RESISTANT ARMOR PLATE

Related Applications

[0001] This application claims priority from United States Provisional Patent Application No. 62/853,486 filed on May 28, 2019 the contents of which are herein expressly incorporated by reference in their entirety.

Technical Field

[0002] The present disclosure relates generally to armor, and more specifically to a spalling- resistant armor plate and a method of making a spalling-resistant armor plate.

Background

[0003] High hardness steel armor has been the conventional type of armor used on military vehicles and personnel for at least thirty years. Steel armor, while efficacious for its intended purpose, has nonetheless suffered from certain shortcomings. These shortcomings include excessive weight (technically known as areal density), difficulty of formation into complex shapes, sensitivity to extreme heat, and brittleness.

[0004] The brittleness of high hardness steel causes a problem known as spalling. Spalling is the high-velocity discharge of fragments off a tank’s armor when the armor is struck by small arms ammunition of the type widely used by infantry personnel. The discharge occurs when the armor is struck at oblique angles and at ballistic speed by ball-type ammunition. This class of ammunition includes virtually every type of conventional munition except armor piercing artillery. This discharge or ricochet of bullets is undesirable as it may harm friendly troops.

[0005] Ceramic suffers similar spalling problems as steel. In some instances, fragments of ceramic may also break off and spall. Some lower grades of steel may also exhibit spalling by having fragments thereof break off and spall.

[0006] There is a need for an armor that would reduce both frontal and rear spalling with its concomitant danger to nearby friendly troops and equipment. It is also desirable that reducing spalling is accomplished without sacrificing the protection, which the armor offers the crew of a military vehicle.

Summary

[0007] According to one aspect of the present disclosure, there is provided a process for making a spalling-resistant armor plate. The process comprises adding a layer of a tough polymer to at least a strike face of a core armor plate. Tough polymer, as defined below, includes both intrinsically tough polymer and toughened polymer.

[0008] In one embodiment, adding the layer of tough polymer to at least the strike face comprises bonding a sheet of tough polymer to the strike face.

[0009] In one embodiment, adding the layer of tough polymer to at least the strike face comprises bonding another sheet of tough polymer to a back face of the core armor plate.

[0010] In one embodiment, adding the layer of tough polymer to at least the strike face comprises applying a resin of the tough polymer to the strike face for forming the layer of tough polymer on the strike face upon curing of the resin.

[0011] In one embodiment, the bonding comprises applying a film adhesive between the sheet of tough polymer and the strike face. In another embodiment, the bonding comprises applying an adhesive paste between the sheet of tough polymer and the strike face.

[0012] In one embodiment, the process for making the spalling-resistant armor plate further comprises manufacturing the sheet of tough polymer using a casting process. In one embodiment, the casting process includes encapsulating the core armor plate with the layer of tough polymer.

[0013] In one embodiment, the process for making the spalling-resistant armor plate further comprises manufacturing the sheet of tough polymer using an injection molding process.

[0014] In accordance with another aspect of the present disclosure, there is provided an anti spall layer comprised of a sheet of tough polymer sized and shaped for adherence to a core armor plate for forming a spalling-resistant armor plate. In one embodiment, the tough comprises Polydicyclopentadiene (PDCPD). In another embodiment, the tough polymer is a toughened polymer. The toughened polymer may comprise urethane.

[0015] In yet another aspect of the present disclosure there is provided a spalling resistant armor plate comprising a core armor plate having a strike face and an opposite back face, and an anti-spall layer of tough polymer added to the strike face.

[0016] In one embodiment, the layer of tough comprises PDCPD.

[0017] In one embodiment, the layer of PDCPD has a minimum thickness of 0.125 inches.

[0018] In one embodiment, the layer of PDCPD has a maximum thickness of 2 inches. In another embodiment, the layer of PDCPD has a maximum thickness of 0.5 inches.

[0019] In another embodiment, the layer of tough polymer is toughened polymer.

[0020] In another embodiment, the layer of tough polymer comprises urethane.

[0021] In one embodiment, the spalling-resistant armor plate further comprises a layer of paste adhesive between the sheet of tough polymer and the impact for bonding the sheet of tough polymer to the strike face.

[0022] In one embodiment, the paste adhesive comprises epoxy. In another embodiment, the paste adhesive comprises polyurethane.

[0023] In one embodiment, the core armor plate comprises steel. In another embodiment, the core armor plate comprises ceramic.

[0024] In one embodiment, the spalling-resistant armor plate further comprises another layer of tough polymer added to the back face.

