A lightweight composite target plate and a method of manufacturing the same

Abstract

This invention relates to the field of bulletproof materials technology and discloses a lightweight composite target plate and its preparation method, comprising the following steps: mixing epoxy resin, curing agent, silane coupling agent, composite boron carbide ceramic, thermally conductive additive, and solvent, and stirring to obtain an epoxy resin binder; applying the epoxy resin binder to the upper and lower surfaces of a wooden board to obtain a wooden board layer; applying the epoxy resin binder to the upper and lower surfaces of a quartz fiber cloth to obtain a quartz fiber cloth layer; stacking a damping rubber plate, a wooden board layer, a PE board, a quartz fiber cloth layer, and a steel plate in a top-to-bottom order, and then rolling and curing to obtain the composite target plate. Silicon carbide nanowires are formed in the boron carbide ceramic, inhibiting crack propagation in the boron carbide ceramic, improving the strength of the boron carbide ceramic, and enhancing the bulletproof performance of the composite target; nano-zinc oxide forms an uneven structure on the surface of the boron carbide ceramic, enhancing the strength of the boron carbide ceramic and improving the bulletproof performance of the composite target.

Description

Technical Field

[0001] This invention relates to the field of bulletproof materials technology, specifically to a lightweight composite material target plate and its preparation method. Background Technology

[0002] With the rapid development of modern high technology and anti-armor weapon technology, the protection of combat personnel and equipment has received increasing attention. This has led to higher demands on the performance of armor protection materials. In modern warfare, armor protection materials must possess excellent impact resistance, penetration resistance, and spalling resistance, while also considering factors such as cost and quality. Lightweight design and strong protection are perpetual themes in the development of armored equipment. Therefore, modern armor protection materials should strive to meet the requirements of high hardness, high strength, high toughness, low density, and low cost. Among these, metal matrix composites, fiber-reinforced composites, ceramic matrix composites, and damping polymer composites, possessing superior hardness, are widely used in armor protection materials.

[0003] Under the powerful impact of a bullet, the composite target plates are not firmly bonded together and are prone to displacement, affecting their ballistic protection performance. Mixing high-hardness ceramic materials with the material of the spacer blocks to form an adhesive that adheres to the interlayer of the composite target plate makes the composite target plate firmly bonded and improves its ballistic protection performance. However, the high-hardness ceramic materials are brittle, and when the huge impact force of the bullet hits the composite target plate, the high-hardness ceramics are prone to breakage, causing the composite target plate to shatter and crack, thus affecting its ballistic protection performance. Summary of the Invention

[0004] This invention provides a lightweight composite material target plate and its preparation method, which solves the problems of weak bonding between composite material target plates and easy breakage of high-hardness ceramic materials, which leads to a decrease in the ballistic performance of composite material target plates.

[0005] The technical solution of this invention:

[0006] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0007] S1. Mix epoxy resin, curing agent, silane coupling agent, composite boron carbide ceramic, thermally conductive additive and solvent, and stir at 300-400 r / min for 30-40 min to obtain epoxy resin adhesive;

[0008] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain a wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain a quartz fiber cloth layer.

[0009] S3. Stack the damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate in order from top to bottom, roll them, and cure them at 70-90℃ for 20-30 minutes to obtain the composite material target plate.

[0010] The composite boron carbide ceramic is obtained by treating boron carbide ceramic loaded with nanowires with potassium permanganate, reacting it with zinc acetate dihydrate and ammonia, and then reacting it with organosilane and pretreated carbon fiber.

[0011] The boron carbide ceramic loaded with nanowires is obtained by mixing and reacting boron carbide ceramic, nickel chloride hexahydrate and methyltrichlorosilane;

[0012] The thermally conductive additive is obtained by mixing and reacting carboxylated cellulose nanofibers, metal ion solution, boron nitride nanosheets and comonomers.

[0013] Furthermore, the dimensions of the damping rubber plate are: length 100-2000mm, width 100-2000mm, and thickness 1-6mm.

[0014] Furthermore, the dimensions of the wooden boards are: 100-2000mm in length, 100-2000mm in width, and 1-7mm in thickness.

[0015] Furthermore, the dimensions of PE boards are: length 100-2000mm, width 100-2000mm, and thickness 5-20mm.

[0016] Furthermore, the dimensions of the quartz fiber cloth are: length 100-2000mm, width 100-2000mm, and thickness 0.5-3mm.

[0017] Furthermore, the steel plate dimensions are 100-2000mm in length, 100-2000mm in width, and 2-6mm in thickness.

[0018] Further, in step S1, the mass ratio of epoxy resin, curing agent, silane coupling agent, composite boron carbide ceramic, thermally conductive additive and solvent is (80-100):(10-20):(8-10):(20-30):(15-20):(50-60).

[0019] Furthermore, the epoxy resin is selected from any one of E51 epoxy resin, E42 epoxy resin, and E44 epoxy resin.

[0020] Furthermore, the curing agent is selected from any one of diaminodiphenylmethane, m-phenylenediamine, and diaminodiphenyl sulfone.

[0021] Furthermore, the silane coupling agent is selected from any one of KH550, KH560, and KH570.

[0022] Furthermore, the solvent is selected from any one of ethanol, toluene, and xylene.

[0023] Furthermore, the composite boron carbide ceramic is specifically prepared by the following steps:

[0024] A1. Add nickel chloride hexahydrate, methyltrichlorosilane and boron carbide ceramic to ethanol, stir evenly, heat to 50-60℃, stir at 500-600 r / min for 40-50 min, introduce argon gas, react at 1000-1200℃ for 1-2 h, cool to room temperature, take out, wash and dry to obtain boron carbide ceramic loaded with nanowires;

[0025] A2. Add potassium permanganate and boron carbide ceramic loaded with nanowires to deionized water, stir at 30-40℃ for 1-2 hours, filter, wash and dry to obtain a solid;

[0026] A3. Add zinc acetate dihydrate, monoethanolamine and ammonia to deionized water, stir until uniform, add solid, stir until uniform, stir and react at 90-110℃ for 2-4 hours, cool to room temperature, take out, wash and dry to obtain modified boron carbide ceramic.

