PELLETS FOR USE IN COMPOSITE ARMOR PANELS

FIELD OF THE INVENTION

[001] The instant invention relates generally to a pellet for deployment in a composite armor panel, for absorbing and dissipating kinetic energy from projectiles and for ballistic armor panels incorporating the same. More particularly, the instant invention relates to improved pellets for use in structural armored plates for providing ballistic protection for light and heavy mobile equipment and vehicles against high-velocity projectiles or fragments.

BACKGROUND

[002] One of the ways of protecting an object from a projectile threat is by equipping that object with armor. The armor is provided typically in the form of a panel, which may vary in shape and size to fit the object that is to be protected. Protective armor for heavy but mobile military equipment, such as tanks and large ships, is known. Such armor usually comprises a thick layer of alloy steel, which is intended to provide protection against heavy and explosive projectiles. Due to its weight, such armor is quite unsuitable for light vehicles such as automobiles, jeeps, light boats, aircraft or light armored vehicles, whose performance is compromised by steel panels having a thickness of more than a few millimeters.

[003] The use of ceramics in constructing armors has gained popularity because of some of the useful properties that ceramics possess. In general, ceramics are inorganic compounds with a crystalline or glassy structure. While being rigid, ceramics are low in weight in comparison with steel; are resistant to heat, abrasion, and compression; have high hardness; and have high chemical stability.

[004] Often, ceramics are used as part of a composite armor system. A known type of composite armor system generally includes two basic elements, namely: a base (backing) element for particle containment which may comprise a plurality of layers of fibrous material embedded in a resinous matrix or which may comprise a metal such as steel or aluminum; and an energy-absorbing body (comprising, for example, one or more layers of material such as ceramic bodies in the form of tiles/pellets, etc.) disposed on the frontal face of the base

element, the energy-absorbing body being impact shatterable for absorbing kinetic energy of a projectile.

[005] The major energy absorption for such a two part composite occurs on impact of the projectile with an element of the energy-absorbing body. Kinetic energy is dissipated on impact by inducing the shattering of the energy-absorbing element, and transferring kinetic energy to the so created debris of the element over a wide area relative to the area of the projectile. The projectile itself fragments as it passes through the debris, which tends to be held in place by the underlying base element, thus dissipating more kinetic energy. The fragmented projectile spreads its kinetic energy over a larger area, making it easier to stop at subsequent layers of the composite armor. The particles (or fragments) of projectile and of the energy-absorbing element are then contained by the base element, such containment also absorbing kinetic energy.

[006] Of course, when a second projectile strikes the composite armor there is an increased probability of penetration. Accordingly, multi-hit armor is known, i.e. one that can withstand more than one projectile impact. For this purpose, the armor is made of separate tiles/pellets that are connected together, as by gluing onto the base element. A projectile hitting the armor may destroy one or more of the tiles/pellets at a time, and the remaining tiles/pellets serve to prevent penetration over the remaining surface of the armor.

[007] In United States Patent 5,972,819, Cohen discloses a ceramic body for deployment in composite armor, said ceramic body being substantially cylindrical in shape, with at least one convexly curved end face, wherein the ratio D/R between the diameter D of said ceramic body and the radius R of curvature of said at least one convexly curved end face is at least 0.64:1. Armor panels that are based on this type of cylindrical ceramic body are said to be somewhat flexible, and also lighter in weight compared to similar panels that are based on ceramic tiles. In addition, it has been suggested that panels containing the cylindrical ceramic bodies are less susceptible to damage resulting from falling rocks or blunt-force weapons. Unfortunately, the area of contact between two adjacent cylindrical ceramic bodies in a panel is very small. When one ceramic body in the panel is shattered as a result of a projectile impact, the force that is exerted on an adjacent ceramic body in the panel, as a result of the movement/displacement of the shattered ceramic body (or its fragments), produces a tremendous pressure on the adjacent ceramic. In fact, a shock wave is transmitted from the

impacted ceramic body to the adjacent ceramic body. This shock (or impact) on the adjacent ceramic body is magnified due to the point loading of the very small contact area between adjacent ceramic bodies in the panel. Test results have shown that several ceramic bodies in a row actually may be split as a result of a single projectile impact. Clearly, it is a serious disadvantage that damage from a single projectile impact may propagate along a row of ceramic bodies in this manner. In extreme instances, a portion of the armor panel may dislodge completely from the rest of the panel, leaving an unprotected area along the armored object and adjacent to the line of the split ceramic bodies. The unprotected area may be of sufficient size to provide a relatively easy target for penetrating the object with subsequent projectiles.

[008] It would be advantageous to provide a pellet for deployment in a composite armor panel that overcomes at least some of the above-mentioned disadvantages of the prior art.

