Articles of ordnance including reactive material enhanced projectiles, and related methods

Abstract

A munition, such as a projectile formed of at least one reactive material. In one embodiment, the projectile includes a body portion formed of at least one reactive material composition wherein the at least one reactive material composition defines at least a portion of an exterior surface of the projectile. In other words, a portion of the reactive material may be left unbuffered or exposed to the barrel of a gun or weapon from which it is launched and similarly exposed to a target with which the projectile subsequently impacts. In one embodiment, the projectile may be formed with a jacket surrounding a portion of the reactive material to provide additional structural integrity. The projectile may be formed by casting or pressing the reactive material into a desired shape, or the reactive material may be extruded into a near-net shape and then machined into the desired shape.

Claims

1. An article of ordnance, comprising: a cartridge casing; a propellant composition disposed within the cartridge casing; and a projectile coupled to the cartridge casing, the projectile comprising: a body portion comprising a reactive material composition; a jacket around the reactive material composition, an intended leading tip and surfaces of sides of the projectile extending from the intended leading tip of the projectile toward the jacket being exposed and comprising the reactive material composition; and a core member substantially surrounded by the reactive material composition.

2. The article of ordnance of claim 1, further comprising a primer in communication with the propellant composition.

3. The article of ordnance of claim 1, wherein the core member comprises another reactive material composition.

4. The article of ordnance of claim 1, wherein the reactive material composition comprises a plurality of reactive material compositions, wherein at least one of the reactive material compositions is more sensitive to initiation upon impact than is at least another of the reactive material compositions.

5. The article of ordnance of claim 1, wherein the jacket extends further along the reactive material composition than the core member extends within the reactive material composition.

6. The article of ordnance of claim 5, wherein the core member comprises a pointed end oriented a same direction as the intended leading tip of the projectile.

7. The article of ordnance of claim 1, wherein the jacket comprises copper or steel.

8. The article of ordnance of claim 1, wherein the core member comprises a penetrating member.

9. The article of ordnance of claim 1, wherein the core member comprises tungsten.

10. The article of ordnance of claim 1, wherein the core member is denser than the reactive material composition.

11. The article of ordnance of claim 1, wherein the reactive material composition is more sensitive to initiation upon impact than the core member.

12. The article of ordnance of claim 1, wherein the reactive material composition of the intended leading tip of the projectile comprises at least one fuel, at least one oxidizer, and at least one binder.

13. The article of ordnance of claim 12, wherein the reactive material composition comprises a thermitic material.

14. A method of forming an article of ordnance, the method comprising: disposing a propellant composition within a cartridge casing; forming a projectile, forming the projectile comprising: disposing a core member within a reactive material composition of a body portion of the projectile, the core member substantially surrounded by the reactive material composition; and forming a jacket around the reactive material composition with an intended leading tip and sides of the projectile extending from the intended leading tip toward the jacket being exposed, the intended leading tip comprising the reactive material composition; and coupling the projectile to the cartridge casing.

15. The method of claim 14, further comprising casting the reactive material composition in a mold and curing the reactive material composition.

16. The method of claim 14, wherein disposing a core member within a reactive material composition comprises disposing a core member comprising tungsten within the reactive material composition.

17. The method of claim 14, wherein disposing a core member within a reactive material composition comprises disposing a core member comprising another reactive material composition within the reactive material composition.

18. The method of claim 14, wherein disposing a core member within a reactive material composition comprises disposing a core member that is denser than the reactive material composition within the reactive material composition.