[0027] A4. Add carbon fiber to Tris-HCl buffer solution, stir well, add dopamine, and after the reaction is complete, filter, wash and dry to obtain pretreated carbon fiber.

[0028] A5. Add organosilane and pretreated carbon fiber to ethanol, stir evenly, add modified boron carbide ceramic, heat to 40-50℃, stir at 300-350r / min for 3-5h, filter, wash and dry to obtain composite boron carbide ceramic.

[0029] Furthermore, in the A1 reaction process described above, nickel chloride hexahydrate serves as a catalyst, and methyltrichlorosilane serves as both a silicon and carbon source. The porous structure of boron carbide ceramics allows methyltrichlorosilane to be adsorbed into the pores of the boron carbide ceramics. When helium gas is introduced and the temperature is 1000-1200℃, methyltrichlorosilane decomposes to form carbon and silicon elements. The carbon and silicon elements are then covalently bonded to form a silicon carbide crystal structure. The carbon elements in the pores of the boron carbide ceramics can also bond with the silicon elements, allowing the silicon carbide crystals to grow along the pore walls of the boron carbide ceramics. This results in the formation of silicon carbide nanowires within the pores of the boron carbide ceramics, thus forming boron carbide ceramics loaded with nanowires.

[0030] Furthermore, in the A2 reaction process described above, potassium permanganate, as an oxidant, can react with the carbon elements on the surface of the boron carbide ceramic loaded with nanowires, thereby introducing a large number of oxygen-containing functional groups on the surface of the boron carbide ceramic loaded with nanowires to obtain a solid, which is beneficial for forming a nano zinc oxide uneven layer on the surface of the boron carbide ceramic loaded with nanowires.

[0031] Furthermore, during the A3 reaction described above, the solid surface contains a large number of oxygen-containing functional groups, which can combine with zinc ions in zinc acetate dihydrate, causing zinc ions to deposit on the boron carbide ceramic surface loaded with nanowires. Ammonia water acts as a precipitant, providing hydroxide ions that can combine with zinc ions, forming hydroxides that are deposited on the boron carbide ceramic surface. At 90-120℃, the hydroxides decompose upon heating, forming nano-zinc oxide crystals. As the reaction proceeds, an uneven nano-zinc oxide coating is formed on the surface of the boron carbide ceramic.

[0032] Furthermore, during the A4 reaction described above, in the Tris-HCl buffer solution, dopamine can self-polymerize on the carbon fiber surface to form polydopamine, which allows the carbon fiber to carry a large number of phenolic hydroxyl groups. This facilitates the formation of a cross-linked network structure between the carbon fiber and the silane hydrolysis products, resulting in pretreated carbon fibers.

[0033] Furthermore, during the A5 reaction described above, organosilanes hydrolyze to form polysiloxanes, and the hydroxyl groups generated by hydrolysis can chemically bond with the phenolic hydroxyl groups on the surface of the pretreated carbon fibers to form a cross-linked network structure. The hydroxyl groups contained on the surface of the modified boron carbide ceramic can also participate in the reaction, thereby forming a cross-linked network structure on the surface of the modified boron carbide ceramic and obtaining a composite boron carbide ceramic.

[0034] Further, in step A1, the ratio of nickel chloride hexahydrate, methyltrichlorosilane, boron carbide ceramic and ethanol is (1-2)g:(5-6)g:(12-13)g:(90-110)mL.

[0035] Further, in step A2, the ratio of potassium permanganate, boron carbide ceramic loaded with nanowires, and deionized water is (0.2-0.4)g:(4-6)g:(35-45)mL.

[0036] Further, in step A3, the ratio of zinc acetate dihydrate, monoethanolamine, ammonia, deionized water, and solid is (2-3)g:(3-5)mL:(0.5-1.5)mL:(45-55)mL:(5-6)g.

[0037] Further, in step A4, the ratio of carbon fiber, Tris-HCl buffer solution, and dopamine is (1-3)g:(55-65)mL:(0.5-0.9)g.

[0038] Further, in step A5, the ratio of the amount of organosilane, pretreated carbon fiber, ethanol and modified boron carbide ceramic is (4-6)g:(2-3)g:(65-75)mL:(8-12)g.

[0039] Furthermore, the organosilane is n-octyltriethoxysilane.

[0040] Furthermore, the carbon fiber has a diameter of 30-40 nm and a length of 3-5 μm.

[0041] Furthermore, the boron carbide ceramic has a pore size of 200-300 nm and a particle size of 0.5-1 mm.

[0042] Furthermore, the thermally conductive additive is prepared by the following steps:

[0043] B1. Add carboxylated cellulose nanofibers to deionized water, stir evenly, add metal ion solution, stir at 200-300 r / min for 20-30 min, let stand, filter, wash and dry to obtain modified carboxylated cellulose nanofibers.

[0044] B2. Boron nitride nanosheets, modified carboxylated cellulose nanofibers, methacrylamide, and acrylic acid are added to ethanol and stirred at 500-600 r / min for 30-40 min. Ammonium persulfate and N-vinyl-2-pyrrolidone are then added, and the mixture is stirred at 50-70℃ for 1-2 h. After filtration, washing, and drying, a thermally conductive additive is obtained.

[0045] Furthermore, during the B1 reaction process described above, the carboxyl groups on the surface of the carboxylated cellulose nanofibers can combine with metal ions in the metal ion solution through positive and negative charges, thereby loading a large number of thermally conductive metal ions on the surface of the carboxylated cellulose nanofibers to obtain modified carboxylated cellulose nanofibers.

[0046] Furthermore, during the B2 reaction process described above, under the action of the initiator ammonium persulfate, methacrylamide and acrylic acid copolymerize to form a cross-linked network, which allows the modified carboxylated cellulose nanofibers and boron nitride nanosheets to be embedded in the cross-linked network, forming a thermally conductive additive.

