阅读说明：本技术 一种层状结构的陶瓷材料 (Ceramic material with layered structure ) 是由 杨金晶 黄政仁 刘学建 陈忠明 黄毅华 于 2020-05-21 设计创作，主要内容包括：本发明提供一种层状结构的陶瓷材料,由共烧结的两层以上的堆叠陶瓷层及陶瓷层间的界面层构成,所述陶瓷层的厚度为0.2mm～20mm,所述界面层的厚度小于1mm,所述界面层的材料采用能使相邻陶瓷层之间不连续地结合的材料。(The invention provides a ceramic material with a layered structure, which is composed of more than two stacked ceramic layers which are sintered together and an interface layer between the ceramic layers, wherein the thickness of the ceramic layers is 0.2-20 mm, the thickness of the interface layer is less than 1mm, and the material of the interface layer is a material which can enable adjacent ceramic layers to be discontinuously combined.)

1. The ceramic material with a layered structure is characterized by comprising more than two stacked ceramic layers which are sintered together and an interface layer between the ceramic layers, wherein the thickness of the ceramic layers is 0.2-20 mm, the thickness of the interface layer is less than 1mm, and the material of the interface layer is a material which can enable adjacent ceramic layers to be discontinuously bonded.

2. The ceramic material of claim 1, wherein the interface layer comprises a first type of interface layer and/or a second type of interface layer, the first type of interface layer is at least one of a perforated or discontinuous paper sheet, a perforated or discontinuous plastic film, and the second type of interface layer is at least one of graphene, carbon nanotubes, carbon fibers, silicon carbide whiskers, alumina fibers, glass fibers, and asbestos.

3. The ceramic material according to claim 1 or 2, wherein the material of the ceramic layer is at least one of alumina ceramic, silicon carbide ceramic, boron carbide ceramic, magnesium aluminum boride ceramic and fiber reinforced composites of the above types of ceramics.

4. Ceramic material according to any of claims 1 to 3, wherein the thickness of the ceramic layer is between 1 and 15 mm.

5. The ceramic material of any of claims 1 to 4, wherein the interface layer has a thickness of 0.02mm to 1 mm.

6. The ceramic material of any of claims 1 to 5, wherein the interfacial layer comprises 10 to 90% by area of the ceramic layer.

7. The ceramic material according to any one of claims 1 to 6, wherein the number of layers of the ceramic layer is 2 or more.

8. The ceramic material of any of claims 1 to 7, wherein the second type of interface layer comprises at least a second type of interface layer bonded to the topmost ceramic layer and a second type of interface layer bonded to the bottommost ceramic layer, in the case where the interface layers have both the first type of interface layer and the second type of interface layer.

9. The ceramic material according to any one of claims 1 to 8, wherein the number of the ceramic layers is three or more, and the thickness of the topmost ceramic layer and the bottommost ceramic layer is greater than that of the remaining ceramic layers.

10. A method for preparing a ceramic material of a layered structure according to any one of claims 1 to 9, comprising:

forming a multilayer structure with ceramic layers and interface layers which are mutually staggered and laminated by using a ceramic layer material and an interface layer material, wherein the topmost layer and the bottommost layer of the multilayer structure are ceramic layers;

and pressing and molding the multilayer structure, and sintering to obtain the ceramic material.

Technical Field

The invention relates to the field of ceramic materials for protecting personnel and equipment, in particular to a ceramic material which can be used for ceramic armor.

Background

The ceramic protective armor is a high-grade excellent protective material and is used for preparing bulletproof vest spiles, and bulletproof plates of vehicles, ships or aircrafts. At present, most ceramic protective armors are prepared from homogeneous ceramics, shock waves are formed after high-speed bullets impact the ceramic armors, the impact surfaces are affected by compressive stress, and the shock waves can be rapidly expanded to the back surfaces to form tensile stress. Because of the high compressive strength and low tensile strength of ceramics, the ceramic armor is destroyed by lower tensile stress, resulting in reduced protection capability.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a ceramic material having a layered structure, which has the advantages of light weight and excellent impact resistance (high protection factor).

In one aspect, the present invention provides a ceramic material having a layered structure, which comprises two or more stacked ceramic layers co-sintered, and an interface layer between the ceramic layers, wherein the ceramic layers have a thickness of 0.2mm to 20mm, the interface layer has a thickness of less than 1mm, and the interface layer is made of a material which enables discontinuous bonding between adjacent ceramic layers.