SUMMARY OF EMBODIMENTS OF THE INVENTION

[009] In accordance with an aspect of the instant invention there is provided a pellet for deployment in a composite armor panel for absorbing and dissipating kinetic energy from high velocity projectiles, the pellet having a first end face at a projectile-receiving end thereof and having a second end face at an end that is opposite the projectile-receiving end, the pellet having an outer surface extending between the first end face and the second end face, the outer surface comprising a plurality of non-contiguous arc-segment surface sections that are arranged in an alternating fashion with a plurality of planar surface sections, such that in a cross-section taken in a plane each one of the arc-segment surface sections lies along the circumference of a circle of diameter D and each one of the plurality of planar surface sections defines a chord within the circle of diameter D.

[0010] In accordance with another aspect of the instant invention there is provided a composite armor for absorbing and dissipating kinetic energy from high velocity projectiles, comprising: a panel comprising a plurality of pellets, each pellet of the plurality of pellets having a first end face at a projectile-receiving end thereof and having a second end face at an end that is opposite the projectile-receiving end, each pellet having an outer surface extending between the first end face and the second end face, the outer surface comprising a plurality of non-contiguous arc-segment surface sections that are arranged in an alternating fashion with a

plurality of planar surface sections, such that in a cross-section taken in a plane each one of the arc-segment surface sections lies along the circumference of a circle of diameter D and each one of the plurality of planar surface sections defines a chord within the circle of diameter D, and, wherein the pellets are arranged within the panel such that each planar surface section of each pellet is disposed in a facing relationship with a planar surface section of an adjacent pellet in the panel, the pellets of the plurality pellets being retained in panel form by a solidified material.

[0011] In accordance with another aspect of the instant invention there is provided a pellet for deployment in a composite armor panel for absorbing and dissipating kinetic energy from high velocity projectiles, the pellet having a first end face at an projectile-receiving end thereof and having a second end face at an end that is opposite the projectile-receiving end, the pellet being elongated in shape and having a length L that is defined between the first end face and the second end face, the pellet having an outer surface extending along the length L between the first end face and the second end face, the outer surface comprising a plurality of non-contiguous arc-segment surface sections that are arranged in an alternating fashion with a plurality of planar surface sections, such that in a cross-section taken in a plane that is normal to the length L each one of the arc-segment surface sections lies approximately along the perimeter of an ellipse having a major axis a and a minor axis b and that is defined by the equation (x/a) ² + (y/b) ² = 1, and each one of the plurality of planar surface sections defines a chord within the said ellipse.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Exemplary embodiments of the invention will now be described in conjunction with the following drawings, in which similar reference numbers designate similar items:

[0013] Figure Ia is a simplified top view showing two pellets of circular cross section disposed in mutual contact;

[0014] Figure Ib is a simplified side view showing the two pellets of Figure Ia;

[0015] Figure 2 is an enlarged view of a portion of Figure Ia, showing the point of contact between the two pellets subsequent to a projectile having impacted one of the two pellets resulting in splitting of the non-impacted pellet;

[0016] Figure 3 is a simplified top view illustrating several pellets that are split and/or dislodged as a result of a projectile impact;

[0017] Figure 4a is a simplified top view showing two pellets according to an embodiment of the instant invention, the two pellets disposed in mutual contact;

[0018] Figure 4b is an enlarged view of a portion of Figure 4a, showing the point of contact between the two pellets subsequent to a projectile having impacted one of the two pellets;

[0019] Figure 5a is a top view of a pellet according to an embodiment of the instant invention;

[0020] Figure 5b is a side view of the pellet of Figure 5a;

[0021] Figure 5c is an enlarged top view showing a portion of the perimeter of the pellet of Figure 5a;

[0022] Figure 6 is a simplified top view showing one packing arrangement for the pellets according to an embodiment of the instant invention;

[0023] Figure 7 is a simplified top view showing another packing arrangement for the pellets according to an embodiment of the instant invention;

[0024] Figure 8a is a top view of a pellet according to an embodiment of the instant invention;

[0025] Figure 8b is a side view of the pellet of Figure 8a;

[0026] Figure 9a is a top view of a pellet according to an embodiment of the instant invention;

[0027] Figure 9b is a side view of the pellet of Figure 9a;

[0028] Figure 10a is a top view of a pellet according to an embodiment of the instant invention;

[0029] Figure 10b is a side view of the pellet of Figure 10a;

[0030] Figure 11 a is a top view of a pellet according to an embodiment of the instant invention;

[0031] Figure 1 Ib is a side view of the pellet of Figure 11a;

[0032] Figure 12a is a top view of a pellet according to an embodiment of the instant invention;

[0033] Figure 12b is a side view of the pellet of Figure 12a;

[0034] Figure 13a is a top view of a pellet according to an embodiment of the instant invention; and,

[0035] Figure 13b is a side view of the pellet of Figure 13a.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0036] The following description is presented to enable a person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and the scope of the invention. Thus, the present invention is not intended to be limited to the embodiments disclosed, but is to be accorded the widest scope consistent with the principles and features disclosed herein. "About" when applied to values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by "about" is not otherwise understood in the art with this ordinary meaning, then "about" as used herein indicates a possible variation of up to 5% of the indicated value (+/-5%).