[0047] Further, in step B1, the ratio of the carboxylated cellulose nanofibers, deionized water, and metal ion solution used is (2-3)g:(45-55)mL:(1-2)mL.

[0048] Further, in step B2, the ratio of boron nitride nanosheets, modified carboxylated cellulose nanofibers, methacrylamide, acrylic acid, ethanol, ammonium persulfate, and N-vinyl-2-pyrrolidone is (2-3)g:(3-4)g:(7-9)g:(8-12)mL:(45-55)mL:(0.1-0.3)g:(0.4-0.6)mL.

[0049] Furthermore, the metal ion solution is selected from any one of silver chloride solution, copper chloride solution, and zinc chloride solution.

[0050] Furthermore, the carboxylated cellulose nanofibers have a diameter of 10-20 nm and a length of 1-3 μm.

[0051] Furthermore, the boron nitride nanosheets have a particle size of 0.1-0.4 μm.

[0052] The present invention has the following beneficial effects:

[0053] (1) In the technical solution of the present invention, silicon carbide nanowires are formed in the pores of boron carbide ceramics. On the one hand, the silicon carbide nanowires formed are randomly distributed in the pores of boron carbide ceramics, which can effectively absorb and disperse the impact energy generated by the projectile, suppress the propagation of cracks in boron carbide ceramics, improve the strength of boron carbide ceramics, and enhance the ballistic performance of composite material targets. On the other hand, the silicon carbide nanowires reduce the porous structure of boron carbide ceramics and serve as a supporting skeleton for boron carbide ceramics, further enhancing the mechanical strength of boron carbide ceramics.

[0054] (2) In the technical solution of the present invention, the boron carbide ceramic loaded with nanowires is pretreated with potassium permanganate, which introduces a large number of oxygen-containing functional groups on the surface of the boron carbide ceramic loaded with nanowires, which is conducive to forming a nano zinc oxide uneven layer on the surface of the boron carbide ceramic loaded with nanowires; the uneven nano zinc oxide coating is formed on the solid surface of the boron carbide ceramic. On the one hand, the formed nano zinc oxide can block the pores on the surface of the boron carbide ceramic, improve the density of the boron carbide ceramic, enhance the strength of the boron carbide ceramic, and avoid the high hardness ceramic from easily breaking under the impact energy generated by the projectile, causing the composite target plate to break and crack, affecting the ballistic performance of the composite target plate; on the other hand, the uneven structure formed by the nano zinc oxide, when the bullet hits the composite target plate, the strong impact force generated acts on the surface of the uneven layer formed by the nano zinc oxide, and the nanoparticles are broken by the impact force. During the breaking process, it can effectively absorb and disperse the impact energy generated by the projectile, reduce the large-area breakage of the boron carbide ceramic due to impact and vibration, enhance the strength of the boron carbide ceramic, and improve the ballistic performance of the composite target.

[0055] (3) In the technical solution of the present invention, dopamine self-polymerizes on the surface of carbon fiber to form polydopamine, which makes the carbon fiber carry a large number of phenolic hydroxyl groups, which is conducive to the formation of a cross-linked network structure between carbon fiber and silane hydrolysis products; carbon fiber and polysiloxane form a cross-linked network structure on the surface of modified boron carbide ceramic. On the one hand, the cross-linked network structure formed by carbon fiber and polysiloxane can absorb and disperse the impact energy generated by the projectile, further improve the strength of boron carbide ceramic, and enhance the ballistic performance of composite target material. On the other hand, the cross-linked network structure formed on the surface of modified boron carbide ceramic is chemically bonded to the molecular chain of epoxy resin in the binder matrix, so that the composite boron carbide ceramic can be uniformly dispersed in the binder matrix, giving full play to the ballistic performance of composite boron carbide ceramic.

[0056] (4) In the technical solution of the present invention, modified carboxylated cellulose nanofibers and hydroxy boron nitride nanosheets are embedded in the cross-linked network formed by the copolymerization of methacrylamide and acrylic acid to form an interconnected cross-linked thermally conductive network, which improves the thermal conductivity of the epoxy resin binder and thus enhances the thermal conductivity of the composite target material. This avoids the large amount of heat generated by the bullet passing through the composite target material, which would cause the binder to fail and affect the ballistic performance of the composite target material. The cross-linked network formed can also improve the mechanical strength of the composite target material. The metal ions on the surface of the modified carboxylated cellulose nanofibers can also combine with the hydroxyl groups on the surface of the boron nitride nanosheets, so that the carboxylated cellulose nanofibers and hydroxy boron nitride nanosheets overlap and stack with each other to form a thermally conductive path, which improves the thermal conductivity of the binder and avoids the heat generated by the bullet passing through the composite target material, which would cause the binder to fail and affect the ballistic performance of the composite target material.

[0057] (5) In the technical solution of the present invention, the damping rubber plate, wood board, PE board, quartz fiber cloth and steel plate are bonded together by epoxy resin adhesive to form a composite material target with excellent impact resistance, penetration resistance and anti-collapse performance, and has the technical effects of simple structure, resistance to multiple impacts, light weight, flexible movement and quick assembly. Detailed Implementation

[0058] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0059] The raw materials used in the embodiments of this invention are shown below, and all reagents used are analytical grade.

[0060] The damping rubber sheet measures 200mm in length, 150mm in width, and 4mm in thickness, and was purchased from Shandong Shenhua Machinery Manufacturing Co., Ltd.

[0061] The wooden board measures 200mm in length, 150mm in width, and 5mm in thickness, and was purchased from Sunshine Fuhe (Beijing) Trading Co., Ltd.

[0062] The PE board measures 200mm in length, 150mm in width, and 10mm in thickness, and was purchased from Shandong Huanchuang Engineering Materials Co., Ltd.

[0063] The quartz fiber cloth measures 200mm in length, 150mm in width, and 2mm in thickness, and was purchased from Henan Shenjiu Tianhang New Materials Co., Ltd.

