Columnar ceramic interlayer hybrid fiber composite bulletproof material and preparation method thereof

Abstract

The invention provides a columnar ceramic interlayer hybrid fiber composite bulletproof material and a preparation method thereof, a columnar ceramic panel adopts B4C ceramic particles and is prepared by a pressureless sintering method, and the ceramic particles are columnar and have excellent penetration resistance; the interlayer hybrid fiber backboard is formed by mixing Kevlar KM2 fibers and UHMWPE fibers according to a specific proportion to form a multi-layer composite structure, and the impact resistance of the material is further improved. The preparation method comprises the following steps: preparing a columnar ceramic panel by a pressureless sintering method, preparing an interlayer hybrid fiber back plate by a layered hot pressing method, and finally bonding the columnar ceramic panel and the interlayer hybrid fiber back plate by an adhesive to form a complete composite material. Compared with a traditional bulletproof material, through the synergistic effect of the columnar ceramics and the hybrid fibers, the bulletproof performance is remarkably improved, the weight of the material is reduced, and the stability of the material in a high-temperature environment is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of preparation of bulletproof materials, and more particularly to a columnar ceramic interlayer hybrid fiber composite bulletproof material and a preparation method thereof. Background Art

[0002] In the field of bulletproof materials, personal protective equipment and military technology, the development of high-performance bulletproof composite materials is one of the key technologies to protect the lives of personnel. Ideal bulletproof materials should have the following characteristics: excellent anti-penetration performance, light weight and portability, good thermal stability and environmental adaptability, efficient energy dispersion and absorption capabilities, and easy production and processing.

[0003] At present, bulletproof materials are mainly composed of metals, ceramics and high-performance fibers. Metal materials (such as steel plates and titanium alloys) are widely used due to their high strength and good ballistic blocking ability, but their high density increases the weight of the equipment, affecting the wearer's flexibility and long-term combat capability. In addition, they are prone to deformation and breakage under high-speed impact.

[0004] Ceramic materials (such as alumina and silicon carbide) have high hardness and excellent impact resistance. They can break quickly when impacted by a projectile, reducing its penetration by consuming the projectile's energy. However, the brittleness of ceramics makes them prone to cracking under impact, and their processing is difficult and costly.

[0005] High-performance fiber materials (such as Kevlar and UHMWPE) are favored for their light weight, high strength, good flexibility and impact resistance, and are stacked and woven to form dense bulletproof layers. However, these fibers may degrade in high temperature environments and have limited protection against multiple hits.

[0006] In order to overcome the limitations of a single material, researchers have tried to combine different materials to take advantage of their respective advantages. Combining the hardness of ceramics with the flexibility of fibers can form a complementary bulletproof structure. However, existing composite materials still show deficiencies in terms of anti-penetration performance, lightweight and durable protection. Therefore, it is urgent to develop new composite bulletproof materials to meet the increasingly severe practical application needs. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a columnar ceramic interlayer hybrid fiber composite bulletproof material and a preparation method thereof, and the specific scheme is as follows:

[0008] A columnar ceramic interlayer hybrid fiber composite bulletproof material, the composite bulletproof material comprising a columnar ceramic panel and an interlayer hybrid fiber backboard; the columnar ceramic panel is prepared from B4C ceramic particles by a pressureless sintering method, the column radius is 7.5 mm, and the arc radius is 21.60 mm; the interlayer hybrid fiber backboard is formed by mixing Kevlar KM2 fiber and UHMWPE fiber in a certain proportion, including structure A and structure B; structure A is a layer of Kevlar KM2 fiber and a layer of UHMWPE fiber; structure B is, from top to bottom, a layer of Kevlar KM2 fiber, a layer of UHMWPE fiber and two layers of Kevlar KM2 fiber.

[0009] Furthermore, the surface density of the columnar ceramic panel is 20 to 25 g / cm 3 .