[0037] Figure Ia is a simplified top view showing two pellets of circular cross section disposed in mutual contact. A simplified side view showing the two pellets is presented in Figure Ib. With reference to Figure Ia and Figure Ib, each pellet 100 and 102 is for deployment in composite armor. Each pellet 100 and 102 is substantially cylindrical in shape, with at least one convexly curved end face 104 and 106, respectively. Each pellet 100

and 102 is made of a ceramic material, glass or a sintered refractory material. For instance, the pellets 100 and 102 are made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, each pellet 100 and 102 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof. By way of one specific and non- limiting example, the ratio D/R between the diameter D of the pellet and the radius R of curvature of the at least one convexly curved end face 104 or 106 is at least 0.64:1.

[0038] As stated supra the pellets 100 and 102 are for deployment in composite armor. In particular, the pellets 100 and 102 are part of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellets 100 and 102 have a longitudinal axis 108 and 110, respectively, extending along a length L thereof and passing through the center of the respective convexly curved end face 104 or 106. Furthermore, the pellets 100 and 102 are in mutual contact within the layer. As is shown within the dotted oval in Figure Ia, the pellets 100 and 102 are in contact one with the other at point 112.

[0039] Figure 2 is an enlarged view of the portion of Figure Ia that is within the dotted oval. Figure 2 shows the point of contact between the two pellets 100 and 102, subsequent to a projectile having impacted one of the two pellets. In this example, a projectile has impacted pellet 100. The force that results from the projectile impacting pellet 100 is transmitted either through displacement of the pellet 100 or by deformation of the pellet 100, as indicated by arrows 116 in Figure 2, which arrows 116 are directed toward the point of contact 112 between pellets 100 and 102. In fact, the force may be considered to be an impact force, which is defined as a high force applied over a short time period. At normal speeds, during a perfectly inelastic collision, an object struck by another object will deform, and this deformation will absorb most, or even all, of the force of the collision. Viewed from the conservation of energy perspective, the kinetic energy of the impacting object is changed into heat and sound energy, as a result of the deformations and vibrations induced in the struck object. However, these deformations and vibrations cannot occur instantaneously. A high velocity collision (an impact), such as when pellet 100 strikes pellet 102, does not provide sufficient time for these deformations and vibrations to occur. Thus, the struck material (pellet 102) behaves as if it were more brittle than it is, and the majority of the applied force

goes into fracturing the material. Or, another way to look at it is that materials actually are more brittle on short time scales than on long time scales. Accordingly, the pressure that is exerted on pellet 102 as a result of the impact force is sufficient, in this example, to cause a split 118 to develop across pellet 102. In practice, as is discussed in greater detail below, the split 118 may even propagate to additional adjacent pellets (not shown) or through the solidified material that binds the pellets in panel form.

[0040] Figure 3 is a simplified top view illustrating several pellets that are split and/or dislodged as a result of a projectile impact. In particular, a plurality of pellets in a hexagonal close-packed arrangement is shown. Pellet 300 has received a projectile impact, causing the pellet to shatter and thereby absorb and dissipate the kinetic energy of the projectile. As will be apparent to one of skill in the art, the fact that the pellet 300 shatters is expected and even necessary in order for the armor to be effective. What is not expected, nor desirable, is that a crack 302 has developed through portions of the panel that are adjacent to pellet 300. For instance, the crack 302 extends through adjacent pellets 304 and 306, and then continues through the solidified material that binds the pellets in panel form, resulting in pellets 308 being dislodged from the hexagonal close-packed arrangement, but not split. While the pellets 308 remain intact, nevertheless the anti-ballistic properties of the panel adjacent the pellets 308 is severely compromised and subsequent projectile impacts in this vicinity will cause massive damage and likely result in the projectile penetrating the composite armor panel. In fact, the splitting may produce sufficient force to deform the panel proximate the projectile impact, including the not illustrated coping that reinforces the edge of the panel, to the extent that a section of the panel actually detaches completely, leaving a large area of the underlying object unprotected. Unfortunately, the unprotected area of the underlying object provides a relatively easy target for penetrating the object.