[0064] The steel plate has the following dimensions: 200mm in length, 150mm in width, and 4mm in thickness. It was purchased from Xinpengyu (Beijing) Metal Materials Co., Ltd.

[0065] The epoxy resin is selected from E 51 epoxy resin.

[0066] The curing agent is selected from diaminodiphenylmethane.

[0067] The silane coupling agent is selected from KH550.

[0068] The solvent is ethanol.

[0069] The organosilane is n-octyltriethoxysilane.

[0070] The carbon fiber has a diameter of 35 nm and a length of 4 μm.

[0071] Boron carbide ceramics have a pore size of 250nm and a particle size of 0.8mm. (Lanxi Fanyi Fine Ceramics Co., Ltd.)

[0072] The metal ion solution was selected from zinc chloride solution with a concentration of 1 mol / L.

[0073] Carboxylated cellulose nanofibers, 15 nm in diameter and 2 μm in length, from Shanghai Maclean Biotechnology Co., Ltd.

[0074] The boron nitride nanosheets have a particle size of 0.3 μm.

[0075] Example 1

[0076] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0077] S1. Mix E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol, and stir at 300 r / min for 30 min to obtain epoxy resin binder.

[0078] The mass ratio of E51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol is 80:10:8:20:15:50.

[0079] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain the wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth layer. The coating amount for both layers is 180 g / m². 2 ;

[0080] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 70℃ for 20min to obtain the composite target plate.

[0081] Composite boron carbide ceramics are prepared by the following steps:

[0082] A1. Add 1g of nickel chloride hexahydrate, 5g of methyltrichlorosilane and 12g of boron carbide ceramic to 90mL of ethanol, stir evenly, heat to 50℃, stir at 500r / min for 40min, place in a reaction vessel, introduce argon gas, react at 1000℃ for 1h, cool to room temperature, take out, wash 3 times with deionized water, and dry in a 70℃ oven for 10min to obtain boron carbide ceramic loaded with nanowires;

[0083] A2. Add 0.2g potassium permanganate and 4g boron carbide ceramic loaded with nanowires to 35mL of deionized water, stir at 30℃ for 1h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain a solid.

[0084] A3. Add 2g of zinc acetate dihydrate, 3mL of monoethanolamine and 0.5mL of ammonia to 45mL of deionized water, stir well, add 5g of solid, stir well, place in a water bath, stir and react at 90℃ for 2h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 80℃ for 10min to obtain modified boron carbide ceramic.

[0085] A4. Add 1g of carbon fiber to 55mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.5g of dopamine, stir and react for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain pretreated carbon fiber.

[0086] A5. Add 4g of n-octyltriethoxysilane and 2g of pretreated carbon fiber to 65mL of ethanol, stir evenly, add 8g of modified boron carbide ceramic, heat to 40℃, stir at 300r / min for 3h, filter, wash 3 times with deionized water and 3 times with ethanol, and dry in an oven at 85℃ for 20min to obtain composite boron carbide ceramic.

[0087] The thermally conductive additive is prepared by the following steps:

[0088] B1. Add 2g of carboxylated cellulose nanofibers to 45mL of deionized water, stir evenly, add 1mL of 1mol / L zinc chloride solution, stir at 200r / min for 20min, let stand for 10min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified carboxylated cellulose nanofibers.

[0089] B2. Add 2g of boron nitride nanosheets, 3g of modified carboxylated cellulose nanofibers, 7g of methacrylamide, and 8mL of acrylic acid to 45mL of ethanol. Stir at 500r / min for 30min. Add 0.1g of ammonium persulfate and 0.4mL of N-vinyl-2-pyrrolidone. After stirring and reacting at 50℃ for 1 minute, filter, wash 3 times with ethanol, wash 3 times with deionized water, and dry in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0090] Example 2

[0091] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0092] S1. Mix E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol, and stir at 350 r / min for 35 min to obtain epoxy resin binder;

[0093] The mass ratio of E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol is 90:15:9:25:18:55.

[0094] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain the wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth layer. The coating amount for both layers is 180 g / m². 2 ;

[0095] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 80℃ for 25min to obtain the composite target plate.

[0096] Composite boron carbide ceramics are prepared by the following steps:

[0097] A1. Add 1.5g nickel chloride hexahydrate, 5.6g methyltrichlorosilane and 12.5g boron carbide ceramic to 100mL ethanol, stir evenly, heat to 55℃, stir at 550r / min for 45min, place in a reaction vessel, introduce argon gas, react at 1100℃ for 1.5h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain boron carbide ceramic loaded with nanowires;

[0098] A2. Add 0.3g potassium permanganate and 5g boron carbide ceramic loaded with nanowires to 40mL of deionized water, stir at 35℃ for 1.5h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain a solid.

[0099] A3. Add 2.5g of zinc acetate dihydrate, 4mL of monoethanolamine and 1mL of ammonia to 50mL of deionized water, stir well, add 5.5g of solid, stir well, place in a water bath, stir and react at 100℃ for 3h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 80℃ for 10min to obtain modified boron carbide ceramic;

[0100] A4. Add 2g of carbon fiber to 60mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.7g of dopamine, stir and react for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain pretreated carbon fiber.

[0101] A5. Add 5g of n-octyltriethoxysilane and 2.5g of pretreated carbon fiber to 70mL of ethanol, stir evenly, add 10g of modified boron carbide ceramic, heat to 45℃, stir at 330r / min for 4h, filter, wash 3 times with deionized water and 3 times with ethanol, dry in an oven at 85℃ for 20min to obtain composite boron carbide ceramic.

[0102] The thermally conductive additive is prepared by the following steps:

[0103] B1. Add 2.5g of carboxylated cellulose nanofibers to 50mL of deionized water, stir well, add 1.5mL of 1mol / L zinc chloride solution, stir at 250r / min for 25min, let stand for 10min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified carboxylated cellulose nanofibers.

