Patent Application
20120174750
The inventive subject matter generally relates to armor material, and more particularly relates to projectile-resistant armor material.
Protective armor is used for protecting a person, vehicle or device from penetrating threats that may originate from devices used for explosive or ballistic events. Conventionally, the protective armor may be made of sheets of ceramic, metal, or a combination of these materials. Although these materials generally provide excellent protection, they may be improved. Specifically, it is desirable to provide a protective armor that may be more lightweight than conventional protective armor. Additionally, it is desirable to have a protective armor that may protect against various forms of projectile threats, such as solid particles and liquid molten metals. Moreover, it is desirable to have a protective armor made from material that is relatively inexpensive and simple to manufacture. Furthermore, other desirable features and characteristics of the inventive subject matter will become apparent from the subsequent detailed description of the inventive subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background of the inventive subject matter.
An armor material, a body armor article, and methods of manufacturing the armor material are provided.
In an embodiment, by way of example only, the armor material includes a first plate, a second plate, and a powder material. The first plate includes a layer comprising a metallic material. The second plate is spaced apart from the first plate and may include a layer comprising a ceramic material. The powder material is disposed between the first and the second plates, and comprises loose powder including at least one of a plurality of ceramic particles and a plurality of metallic particles.
In another embodiment, by way of example only, the body armor article includes a panel. The panel includes an armor material that has a first plate, a second plate, and a powder material. The first plate includes a layer comprising a metallic material. The second plate is spaced apart from the first plate and includes a layer comprising a ceramic material. The powder material is disposed between the first and the second plates, and comprises loose powder including at least one of a plurality of ceramic particles and a plurality of metallic particles.
In still another embodiment, by way of example only, the method includes placing and compacting loose powder material in selected cells of a plurality of cells between a first and a second plate.
The inventive subject matter will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
The following detailed description is merely exemplary in nature and is not intended to limit the inventive subject matter or the application and uses of the inventive subject matter. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
In an embodiment, the armor material 100 is configured to dissipate and absorb kinetic energy of a projectile by maintaining the projectile intact and/or by adding material to the projectile as it travels through the armor material 100. Generally, the armor material 100 includes a first plate 102, a second plate 104, and a powder material 106, according to an embodiment. As shown in
The first plate 102 may be initially impacted by the projectile and thus, is configured to absorb at least a portion of the kinetic energy therefrom. In an embodiment, the first plate 102 may be made of a metallic material, such as aluminum, titanium or steel. In an embodiment, the first plate 102 may have a thickness of between about 0.2 and about cm. In another embodiment, the first plate 102 may be a laminate and may include a first layer 110 and a second layer 112. Each layer 110, 112 may have a thickness of between about 0.1 cm and about 5 cm. At least one of the layers 110, 112 may comprise a first metallic material, such as aluminum, while the other layer 110, 112 may comprise a second metallic material, such as steel, titanium, or aluminum. The second layer 112 or an additional layer may comprise a ceramic material. Suitable ceramic materials include, but are not limited to, alumina, aluminum nitride, aluminosilicate, boron carbide, boron nitride silica, silicon nitride, silicon carbide, and zirconia. In an embodiment, where the first layer 110 is a soft metal such as aluminum and the second layer 112 is made of a relatively hard metal or ceramic material, the first layer 110 may facilitate projectile deformation (pancaking) on an outer surface of the armor material 100 with minimal shear stress transmitted to the second layer 112. As a result, the second layer 112 may have an enhanced ability to resist projectile penetration.
The powder material 106 is configured to absorb another portion of kinetic energy from the moving projectile to further reduce the speed at which the projectile is traveling, in an event in which the projectile passes through the first plate 102. In this regard, the powder material 106 may be disposed between the first plate 102 and the second plate 104 as a loose powder or partially compacted powder. In this way, the powder material 106 becomes compacted when impacted by the projectile. The work required for compaction of the powder thereby absorbs another portion of the impacting projectile's kinetic energy. In an embodiment, the powder material 106 may be disposed between the plates 102, 104 such that it is a loose powder. Depending on powder particle size and shape, the loose powder may be pre-compacted to have a weight that is about 30% of the weight of the solid from which the powder material 106 is made. In another embodiment, the powder material 106 may be precompacted, and may have a weight that may be about 50% of the weight of its solid form. In still other embodiments, it may be desirable for the powder material 106 to have a compacted density that creates an even higher pressure when the projectile impacts the powder; for such embodiments, the powder material 106 may be pre-compacted to a form a preform having a predetermined density, which may also facilitate packaging of the powder. For example, the powder may be precompacted to about 70% of the weight of the solid form.