[0010] Furthermore, the weight percentage of ceramic particles in the columnar ceramic panel is 90-95%; the weight ratio of Kevlar KM2 to UHMWPE in the interlayer mixed fiber backplane structure A is 1:7; in structure B, Kevlar KM2 accounts for 20%-30% of the total weight percentage; UHMWPE accounts for 70%-80% of the total weight percentage.

[0011] Furthermore, the surface density of the columnar ceramic panel is 24.48 g / cm 3 .

[0012] A method for preparing a composite bullet-proof material of a columnar ceramic interlayer hybrid fiber, the method comprising the following steps:

[0013] S1: Preparation of columnar ceramic panels by pressureless sintering;

[0014] S2: interlayer hybrid fiber backsheet is prepared by layered hot pressing method;

[0015] S3: spraying adhesive evenly on the bottom layer of the columnar ceramic panel and the surface layer of the interlayer hybrid fiber back panel, and bonding the two by hot pressing to obtain a columnar ceramic interlayer hybrid fiber composite material.

[0016] Furthermore, S1 also includes the following sub-steps:

[0017] S101, mold opening and firing: using a mold with an inner column radius of 7.5 mm, a column height of 8.93 mm, and a curved surface radius of 21.60 mm, the B4C ceramic particles are prepared by a pressureless sintering method, and the column diameter dimensional tolerance is controlled within ±0.1 mm;

[0018] S102, cleaning ceramics: placing the fired ceramic particles in anhydrous ethanol and ultrasonically vibrating for 30 minutes, wiping the surface and drying in an oven at 60° C. for 30 minutes;

[0019] S103, mold preparation: wrap the inner wall of the 300mm×300mm mold with release paper;

[0020] S104, glue primer: mix acrylic resin A and B components in a ratio of 1:1.8, and evenly apply to the bottom of the mold;

[0021] S105, splicing ceramics: placing ceramic particles into a mold in a predetermined arrangement, and adjusting the mold to ensure that there are no gaps between the ceramic particles;

[0022] S106, resin pouring: acrylic resin A and B components are prepared into a mixed resin in a ratio of 1:1.8 and poured into the mold;

[0023] S107, vacuum leveling: put the mold into a vacuum oven at 60°C to eliminate bubbles generated by stirring for 20 minutes;

[0024] S108. Demoulding and sampling: Take out the ceramic panel with a smooth surface without bubbles and closely arranged particles from the mould, and let it stand at room temperature for 12 hours before use.

[0025] Furthermore, S2 also includes the following sub-steps:

[0026] S201, layer arrangement: Kevlar KM2 and UHMWPE fibers are laid orthogonally and staggered according to the proportion and arrangement of the structural design, and covered with release film on the upper and lower sides;

[0027] S202 Separate hot pressing: The Kevlar KM2 layer and the UHMWPE layer are hot pressed separately. The hot pressing temperature of the Kevlar KM2 layer is raised to 80°C, and that of the UHMWPE layer is raised to 128°C. Exhaust is performed multiple times during the pressing process.

[0028] S203, hot pressing composite: stacking the two laminates and performing hot pressing again to obtain an interlayer mixed fiber composite board.

[0029] Furthermore, during S107, the defoaming degree and liquid level are observed through the vacuum box window glass; if the liquid level is significantly lower than the top of the ceramic, the resin is appropriately supplemented; when the liquid level is substantially flush with the top of the ceramic and there are no obvious bubbles on the surface, the negative pressure device is closed, and the ceramic panel is allowed to stand in a 60°C oven for 6 hours for self-leveling curing.

[0030] Furthermore, in S201, the Kevlar KM2 weftless fabric and the UHMWPE weftless fabric are laid flat in an orthogonal manner of 0 / 90° according to the Kevlar mixed thickness and the UHMWPE thickness.

[0031] Furthermore, the specific steps of separate hot pressing in S203 are: first, preheat the UHMWPE laminated non-woven fabric surface by pressing 5MPa, and when the internal temperature of the pressed non-woven fabric rises to 80°C, open the mold to vent 2-3 times; then close the mold and pressurize to 10MPa, and raise the internal temperature of the UHMWPE non-woven fabric to 100°C, and open the mold to vent 2-3 times. Close the mold again and pressurize to 24MPa, and raise the temperature to 128°C, maintain constant temperature and pressure for 30 minutes, then turn off the heating, cool the heating plate of the flat vulcanizer, and maintain a constant pressure of 24MPa; when the temperature cools to 30-40°C, release the pressure and open the mold to obtain the UHMWPE laminate.