Brief Description of the Drawings

[0025] Embodiments of the present disclosure will be presented with reference to the attached drawings in which: [0026] FIG. l is a front elevational view of an anti-spall layer comprised of a sheet of tough polymer sized and shaped for adherence to a core armor plate to form a spalling-resistant armor plate, in accordance with an aspect of the present disclosure;

[0027] FIG. 2 is a cross-sectional side view of the sheet of tough polymer of FIG. 1;

[0028] FIG. 3 is a an enlarged cross-sectional side view of region 3 of FIG. 2;

[0029] FIG. 4 is a front elevational view of a spalling-resistant armor plate having a core armor plate and an anti-spall layer formed and cured to the strike face thereof, in accordance with an embodiment of the present disclosure;

[0030] FIG. 5 is a cross-sectional side view of the spalling-resistant armor plate of FIG. 4;

[0031] FIG. 6 is an enlarged cross-sectional side view of region 6 of FIG. 5;

[0032] FIG. 7 is a front elevational view of a spalling-resistant armor plate having a core armor plate and an anti-spall layer in the form of a sheet of tough polymer bonded to the strike face the core plate by means of an adhesive, in accordance with another embodiment of the present disclosure;

[0033] FIG. 8 is a cross-sectional side view of the spalling-resistant armor plate of FIG. 7;

[0034] FIG. 9 is an enlarged cross-sectional side view of region 9 of FIG. 8;

[0035] FIG. 10 is a front elevational view of a spalling-resistant armor plate having a core armor plate and an anti-spall layer in the form of a sheet of tough polymer bonded to each of the strike and back faces of the core plate by means of an adhesive, in accordance with yet another embodiment of the present disclosure;

[0036] FIG. 11 is cross-sectional side view of the spalling-resistant armor plate of FIG. 10;

[0037] FIG. 12 is an enlarged cross-sectional side view of region 12 of FIG. 11; [0038] FIG. 13 is a front elevational view of a spalling-resistant armor plate in which a core plate is fully encased in an anti-spall layer, in accordance with yet another embodiment of the present disclosure;

[0039] FIG. 14 is a cross-sectional side view of the armor construct of FIG. 13; and

[0040] FIG. 15 is a side perspective view of the armor construct of FIG. 13.

Detailed Description of the Embodiments

[0041] The present disclosure relates to an anti-spalling armor plate and a process for making an anti-spalling armor plate. The process involves adding a layer of a tough polymer to at least the strike face of a core armor plate. The spalling-resistant armor plate reducing or eliminates spalling by causing bullets fired on the anti-spall layer to remain stuck in the anti-spall layer .Embodiments are presented below by way of example only and not limitation.

[0042] Directional terms such as“top”,“bottom”,“upwards”,“downwards”,“ve rtically” and “laterally” are used in the following description for the purpose of providing relative reference only, and are not intended to suggest any limitations on how any article is to be positioned during use, or to be mounted in an assembly or relative to an environment. The use of the word“a” or “an” when used herein in conjunction with the term“comprising” may mean“one,” but it is also consistent with the meaning of“one or more,”“at least one” and“one or more than one.” Any element expressed in the singular form also encompasses its plural form. Any element expressed in the plural form also encompasses its singular form. The term“plurality” as used herein means more than one, for example, two or more, three or more, four or more, and the like.

[0043] In this disclosure, the terms“comprising”,“having”,“including”, and“containing”, and grammatical variations thereof, are inclusive or open-ended and do not exclude additional, un recited elements and/or method steps. The term“consisting essentially of’ when used herein in connection with a composition, use or method, denotes that additional elements, method steps or both additional elements and method steps may be present, but that these additions do not materially affect the manner in which the recited composition, method, or use functions. The term “consisting of’ when used herein in connection with a composition, use, or method, excludes the presence of additional elements and/or method steps.

[0044] In this disclosure, the terms“urethane” and“polyurethane” are used interchangeably.

[0045] In this disclosure, the term“toughened polymer” refers to a polymer resin loaded with a toughening agent.

[0046] In this disclosure, the term“tough polymer” refers generally to both a polymer that is intrinsically tough (such as Polydicyclopentadiene) without requiring a toughening agent; as well as to a“toughened polymer” as defined above.

[0047] Conventional steel armor of the type popularly used on many current armored vehicles possesses an areal density (measured as weight per unit of surface area) of about twenty pounds per square foot (20 lb/ft ² ). There is a need to effect a reduction in this areal density in order to reduce the weight and improve the mobility of the vehicle equipped with the armor. Additionally, it is desirable to have an armor that could be readily made to conform to the outer structural members of a vehicle to be armored. Furthermore, an armor, which is less brittle than high hardness steel, is desired to reduce spalling.

[0048] The present disclosure utilizes an anti-spall layer made from a tough polymer and attached in some fashion to a core armor plate, which is usually made of steel or ceramic although other materials may also be used.

[0049] FIGS. 1-3 show an anti-spall layer 100 in the form of a sheet of tough polymer 110. The sheet of tough polymer 110 as depicted in FIG. 1, is in the form of a square having a side of 12 inches, and a thickness of about 0.19 inches although in other embodiments, the sheet of tough polymer 110 may have other shapes and sizes. The sheet of tough polymer 110 is typically sized and shaped for adherence to a core armor plate to form a spalling-resistant armor plate as will be explained below. [0050] As defined above, tough polymer 100 may be a polymer that is already tough without requiring a toughening agent, or a toughened polymer comprising a polymer resin loaded with a toughening agent.

