Preparation method of bulletproof ceramic with bionic layered structure

Abstract

The invention discloses a preparation method of bulletproof ceramic with a bionic layered structure, which is characterized by comprising the following steps: S1, preparing ceramic powder into foamed ceramic biscuits with different foaming ratios by adopting a foaming process; s2, cutting the foamed ceramic biscuit into sheet biscuits with different thicknesses; s3, alternately stacking the biscuit sheets together, uniformly coating an adhesive on an interlayer interface, and performing pre-pressing molding to form a ceramic body with a layered structure; and S4, putting the pre-pressed ceramic green body with the layered structure into a mold, and carrying out glue discharging and sintering to prepare the bulletproof ceramic with the bionic layered structure. According to the method provided by the invention, the impact resistance and the damage tolerance of the bulletproof ceramic are remarkably improved, and the bulletproof ceramic has the advantages of controllable layer thickness, flexible process, adjustable interface, high performance, suitability for industrial production and the like.

Description

Technical Field

[0001] The present application relates to the technical field of the preparation of ceramic composites, and specifically, to a method for preparing a bionic layered structure bulletproof ceramic. Background Art

[0002] The bionic layered structure bulletproof ceramic stacks materials with different properties through a composite technology, simulating the nacre structure to improve toughness and impact resistance. Its performance is mainly determined by the intrinsic properties of the matrix layer and the bonding state of the interlayer interface. Multiple interfaces and residual compressive stress in the interface layer are the key. However, the precise replication of the bionic layered structure, especially the precise control of the layer thickness, has always been a bottleneck in the preparation process. Early methods such as tape casting and rolling film processes can obtain a layered structure, but the layer thickness is relatively large (0.1 - 2 mm), which is different from the multi-scale layered structure of natural nacre, and the impact resistance is limited.

[0003] Therefore, how to provide a preparation method for a bionic layered structure bulletproof ceramic that can solve the problems of low toughness and poor reliability of ceramic materials at the present stage and cannot meet the requirements of modern industrial sectors for high-performance ceramic matrix composites has become an urgent problem to be solved in this field. Summary of the Invention

[0004] The present application provides a method for preparing a bionic layered structure bulletproof ceramic, comprising the following steps: S1. Using a foaming process to make foam ceramic green bodies with different foaming ratios from ceramic powder; S2. Cutting the foam ceramic green bodies into thin sheet green bodies with different thicknesses; S3. Alternately stacking the thin sheet green bodies together, and evenly applying a binder at the interlayer interface, and pre-pressing to form a layered structure ceramic green body; S4. Placing the pre-pressed layered structure ceramic green body into a mold, and performing debinding and sintering to make a bionic layered structure bulletproof ceramic.

[0005] The method for preparing a bionic layered structure bulletproof ceramic as described above, wherein the foaming process includes any one or a combination of a particle-stabilized direct foaming method, a polyurethane foaming method, an organic foam impregnation method, a pore-forming agent addition method, a hollow sphere method, a freeze-drying method, 3D printing, and a ceramic fiber method.

[0006] The method for preparing a bionic layered structure bulletproof ceramic as described above, wherein the ceramic powder is any one or a mixture of boron carbide, silicon carbide, silicon nitride, aluminum nitride, alumina, and titanium boride.

[0007] The method for preparing a bionic layered structure bulletproof ceramic as described above, wherein the foaming ratio of the foam ceramic is 2 - 10 times.

[0008] The method for preparing a bionic layered structure bulletproof ceramic as described above, wherein the thickness of the thin sheet green body is 0.1 - 5 mm.

[0009] The preparation method of the bionic laminated structure bulletproof ceramic as described above, wherein the binder is any one or a mixture of phenolic resin, epoxy resin, and polyurethane.

[0010] The preparation method of the bionic laminated structure bulletproof ceramic as described above, wherein the pressure of pre-pressing is 0 - 30 MPa, and the pressure holding time is 0 - 240 s.

[0011] The preparation method of the bionic laminated structure bulletproof ceramic as described above, wherein the sintering process is any one of vacuum non-pressure sintering, vacuum hot pressing sintering method, or spark plasma sintering method.

[0012] The preparation method of the bionic laminated structure bulletproof ceramic as described above, wherein in the process of making the bionic laminated structure bulletproof ceramic through debinding and sintering, the debinding temperature is 600 - 700 °C, the debinding time is 2 - 3 h, the sintering temperature is 1200 - 2200 °C, the heat preservation time is 120 - 240 min, the sintering pressure is 0 - 50 MPa, and the pressure holding time is 0 - 120 min.