[0041] Figure 4a is a simplified top view showing two pellets according to an embodiment of the instant invention, the two pellets being shown disposed in mutual contact. Each pellet 400 and 402 is for deployment in composite armor. The structure of each pellet 400 and 402 is discussed in greater detail below, with reference to Figures 5a-c. In general, each pellet 400 and 402 is made of a ceramic material, glass or a sintered refractory material. For instance, the pellets 400 and 402 are made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting

examples, each pellet 400 and 402 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof.

[0042] Each pellet 400 and 402 has an outer surface, the periphery of which is seen in top view in Figure 4a. The outer surface of each pellet 400 and 402 comprises a plurality of noncontiguous arc-segment surface sections that are arranged in an alternating fashion with a plurality of planar surface sections. More particularly, pellet 400 includes six planar surface sections 404a-f, and pellet 402 includes six planar surface sections 406a-f. As is shown within the dotted oval in Figure 4a, the two pellets 400 and 402 are in contact 408 along the portions of the outer surfaces designated at 404f and 406f, respectively. Accordingly, the area of mutual contact between pellets 400 and 402 is larger than the area of mutual contact between pellets 100 and 102.

[0043] Figure 4b is an enlarged view of a portion of Figure 4a that is within the dotted oval. Figure 4b shows the area of mutual contact 408 between the two pellets 400 and 402, subsequent to a projectile having impacted one of the two pellets. In this example, a projectile has impacted pellet 400 causing it to shatter. The force that results from the shattering of pellet 400 is indicated using arrows 410 in Figure 4b. The arrows 410 are directed toward the area of mutual contact 408 between pellets 400 and 402. Because the pellets 400 and 402 are in contact one with the other via the planar surface portions 404f and 406f, the force 410 is spread out over the whole area of mutual contact 408. Since the force 410 is spread out over a greater area, the pressure exerted on pellet 402 when pellet 400 shatters is reduced compared to the pressure that is exerted on pellet 102 when pellet 100 shatters. In particular, the pressure that is exerted on pellet 402 is insufficient to cause a split to develop across pellet 402. Instead, the energy resulting from the projectile impact is converted into heat as the pellets and/or the solidified material that binds the pellets in panel form vibrates and deforms.

[0044] Figure 5a is a top view of a pellet according to an embodiment of the instant invention. Figure 5b is a side view of the pellet of Figure 5a. With reference to Figure 5a and Figure 5b, the pellet 400, which is for deployment in composite armor, is elongated in shape, with a first end face 500 and a second end face 504. In particular, the first end face 500 is at a projectile-receiving end of the pellet 400 and in this specific embodiment it is

curved convexly. By way of one specific and non-limiting example, the ratio D/R between the diameter D of the pellet and the radius R of curvature of the first end face 500 is at least 0.64: 1. The second end face 504 is at the end of pellet 400 that is opposite the projectile- receiving end, and in this specific embodiment it is planar. Optionally, the second end face 504 also is curved convexly. Further optionally, the second end face 504 is substantially hemispherical with a radius of curvature S, wherein S is optionally the same as, or different than, R. Further optionally, the second end face 504 defines one of a parabola and a catenary curve joining two opposite arc-segment surface sections, when viewed in a cross section that is taken in the plane of the page. The shape of the second end face 504 is selected in dependence upon the type of backing material being used. For instance, the second end face 504 may be planar when a metal or composite backing material is used, but may be curved when a flexible backing material is used.

[0045] Pellet 400 is made of a ceramic material, glass or a sintered refractory material. For instance, pellet 400 is made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, pellet 400 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof.

[0046] As stated supra the pellet 400 is for deployment in composite armor. For instance, the pellet 400 is one of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellet 400 has a longitudinal axis 502 extending along a length L thereof and passing through the center of the first and second end faces 500 and 504, respectively. Furthermore, the pellet 400 is in mutual contact with other pellets in the layer. In this specific example the pellet 400 has six planar surface sections 404a-f, each one of the six planar surface sections 404a-f being in contact with, or at least facing, a planar surface section of an adjacent pellet when the pellet 400 is assembled and bound in panel form. Of course, in Figure 5b only three of the six planar surface sections (404c, 404d and 404e) are visible, the other three of the six planar surface sections (404b, 404a and 404f) are disposed along the opposite side of the pellet 400. Optionally a number of planar surface sections greater than six or less than six are provided. The number of planar surface sections is selected in dependence upon the desired packing arrangement of the pellets within the final

armor panel product. For instance, optionally each pellet includes four planar surface sections.

