EP3141863A1 - Component for ballistic armour applications and method for producing the same - Google Patents

Abstract

The invention relates to components made of ceramic or non-ceramic materials for ballistic protection applications. In particular, such components are used for arming vehicles and for lifejackets. The core of the invention is that two or more ceramic or non-ceramic materials are bonded in the production process in a layer or in the form of a material gradient, whereby stresses are induced in the layer structure in a targeted manner. With the proposed component thus both functions (destruction of the projectile and interception of the splitter) are united in a composite and there is an optimal energy destruction or impulse transmission

Description

The invention relates to components made of ceramic or non-ceramic materials for ballistic protection applications. In particular, such components are used for arming vehicles and for lifejackets.

Ceramic has been used for many years in combination with other materials as ballistic protection of persons and objects. The decisive advantage of a ceramic armor is a significant weight saving of the ceramic composite systems of more than 50% compared to conventional armor steels. The properties of a ceramic material for ballistic or similar protection applications can be varied by the choice of the raw materials used, their composition and the process parameters during production (hardness, strength, toughness, density). However, optimum protection, especially with multi-hit stress, can only be achieved through a combination of materials with high hardness (front) and high toughness (behind). The hard layer in the front area has the task to deform or break the projectile. The underlying layer or layers serve to intercept the projectile or its debris and the splinters of the destroyed ceramic. Crucial is that the entire kinetic energy of the projectile is converted during the penetration into the ballistic protection by the destruction of the material into work and heat. So far, the problem is usually solved by a sandwich construction of ceramic materials and / or synthetic fibers and / or metals. With the DE 103 03 351 B3 Such a component is disclosed in an intermetallic matrix metal / ceramic composite, its use as an armor material, and the method of making the same.

The invention has for its object to propose a component for ballistic protection applications, which ensures more effective protection over the prior art. In addition, the invention has for its object to propose a method for its production.

According to the invention the object is achieved by a component for ballistic protection applications with front and back, consisting of a multilayer Function composite or a functional composite of the front and back has a material gradients achieved in that the Funktionskomposit introduced mechanical stress states.
Further, the object is achieved by a method for producing a front and back component for ballistic protection applications, wherein two or more ceramic or non-ceramic materials are layered or in the form of a material gradient in the manufacturing process, such that the front side functionally has high hardness and compressive strength for erosion and reduction of the penetration depth of a projectile and the underlying layer towards the back to trap the remnants of the projectile and the material splitter was formed in that targeted mechanical stresses are induced in the layer structure.

The core of the invention is that two or more ceramic or non-ceramic materials are bonded in the production process in a layer or in the form of a material gradient, whereby stresses are induced in the layer structure in a targeted manner. With the proposed component thus both functions (destruction of the projectile and interception of the splitter) are united in a composite and there is an optimal energy destruction or impulse transmission

In particular, the advantages achieved by the invention are that the first layer of material facing the stress (e.g., projectile) has high hardness and results in deformation, fragmentation and erosion of the impacting body. The underlying material or materials have a higher toughness and thus hinder the crack propagation and thereby limit the damaged volume of the armor.

Due to the conservation of momentum, the primary impulse of an impinging projectile is transferred to the protective body built up from layers or material gradients and split into as many small individual impulses as possible in different directions (billiard balls principle). The compressive and tensile stresses introduced into the layer structure contribute to increasing the mechanical strength of individual or several layers. By releasing or freeing of tension, a targeted distribution and deflection of the impulse of the impinging body on the layer structure or the resulting fragments can take place. The taut formed from layers or material gradients shaped body thus takes over an active function, so to speak. The mechanical energy is converted into work for fragmentation or comminution of the composite in the vicinity of the impact. The smaller the fragments produced in a given volume, the more energy can be absorbed. If a curved, non-planar geometry is generated by tension, this can also be used to deflect the primary pulse. This behavior can improve the energy conversion and thus the protective effect especially in multi-hit stress and z. B. lead to a reduction of the material thickness or the basis weight of an armor.

The different material layers or the material gradient of the composite are usually already produced during the molding in the green state before sintering. The component can consist of dense and porous material layers or have a density gradient.

Porous layers can be filled or infiltrated after sintering with plastics, glasses or metals to modify certain properties.

Shaping may be by uniaxial dry pressing or other conventional molding techniques (e.g., casting, tape casting, spraying, isostatic pressing, printing).

In the shaping, the various materials can be separated or successively added to the tool or the mold and simultaneously formed into a green body.

The production can also be carried out by two or more successive shaping processes.

It is also possible to combine different shaping methods.

All or individual layers of the composite may alternatively be prepared by joining molded articles or sheets of different materials by sintering, soldering or gluing.