[0104] B2. Add 2.5g boron nitride nanosheets, 3.5g modified carboxylated cellulose nanofibers, 8g methacrylamide, and 10mL acrylic acid to 50mL ethanol. Stir at 550r / min for 35min. Add 0.2g ammonium persulfate and 0.5mL N-vinyl-2-pyrrolidone. Stir and react at 60℃ for 1.5 minutes. After filtration, wash three times with ethanol and three times with deionized water. Dry in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0105] Example 3

[0106] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0107] S1. Mix E51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol, and stir at 400 r / min for 40 min to obtain epoxy resin binder.

[0108] The mass ratio of E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol is 100:20:10:30:20:60.

[0109] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain the wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth layer. The coating amount for both layers is 180 g / m². 2 .

[0110] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 90℃ for 30min to obtain the composite target plate.

[0111] Composite boron carbide ceramics are prepared by the following steps:

[0112] A1. Add 2g of nickel chloride hexahydrate, 6g of methyltrichlorosilane and 13g of boron carbide ceramic to 110mL of ethanol, stir evenly, heat to 60℃, stir at 600r / min for 50min, place in a reaction vessel, introduce argon gas, react at 1200℃ for 2h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain boron carbide ceramic loaded with nanowires;

[0113] A2. Add 0.4g potassium permanganate and 6g boron carbide ceramic loaded with nanowires to 45mL of deionized water, stir at 40℃ for 2h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain a solid.

[0114] A3. Add 3g of zinc acetate dihydrate, 5mL of monoethanolamine and 1.5mL of ammonia to 55mL of deionized water, stir well, add 6g of solid, stir well, place in a water bath, stir and react at 110℃ for 4h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 80℃ for 10min to obtain modified boron carbide ceramic.

[0115] A4. Add 3g of carbon fiber to 65mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.9g of dopamine, stir for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain pretreated carbon fiber.

[0116] A5. Add 6g of n-octyltriethoxysilane and 3g of pretreated carbon fiber to 75mL of ethanol, stir evenly, add 12g of modified boron carbide ceramic, heat to 50℃, stir at 350r / min for 5h, filter, wash 3 times with deionized water and 3 times with ethanol, and dry in an oven at 85℃ for 20min to obtain composite boron carbide ceramic.

[0117] The thermally conductive additive is prepared by the following steps:

[0118] B1. Add 3g of carboxylated cellulose nanofibers to 55mL of deionized water, stir evenly, add 2mL of 1mol / L zinc chloride solution, stir at 300r / min for 30min, let stand for 10min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified carboxylated cellulose nanofibers.

[0119] B2. Add 3g boron nitride nanosheets, 4g modified carboxylated cellulose nanofibers, 7g methacrylamide, and 12mL acrylic acid to 55mL ethanol, stir at 600r / min for 40min, add 0.3g ammonium persulfate and 0.6mL N-vinyl-2-pyrrolidone, stir and react at 70℃ for 2h, filter, wash 3 times with ethanol, wash 3 times with deionized water, and dry in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0120] Comparative Example 1

[0121] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0122] S1. Mix E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol, and stir at 400 r / min for 40 min to obtain epoxy resin binder.

[0123] The mass ratio of E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol is 100:20:10:30:20:60.

[0124] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain the wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth layer. The coating amount for both layers is 180 g / m². 2 .

[0125] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 90℃ for 30min to obtain the composite target plate.

[0126] Composite boron carbide ceramics are prepared by the following steps:

[0127] A1. Add 0.4g potassium permanganate and 6g boron carbide ceramic to 45mL of deionized water, stir at 40℃ for 2h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain a solid.

[0128] A2. Add 3g of zinc acetate dihydrate, 5mL of monoethanolamine and 1.5mL of ammonia to 55mL of deionized water, stir well, add 6g of solid, stir well, place in a water bath, stir and react at 110℃ for 4h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 80℃ for 10min to obtain modified boron carbide ceramic.

[0129] A3. Add 32g of carbon fiber to 65mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.9g of dopamine, stir for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain pretreated carbon fiber.

[0130] A4. Add 6g of n-octyltriethoxysilane and 3g of pretreated carbon fiber to 75mL of ethanol, stir evenly, add 12g of modified boron carbide ceramic, heat to 50℃, stir at 350r / min for 5h, filter, wash 3 times with deionized water and 3 times with ethanol, and dry in an oven at 85℃ for 20min to obtain composite boron carbide ceramic.

[0131] The thermally conductive additive is prepared by the following steps:

[0132] B1. Add 3g of carboxylated cellulose nanofibers to 55mL of deionized water, stir evenly, add 2mL of 1mol / L zinc chloride solution, stir at 300r / min for 30min, let stand for 10min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified carboxylated cellulose nanofibers.

[0133] B2. Add 3g boron nitride nanosheets, 4g modified carboxylated cellulose nanofibers, 7g methacrylamide, and 12mL acrylic acid to 55mL ethanol, stir at 600r / min for 40min, add 0.3g ammonium persulfate and 0.6mL N-vinyl-2-pyrrolidone, stir and react at 70℃ for 2h, filter, wash 3 times with ethanol, wash 3 times with deionized water, and dry in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0134] Comparative Example 2

[0135] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0136] S1. Mix E51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol, and stir at 400 r / min for 40 min to obtain epoxy resin binder.

[0137] The mass ratio of E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol is 100:20:10:30:20:60.

[0138] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain the wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth layer. The coating amount for both layers is 180 g / m². 2 .

[0139] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 90℃ for 30min to obtain the composite target plate.

[0140] Composite boron carbide ceramics are prepared by the following steps:

[0141] A1. Add 2g of nickel chloride hexahydrate, 6g of methyltrichlorosilane and 13g of boron carbide ceramic to 110mL of ethanol, stir evenly, heat to 60℃, stir at 600r / min for 50min, place in a reaction vessel, introduce argon gas, react at 1200℃ for 2h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain boron carbide ceramic loaded with nanowires;

[0142] A2. Add 32g of carbon fiber to 65mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.9g of dopamine, stir for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain pretreated carbon fiber.