The ceramic material of the invention is composed of co-sintered stacked ceramic layers and interface layers among the ceramic layers, the thickness of the ceramic layers is 0.2 mm-20 mm, the thickness of the interface layers is less than 1mm, and the adjacent ceramic layers can be discontinuously bonded through the interface layers. The high-speed impact energy forms compressive stress on the impacted surface of the ceramic, and transmits the compressive stress to the reverse surface in the ceramic structure in the form of shock waves to form tensile stress. If a homogeneous block ceramic material is adopted, the shock wave energy is completely transmitted to the reverse side of the ceramic homogeneous block, so that the whole body is crushed; according to the invention, the laminated ceramic structure is combined with the weak interface (weak combination interface is formed between the ceramic layers after co-sintering), so that shock waves can be effectively isolated and dispersed, damage caused by shock wave concentration is prevented, and the quality protection capability is improved. The ceramic material of the present invention can be used for ceramic armor and the like. When the ceramic armor is used for ceramic armor, the laminated structure can prevent the integral destruction of the ceramic armor, reduce the fragmentation area after the first strike and improve the strike resistance times of the ceramic armor.

Preferably, the interface layer has a first type interface layer and/or a second type interface layer, the material of the first type interface layer is at least one of perforated or discontinuous paper sheets and perforated or discontinuous plastic films, and the material of the second type interface layer is at least one of graphene, carbon nanotubes, carbon fibers, silicon carbide whiskers, alumina fibers, glass fibers and asbestos.

The ceramic layer can be made of at least one of alumina ceramic, silicon carbide ceramic, boron carbide ceramic, magnesium aluminum boride ceramic and fiber reinforced composite materials of the above types of ceramics.

The thickness of the ceramic layer can be 1 mm-15 mm.

The thickness of the interface layer may be 0.02mm to 1 mm.

The area ratio of the interface layer to the ceramic layer may be 10% to 90%.

Preferably, the area ratio of the interface layer to the ceramic layer is 70-80%.

The number of the ceramic layers may be 2 or more.

Preferably, in the case that the interface layer has both the first type interface layer and the second type interface layer, the second type interface layer includes at least the second type interface layer bonded to the topmost ceramic layer and the second type interface layer bonded to the bottommost ceramic layer.

Preferably, the number of the ceramic layers is three or more, and the thickness of the top ceramic layer and the bottom ceramic layer is larger than that of the rest ceramic layers.

In another aspect, the present invention further provides a method for preparing any of the above ceramic materials with a layered structure, comprising: forming a multilayer structure with ceramic layers and interface layers which are mutually staggered and laminated by using a ceramic layer material and an interface layer material, wherein the topmost layer and the bottommost layer of the multilayer structure are ceramic layers; and pressing and molding the multilayer structure, and sintering to obtain the ceramic material.

The green body of the ceramic layer can be prepared by methods such as casting, extrusion, casting, and press forming.

Drawings

Fig. 1 schematically shows the structure of a ceramic material according to an embodiment of the present invention.

Detailed Description

The present invention is further described below in conjunction with the following embodiments, which are intended to illustrate and not to limit the present invention.

The present disclosure relates to a ceramic material, which is suitable for protection of personnel and equipment, and can be used for ceramic armor. The ceramic material with the layered structure is formed by stacking and then co-sintering a plurality of layers of ceramics and interface layers; through the design of a layered structure and the compounding of a weak connection interface, the transmission of shock waves in the ceramic material is blocked, and the integral crushing is prevented. For example, when the composite material is used for ceramic armor, the transmission of shot shock waves in the armor material can be blocked, the integral crushing is prevented, and the bulletproof performance of the ceramic armor is improved.

The layered structure ceramic material of the present disclosure is composed of two or more stacked ceramic layers co-sintered and interface layers between the ceramic layers. Here, "two or more stacked ceramic layers and interface layers between the ceramic layers" means a multilayer structure in which ceramic layers (two or more ceramic layers) and interface layers are alternately stacked, and the topmost layer and the bottommost layer of the multilayer structure are ceramic layers (see fig. 1).

