IL170927A

IL170927A - High-strength planar structures for end ballistic protection and protection against wear and method for producing the same

Info

Publication number: IL170927A
Application number: IL170927A
Authority: IL
Original assignee: Fraunhofer Ges Forschung
Priority date: 2003-03-19
Filing date: 2005-09-18
Publication date: 2010-06-30
Also published as: DE502004007489D1; DE10313231B4; ES2309510T3; DE10313231A1; EP1606572A1; EP1606572B1; ATE399973T1; WO2004083768A1

Abstract

The invention relates to the field of materials science and to high-strength planar structures for the protection of vehicles and people. The aim of the invention is to provide high-strength planar structures which are characterized in that the planar structure is only destroyed in the immediate vicinity of an impact. This aim is achieved by a high-strength planar structure that consists of individual elements that give, applied to a backing material, the high-strength planar structure. The individual elements have the shape of regular pyramids and tetrahedrons or irregular pentahedrons and/or hexahedrons and/or the individual elements consist of combined and interlinked shapes (compound shapes) of regular pyramids and tetrahedrons or irregular pentahedrons and/or hexahedrons. The aim is also achieved by a method which is characterized in that individual elements and/or shapes (compound shapes) combined from such individual elements and interlinked are combined to give a planar structure and are non-positively linked with a backing material at least on one side.

Description

170927 i?'Ji I 453368 TAIN HIGH-STRENGTH PLANAR STRUCTURES FOR END-BALLISTIC PROTECTION AND PROTECTION AGAINST WEAR AND METHOD FOR PRODUCING THE SAME o»mvy » O WQ οηΐϋ^ iiwm n ^n\y ¾«n roam Field of the Invention The invention relates to the fields of material science, ceramics, materials for protective armor plating and for high wear strain and deals with high-strength planar structures for end-ballistic protection, for example for vehicles and persons as well as for protection against wear, in use for crushing machines, grinders, conveying chutes or pipes as well as to methods of producing same.

Background of the Invention For the protection of persons, vehicles and facilities in military and also in civil domains, the protective structure for a given object is chosen depending on the specific threat to which this object is exposed. The survival of such protected objects can be improved by use of protective plating made of bullet-proof materials. Because the durability of armor plating of such kind depends mainly on the surface firmness of the plating protective elements, special high-strength steel types with appropriately adapted resolution as well as ceramic materials have been primarily used to date for this purpose.

Protective ballistic armor plating consisting of tiles mounted on backing material are known from DE 198 56 597 Al, DE 34 26 457 CI and US 6,322,390. These bulletproof coating materials are planar structures combined with covering laminate (backing material), onto which ceramic plates are affixed by positive locking. These combined materials are intended to reduce the effect of projectiles, especially high-velocity armor piercing projectiles with high impact energy. The energy of the projectile is absorbed mainly at the bullet entry site by the tile that was hit.

Steel is applied in many instances for armoring against projectiles in spite of its heavy weight, mainly due to its hardiness and elasticity, which are responsible for the relatively minor damage caused to the armoring material and due to the fact that new impacts, which are even only several millimeters distant from the first impact site, can be withstood.

This is quite different with ceramic materials. In this case, although it is possible to withhold the first impact by a much thinner protective layer that is also much lighter than steel, each impact still destroys a relatively great area of the ceramic layer, and therefore, any next bullet can be withheld only if it hits another piece of the ceramic coating, unrelated to the first one and affixed separately onto the backing material. The result is that ceramic elements, in particular small ceramic tiles, must be used in order to prevent the effect of another hit in the vicinity of the previous one, if the protective action is to be maintained. Adaptation of the plate size depends, therefore, on the estimated possible distance between two subsequent hits and requires that the tile elements be relatively small. This leads to another problem, namely how the tiles should be positioned relative to one another in order that the narrow spaces between them, being naturally of lesser resistance, reduce the protective mechanism of the combined structure as little as possible.