[0051] The sheet of toughened polymer 110 may be manufactured using a casting process and therefore may be shaped to suit the intended application. The sheet of tough polymer 110 may, alternatively be made using an injection molding process.

[0052] In one embodiment, the tough polymer 110 comprises Polydicyclopentadiene (PDCPD). In another embodiment, the tough polymer 110 comprises urethane.

[0053] FIGS. 4-6 are simplified diagrams of a spalling-resistant armor plate 200 comprising an anti-spall layer in the form of a sheet of tough polymer 110 formed on a strike face of a core armor plate 120. The spalling-resistant armor plate 200 may be formed by applying a resin of the tough polymer to the strike face for forming the layer of tough polymer 110 on the strike face of the core armor plate 120 upon curing of the resin.

[0054] FIG. 7-9 show a spalling-resistant armor plate 300 comprising an anti-spall layer in the form of a sheet of tough polymer 110 bonded to the strike face of a core armor plate 120 by bonding means 115. In one embodiment, the bonding means 115 includes a film adhesive disposed between the sheet of tough polymer 110 and the strike face of core armor plate 120. In another embodiment, the bonding means 115 includes a paste adhesive applied between the sheet of tough polymer 110 and the strike face of core armor plate 120. In yet another embodiment, the paste adhesive comprises epoxy. In yet another embodiment of the spalling-resistant armor plate 300, the paste adhesive comprises polyurethane. Other types of paste adhesives may also be used in other embodiments.

[0055] FIGS. 10-12 depict a spalling-resistant armor plate 400 having two anti-spall layers in the form of two sheets of a tough polymer 110 bonded to both the strike and back faces of a core armor plate 120 by bonding means 115. As noted above, tough polymer 110 may be a an intrinsically tough polymer or a toughened polymer. In one embodiment, the bonding means 115 comprise a film adhesive disposed between the sheet of tough polymer 110 and the strike face of core plate 120. In another embodiment, the bonding means 115 comprise an adhesive paste applied between the sheet of the tough polymer 110 and the strike face of cover plate 120.

[0056] FIGS. 13-15 show a spalling-resistant armor plate 500 comprising a core plate 120, which is fully encapsulated into an anti-spall layer of tough polymer. The spalling-resistant armor plate 500 may be formed by a casting process in which the core plate 120 is placed into the resin of tough polymer layer 110 until the anti-spall layer fully encapsulates the core plate 120.

[0057] Various configurations and thicknesses may be needed when using an anti-spall layer of PDCPD. For example, the minimum thickness of 0.125 inches and a maximum thickness of 2 inches were used when using an anti-spall layer of PDCPD. In some applications, a maximum thickness of 0.5 inches was sufficient.

[0058] The core armor plate 120 may be made of steel or ceramic. The anti-spall layer may be applied to the strike face or the back face of the core armor plate 120 by repeated spraying of resin and curing thereof on until the desired thickness of the corresponding tough polymer layer 110 is reached.

[0059] Ballistic tests have been conducted on embodiments of the spalling-resistant armor plate described in the present disclosure. In one embodiment, the anti-spall layer is made of a sheet of PDCPD. In another embodiment, the anti-spall layer is made of a sheet of urethane. A bullet fired on the spalling-resistant armor plate penetrates the anti-spall layer, which then closes up behind the bullet in a self-healing manner so that the bullet remains caught in the anti-spall layer thereby eliminating spalling. In ballistic tests conducted using anti-spall layers made of both PDCPD and urethane, it has been observed that urethane anti-spall layers require about twice the thickness of anti-spall layers of PDCPD in order to achieve the same anti-spall ballistic performance.

[0060] A process for making a spalling-resistant armor plate, exemplary of the present disclosure, includes adding a layer of tough polymer to at least the strike face of a core armor plate. The layer can also be added to the back face of the core armor plate. [0061] In this embodiment, adding the layer of tough polymer to the strike face includes bonding a sheet of tough polymer to the strike face. Adding a layer of tough polymer to the back face includes bonding a sheet of tough polymer to the back face. Adding a layer of tough polymer to the strike face may in turn involve applying a resin of tough polymer to the strike face to form the layer of tough polymer on the strike face upon curing of the resin.

[0062] Bonding typically involves the use of bonding means. In one embodiment of the process, bonding the sheet of tough polymer to the armor plate may include applying a film adhesive between the sheet of tough polymer and the armor plate while in another embodiment the bonding may involve applying an adhesive paste between the sheet of tough polymer and the strike face.

[0063] The sheet of tough polymer may be manufactured using a casting process which in turn may involve encapsulating the core armor plate with the layer of tough polymer. Alternately the sheet of tough polymer can be manufactured using injection molding.

[0064] The above-described embodiments are intended to be examples of the present disclosure and alterations and modifications may be effected thereto, by those of skill in the art, without departing from the scope of the invention, which is defined solely by the claims appended hereto.