The ceramic layer material may be alumina (Al)₂O₃) Ceramics, silicon carbide (SiC) ceramics, boron carbide (B)₄C) Ceramics, magnesium aluminium boride ceramics (AlMgB)_n) Ceramics and ceramics of the above type (Al)₂O₃Ceramics, SiC ceramics, B₄C ceramic, AlMgB_nCeramic) fiber-reinforced composite material. The material performance among different laminated layers can be adjusted by adjusting the composition and components of the ceramic raw materials according to different requirements on impact resistance (protection), so that the ceramic material after the laminated layers are sintered has the best performance. In one example, the ceramic layer material may be silicon carbide, boron carbide, magnesium aluminum boride ceramic, which may be used for personnel and aircraft protection, for example, to achieve an excellent quality protection factor. In another example, the ceramic layer material can be alumina and silicon carbide, and when the ceramic layer material is used for protection of vehicle and ship equipment, for example, the ceramic layer material has a better quality protection coefficient at a lower protection cost.

The material of the interface layer is such that the adjacent ceramic layers are discontinuously bonded to each other. By "discontinuously bonded" is meant that in the ceramic material obtained by co-sintering the ceramic layers and the interface layer, a discontinuously bonded interface is formed between adjacent ceramic layers, forming a layered ceramic material with an integral bond but with a discontinuous interface. The upper ceramic layer and the lower ceramic layer are discontinuously combined after the ceramic material is sintered to form a weak bonding interface. The "upper and lower ceramic layers" herein may also be referred to as adjacent ceramic layers, and the "upper and lower" does not limit the arrangement direction of the ceramic layers. The interface layers may include thin film void layers (first type interface layers) and/or composite interlayers (second type interface layers) that form weak bonding interfaces between adjacent ceramic layers after sintering, allowing shock waves to be blocked and dispersed as the ceramic material propagates. The film void layer can be made of perforated or discontinuous film interlayers, such as perforated paper sheets, perforated plastic films and the like which are uniformly distributed, and the materials can discontinuously separate the upper ceramic layer and the lower ceramic layer in the ceramic forming process, prevent the upper ceramic layer and the lower ceramic layer from being diffused and combined in the sintering process, and are burnt to form voids in the ceramic sintering process, so that a weak combination interface with the voids is formed on the whole structure, and the ceramic material can be prepared at low cost. The holes of the perforated paper sheet (perforated plastic film) are uniformly distributed, and the diameter of the internal connection circle of the holes is preferably not less than 5mm, so that the adjacent ceramic layers can be effectively combined in a diffusion mode. The ratio of the pore area to the total area of the paper sheet (plastic film) may be 15% to 90%, a smaller pore area may form a larger weak interface region but may be disadvantageous for sintering, and from the viewpoint of facilitating the overall sintering, it is desirable that the wet and semi-wet ceramic forming process is not less than 10% in pore area and the dry forming is not less than 15% in pore area; on the other hand, a larger pore area reduces the weak interface region, and a pore area of not more than 85% is desirable in view of the better impact resistance after sintering than that of the conventional dense bulk material. The thickness of the interface layer may be 0.02mm to 1 mm. The thickness of the interface layer is preferably 0.5mm or less so that the ceramic material of the present disclosure can be easily obtained. In one embodiment, the thickness of the paper sheet (plastic film) may be 0.02mm to 0.5mm, and a paper sheet (plastic film) having a thickness of not less than 0.02mm is desirable in order to form a significant void layer after ignition loss. Composite spacers may employ composite filler materials such as graphene, carbon nanotubes, carbon fibers, silicon carbide whiskers, alumina fibers, glass fibers, asbestos, and the like. By utilizing the high tensile strength of materials such as graphene and fibers, crack propagation can be more effectively prevented when the ceramic is cracked. The materials such as graphene or fiber should be laid uniformly, and the laying density can be 15% -90% (namely 10% -85% of gaps). The laying density is the area of the interlayer material which can separate the upper and lower ceramic layers, prevent sintering diffusion and form a gap layer and accounts for the total area of the single-layer interface layer. Under the condition of the same ceramic layer material, the layered material of the interface layer prepared by the composite interlayer always has better impact resistance than the layered material of the interface layer prepared by the thin film interlayer, but the preparation process is more complex and has higher cost, and one or two interface layers can be adopted or simultaneously adopted according to different impact resistance requirements and cost control adjustment. Where an interface layer is employed having both a thin film voided layer and a composite barrier layer, it may include at least a composite barrier layer bonded to the topmost (e.g., the layer closest to the projectile in fig. 1) ceramic layer and a composite barrier layer bonded to the bottommost (e.g., the layer furthest from the projectile in fig. 1) ceramic layer. In one example, the interface layer material can be carbon fiber or graphene, and can be used for protecting people and aircrafts, so that a better protection effect is obtained. In another example, the interface layer material may be a thin film material that may be used, for example, for protection in a vehicle or boat setting, thereby reducing costs.