[0013] This application has the following beneficial effects:

[0014] (1) In this application, the foam ceramic green body is prepared by the foaming process and cut into thin slices, which can precisely control the layer thickness, realize the fine assembly of the bionic laminated structure, solve the problem of large layer thickness in the traditional process, and be closer to the multi-scale laminated structure of natural nacre.

[0015] (2) In this application, by coating the binder at the interlayer interface and combining with the pre-pressing process, the interface bonding strength can be regulated, realizing the design of weak interfaces or strong interfaces, and optimizing the fracture toughness and impact resistance of the material.

[0016] (3) Through the bionic laminated structure design and combining multiple interfaces and residual compressive stress in the interface layer, this application significantly improves the toughness and impact resistance of the material, and is suitable for the field of high-speed impact protection.

[0017] (4) The method proposed in this application significantly improves the impact resistance and damage tolerance of the bulletproof ceramic, and is suitable for the field of high-speed impact protection. It has the advantages of controllable layer thickness, flexible process, adjustable interface, high performance, and suitability for industrial production, and has important application value and popularization prospects. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0019] Figure 1Flow chart of the preparation method of the bionic laminated structure bulletproof ceramic provided by the embodiment of the present application. Detailed implementation manners

[0020] Combined with the accompanying drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present application.

[0021] The present application proposes a preparation method of a bionic laminated structure bulletproof ceramic. The ceramic powder is prepared into a foam ceramic by the particle-stabilized foaming method, polyurethane foaming method, template sacrificial method, pore-forming agent addition method, organic foam impregnation method, sol-gel method, or foaming method. Then, it is cut into thin slices according to weight, and then stacked and hot-pressed and sintered to obtain a laminated ceramic material with a relatively thin and controllable layer thickness.

[0022] The precise control of the layer thickness (0.1 - 5 mm) is achieved through the foaming process and cutting technology, which is closer to the fine laminated structure of natural shells; the selection of various foaming processes and binders endows the process with flexibility and adjustable interfacial bonding strength, optimizing crack deflection and residual stress distribution; combined with vacuum hot pressing or spark plasma sintering, the problems of large layer thickness (0.1 - 2 mm) and complex process of traditional laminated ceramics are solved, ensuring that the material has both high strength and high toughness; the process is efficient and stable, avoiding defects such as debinding cracking and delamination, and is suitable for industrial production.

[0023] Figure 1 The steps of the preparation method of the bionic laminated structure bulletproof ceramic according to the embodiment of the present invention are shown. The preparation method of the bionic laminated structure bulletproof ceramic is described in detail below in combination with several embodiments.

[0024] Embodiment 1

[0025] Step S1: The ceramic powder is made into a foam ceramic green body with different foaming ratios by the foaming process.

[0026] The foaming process includes any one or a combination of the particle-stabilized direct foaming method, polyurethane foaming method, organic foam impregnation method, pore-forming agent addition method, hollow sphere method, freeze-drying method, 3D printing, and ceramic fiber method.

[0027] The ceramic powder is any one or a mixture of boron carbide, silicon carbide, silicon nitride, aluminum nitride, alumina, and titanium boride.

[0028] The foaming ratio of the foam ceramic is 2 - 10 times.

[0029] In this embodiment, a particulate-stabilized foaming process is used to fabricate a foam ceramic green body with a 4-fold foaming ratio from 500 g of boron carbide ceramic powder.

[0030] Step S2: Cut the foam ceramic green body into thin green body slices with different thicknesses.

[0031] The thickness of the thin green body slices is 0.1 - 5 mm.

[0032] In this embodiment, the foam ceramic green body is cut into thin green body slices with a thickness of 2 mm.

[0033] Step S3: Stack the thin green body slices alternately, and evenly apply a binder at the interlayer interface, then pre-press to form a laminated structure ceramic green body.

[0034] The binder is any one or a mixture of phenolic resin, epoxy resin, and polyurethane.

[0035] The pressure for pre-pressing is 0 - 30 MPa, and the pressure holding time is 0 - 240 s.

[0036] In this embodiment, the thin green body slices are stacked alternately, and a phenolic resin binder is evenly applied at the interlayer interface, then pre-press at a pressure of 30 MPa for a pressure holding time of 60 s.