[0047] Figure 5c is an enlarged top cross-sectional view showing a portion of the perimeter of the pellet of Figure 5a and Figure 5b, wherein the pellet is shown in a cross-section that is taken in a plane normal to the longitudinal axis 502. The planar surface portion 404a is shown disposed between two arc-segment surface sections 504 and 506. Each one of the arc- segment surface sections 504 and 506 lies along the circumference of a circle 508 of diameter D. Furthermore, the planar surface section 404a defines a chord within the circle 508 of diameter D between the points 510 and 512 along the circumference of the circle 508 of diameter D. Similarly, each one of the remaining five planar surface sections 404b-f also is disposed between two arc-segment surface sections and defines a chord within the circle 508 of diameter D.

[0048] Figure 6 is a simplified top view showing one packing arrangement for the pellets according to an embodiment of the instant invention. In Figure 6, the pellets are arranged in a single layer and each pellet is in contact with six adjacent pellets. Accordingly, each pellet has six planar surface sections, and is arranged in the layer such that each one of the six planar surface sections is in a facing relationship with one planar surface section of an adjacent pellet. When bound in panel form, the pellets so arranged are embedded in a solidified material, as discussed in more detail below.

[0049] Figure 7 is a simplified top view showing another packing arrangement for the pellets according to an embodiment of the instant invention. In Figure 7, the pellets are arranged in a single layer and each pellet is in contact with four adjacent pellets. Accordingly, each pellet has four planar surface sections, and is arranged in the layer such that each one of the four planar surface sections is in a facing relationship with one planar surface section of an adjacent pellet. When bound in panel form, the pellets so arranged are embedded in a solidified material, as discussed in more detail below.

[0050] Figure 8a is a top view of a pellet according to an embodiment of the instant invention. Figure 8b is a side view of the pellet of Figure 8a. With reference to Figure 8a and Figure 8b, the pellet 800, which is for deployment in composite armor, is elongated in shape and has a length L. A top cross-sectional view taken in a plane normal to the length L of pellet 800 reveals that the perimeter of the pellet 800 comprises a plurality of non-

contiguous arc-segment surface sections that are arranged in an alternating fashion with a plurality of planar surface sections. Each one of the plurality of non-contiguous arc-segment surface sections lies along a portion of an ellipse defined by the equation (x/α) ² + (y/b) ² = 1 , and each one of the plurality of planar surface sections defines a chord within the ellipse defined by the equation (x/α) ² + (y/b) ² = 1. The pellet 800 includes a first end face 802 and a second end face 808. In particular, the first end face 802 is at a projectile-receiving end of the pellet 800 and in this specific embodiment it is curved convexly. By way of one specific and non-limiting example, the first end face 802 has a radius of curvature R that is defined within a plane bisecting the pellet 800 along the major axis a, where the ratio a/R is at least 0.64: 1. Optionally, the first end face 802 is planar, or curved differently than described supra. In addition, the pellet 800 also has a second end face 808 at the end that is opposite the projectile-receiving end. In the specific example that is shown in Figure 8b, the second end face 808 is planar. Optionally, the second end face 808 is also curved convexly. Further optionally, the second end face 808 has a radius of curvature S that is defined within a plane bisecting the pellet 800 along the major axis a, wherein S is optionally the same as, or different than, R. Further optionally, the second end face 808 defines one of a parabola and a catenary curve joining two opposite arc-segment surface sections, when viewed in a cross section that is taken in the plane bisecting the pellet 800 along the major axis a.

[0051] Pellet 800 is made of a ceramic material, glass or a sintered refractory material. For instance, pellet 800 is made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, pellet 800 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof. By way of one specific and non-limiting example, the ratio a/R is at least 0.64: 1.

[0052] As stated supra the pellet 800 is for deployment in composite armor. For instance, the pellet 800 is one of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellet 800 has a longitudinal axis 806 extending along the length L thereof and passing through the center of the first and second end faces 802 and 808, respectively. Furthermore, the pellet 800 is in mutual contact with other not illustrated pellets in the layer. In this specific example the pellet 800 has six planar surface

sections 804a-f, each one of the six planar surface sections 804a-f being in contact with, or at least facing, a planar surface section of an adjacent pellet when the pellet 800 is assembled and bound in panel form. Of course, in Figure 8b only three of the six planar surface sections (804c, 804d and 804e) are visible, the other three of the six planar surface sections (804b, 804a and 804f) are disposed along the opposite side of the pellet 800. Optionally a number of planar surface sections greater than six or less than six are provided. The number of planar surface sections is selected in dependence upon the desired packing arrangement of the pellets within the final armor panel product. For instance, optionally each pellet includes four planar surface sections.