The second plate 104 may be configured to absorb at least a portion of the kinetic energy remaining in a projectile with which it comes into contact. For example, in an embodiment, the second plate 104 may be made of a ceramic material. Suitable ceramic materials include, but are not limited to, alumina, aluminum nitride, aluminosilicate, boron carbide, boron nitride, silica, silicon nitride, silicon carbide, zirconia, and sand (calcia-magnesia-alumina-silicate). In an embodiment, the second plate 104 may have a thickness of between about 0.1 and about 5 cm. In another embodiment, the second plate 104 may be a laminate and may include a first layer 116 and a second layer 118. The layers 116, 118 may or may not have substantially identical thicknesses and may have thicknesses between about 0.1 and about 5 cm. At least one of the layers 116, 118 may comprise a first metallic material, while the other of the layers 116, 118 may comprise a second metallic material. In another embodiment, the second layer 118 or an additional layer may comprise may be a metallic material, such as aluminum, titanium or steel. In an embodiment, the second plate 104 may make up a wall of a device or vehicle into which the armor material 100 is being incorporated.
A fiber-composite fabric 108 (shown in phantom) may be positioned adjacent to the second plate 104 and may be separate from or adhered thereto. The fiber-composite fabric 108 may serve to catch projectiles that still have kinetic energy and thereby block the projectile from completely traveling through the armor material 100. The fiber-composite fabric 108 may be made from aramids, high molecular weight polyethylene fiber, or glass fiber. In an embodiment, the fiber-composite fabric 108 may be Spectra® fiber available through Honeywell International, Inc., Specialty Materials Group, of Morristown, N.J.
As mentioned briefly above, the powder material 106 is disposed between the first plate 102 and the second plate 104 and comprises loose powder. The powder material 106 may include at least one of a plurality of ceramic particles and a plurality of metallic particles. Thus, in some embodiments, the powder material 106 may be a mixture of ceramic particles and metallic particles. In an embodiment, the powder material 106 occupies substantially all of a volume defined between the first and the second plates 102, 104. In another embodiment, the powder material 106 may be disposed in structures that are incorporated between the first and the second plates 102, 104.
The cells 214 may have any one of numerous configurations. In an embodiment, the cells 214 are capsules having a predetermined shape. The capsules may be made of a material capable of deforming when impacted by the projectile to allow the powder material 106 to be compacted. The capsules may be configured to plastically deform to thereby absorb at least a portion of the energy of the projectile. Suitable capsule materials include, but are not limited to glass, ceramic, plastic, aluminum, titanium, copper and steel. The predetermined shape of the capsules may be spherical, ovular, cubic, or hexagonal. In an embodiment, the capsules may have a diameter of between about 2 mm and about 50 mm. In another embodiment, the capsules may include a wall 220 having a thickness of between about 0.1 mm and about 10 mm.
The powder material 306 in this embodiment is disposed in at least a portion of the cells 314. In an embodiment, the powder material 306 is disposed in substantially all of the cells 314 and fills substantially an entire volume of each cell 314 occupied. In other embodiments, between about 5% and about 95% of the plurality of cells 314 is filled with the powder material 306. In another embodiment, the powder material 306 is disposed in about 50% of the plurality of cells 314, and occupies substantially an entire volume of each occupied cell 314. In any event, the occupied cells 314 may form a pattern. For example, one or more occupied cells 314 may be interposed between two or more empty cells.
The cells 314 shown in
In another embodiment, a first portion of the plurality of cells 514 in the first layer 522 includes powder material 506, while a second portion of the plurality of cells 514 in the first layer 522 is empty. In still another embodiment, the cells of the first layer 522 may have an opening that communicates with an opening formed in the cells of the second layer 524. The opening may have a width that is slightly smaller (e.g. about 10% smaller) than the size of a particle of the powder material 506 so that flow of the powder material 506 may occur by back extrusion after the powder is nearly fully compacted. The armor material 500 may be further configured such that a first portion of the plurality of cells 514 in the first layer 522 may include the powder material 506. In an embodiment, the plurality of cells 514 in the second layer 524 communicating with the first portion of the plurality of cells 514 in the first layer 522 may not initially include powder material 506. Thus, when the armor material 500 is subjected to projectile impact, the powder material 506 can flow from the first layer 522 to the second layer 524 to provide an improved ability to absorb the projectiles' energy and also to withstand repeated impacts. In another embodiment, those cells in the second layer 524, which may oppose the filled cells of the first layer 522 may be filled with powder material 506. The layers 522, 524, may have cells and cell walls made of material that has a melting point that is greater than a molten projectile and powder material 506 having a melting point that is greater than the molten projectile. As a result, the compacted powder-filled cells form a high-melting point barrier to molten projectiles. Additionally, energy from the impact of the molten projectile may dissipate due to the powder compaction, friction between sliding cells of the layers 522, 524, and buckling of the cell walls.