[0037] Step S4: Place the pre-pressed laminated structure ceramic green body into a mold, and fabricate a bionic laminated structure bulletproof ceramic through debinding and sintering.

[0038] The sintering process is any one of vacuum pressureless sintering, vacuum hot pressing sintering method, or spark plasma sintering method.

[0039] The debinding temperature is 600 - 700 °C, and the debinding time is 2 - 3 h; the sintering temperature is 1200 - 2200 °C, the heat preservation time is 120 - 240 min, the sintering pressure is 0 - 50 MPa, and the pressure holding time is 0 - 120 min.

[0040] In this embodiment, the pre-pressed laminated structure ceramic green body is placed into a mold, debinded at 600 °C for 2 h, sintered at a temperature of 2080 °C, heat-preserved for 120 min, sintered at a pressure of 30 MPa, and the pressure holding time is 120 min.

[0041] Embodiment 2

[0042] Step S1: Fabricate foam ceramic green bodies with different foaming ratios from ceramic powders using a foaming process.

[0043] The foaming process includes any one or a combination of particulate-stabilized direct foaming method, polyurethane foaming method, organic foam impregnation method, pore-forming agent addition method, hollow sphere method, freeze-drying method, 3D printing, and ceramic fiber method.

[0044] The ceramic powder is any one or a mixture of more than one of boron carbide, silicon carbide, silicon nitride, aluminum nitride, alumina, and titanium boride.

[0045] The foaming ratio of the ceramic foam is 2 to 10 times.

[0046] In this embodiment, 500 g of silicon carbide ceramic powder is made into a ceramic foam green body with a foaming ratio of 6 times by using a polyurethane foaming process.

[0047] Step S2: Cut the ceramic foam green body into thin green bodies with different thicknesses.

[0048] The thickness of the thin green body is 0.1 to 5 mm.

[0049] In this embodiment, the ceramic foam green body is cut into a thin green body with a thickness of 0.2 mm.

[0050] Step S3: Stack the thin green bodies alternately, and evenly apply a binder at the interlayer interface, and pre-press to form a laminated ceramic green body.

[0051] The binder is any one or a mixture of more than one of phenolic resin, epoxy resin, and polyurethane.

[0052] The pressure for pre-pressing is 0 to 30 MPa, and the pressure holding time is 0 to 240 s.

[0053] In this embodiment, the thin green bodies are stacked alternately, and a polyurethane binder is evenly applied at the interlayer interface, and pre-pressed at a pressure of 20 MPa for a pressure holding time of 120 s.

[0054] Step S4: Put the pre-pressed laminated ceramic green body into a mold, and make a bionic laminated bulletproof ceramic through debinding and sintering.

[0055] The sintering process is any one of vacuum pressureless sintering, vacuum hot pressing sintering method, or spark plasma sintering method.

[0056] The debinding temperature is 600 to 700 °C, and the debinding time is 2 - 3 h; the sintering temperature is 1200 to 2200 °C, the heat preservation time is 120 to 240 min, the sintering pressure is 0 to 50 MPa, and the pressure holding time is 0 to 120 min.

[0057] In this embodiment, the pre-pressed laminated ceramic green body is put into a mold, debound at 700 °C for 1 h, sintered at a temperature of 1950 °C, heat-preserved for 120 min, sintered at a pressure of 20 MPa, and the pressure holding time is 90 min.

[0058] Example Three

[0059] Step S1: Use the foaming process to make foam ceramic green bodies with different foaming ratios from ceramic powder.

[0060] Among them, the foaming process includes any one or a combination of more than one of the particle-stabilized direct foaming method, polyurethane foaming method, organic foam impregnation method, pore-forming agent addition method, hollow sphere method, freeze-drying method, 3D printing, and ceramic fiber method.

[0061] Among them, the ceramic powder is any one or a mixture of more than one of boron carbide, silicon carbide, silicon nitride, aluminum nitride, alumina, and titanium boride.

[0062] Among them, the foaming ratio of the foam ceramic is 2 to 10 times.

[0063] In this embodiment, use the organic foam impregnation process to make a foam ceramic green body with an 8-fold foaming ratio from 500 g of alumina ceramic powder.

[0064] Step S2: Cut the foam ceramic green body into thin green body slices with different thicknesses.

[0065] Among them, the thickness of the thin green body slice is 0.1 to 5 mm.

[0066] In this embodiment, cut the foam ceramic green body into thin green body slices with a thickness of 0.5 mm.