[0032] Beneficial effects:

[0033] The present invention provides a columnar ceramic interlayer hybrid fiber composite bulletproof material and a preparation method thereof, which has the following advantages:

[0034] 1. Significantly improve the bulletproof performance: The present invention adopts a design that combines a columnar ceramic panel with an interlayer hybrid fiber backboard. By optimizing the radius of the ceramic column, the radius of the arc surface and the surface density, the anti-penetration ability of the ceramic panel is significantly improved. Columnar ceramics can effectively form a "ceramic cone" under the impact of bullets, absorb and disperse the energy of bullets, and enhance the protective effect. At the same time, the interlayer hybrid fiber backboard utilizes the complementary properties of Kevlar and UHMWPE fibers to further absorb the remaining energy through the fiber shear and tensile failure mechanism, effectively preventing bullet penetration. Experiments have shown that compared with a pure UHMWPE backboard, the hybrid backboard can effectively reduce the back convex depth by 3-5mm, significantly improving the bulletproof performance.

[0035] 2. Solve the contradiction between "lightweight and high strength": This invention achieves a perfect balance between lightweight and high strength of bulletproof materials through careful material selection and structural design. The columnar ceramic panel uses lightweight and high-strength B4C ceramics, while the hybrid fiber backboard combines the high modulus and high toughness of Kevlar and the high strength and low density of UHMWPE, so that the overall composite material can significantly reduce weight while ensuring high performance, thereby improving the mobility and comfort of soldiers.

[0036] 3. Enhanced environmental adaptability: The composite material design of the present invention fully considers the application requirements of battlefields and extreme environments, and has high environmental adaptability. Kevlar fiber has excellent stability in high temperature environments, avoiding the problem of UHMWPE fiber failing due to high temperature melting, and ensuring the stable bulletproof performance of the composite material under various climatic conditions. In addition, the optimized ceramic panel and fiber backplane structure also enhances the durability and resistance to multiple strikes of the material, extending the service life of the material.

[0037] 4. Provide a reliable numerical simulation prediction model: The present invention constructs a numerical simulation model based on the SPH-FE coupling algorithm, and introduces the strain rate effect function of the modulus and strength and the temperature effect correction parameter into the constitutive model of the fiber material, realizing a reliable prediction of the anti-penetration behavior of the columnar ceramic / interlayer hybrid fiber composite material. The error between the back convex depth of the composite material predicted by the model and the actual test result does not exceed 10%, which provides strong theoretical support for the iterative optimization design of bulletproof materials, saves R&D costs, and improves R&D efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural diagram of a hybrid fiber composite bulletproof material between columnar ceramic layers.

[0039] Reference numerals:

[0040] 1. Columnar ceramic panel; 2. One layer of Kevlar KM2 fiber; 3. UHMWPE fiber layer; 4. Two layers of Kevlar KM2 fiber. DETAILED DESCRIPTION

[0041] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0042] The present invention proposes a columnar ceramic / interlayer hybrid fiber composite material and a preparation method thereof, aiming to achieve high performance and light weight of bulletproof materials by optimizing the material structure and preparation process. The specific scheme is as follows:

[0043] (1) Raw materials and their usage:

[0044] ① Columnar ceramic panel: B4C ceramic particles are used, with a weight percentage of 90%-95%. The specific surface density is set to 24.48g / cm according to the optimization results. 3 , prepared by pressureless sintering method, ensuring that the column radius is 7.5mm, the arc radius is 21.60mm, and the column height is adjusted according to the surface density.