[0053] Figure 9a is a top view of a pellet according to an embodiment of the instant invention. Figure 9b is a side view of the pellet of Figure 9a. With reference to Figure 9a and Figure 9b, the pellet 900, which is for deployment in composite armor, is elongated in shape, with a first end face 902 and a second end face 908. In particular, the first end face 902 is at a projectile-receiving end of the pellet 900 and in this specific embodiment it is planar. The second end face 908 is at the end of pellet 900 that is opposite the projectile- receiving end, and in this specific embodiment it is planar. Optionally, one or both of the first and the second end faces 902 and 908, respectively, are curved convexly. Further optionally, one or both of the first and the second end faces 902 and 908, respectively, is substantially hemispherical with a radius of curvature R and S, respectively, wherein S is optionally the same as, or different than, R. Further optionally, one or both of the first and the second end faces 902 and 908, respectively, is curved convexly with other than a hemispherical shape. In general, the shape of the second end face 908 is selected in dependence upon the type of backing material being used. For instance, the second end face 908 may be planar when a metal or composite backing material is used, but may be curved when a flexible backing material is used.

[0054] Pellet 900 is made of a ceramic material, glass or a sintered refractory material. For instance, pellet 900 is made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, pellet 900 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof.

[0055] As stated supra the pellet 900 is for deployment in composite armor. For instance, the pellet 900 is one of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellet 900 has a longitudinal axis 906 extending along a length L thereof and passing through the center of the first and second end faces 902 and 908, respectively. Furthermore, the pellet 900 is in mutual contact with other pellets in the layer. In this specific example the pellet 900 has six planar surface sections 904a-f, each one of the six planar surface sections 904a-f being in contact with, or at least facing, a planar surface section of an adjacent pellet when the pellet 900 is assembled and bound in panel form. Of course, in Figure 9b only three of the six planar surface sections (904c, 904d and 904e) are visible, the other three of the six planar surface sections (904b, 904a and 904f) are disposed along the opposite side of the pellet 900. Optionally a number of planar surface sections greater than six or less than six are provided. The number of planar surface sections is selected in dependence upon the desired packing arrangement of the pellets within the final armor panel product. For instance, optionally each pellet includes four planar surface sections.

[0056] Figure 1 Oa is a top view of a pellet according to an embodiment of the instant invention. Figure 10b is a side view of the pellet of Figure 10a. With reference to Figure 10a and Figure 10b, the pellet 1000, which is for deployment in composite armor, is elongated in shape, with a first end face 1002 and a second end face 1008. In particular, the first end face 1002 is at a projectile-receiving end of the pellet 1000 and in this specific embodiment it is curved convexly. By way of one specific and non-limiting example, the ratio D/R between the diameter D of the pellet and the radius R of curvature of the first end face 1002 is at least 0.64:1. The second end face 1008 is at the end of pellet 1000 that is opposite the projectile- receiving end, and in this specific embodiment it is also curved convexly, with a radius of curvature R that is about the same as that of the first end face 1002. Optionally, the second end face 1008 has a radius of curvature S that is different than R. Further optionally, one or both of the first and the second end faces 1002 and 1008, respectively, is curved convexly with other than a hemispherical shape. In general, the shape of the second end face 1008 is selected in dependence upon the type of backing material being used. For instance, the second end face 1008 may be planar when a metal or composite backing material is used, but may be curved when a flexible backing material is used.

[0057] Pellet 1000 is made of a ceramic material, glass or a sintered refractory material. For instance, pellet 1000 is made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, pellet 1000 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof.

[0058] As stated supra the pellet 1000 is for deployment in composite armor. For instance, the pellet 1000 is one of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellet 1000 has a longitudinal axis 1006 extending along a length L thereof and passing through the center of the first and second end faces 1002 and 1008, respectively. Furthermore, the pellet 1000 is in mutual contact with other pellets in the layer. In this specific example the pellet 1000 has six planar surface sections 1004a-f, each one of the six planar surface sections 1004a-f being in contact with, or at least facing, a planar surface section of an adjacent pellet when the pellet 1000 is assembled and bound in panel form. Of course, in Figure 10b only three of the six planar surface sections (1004c, 1004d and 1004e) are visible, the other three of the six planar surface sections (1004b, 1004a and 1004f) are disposed along the opposite side of the pellet 1000. Optionally a number of planar surface sections greater than six or less than six are provided. The number of planar surface sections is selected in dependence upon the desired packing arrangement of the pellets within the final armor panel product. For instance, optionally each pellet includes four planar surface sections.