[0067] Step S3: Stack the thin green body slices alternately, and evenly apply a binder at the interlayer interface, and pre-press to form a laminated structure ceramic green body.

[0068] Among them, the binder is any one or a mixture of more than one of phenolic resin, epoxy resin, and polyurethane.

[0069] Among them, the pressure for pre-pressing is 0 to 30 MPa, and the pressure holding time is 0 to 240 s.

[0070] In this embodiment, stack the thin green body slices alternately, and evenly apply an epoxy resin binder at the interlayer interface, and pre-press at a pressure of 10 MPa for a pressure holding time of 180 s.

[0071] Step S4: Put the pre-pressed laminated structure ceramic green body into a mold, and make a bionic laminated structure bulletproof ceramic through debinding and sintering.

[0072] Among them, the sintering process is any one of vacuum pressureless sintering, vacuum hot pressing sintering method, or spark plasma sintering method.

[0073] Among them, the debinding temperature is 600 to 700 °C, and the debinding time is 2 - 3 h; the sintering temperature is 1200 to 2200 °C, the heat preservation time is 120 to 240 min, the sintering pressure is 0 to 50 MPa, and the pressure holding time is 0 to 120 min.

[0074] In this embodiment, the pre-pressed laminated ceramic green body is placed in a mold, debinded at 650°C for 2 h, sintered at a temperature of 1450°C, held for 180 min, sintered under a pressure of 10 MPa, and the pressure is held for 180 min.

[0075] The present application has the following beneficial effects:

[0076] (1) By preparing the foam ceramic green body through a foaming process and cutting it into thin slices, the present application can precisely control the layer thickness, achieve the fine assembly of the bionic laminated structure, solve the problem of large layer thickness in the traditional process, and be closer to the multi-scale laminated structure of natural nacre.

[0077] (2) By coating a binder at the interlayer interface and combining with a pre-pressing forming process, the present application can regulate the interfacial bonding strength, achieve the design of weak interfaces or strong interfaces, and optimize the fracture toughness and impact resistance of the material.

[0078] (3) Through the bionic laminated structure design, combining multiple interfaces and the residual compressive stress in the interface layer, the present application significantly improves the toughness and impact resistance of the material, and is applicable to the field of high-speed impact protection.

[0079] (4) The method proposed in the present application significantly improves the impact resistance and damage tolerance of bulletproof ceramics, and is applicable to the field of high-speed impact protection. It has the advantages of controllable layer thickness, flexible process, adjustable interface, high performance and suitability for industrial production, and has important application value and promotion prospects.

[0080] Although the examples referred to in the current application are described, they are only for the purpose of explanation and not a limitation of the present application. Changes, additions, and / or deletions to the embodiments can be made without departing from the scope of the present application.

[0081] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing a bionic layered bulletproof ceramic, characterized in that: The following steps are involved: Step S1, using a foaming process to make ceramic powder into foam ceramic blanks with different foaming ratios; Step S2, cutting the foam ceramic blank into thin blanks of different thicknesses; Step S3, alternately stacking the green sheets together, evenly coating the interface between the layers with a binder, and pre-pressing to form a layered ceramic body; Step S4, placing the pre-pressed layered structure ceramic body into a mold, and manufacturing the bionic layered structure bulletproof ceramic through debinding and sintering.

2. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: The foaming process includes any one or more combinations of a particle-stabilized direct foaming method, a polyurethane foaming method, an organic foam impregnation method, a pore-forming agent addition method, a hollow ball method, a freeze-drying method, 3D printing, and a ceramic fiber method.

3. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: The ceramic powder is a mixture of any one or more of boron carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, and titanium boride.

4. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: The expansion ratio of foam ceramics is 2 to 10 times.

5. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: The thickness of the sheet blank is 0.1 to 5 mm.

6. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: The adhesive is a mixture of any one or more of phenolic resin, epoxy resin and polyurethane.

7. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: The pre-pressing pressure is 0-30 MPa, and the holding time is 0-240 s.

8. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: The sintering process is any one of vacuum pressureless sintering, vacuum hot pressing sintering or spark plasma sintering.

9. The method for preparing the bionic layered bulletproof ceramic according to claim 1, characterized in that: In the bionic layered bulletproof ceramics made by debinding and sintering, the debinding temperature is 600-700°C, the debinding time is 2-3h, the sintering temperature is 1200-2200°C, the insulation time is 120-240min, the sintering pressure is 0-50MPa, and the pressure holding time is 0-120min.

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