The mosaic pattern of ceramic tiles makes it necessary, due to the mere fact of the edge problem in spite of the recognized configuration of a composite brickwork (DE 34 36 457 CI), to use thicker layers leading to increased weight. The problem of lesser resistant edge gaps is thereby diminished, but a uniformly equal retaining efficacy at the tile edges and complete protective action, cannot be guaranteed.

There are applications for protective armoring in the sphere of protection against wear as well as, for example, against collision stress or sliding wear. Plates or plain fittings in conduits, containers, classifiers, cyclones under high temperatures, mills or crushers that are exposed to heavy wear show especially severe abrasive phenomena at the edges of adjacent tiles. The durability of the armoring against wear is therefore primarily dependent on the edge stability, necessitating thicker lining layers.

Brief Description of the Invention The object of the invention is to define high-strength planar structures for the end-ballistic protection and protection against wear, in which only the immediate environment of the projectile impact or of the local wear is subject to destruction, as well as providing an easy manufacturing method.

This object is achieved by the proposed invention as described in the patent claims. Further embodiments are the subject of the sub-claims.

The high-strength planar structure for end-ballistic protection and protection against wear according to this invention is composed of individual elements that are either connected with, or attached to, a backing material and/or entirely or partially enclosed in the backing material, resulting in a high-strength planar structure in which the individual elements have the form of regular pyramids and tetrahedrons or irregular pentahedrons and/or hexahedrons, and/or the individual elements are composed of combined forms (compound shapes) composed of regular pyramids and tetrahedrons or irregular pentahedrons and/or hexahedrons.

Preferably, the individual elements and/or the compound shapes containing them are made entirely or partially of ceramic and/or metallic materials, most preferably of ceramic metals such as SiC, Si3N4, A1203, of metals such as hard metals, high tensile steel such as V2A steel, ST 52-3, or of ceramic-metallic compounds.

It is also preferable that the individual elements, and/or the compound shapes resulting from them, be 5 to 200 mm in size, even more preferably 10 to 100 mm.

It is furthermore preferable that there be partial and/or full form-fitting contact of the faces and/or edges between all or most of the individual elements of the planar structure.

If gaps are present between the faces and/or edges of the individual elements and/or the compound shapes resulting therefrom, they are completely filled out. The filling can be glued, soldered or be constituted by a fabric.

Gaps between the faces and/or edges of the individual elements and/or the compound shapes resulting therefrom should be preferably between 0.1 and 10 mm in width; at smaller dimensions of the individual elements and/or the compound shapes the gaps, are smaller as well.

According to the present invention, the method for manufacturing high-strength planar structures for end-ballistic protection and protection against wear comprises reassembling a planar structure composed of individual elements having the form of regular pyramids and tetrahedrons or irregular pentahedrons and/or hexahedrons and/or of compound shapes composed of the said individual elements, regular pyramids and tetrahedrons or irregular pentahedrons and/or hexahedrons, force-locked at least on one side to a backing material, and/or entirely or partially enclosed by the backing material.

It is advantageous if the force-locking of the individual elements and/or of the compound shapes with the backing material and/or with another planar material is performed by gluing, soldering, compression molding or welding.

It is also an advantage if five pyramids and four tetrahedrons are used for forming a compound shape, which is repeated as often as needed, and alternatively, placed in reverse direction (face up and face down), showing a flat and/or curved and/or dome-shaped surface towards the backing material and/or the impact area.

The solution provided by the present invention enables improved end-ballistic protection and/or protection against wear by assuring that the destruction caused by projectiles or wear be limited to the immediate vicinity of the impact by projectiles of a certain caliber, thereby providing better resistance against repeat shooting or continuous strain. This is achieved by means of making the individual elements smaller. On the one hand, this has a disadvantage because a greater number of surfaces are needed at the impact area, but, on the other hand, there is the advantage of better shoot-protective and wear inhibiting action. This advantage is accomplished by minimizing the weak spots of such compound shapes existing in the previous state of technology and by making them now less extensive or located further from the immediate impact of shots or wear.