[0143] A5. Add 6g of n-octyltriethoxysilane and 3g of pretreated carbon fiber to 75mL of ethanol, stir evenly, add 12g of boron carbide ceramic loaded with nanowires, heat to 50℃, stir at 350r / min for 5h, filter, wash 3 times with deionized water and 3 times with ethanol, and dry in an oven at 85℃ for 20min to obtain composite boron carbide ceramic.

[0144] The thermally conductive additive is prepared by the following steps:

[0145] B1. Add 3g of carboxylated cellulose nanofibers to 55mL of deionized water, stir evenly, add 2mL of 1mol / L zinc chloride solution, stir at 300r / min for 30min, let stand for 10min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified carboxylated cellulose nanofibers.

[0146] B2. Add 3g boron nitride nanosheets, 4g modified carboxylated cellulose nanofibers, 7g methacrylamide, and 12mL acrylic acid to 55mL ethanol, stir at 600r / min for 40min, add 0.3g ammonium persulfate and 0.6mL N-vinyl-2-pyrrolidone, stir and react at 70℃ for 2h, filter, wash 3 times with ethanol, wash 3 times with deionized water, and dry in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0147] Comparative Example 3

[0148] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0149] S1. Mix E 51 epoxy resin, diaminodiphenylmethane, KH550, modified boron carbide ceramic, thermally conductive additive and ethanol, and stir at 400 r / min for 40 min to obtain epoxy resin binder.

[0150] The mass ratio of E 51 epoxy resin, diaminodiphenylmethane, KH550, modified boron carbide ceramic, thermally conductive additive and ethanol is 100:20:10:30:20:60.

[0151] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain the wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth layer. The coating amount for both layers is 180 g / m². 2 .

[0152] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 90℃ for 30min to obtain the composite target plate.

[0153] Modified boron carbide ceramics are prepared by the following steps:

[0154] A1. Add 2g of nickel chloride hexahydrate, 6g of methyltrichlorosilane and 13g of boron carbide ceramic to 110mL of ethanol, stir evenly, heat to 60℃, stir at 600r / min for 50min, place in a reaction vessel, introduce argon gas, react at 1200℃ for 2h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain boron carbide ceramic loaded with nanowires;

[0155] A2. Add 0.4g potassium permanganate and 6g boron carbide ceramic loaded with nanowires to 45mL of deionized water, stir at 40℃ for 2h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain a solid.

[0156] A3. Add 3g of zinc acetate dihydrate, 5mL of monoethanolamine and 1.5mL of ammonia to 55mL of deionized water, stir well, add 6g of solid, stir well, place in a water bath, stir and react at 110℃ for 4h, cool to room temperature, take out, wash 3 times with deionized water, and dry in an oven at 80℃ for 10min to obtain modified boron carbide ceramic.

[0157] The thermally conductive additive is prepared by the following steps:

[0158] B1. Add 3g of carboxylated cellulose nanofibers to 55mL of deionized water, stir evenly, add 2mL of 1mol / L zinc chloride solution, stir at 300r / min for 30min, let stand for 10min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified carboxylated cellulose nanofibers.

[0159] B2. Add 3g boron nitride nanosheets, 4g modified carboxylated cellulose nanofibers, 7g methacrylamide, and 12mL acrylic acid to 55mL ethanol, stir at 600r / min for 40min, add 0.3g ammonium persulfate and 0.6mL N-vinyl-2-pyrrolidone, stir and react at 70℃ for 2h, filter, wash 3 times with ethanol, wash 3 times with deionized water, and dry in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0160] Comparative Example 4

[0161] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0162] S1. Mix E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol, and stir at 400 r / min for 40 min to obtain epoxy resin binder.

[0163] The mass ratio of E51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol is 100:20:10:30:20:60.

[0164] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain a wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain a quartz fiber cloth layer. The coating amount is 180g / m2 for both.

[0165] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 90℃ for 30min to obtain the composite target plate.

[0166] Composite boron carbide ceramics are prepared by the following steps:

[0167] A1. Add 2g of nickel chloride hexahydrate, 6g of methyltrichlorosilane and 13g of boron carbide ceramic to 110mL of ethanol, stir evenly, heat to 60℃, stir at 600r / min for 50min, place in a reaction vessel, introduce argon gas, react at 1200℃ for 2h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain boron carbide ceramic loaded with nanowires;

[0168] A2. Add 0.4g potassium permanganate and 6g boron carbide ceramic loaded with nanowires to 45mL of deionized water, stir at 40℃ for 2h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain a solid.

[0169] A3. Add 3g of zinc acetate dihydrate, 5mL of monoethanolamine and 1.5mL of ammonia to 55mL of deionized water, stir well, add 6g of solid, stir well, place in a water bath, stir and react at 110℃ for 4h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 80℃ for 10min to obtain modified boron carbide ceramic.

[0170] A4. Add 32g of carbon fiber to 65mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.9g of dopamine, stir for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain pretreated carbon fiber.

[0171] A5. Add 6g of n-octyltriethoxysilane and 3g of pretreated carbon fiber to 75mL of ethanol, stir evenly, add 12g of modified boron carbide ceramic, heat to 50℃, stir at 350r / min for 5h, filter, wash 3 times with deionized water and 3 times with ethanol, and dry in an oven at 85℃ for 20min to obtain composite boron carbide ceramic.

[0172] The thermally conductive additive is prepared by the following steps:

[0173] 3g of boron nitride nanosheets, 4g of cellulose nanofibers, 7g of methacrylamide and 12mL of acrylic acid were added to 55mL of ethanol and stirred at 600r / min for 40min. Then, 0.3g of ammonium persulfate and 0.6mL of N-vinyl-2-pyrrolidone were added and stirred at 70℃ for 2h. After filtration, the mixture was washed three times with ethanol and three times with deionized water, and dried in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0174] Comparative Example 5

[0175] A method for preparing a lightweight composite target plate includes the following preparation steps:

[0176] S1. Mix E 51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol, and stir at 400 r / min for 40 min to obtain epoxy resin binder.