[0045] ② Interlayer mixed fiber backboard: It is mixed with Kevlar KM2 fiber and UHMWPE fiber in a certain proportion, including structure A and structure B; structure A includes K / U (the weight ratio of Kevlar:UHMWPE is about 1:7), and structure B is K / U / K (sandwich structure, the middle layer is UHMWPE, the two sides are Kevlar, Kevlar accounts for about 20%-30% of the total weight percentage, and UHMWPE accounts for about 70%-80%).

[0046] (2) Preparation process:

[0047] ① Preparation of columnar ceramic panels

[0048] (a) Mold opening and firing: A firing mold with an internal column radius of 7.50 mm, a column height of 8.93 mm, and a curved surface radius of 21.60 mm was customized. B4C ceramic particles were prepared by pressureless sintering. The geometric morphology of the fired ceramic particles is r1R2ρ3, and the column diameter dimensional tolerance is controlled within ±0.1 mm to ensure the accuracy of the ceramic splicing position.

[0049] (b) Cleaning the ceramic: Immerse the ceramic in anhydrous ethanol and ultrasonically vibrate for 30 minutes to remove the powder attached to the surface. Then wipe the ceramic surface with cotton cloth and dry it in a 60℃ oven for 30 minutes to ensure that the ceramic surface is clean and free of ethanol residue. This step is to ensure the bonding strength between the ceramic and the resin.

[0050] (c) Mold preparation: Wrap the inner wall of the previously prepared 300 mm × 300 mm mold with release paper to prevent leakage during the subsequent resin pouring process and to facilitate the final demolding and sampling.

[0051] (d) Prime with glue: Take a small amount of acrylic resin A and B components, mix them evenly in a mass ratio of 1:1.8, and evenly apply them to the bottom of the inner wall of the mold to observe whether the resin leaks. If there is no leakage, wait until the resin is self-leveling before starting to splice the ceramics.

[0052] (e) Splicing ceramics: Splice the ceramics according to Figure 1 The splicing method shown is arranged in the mold. After the ceramic fills the inner wall of the mold, adjust the mold expansion screw inward to ensure that the adjacent ceramic particles are pressed tightly against each other, and there is no gap between the outer side of the ceramic and the inner wall of the mold, so as to prevent the ceramic panel's anti-ballistic performance from decreasing due to the lack of constraints on the ceramic layer.

[0053] (f) Resin pouring: Take acrylic acid resin A and B components, mix them evenly according to the mass ratio of 1:1.8, defoam them in a vacuum box for 5 minutes, then take them out and pour them into the mold. Use a scraper to scrape away the excess resin, ensure that the resin liquid level is about 1-2mm higher than the top of the ceramic, and put them into a vacuum box for secondary defoaming.

[0054] (g) Vacuum leveling: Place the mold in a 60°C vacuum oven to eliminate bubbles generated by stirring for about 20 minutes. During this period, observe the degree of defoaming and the liquid level through the vacuum box window glass. If the liquid level is significantly lower than the top of the ceramic, add appropriate amount of resin. When the liquid level is basically flush with the top of the ceramic and there are no obvious bubbles on the surface, turn off the negative pressure device and let the ceramic panel stand in a 60°C oven for 6 hours to self-level and cure.

[0055] (h) Demolding and sampling: Take out the ceramic panel with a smooth surface without bubbles and closely arranged particles from the mold and let it stand at room temperature for 12 hours before use.

[0056] ② Preparation of interlayer hybrid fiber backplane

[0057] (a) Layer arrangement: Take a certain thickness of Kevlar and UHMWPE single-layer non-woven fabric, cut it into 300mm×300mm size, and lay it flat in a 0 / 90° orthogonal manner according to the Kevlar mixed thickness and UHMWPE thickness. After the layering, cover the top and bottom of the non-woven fabric with a layer of release film.