[0059] Figure 11 a is a top view of a pellet according to an embodiment of the instant invention. Figure 1 Ib is a side view of the pellet of Figure 1 Ia. With reference to Figure 1 Ia and Figure l ib, the pellet 1100, which is for deployment in composite armor, is elongated in shape, with a first end face 1102 and a second end face 1 108. In particular, the first end face 1102 is at a projectile-receiving end of the pellet 1100 and in this specific embodiment it is curved convexly. By way of one specific and non-limiting example, the ratio D/R between the diameter D of the pellet and the radius R of curvature of the first end face 1102 is at least 0.64:1. The second end face 1108 is at the end of pellet 1100 that is opposite the projectile- receiving end, and in this specific embodiment it is also curved convexly, with a radius of curvature S that is different than that of the first end face 1102. Further optionally, one or

both of the first and the second end faces 1102 and 1108, respectively, is curved convexly with other than a hemispherical shape. In general, the shape of the second end face 1108 is selected in dependence upon the type of backing material being used. For instance, the second end face 1108 may be planar when a metal or composite backing material is used, but may be curved when a flexible backing material is used.

[0060] Pellet 1100 is made of a ceramic material, glass or a sintered refractory material. For instance, pellet 1100 is made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, pellet 1100 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof.

[0061] As stated supra the pellet 1100 is for deployment in composite armor. For instance, the pellet 1100 is one of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellet 1100 has a longitudinal axis 1106 extending along a length L thereof and passing through the center of the first and second end faces 1102 and 1108, respectively. Furthermore, the pellet 1100 is in mutual contact with other pellets in the layer. In this specific example the pellet 1 100 has six planar surface sections 1104a-f, each one of the six planar surface sections 1 104a-f being in contact with, or at least facing, a planar surface section of an adjacent pellet when the pellet 1100 is assembled and bound in panel form. Of course, in Figure l ib only three of the six planar surface sections (1104c, 1104d and 1104e) are visible, the other three of the six planar surface sections (1104b, 1104a and 1104f) are disposed along the opposite side of the pellet 1100. Optionally a number of planar surface sections greater than six or less than six are provided. The number of planar surface sections is selected in dependence upon the desired packing arrangement of the pellets within the final armor panel product. For instance, optionally each pellet includes four planar surface sections.

[0062] Figure 12a is a top view of a pellet according to an embodiment of the instant invention. Figure 12b is a side view of the pellet of Figure 12a. With reference to Figure 12a and Figure 12b, the pellet 1200, which is for deployment in composite armor, is elongated in shape, with a first end face 1202 and a second end face 1208. In particular, the first end face

1202 is at a projectile-receiving end of the pellet 1200 and in this specific embodiment it is curved. In particular, the first end face is substantially a rotated parabola, rather than being hemispherical. The second end face 1208 is at the end of pellet 1200 that is opposite the projectile-receiving end, and in this specific embodiment it is planar. Optionally, the second end face 1208 is also curved convexly. Further optionally, the second end face 1208 is substantially hemispherical with a radius of curvature S. Further optionally, the second end face 1208 is curved convexly with other than a hemispherical shape. In general, the shape of the second end face 1208 is selected in dependence upon the type of backing material being used. For instance, the second end face 1208 may be planar when a metal or composite backing material is used, but may be curved when a flexible backing material is used.

[0063] Pellet 1200 is made of a ceramic material, glass or a sintered refractory material. For instance, pellet 1200 is made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, pellet 1200 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof.

[0064] As stated supra the pellet 1200 is for deployment in composite armor. For instance, the pellet 1200 is one of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellet 1200 has a longitudinal axis 1206 extending along a length L thereof and passing through the center of the first and second end faces 1202 and 1208, respectively. Furthermore, the pellet 1200 is in mutual contact with other pellets in the layer. In this specific example the pellet 1200 has six planar surface sections 1204a-f, each one of the six planar surface sections 1204a-f being in contact with, or at least facing, a planar surface section of an adjacent pellet when the pellet 1200 is assembled and bound in panel form. Of course, in Figure 12b only three of the six planar surface sections (1204c, 1204d and 1204e) are visible, the other three of the six planar surface sections (1204b, 1204a and 1204f) are disposed along the opposite side of the pellet 1200. Optionally a number of planar surface sections greater than six or less than six are provided. The number of planar surface sections is selected in dependence upon the desired packing arrangement of the pellets within the final armor panel product. For instance, optionally each pellet includes four planar surface sections.

[0065] Figure 13a is a top view of a pellet according to an embodiment of the instant invention. Figure 13b is a side view of the pellet of Figure 13a. With reference to Figure 13a and Figure 13b, the pellet 1300, which is for deployment in composite armor, is elongated in shape, with a first end face 1302 and a second end face 1308. In particular, the first end face 902 is at a projectile-receiving end of the pellet 900 and in this specific embodiment it is defined by a caternary curve when viewed in a cross section that is taken in the plane of the page. The second end face 1308 is at the end of pellet 1300 that is opposite the projectile- receiving end, and in this specific embodiment it is planar. Optionally, the second end face 1308 is curved convexly. Further optionally, the second end facel308 is substantially hemispherical with a radius of curvature S. Further optionally, the second end face 1308 is curved convexly with other than a hemispherical shape. In general, the shape of the second end face 1308 is selected in dependence upon the type of backing material being used. For instance, the second end face 1308 may be planar when a metal or composite backing material is used, but may be curved when a flexible backing material is used.