[0177] The mass ratio of E51 epoxy resin, diaminodiphenylmethane, KH550, composite boron carbide ceramic, thermally conductive additive and ethanol is 100:20:10:30:20:60.

[0178] S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain the wood board layer. Apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain the quartz fiber cloth layer. The coating amount for both layers is 180 g / m². 2 .

[0179] S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled at 15MPa and cured at 90℃ for 30min to obtain the composite target plate.

[0180] Composite boron carbide ceramics are prepared by the following steps:

[0181] A1. Add 2g of nickel chloride hexahydrate, 6g of methyltrichlorosilane and 13g of boron carbide ceramic to 110mL of ethanol, stir evenly, heat to 60℃, stir at 600r / min for 50min, place in a reaction vessel, introduce argon gas, react at 1200℃ for 2h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain boron carbide ceramic loaded with nanowires;

[0182] A2. Add 0.4g potassium permanganate and 6g boron carbide ceramic loaded with nanowires to 45mL of deionized water, stir at 40℃ for 2h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain a solid.

[0183] A3. Add 3g of zinc acetate dihydrate, 5mL of monoethanolamine and 1.5mL of ammonia to 55mL of deionized water, stir well, add 6g of solid, stir well, place in a water bath, stir and react at 110℃ for 4h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 80℃ for 10min to obtain modified boron carbide ceramic.

[0184] A4. Add 32g of carbon fiber to 65mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.9g of dopamine, stir for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain pretreated carbon fiber.

[0185] A5. Add 6g of n-octyltriethoxysilane and 3g of pretreated carbon fiber to 75mL of ethanol, stir evenly, add 12g of modified boron carbide ceramic, heat to 50℃, stir at 350r / min for 5h, filter, wash 3 times with deionized water and 3 times with ethanol, and dry in an oven at 85℃ for 20min to obtain composite boron carbide ceramic.

[0186] The thermally conductive additive is prepared by the following steps:

[0187] B1. Add 3g of carboxylated cellulose nanofibers to 55mL of deionized water, stir evenly, add 2mL of 1mol / L zinc chloride solution, stir at 300r / min for 30min, let stand for 10min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified carboxylated cellulose nanofibers.

[0188] B2. Add 4g of modified carboxylated cellulose nanofibers, 7g of methacrylamide and 12mL of acrylic acid to 55mL of ethanol, stir at 600r / min for 40min, add 0.3g of ammonium persulfate and 0.6mL of N-vinyl-2-pyrrolidone, stir and react at 70℃ for 2h, filter, wash 3 times with ethanol and 3 times with deionized water, and dry in an oven at 60℃ for 10min to obtain a thermally conductive additive.

[0189] The performance of the composite target plates prepared in Examples 1-3 and Comparative Examples 1-5 was then tested.

[0190] The ballistic performance was tested according to the standard "GJB59.18-88 Armored Vehicle Test Procedure Armor Plate Anti-bullet Performance Test", with a firing angle of 0 degrees, a projectile velocity of 820m / s, and 5 effective projectiles fired.

[0191] Test the damage level of the Type 53 rifle, 7.62mm ordinary steel bullet, at a shooting distance of 100m, and observe whether the bullet penetrates the surface of the composite material target plate;

[0192] Test the damage level of the QBZ-191 precision rifle, 5.8mm steel core bullet, at a shooting distance of 100m, and observe whether the bullet penetrates the surface of the composite material target plate;

[0193] Testing of the Type 53 firearm, using 7.62mm armor-piercing incendiary rounds, at a firing distance of 15m to determine the damage level and observe whether the bullet penetrated the surface of the composite material target plate; 5.8mm steel-core projectiles with 7.62mm armor-piercing incendiary rounds.

[0194] The test results are shown in Table 1 below.

[0195] Table 1 Performance testing of composite target plates prepared in Examples 1-3 and Comparative Examples 1-5

[0196]

[0197]

[0198] As can be seen from the data in Table 1, the composite target plates prepared in Examples 1-3 have good ballistic protection performance. In Comparative Example 1, the composite boron carbide ceramic prepared by replacing the boron carbide ceramic loaded with nanowires with boron carbide ceramic was added to the epoxy resin binder for bonding the composite target material. Its ballistic protection performance decreased, which proves that the formation of silicon carbide nanowires in the pores of boron carbide ceramic can effectively absorb and disperse the impact energy generated by the projectile, enhance the ballistic protection performance of the composite target material, and serve as a supporting skeleton for boron carbide ceramic, further enhancing the mechanical strength of boron carbide ceramic.

[0199] In Comparative Example 2, the modified boron carbide ceramic was replaced with boron carbide ceramic loaded with nanowires. The resulting composite boron carbide ceramic was added to an epoxy resin binder and used to bond the composite target. Its ballistic performance decreased, demonstrating that the formation of an uneven nano-zinc oxide coating on the solid surface of the boron carbide ceramic can effectively absorb and disperse the impact energy generated by the projectile, reduce the large-area fragmentation of the boron carbide ceramic caused by impact and vibration, enhance the strength of the boron carbide ceramic, and improve the ballistic performance of the composite target.

[0200] In Comparative Example 3, the composite boron carbide ceramic was replaced with modified boron carbide ceramic added to the epoxy resin binder for bonding the composite target. The ballistic performance of the composite target decreased, indicating that the carbon fiber and polysiloxane formed a cross-linked network structure on the surface of the modified boron carbide ceramic, which improved the strength of the boron carbide ceramic and enhanced the ballistic performance of the composite target. Furthermore, the composite boron carbide ceramic can be uniformly dispersed in the binder matrix, thus fully utilizing the ballistic performance of the composite boron carbide ceramic.

[0201] Comparative Example 4: The modified carboxylated cellulose nanofibers were replaced with a thermally conductive additive prepared from carboxylated cellulose nanofibers and added to an epoxy resin binder for bonding composite target materials. The ballistic protection performance of the target material decreased, which proved that the metal ions on the surface of the modified carboxylated cellulose nanofibers can combine with boron nitride nanosheets to improve the thermal conductivity of the binder and avoid the heat generated by the bullet passing through the composite target material, which would cause the binder to fail and affect the ballistic protection performance of the composite target material.