[0058] (b) Separate hot pressing: Kevlar laminated non-woven fabric and UHMWPE laminated non-woven fabric are placed in a flat vulcanizer for hot pressing. First, the UHMWPE laminated non-woven fabric is preheated by pressing 5MPa. When the internal temperature of the pressed non-woven fabric rises to 80°C, the mold is opened to vent 2-3 times. Then the mold is closed and pressurized to 10MPa, and the internal temperature of the UHMWPE non-woven fabric is raised to 100°C, and the mold is opened to vent 2-3 times. The mold is closed again and pressurized to 24MPa, and the temperature is raised to 128°C. The constant temperature and pressure are maintained for 30 minutes, and then the heating is turned off, the heating plate of the flat vulcanizer is cooled, and the constant pressure is maintained at 24MPa. When the temperature cools to 30-40°C, the pressure is released and the mold is opened to obtain the UHMWPE laminate. The preparation process of the Kevlar laminate is the same as above. During this period, the temperature can be appropriately increased and the hot pressing time can be extended to ensure the interlayer peeling strength of the Kevlar laminate.

[0059] (c) Hot-pressing compounding: Remove the release films on the surfaces of the Kevlar laminate and the UHMWPE laminate, stack the two laminates of a certain thickness according to the structural design requirements, re-cover the release films on the upper and lower surfaces, and then place them in a flat-plate vulcanizer for hot-pressing compounding. The interlayer mixed fiber laminate required by the composite structure design is obtained.

[0060] ③ Composite material molding

[0061] (a) Use a glue coating machine to evenly spray adhesive on the bottom layer of the ceramic panel and the surface layer of the fiber back panel. After bonding, put them into a flat vulcanizer for hot pressing to obtain the columnar ceramic / interlayer hybrid fiber composite material sample required for this project.

[0062] (b) The material side is coated with foam adhesive and then tightly wrapped with black nylon oxford cloth to obtain a ballistic test sample.

[0063] The columnar ceramic panels of product examples 1 to 4 of the present invention all use the same optimized structural parameters, while the ratios of Kevlar and UHMWPE fibers in the interlayer mixed fiber backplane are different. The specific formulas and properties are shown in Tables 1 and 2.

[0064] Table 1

[0065]

[0066] Table 2

[0067]

[0068] Note: The formula and preparation process of the columnar ceramic panel in all examples are the same (column radius is 7.5 mm, arc radius is 21.6 mm, surface density is 24.48 g / cm 3 ).

[0069] The test results show that the composite materials prepared in Examples 1 to 4 all exhibit excellent anti-ballistic performance, among which Example 4 performs best in terms of back convex depth and energy absorption.

[0070] In summary, the feasibility and superiority of the columnar ceramic / interlayer hybrid fiber composite material and the preparation method thereof proposed in the present invention are fully verified through the preparation and testing of Examples 1 to 4. The composite material exhibits significant advantages in terms of anti-ballistic performance, light weight, and environmental adaptability, and has extremely high application value.

[0071] As a further improvement, the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A columnar ceramic interlayer hybrid fiber composite bulletproof material, characterized in that: The composite bulletproof material includes a columnar ceramic panel and an interlayer hybrid fiber backboard; the columnar ceramic panel is prepared from B4C ceramic particles by a pressureless sintering method, the column radius is 7.5 mm, and the arc radius is 21.60 mm; the interlayer hybrid fiber backboard is mixed with Kevlar KM2 fiber and UHMWPE fiber in a certain proportion, including structure A and structure B; structure A is a layer of Kevlar KM2 fiber and a layer of UHMWPE fiber; structure B is, from top to bottom, a layer of Kevlar KM2 fiber, a layer of UHMWPE fiber and two layers of KevlarKM2 fiber.

2. The columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 1, characterized in that: The surface density of the columnar ceramic panel is 20-25g / cm 3 .

3. The columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 1, characterized in that: The weight percentage of ceramic particles in the columnar ceramic panel is 90-95%; the weight ratio of Kevlar KM2 to UHMWPE in the interlayer mixed fiber backplane structure A is 1:7; in the structure B, Kevlar KM2 accounts for 20%-30% of the total weight percentage; UHMWPE accounts for 70%-80% of the total weight percentage.

4. The columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 2, characterized in that: The surface density of the columnar ceramic panel is 24.48g / cm 3 .