The stresses can be achieved by the targeted selection or influencing of the coefficients of thermal expansion of the materials used in the layer structure, the greening of the layers or material gradients during shaping, the temperature-time profile used in debinding and sintering or the joining processes used to construct the composite in which the layer structure are introduced.

If materials with different coefficients of thermal expansion are sintered, bonded or soldered, compressive or tensile stresses are produced in the layers during cooling of the molding or laminate. A layer with a higher coefficient of thermal expansion contracts more during cooling and a tensile stress forms in this layer. In the adjacent layer with a lower coefficient of expansion thereby creates a compressive stress.

In the ceramic molding of a material, e.g. the green density before sintering can be influenced by the pressing pressure or the binder system. A higher green density reduces the shrinkage during the sintering process, a low green density leads to a greater shrinkage. By adjusting the green density, the shrinkage can be varied in the range of almost 0% to 5% without significantly affecting the final density after sintering. If the green densities of one or more materials are influenced as described during the shaping of the layer system, tensile or compressive stresses can be set by the different shrinkages.

Due to the limited heat conductivity in the molded body, temperature gradients can form in the materials to be sintered by rapid heating or cooling. These temperature gradients can cause areas of higher temperature to fade faster than areas of lower temperature, causing again tensions in the molding or layer structure are formed. By rapid cooling, thermal expansion can also create stresses between the surface and the volume of a molded article.

• durch unterschiedliche Ausdehnungskoeffizienten von Lot und Schichtmaterialien,
• durch die Schwindung der Lotschicht oder
• durch chemische Reaktionen des Lotes mit den zu fügenden Materialien Spannungen in der Grenzschicht induziert werden.

In the production of a layer structure by soldering, in the joining zone:

• by different coefficients of expansion of solder and layer materials,
• by the shrinkage of the solder layer or
• chemical reactions of the solder with the materials to be joined induce stresses in the boundary layer.

Comparable voltages can z. B. when drying adhesives are produced by an occurring shrinkage.

The generated stresses must be "adjusted" so that they do not lead to cracks or delamination in the coating system.

The introduced stresses can be used during sintering or during joining processes to form curved contours of the finished molded bodies. The resulting geometry contributes to the targeted impulse deflection.

Fig. 1

ein aus drei Schichten bestehendes Bauteil,

Fig. 2

ein Bauteil gemäß Fig. 1 mit einer weiteren Schicht und

Fig. 3

gekrümmtes Bauteil.

The invention will be explained in more detail with reference to embodiments and figures. Showing:

Fig. 1

a three-layer component,

Fig. 2

a component according to Fig. 1 with another layer and

Fig. 3

curved component.

In the FIGS. 1 to 3 are shown components with different layer structures. According to Fig. 1 the component consists of a first layer 1, a second layer 2 and a third layer 3. First layer 1 and third layer 3 consist of different ceramic materials. The second layer 2 consists of a mixture of the materials of the first layer 1 and the third layer 3. The first Layer 1 is functionally the particularly hard layer that destroys the projectile and the following layers catch the splinters. The component according to Fig. 2 has in addition to the structure according to Fig. 1 a connected via a joining zone 4 porous layer 5, which is filled with a plastic. In the component according to Fig. 3 the stresses are introduced in such a way that a curved geometry of the layer structure is generated. The geometry designed in this way contributes to targeted impulse deflection.

LIST OF REFERENCE NUMBERS

1

first shift

2

second layer

3

third layer

4

joint zone

5

porous layer

Claims (8)

Component for ballistic protective applications with front and back, consisting of a multi-layered functional composite or a functional composite which has a material gradient between the front and back, characterized in that the functional composite has introduced mechanical stress states. Component according to claim 1, characterized in that the functional composite has a curved geometry. Component according to one of claims 1, characterized in that the boundary surface of the layers with respect to the front or back are not parallel. A method of making a front and back component for ballistic protection applications wherein two or more ceramic or non-ceramic materials are layered or in the form of a material gradient in the manufacturing process, such that the front side has high hardness and compressive strength to erode and reduce the penetration depth of a projectile has formed and the underlying layer towards the back to intercept the remnants of the projectile and the material splitter, characterized in that in the layer structure targeted mechanical stresses are induced. A method according to claim 4, characterized in that the voltages are induced by the fact that materials with different coefficients of thermal expansion are selected for the different layers and then sintered into a component or glued or soldered. A method according to claim 4, characterized in that the stresses in the shaping of the component are induced by different green densities of the adjacent layers. A method according to claim 4, characterized in that the stresses in the debinding and sintering are induced by targeted application of a temperature-time profile. A method according to claim 4, characterized in that the stresses are induced by introducing joining zones between two adjacent layers, wherein for the joining zone, a material is selected which has a different coefficient of expansion than the layers to be joined.

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