[0202] In Comparative Example 5, the thermally conductive additive prepared without boron nitride nanosheets was added to an epoxy resin binder for bonding composite target materials. The ballistic performance of the target material decreased, demonstrating that the boron nitride nanosheets overlapped and stacked with the modified carboxylated cellulose nanofibers and hydroxy boron nitride nanosheets, improving the thermal conductivity of the binder and preventing the heat generated when the bullet passed through the composite target material.

[0203] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0204] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing a lightweight composite target plate, characterized in that, The preparation steps include the following: S1. Mix epoxy resin, curing agent, silane coupling agent, composite boron carbide ceramic, thermally conductive additive and solvent, and stir at 300-400 r / min for 30-40 min to obtain epoxy resin adhesive; S2. Apply epoxy resin adhesive to the upper and lower surfaces of the wood board to obtain a wood board layer, and apply epoxy resin adhesive to the upper and lower surfaces of the quartz fiber cloth to obtain a quartz fiber cloth layer. S3. The damping rubber plate, wood board layer, PE board, quartz fiber cloth layer and steel plate are stacked in the order from top to bottom, rolled and cured at 70-90℃ for 20-30 minutes to obtain the composite material target plate. The composite boron carbide ceramic is obtained by treating boron carbide ceramic loaded with nanowires with potassium permanganate, reacting it with zinc acetate dihydrate and ammonia, and then reacting it with organosilane and pretreated carbon fibers. The boron carbide ceramic loaded with nanowires is obtained by mixing and reacting boron carbide ceramic, nickel chloride hexahydrate and methyltrichlorosilane; The thermally conductive additive is obtained by mixing and reacting carboxylated cellulose nanofibers, metal ion solution, boron nitride nanosheets and comonomers.

2. The method for preparing a lightweight composite target plate according to claim 1, characterized in that, The composite boron carbide ceramic is specifically prepared by the following steps: A1. Add nickel chloride hexahydrate, methyltrichlorosilane and boron carbide ceramic to ethanol, stir evenly, heat to 50-60℃, stir at 500-600 r / min for 40-50 min, introduce argon gas, react at 1000-1200℃ for 1-2 h, cool to room temperature, take out, wash and dry to obtain boron carbide ceramic loaded with nanowires; A2. Add potassium permanganate and boron carbide ceramic loaded with nanowires to deionized water, stir at 30-40℃ for 1-2 hours, filter, wash and dry to obtain a solid; A3. Add zinc acetate dihydrate, monoethanolamine and ammonia to deionized water, stir until uniform, add solid, stir until uniform, stir and react at 90-110℃ for 2-4 hours, cool to room temperature, take out, wash and dry to obtain modified boron carbide ceramic. A4. Add carbon fiber to Tris-HCl buffer solution, stir well, add dopamine, and after the reaction is complete, filter, wash and dry to obtain pretreated carbon fiber. A5. Add organosilane and pretreated carbon fiber to ethanol, stir evenly, add modified boron carbide ceramic, heat to 40-50℃, stir at 300-350r / min for 3-5h, filter, wash and dry to obtain composite boron carbide ceramic.

3. The method for preparing a lightweight composite target plate according to claim 2, characterized in that, In step A1, the ratio of nickel chloride hexahydrate, methyltrichlorosilane, boron carbide ceramic and ethanol is (1-2)g:(5-6)g:(12-13)g:(90-110)mL.

4. The method for preparing a lightweight composite target plate according to claim 2, characterized in that, In step A2, the ratio of potassium permanganate, boron carbide ceramic loaded with nanowires, and deionized water is (0.2-0.4)g:(4-6)g:(35-45)mL; In step A3, the ratio of zinc acetate dihydrate, monoethanolamine, ammonia, deionized water, and solid is (2-3)g:(3-5)mL:(0.5-1.5)mL:(45-55)mL:(5-6)g.

5. The method for preparing a lightweight composite target plate according to claim 2, characterized in that, In step A4, the ratio of carbon fiber, Tris-HCl buffer solution, and dopamine is (1-3)g:(55-65)mL:(0.5-0.9)g; In step A5, the ratio of the amount of organosilane, pretreated carbon fiber, ethanol and modified boron carbide ceramic is (4-6)g:(2-3)g:(65-75)mL:(8-12)g.

6. The method for preparing a lightweight composite target plate according to claim 1, characterized in that, The thermally conductive additive is prepared by the following steps: B1. Add carboxylated cellulose nanofibers to deionized water, stir evenly, add metal ion solution, stir at 200-300 r / min for 20-30 min, let stand, filter, wash and dry to obtain modified carboxylated cellulose nanofibers. B2. Boron nitride nanosheets, modified carboxylated cellulose nanofibers, methacrylamide, and acrylic acid are added to ethanol and stirred at 500-600 r / min for 30-40 min. Ammonium persulfate and N-vinyl-2-pyrrolidone are then added, and the mixture is stirred at 50-70℃ for 1-2 h. After filtration, washing, and drying, a thermally conductive additive is obtained.

7. The method for preparing a lightweight composite target plate according to claim 6, characterized in that, In step B1, the ratio of the carboxylated cellulose nanofibers, deionized water, and metal ion solution used is (2-3)g:(45-55)mL:(1-2)mL.

8. The method for preparing a lightweight composite target plate according to claim 6, characterized in that, In step B2, the ratio of boron nitride nanosheets, modified carboxylated cellulose nanofibers, methacrylamide, acrylic acid, ethanol, ammonium persulfate, and N-vinyl-2-pyrrolidone is (2-3)g:(3-4)g:(7-9)g:(8-12)mL:(45-55)mL:(0.1-0.3)g:(0.4-0.6)mL.

9. A composite material target plate prepared by the preparation method according to any one of claims 1-8.

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