylate contains an aromatic ring and lateral hydroxyl groups in its molecular structure, which helps to improve the adhesion of the resin. The aromatic ring structure endows the resin with higher rigidity and tensile strength, and bisphenol A epoxy acrylate has a fast curing rate and high hardness after curing; the urethane bond in hexafunctional polyurethane acrylate can promote the formation of multiple hydrogen bonds between molecular chains during the polymerization of the resin, which makes the formed resin have good wear resistance and a relatively high elongation at break. At the same time, hexafunctional polyurethane acrylate can increase the flexibility of the photocurable resin, reduce the shrinkage of the resin curing stress, and enhance the adhesion between the resin and the adherend.

3. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1 or 2, characterized in that The thickener is hydroxypropyl cellulose or hydroxypropyl methyl cellulose.

4. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1 or 2, characterized in that, The dispersant is BYK111 or BYK180.

5. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1 or 2, characterized in that The inert plasticizer is dioctyl sebacate (DOS). The typical function of the plasticizer is to improve the mechanical properties of the printed product and reduce the shrinkage caused by curing, which is especially important for additive manufacturing.

6. A method for toughening and photocuring 3D printing of energetic slurries according to claim 1 or 2, characterized in that, The energetic particles can be cyclotrimethylenetrinitramine, octogen, or CL - 20.

7. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1 or 2, characterized in that When adding 1 - 2 parts of thickener hydroxypropyl cellulose and 2 - 4 parts of dispersant BYK - 111 by weight, the stability of the energetic particles dispersed in the photocurable resin is the best.

8. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1 or 2, characterized in that, The maximum amount of energetic particles added by weight is 185 parts. When it exceeds this amount, the viscosity is too high and photocurable 3D printing cannot be carried out.

9. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1 or 2, characterized in that, The function of adding whiskers by weight is to prevent the further expansion of micro - cracks through the crack bridging, crack deflection, and pull - out effect of the whiskers, and strengthen and toughen the composite material.

10. A method for toughening and photocuring 3D printing of an energetic slurry according to claim 1 or 2, characterized in that, The surface treatment method of silicon carbide whiskers is as follows: Put the SiC whiskers into an ammonium fluoride solution with a mass fraction of 10%, and clean them by oscillating with an ultrasonic oscillator. Determine the cleaning time according to the amount of whiskers. After the whiskers are evenly dispersed, take out the whiskers and bake them at a temperature of 80°C for 5 hours; The silane coupling agent KH550 is dissolved in a mixed solvent composed of 3 parts of absolute ethanol and 1 part of distilled water with a mass fraction of 2%. Add acetic acid dropwise to adjust the pH value of the solution to about 4-5. Put the cleaned SiC fibers into an ultrasonic oscillator and oscillate, while slowly adding the pre-hydrolyzed silane solution dropwise, stir evenly with a magnetic stirrer, pour it into a petri dish and let it stand at room temperature for 2 hours, then dry it in a vacuum drying oven at 80°C for 8 hours to obtain the treated whiskers, and store them in a dry and airtight manner.

11. A method for toughening and photocuring 3D printing of an energetic slurry according to claim 1 or 2, characterized in that, The surface treatment method of calcium sulfate whiskers is as follows: First, add 4g of anhydrous calcium sulfate whiskers to a sodium phosphate solution with a concentration of 0.015mol / L and disperse them ultrasonically for 2 minutes, then continue to stir for 10 minutes, filter by suction, wash, add the filter cake to 100mL of absolute ethanol, heat it in an oil bath to 90°C, add an absolute ethanol solution containing a stearic acid modifier, the amount of stearic acid is 6wt%, filter while it is hot after 5 minutes of modification treatment, wash three times with absolute ethanol, and dry at 100°C to obtain the modified product.

12. A method for toughening an energetic slurry and photocuring 3D printing according to claim 1 or 2, characterized in that The photoinitiator is photoinitiator 819 or photoinitiator TPO. The photoinitiator is responsible for generating free radicals by breaking during ultraviolet irradiation to initiate free radical polymerization reactions. The light absorber is Sudan III; the light absorber is responsible for absorbing the excess light intensity during ultraviolet irradiation, reducing the light dispersion, and improving the printing accuracy.

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