The same advantage refers also to the area of protection against wear, where the strain of the impact on the armoring applies.

In addition to the improved adaptability of the planar structure to irregular forms, the solution according to the present invention also has the advantage of lower specific weight, without compromising the protective action. Moreover, in many cases the protective action is even improved. The solution according to the invention entirely or partially eliminates the critical problem of edge stability and edge hardness of planar structures to be joined with a backing material, and possibly with an additional planar material, as well as the hardness of the planar structure material.

Within the context of this invention, the term "backing material" refers to a material which is affixed to individual elements and/or onto one or more compound shapes and/or completely encloses an individual element and/or one or more compound shapes. In the event of end-ballistic protection, the backing material is preferably fiber mesh, and in the event of protection against wear it is made of metals, for example in the form of sheets. The use of metal sheets as backing material for end-ballistic protection as well as the use of fiber mesh as backing material for the protection against wear, is also possible.

In the following, the invention is explained using several examples: Example 1 : 400 irregular pentahedrons measuring 30 x 20 x 20 mm3 (always the largest length x width x height) are manufactured from ceramic plates of liquid-phase sintered silicon carbide by abrasive cutting. The form corresponds to the combination of a regular pyramid and a tetrahedron, which are combined in such a way that they form together a wedge, two sides giving the form of a parallelogram, two other sides having the form of an equal-sided triangle and the base being a square.

These pentahedrons are combined together such that the planar surfaces always lie opposite the backing material, which is an Aramid fiber body with the dimensions 400 x 400 mm, as well as opposite the future planar structure.

The planar sides of the combined 400 pentehedrons cover the entire backing material and are firmly glued to it by means of two-component epoxy resin glue.

Such A planar structure is assembled to a military vehicle as protective armoring.

By a perpendicular hit of a 12.7 mm projectile, a maximum six pentahedrons, but normally only two to four, will be destroyed in the immediate vicinity of the shot site. Due to the overlay of the armor plates, the protective action in the immediate vicinity of the shot site, in contrast to conventional ceramic protective plates, is maintained. The maximum destroyed area is 40 x 40 mm, but is normally only 20 x 40 mm.

In comparison, in conventional array of armoring plates measuring 75 x 75 x 20 mm in a brick- work form, under the same conditions, a maximum area of 150 x 150 mm but usually a 75 x 75 mm area, is destroyed.

The solution provided by this invention also warrants withholding of a projectile when it hits the adjacent edges of the pentahedrons.

In contrast, the conventional array of armoring plates does not withhold the projectile when it hits the adjacent edges of the pentahedrons. Therefore, the conventional method requires a thicker plate of minimum 30 mm in order to reliably withhold a shot, and this results in 33% weight increase.

Example 2: Continuously cast high-strength steel (ST 52-3) with a triangular cross section is cut by oblique cutting to form pyramids with base area of 40 x 40 mm, subsequently processed to obtain the height of 40 mm. From a similar steel block, tetrahedrons are cut by subsequent oblique cutting, whereby the right-angled edges are 40 mm long and the height is 40 mm. 200 pyramids are soldered together with 200 such tetrahedrons with soft soldering to form compound shapes. The compound shapes consisting of a pyramid and a tetrahedron are placed together in a frame to form a planar structure. The side adjacent to the backing material is soldered with soft soldering and an appropriate flux to the backing material consisting of a steel sheet (of quality ST37), the dimensions of which are 400 x 400 mm.

The planar structure thus manufactured is mounted as a protective armoring of a deflector plate, of a hammer crusher.

During the abrasive stress exerted upon the deflector plate, the adjacent edges are eroded to an higher degree than the plate itself.