5. The method for preparing a composite bullet-proof material according to any one of claims 1 to 4, characterized in that: The composite bulletproof material preparation method comprises the following steps: S1: Preparation of columnar ceramic panels by pressureless sintering; S2: interlayer hybrid fiber backsheet is prepared by layered hot pressing method; S3: spraying adhesive evenly on the bottom layer of the columnar ceramic panel and the surface layer of the interlayer hybrid fiber back panel, and bonding the two by hot pressing to obtain a columnar ceramic interlayer hybrid fiber composite material.

6. The method for preparing a columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 5, characterized in that: S1 also includes the following sub-steps: S101, mold opening and firing: using a mold with an inner column radius of 7.5 mm, a column height of 8.93 mm, and a curved surface radius of 21.60 mm, the B4C ceramic particles are prepared by a pressureless sintering method, and the column diameter dimensional tolerance is controlled within ±0.1 mm; S102, cleaning ceramics: placing the fired ceramic particles in anhydrous ethanol and ultrasonically vibrating for 30 minutes, wiping the surface and drying in an oven at 60° C. for 30 minutes; S103, mold preparation: wrap the inner wall of the 300mm×300mm mold with release paper; S104, glue primer: mix acrylic resin A and B components in a ratio of 1:1.8, and evenly apply to the bottom of the mold; S105, splicing ceramics: placing ceramic particles into a mold in a predetermined arrangement, and adjusting the mold to ensure that there are no gaps between the ceramic particles; S106, resin pouring: acrylic resin A and B components are prepared into a mixed resin in a ratio of 1:1.8 and poured into the mold; S107, vacuum leveling: put the mold into a vacuum oven at 60°C to eliminate bubbles generated by stirring for 20 minutes; S108. Demoulding and sampling: Take out the ceramic panel with a smooth surface without bubbles and closely arranged particles from the mould, and let it stand at room temperature for 12 hours before use.

7. The method for preparing a columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 5, characterized in that: S2 also includes the following sub-steps: S201, layer arrangement: Kevlar KM2 and UHMWPE fibers are laid orthogonally and staggered according to the proportion and arrangement of the structural design, and covered with release film on the upper and lower sides; S202 Separate hot pressing: The Kevlar KM2 layer and the UHMWPE layer are hot pressed separately. The hot pressing temperature of the Kevlar KM2 layer is raised to 80°C, and that of the UHMWPE layer is raised to 128°C. Exhaust is performed multiple times during the pressing process. S203, hot pressing composite: stacking the two laminates and performing hot pressing again to obtain an interlayer mixed fiber composite board.

8. The method for preparing a columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 6, characterized in that: During S107, observe the defoaming degree and liquid level through the vacuum box window glass; if the liquid level is significantly lower than the top of the ceramic, add appropriate amount of resin; when the liquid level is basically flush with the top of the ceramic and there are no obvious bubbles on the surface, turn off the negative pressure device and allow the ceramic panel to stand in a 60°C oven for 6 hours for self-leveling curing.

9. The method for preparing a columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 7, characterized in that: In S201, Kevlar KM2 weftless fabric and UHMWPE weftless fabric are laid flat in an orthogonal manner of 0 / 90° according to the Kevlar mixed thickness and UHMWPE thickness.

10. The method for preparing a columnar ceramic interlayer hybrid fiber composite bulletproof material according to claim 7, characterized in that: The specific steps of separate hot pressing in S203 are: first, preheat the UHMWPE laminated non-woven fabric surface by pressing it at 5MPa, and when the internal temperature of the pressed non-woven fabric rises to 80°C, open the mold to vent 2-3 times; then close the mold and pressurize it to 10MPa, and raise the internal temperature of the UHMWPE non-woven fabric to 100°C, and open the mold to vent 2-3 times. Close the mold again and pressurize it to 24MPa, and raise the temperature to 128°C, keep constant temperature and pressure for 30 minutes, then turn off the heating, cool the heating plate of the flat vulcanizer, and keep a constant pressure of 24MPa; when the temperature cools to 30-40°C, release the pressure and open the mold to obtain the UHMWPE laminate.

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