The number of ceramic stacked layers is 2 or more. Generally, under the same process conditions, increasing the number of layers always increases the impact resistance. According to the application background mainly of the protection chemical kinetic energy, 2-15 layers are ideal in view of the protection improvement brought by the structure compared with the improvement of the process cost. The thickness of each ceramic layer can be 0.2mm to 20mm, and the thickness of the ceramic layer is preferably 1mm to 15 mm. The thickness of the interface layer may be less than 0.5mm, preferably 0.02mm to 0.5 mm. The number of ceramic layers and the thicknesses of the ceramic layers and the interface layers can be adjusted according to different impact resistance requirements. For example, an example of the protection for personnel and aircraft and an example of the protection for vehicle and ship equipment are shown in the following tables, respectively;

the thickness of each layer can be designed to be equal or unequal according to different impact resistance requirements. For example, when the number of ceramic layers is three or more, the thickness of the surface layer (the top ceramic layer and the bottom ceramic layer) may be larger than that of the remaining ceramic layer (the intermediate layer).

The area ratio of the interface layer to the ceramic layer may be 10% to 85%. Here, the "area ratio of the interface layer to the ceramic layer" indicates the area of the contact portion between the interface layer and the ceramic layer. The bonding strength between the upper and lower ceramic layers after sintering can be controlled by controlling the contact area between the interface layer and the ceramic layer.

Preparation of the layered structured ceramic Material of the present disclosure

Firstly, according to the required thickness, layer number, area ratio and the like, the corresponding ceramic layer material is usedAnd interface layer material to form a multilayer structure with ceramic layers and interface layers alternately stacked, and the topmost layer and the bottommost layer of the multilayer structure are ceramic layers. According to the requirement of impact resistance (protection), the ceramic sheet blank with a certain thickness and a certain number of layers can be designed and prepared, the ceramic blank is stacked, and a composite interlayer or a paper sheet or a plastic film sheet material (a film gap layer) is discontinuously paved between the layers. The ceramic layer raw material can be used to prepare a green body of a desired thickness before stacking (laying). The ceramic layer can be made of Al₂O₃、SiC、B₄C、AlMgB_n. The green body of the ceramic layer can be prepared by adopting forming methods such as a wet method, a semi-wet method, dry pressing and the like. For example, in some embodiments, the molding process is a casting, extrusion, casting, dry pressing, isostatic pressing process. The ceramic layer can be formed by a general forming method. In addition, the use of ceramic sintering aids, additives, etc. may be determined as a general sintering process.

And then, pressing and molding the multilayer structure, and sintering to obtain the ceramic material. And sintering the stacked ceramic blanks at high temperature to form the layered ceramic armor which is integrally combined and has a discontinuous interface. The sintering schedule is consistent with the ceramic sintering schedule of the type. Sintering may be carried out in a conventional manner.

The ceramic material is prepared by combining the laminated ceramic structure with the weak interface, so that shock waves can be effectively blocked and dispersed, damage caused by shock wave concentration is prevented, and the quality protection capability is improved; the layered structure can prevent the whole damage of the ceramic material, reduce the fragmentation area after the first striking and improve the striking resistant times of the ceramic material. The material properties of different laminated layers can be adjusted by adjusting the composition and components of the ceramic raw materials according to different protection requirements, so that the ceramic material after the laminated layers are sintered has the best properties.

The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that certain insubstantial modifications and adaptations of the invention by those skilled in the art may be made in light of the above teachings. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below.

In the following examples, reagents, materials and instruments used are all conventional reagents, conventional materials and conventional instruments, which are commercially available, if not specifically mentioned, and the reagents involved therein can also be synthesized by conventional synthesis methods.