Due to the arrangement of pyramids and tetrahedrons, the solution according to the present invention causes the strain distribution to run along oblique lines in the direction of strain, which creates less abrasion of the adjacent edges. This results in 1 ½ times longer duration of use. Due to the kind of soldering, it is possible to exchange the protective plates, and thus, to re-use the protective equipment.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

- 9 - 170927/2 CLAIMS;

1. High-strength large-area structure for final-ballistic protection and wear protection, comprising individual bodies which, when assembled and mounted on a backing material and/or entirely or partially surrounded by a backing material, produce the high-strength large-area structure, characterized in that the individual bodies are in the form of regular pyramids and tetrahedra or irregular pentahedra and/or hexahedra, or the individual bodies comprise a shape composite composed of assembled shapes, connected to one another, of regular pyramids and tetrahedra or irregular pentahedra and/or hexahedra, with the large-area structure in each case having essentially smooth surfaces on the upper face and lower face, and having no further flaws apart from the gaps between the individual bodies.

2. Large-area structure according to Claim 1, in which the individual bodies and/or the shape composites assembled from them are entirely or partially composed of ceramic and/or metallic materials.

3. Large-area structure according to Claim 2, in which SiC, S13N4 and AI2O3 are used as ceramic materials.

4. Large-area structure according to Claim 2, in which hard metals or high-strength steels are used as metallic materials.

5. Large-area structure according to Claim 2, in which the individual bodies and/or the shape composites assembled from them are composed of ceramic-metal composite materials.

6. Large-area structure according to Claim 1, in which a shape composite comprises five pyramids and four tetrahedra, is repeated a plurality of times and is in each case assembled, alternately reversed, as a shape composite which forms the large-area structure. - 10 - 170927/2

7. Large-area structure according to Claim 1, in which the individual bodies are connected by adhesive bonding, welding, soldering or by means of brackets.

8. Large-area structure according to Claim 1, in which the individual bodies of the large-area structure each have only one connection to the backing material and/or to some other large-area material and then, when assembled reversed, result in a complete large-area structure.

9. Large-area structure according to Claim 8, in which the touching surfaces of the individual bodies are connected to one another by force fits.

10. Large-area structure according to Claim 1, in which the individual bodies and/or the shape composites assembled from them have dimensions with edge lengths from 5 to 200 millimetres.

11. Large-area structure according to Claim 10, in which the individual bodies and/or the shape composites assembled from them have dimensions with edge lengths from 10 to 100 millimetres.

12. Large-area structure according to Claim 1, in which there is an interlocking contact between the surfaces and/or edges of all, of a plurality or of single individual bodies in the large-area structure.

13. Large-area structure according to Claim 1, in which, when there are gaps between the surfaces and/or edges of the individual bodies and/or the shape composites assembled from them, these gaps are completely filled.

14. Large-area structure according to Claim 13, in which the gaps are filled by an adhesive, a solder or a fabric.

15. Large-area structure according to Claim 13, in which the gaps between the surfaces and/or edges of the individual bodies and/or of the shape composites assembled from them have a width of between 0.1 and 10 millimetres, with smaller gap dimensions also being possible if the dimensions of the individual bodies and/or of the shape composites are smaller. - 11 - 170927/2

16. Method for production of high-strength large-area structures for final-ballistic protection and wear protection according to at least one of Claims 1 to 15, characterized in that - individual bodies in the form of regular pyramids and tetrahedra or irregular pentahedra and/or hexahedra or individual bodies as a shape composite of assembled shapes, connected to one another, of regular pyramids and tetrahedra or irregular pentahedra and/or hexahedra are assembled to form a large-area structure, with the large-area structure in each case having essentially smooth surfaces on the upper face and lower face and having no further flaws apart from the gaps between the individual bodies, and being connected with a force fit to a backing material on at least one side and/or being entirely or partially surrounded by a backing material.

17. Method according to Claim 16, in which the individual bodies and/or the shape composites assembled from them are connected by force fits to the backing material and/or to some other large-area material by adhesive bonding, soldering, pressing or welding.

18. Method according to Claim 16, in which a shape composite is produced from 5 pyramids and 4 tetrahedra, is repeated as often as desired, and the shape composites are in each case assembled alternately reversed, thus forming a smooth and/or curved and/or convex surface on the backing material and/or on the touching side. For the Applicants, WOLFF, BREGMAN AND GOLLER