[0066] Pellet 1300 is made of a ceramic material, glass or a sintered refractory material. For instance, pellet 1300 is made of a ceramic material selected from the group consisting of sintered oxides, nitrides, carbides and borides of alumina, magnesium, zirconium, tungsten, molybdenum, titanium and silica. By way of several non-limiting examples, pellet 1300 is made of a material selected from the group consisting of alumina, boron carbide, boron nitride, titanium diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide, silicon aluminum oxynitride and mixtures thereof.

[0067] As stated supra the pellet 1300 is for deployment in composite armor. For instance, the pellet 1300 is one of a plurality of pellets that are bound together into a layer and retained in panel form by a solidified material. The pellet 1300 has a longitudinal axis 1306 extending along a length L thereof and passing through the center of the first and second end faces 1302 and 1308, respectively. Furthermore, the pellet 1300 is in mutual contact with other pellets in the layer. In this specific example the pellet 1300 has six planar surface sections 1304a-f, each one of the six planar surface sections 1304a-f being in contact with, or at least facing, a planar surface section of an adjacent pellet when the pellet 1300 is assembled and bound in panel form. Of course, in Figure 13b only three of the six planar surface sections (1304c, 1304d and 1304e) are visible, the other three of the six planar surface sections (1304b, 1304a and 1304f) are disposed along the opposite side of the pellet

1300. Optionally a number of planar surface sections greater than six or less than six are provided. The number of planar surface sections is selected in dependence upon the desired packing arrangement of the pellets within the final armor panel product. For instance, optionally each pellet includes four planar surface sections.

[0068] One specific and non-limiting example of a process for fabricating armor panels of various shapes and sizes using the pellets according to the instant invention will now be discussed briefly. Although a particular molding process is disclosed, it is to be clearly understood that other processes for fabricating the desired armor panels may be used without departing from the scope of the instant invention. According to a typical molding process, an array of pellets that is arranged as described with reference to Figure 6 or Figure 7 is placed in a horizontal mold, and a plate-forming material, in liquid form, is either poured or sprayed into the mold. It should be noted that any one of the pellet types discussed supra might be assembled into an armor panel using this method. In the general case, each pellet has a first end face at a projectile-impacting end thereof and a second end face at an end that is opposite the projectile-impacting end. Optionally, the first and second end faces have the same shape or are of different shapes. For instance, by way of several non-limiting examples, each pellet may have two planar end faces, or a convex first end face having a radius of curvature R and a planar second end face, or a convex first end face having a radius of curvature R and a convex second end face having a radius of curvature S, where S is either the same as or different than R, etc. After the plate-forming material has been allowed to solidify, the panel may be removed from the horizontal mold. The plate-forming material is selected from any suitable material which retains elasticity upon hardening at the thickness used, such as epoxy, a thermoplastic polymer, or a thermoset plastic, thereby allowing curvature of the plate without cracking to match curved surfaces to be protected, including body surfaces, as well as elastic reaction of the plate to incoming projectiles to allow increased contact force between adjacent pellets at the point of impact. In the final product, the first end face of each pellet is adjacent to a projectile-receiving surface of the panel, and the second end face of each pellet is adjacent to a rear surface of the panel.

[0069] When the object to be protected is an armored vehicle or another asset having a metal or composite outer body, the armor panels described supra optionally are affixed directly to the object without an additional backing layer between the object and the rear surface of the panel. Optionally, there is provided a multi-layered armor plate, comprising an

outer, projectile-receiving panel of composite armor as described supra, for deforming and shattering an impacting high velocity projectile, and an inner layer disposed adjacent to the rear surface of said outer panel, comprising a second panel of tough material for causing an asymmetric deformation of the remaining fragments of said projectile and for absorbing the remaining kinetic energy from said fragments. For instance, the tough material comprises alternating layers of unidirectional fibers, such as one of DYNEEMA®, SPECTRA® and FAMASTONE®, which are both made of polyethylene fibers, or KEVLAR® or TWARON®, which is made of aramid fibers. Optionally, pellets of the type that is shown at one of 800, 900, 1000, 1100, 1200 or 1300 are used to form the armor panel. In that case, a plurality of the pellets that is shown at one of 800, 900, 1000, 1100, 1200 or 1300 are assembled into an array similar to one that is shown in either of Figure 6 or Figure 7, placed into a horizontal mold and bound with the plate-forming material as described supra.

[0070] Numerous other embodiments may be envisaged without departing from the spirit and scope of the invention.