In any case, the powder material 106, 206, 306, 506 may be formed to reduce the kinetic energy of one or more different types of projectiles. In this regard, the powder material 106, 206, 306, 506 may have particular characteristics suitable for reducing kinetic energy when impacted by projectiles. For example, the powder material 106, 206, 306, 506 may include particles having predetermined shapes, such as spherical. The particles may or may not be uniform in shape. In another example, the powder material 106, 206, 306, 506 may have a particular granularity having an irregular atomized shape. The particles may also be relatively flat having a shape characteristic of powder made by mechanical alloying. For instance, in an embodiment, the particles of the powder material 106, 206, 306, 506 may be fine and may have each particle may have a diameter of between about 10 μm and about 300 μm. In another embodiment, the particles may be relatively coarse and have a diameter of between about 0.5 mm and about 5 mm.
The type of powder selected for use may depend on an ability of the powder to obtain maximum absorption of the projectile energy and on the probable type of projectile. In an embodiment, the powder material 106, 206, 306, 506 may be formulated to reduce the kinetic energy of a projectile that may be a solid particle, and the powder material 106, 206, 306, 506 may include a plurality of particles that may deform when impacted by the projectile to thereby weld thereto and increase the size thereof. Suitable particles include, but are not limited to, one or more types of metals or alloys thereof, such as aluminum, iron, steel or copper. In another example, the projectile may comprise liquid metal, and the powder material 106, 206, 306, 506 may include a plurality of particles having a melting point that may be greater than that of the material from which the fully or partially molten projectile may originate. These types of particles may be relatively difficult to compact and may absorb kinetic energy from the molten particle. Suitable particles may include metals such as steels or superalloys or ceramics particles, such as Al2O3, SiN4, SiC, SiO2, and the like. Other suitable particles may be those having a melting point that is greater than that of copper (e.g., 1085° C.). In cases in which the armor material 100, 200, 300, 500 may be subjected to multiple types of projectiles, the powder material 106 may be a mixture of metallic particles and ceramic particles. It will be appreciated that a ratio of metallic particles to ceramic particles may be selected based on a predicted likelihood of a particular threat that may be encountered.
To maintain the powder material 106, 206, 306, 506 in loose form, one or more additives may be included. For example, the powder material 106, 206, 306, 506 may include a small amount of an organic additive (e.g., less than about 5% by weight). The organic additive may serve as a contaminant that prevents or inhibits welding of the particles of the powder material 106, 206, 306, 506. Possible organic contaminates include, but are not limited to, carbon, epoxy, foam or glue. Epoxy or glue may be formulated to adhere to a portion of the particles of the powder material 106, 206, 306, 506 so that the particles remain separate from each other even when subjected to vibration.
In an embodiment, the organic additive, either the foam, glue, or another material, may be formulated to vaporize due to heat energy resulting from compaction of the powder material 106, 206, 306, 506 upon projectile impact. The resulting vapor may contaminate substantially all of the powder particles to thereby prevent the particles from welding together and to improve an ability of the armor material 100, 200, 300, 500 to withstand repeated impact to an area. In another example, the additives may include plastics having a melting point below a temperature of the heat energy resulting from compaction of the powder material 106 upon projectile impact. The plastics may further be formulated to vaporize due to the compaction of the powder material 106. Suitable low-melting plastics include, but are not limited to polyacrylonitrile butadiene styrene, nylon, nylon6, polypropylene, polystyrene, polytetra fluoro ethylene, polyfloride and polychloride.
The armor materials discussed above may be manufactured using any suitable method. One example of a suitable method 700 is provided in
After manufacture, the armor material may be incorporated into any article that may be worn on a person or may be incorporated into a vehicle. For example,
Armor materials have now been provided that may be more lightweight than conventional armor materials. Additionally, the armor materials may be used as a shield against solid and/or molten and liquid projectile threats by providing a compactable, alloyable, and collapsible structure. The structure may be used to absorb kinetic energy of a projectile, while either adding material thereto. Moreover, the armor materials may be relatively simple and inexpensive to manufacture, compared to conventional materials.
While at least one exemplary embodiment has been presented in the foregoing detailed description of the inventive subject matter, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the inventive subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the inventive subject matter. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the inventive subject matter as set forth in the appended claims.