19. An article of ordnance, comprising: a propellant disposed within a cartridge casing; a primer coupled to the propellant and configured to ignite the propellant; and a projectile coupled to the cartridge casing, the projectile comprising: a core member substantially surrounded by a reactive material composition; and a jacket around the reactive material composition, the reactive material composition comprising an exposed portion at an intended leading tip of the projectile and at surfaces of sides extending from the intended leading tip toward the jacket.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

(2) FIG. 1 is a partial cross-sectional side view of a cartridge containing a projectile in accordance with one embodiment of the present invention;

(3) FIG. 2 is an enlarged partial cross-sectional side view of a projectile shown in FIG. 1;

(4) FIG. 3 is a partial cross-sectional view of a projectile in accordance with another embodiment of the present invention;

(5) FIG. 4 is a cross-sectional view of a projectile in accordance with yet another embodiment of the present invention; and

(6) FIG. 5 is a cross-sectional view of a projectile in accordance with yet another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) Referring to FIG. 1, an assembled cartridge 100 having a projectile 102 in accordance with one embodiment of the present invention is shown. The cartridge 100 includes a cartridge casing 104 containing, for example, gunpowder or another appropriate conventional propellant composition 106. An initiating or detonation device 108, commonly termed a primer, is in communication with and configured to ignite the propellant composition 106. The projectile 102 is coupled with the cartridge casing 104 such as, for example, by mechanically press-fitting the projectile 102 into an open end of the casing 104.

(8) Upon actuation of the detonation device 108, such as by a firing pin of a gun or other artillery weapon (none shown), the detonation device 108 ignites the propellant composition 106 causing the projectile to be expelled from the casing 104 and from the barrel of a gun, or other weapon in which the cartridge 100 is housed, at a very high rate of speed. For example, in one embodiment, the cartridge may be designed as a .50 caliber round, wherein the projectile 102 may exhibit a muzzle velocity (the velocity of the projectile as it leaves the muzzle or barrel of a weapon) of approximately 2,500 to 3,000 feet per second (approximately 760 to 915 meters per second).

(9) Of course, the present invention may be practiced by forming the cartridge 100 and projectile 102 as different sizes such as, for example, 5.56 mm, 7.62 mm, 9 mm, .40 caliber, .45 caliber, 20 mm, 25 mm, 30 mm, 35 mm or other sizes of ammunition.

(10) Referring now to FIG. 2, an enlarged cross-sectional view of the projectile 102 is shown. The projectile 102 is formed as a substantially monolithic structure of a desired reactive material 111 composition. The projectile 102 is configured so that the reactive material 111 defines at least a portion of the projectile's exterior surface 112, i.e., the surface that is exposed during firing from a weapon and just prior to impact with an intended target.

(11) In other words, the projectile 102 is configured so that at least a portion thereof is without a buffer between the reactive material and the barrel of a gun or other weapon from which the projectile is launched. Additionally, the projectile 102 is without a buffer between the reactive material from which it is formed and the target with which the projectile 102 is intended to impact. Thus, the projectile 102 is particularly useful against thin-skinned targets wherein the reactive material of the projectile will substantially immediately react, such as by an explosive or incendiary reaction, upon impact with such a target without impediment of such a buffer or casing.

(12) Due to the design of the projectile 102, it will function upon initial impact with various types of targets including, for example, thin-skinned metal targets as well as fiberglass and glass targets. The unbuffered reactive material of the projectile 102, such as at the intended leading tip 116 thereof, greatly increases the initiation rate of the reactive material 111 upon impact of the projectile 102 with a given target as compared to reactive materials that are buffered from their target to some degree by a housing, casing or other jacket material. This enables the reactive material 111 to react more readily on thin-skinned targets where other projectiles may penetrate the target without initiating the reactive material contained therein.

(13) Once initiated, the reactive material of the projectile 102 rapidly combusts generating a high overpressure, large amounts of heat, and significant damage to the target impacted thereby. In some applications, the energy release from such a projectile has been determined to have increased energy release, based on plume size and plate (or target) damage, by more than 50% as compared to conventional projectiles with buffered reactive or energetic materials contained therein.

(14) The projectile 102 may be utilized in a number of applications, or against a number of intended target types, including, for example, active protection of ships from incoming missiles or projectiles, against aircraft, watercraft, or to damage and initiate combustion of fuel storage containers or fuel tanks on numerous types of vehicles, aircrafts, watercrafts or other structures.

(15) The projectile 102 may be formed using a number of different manufacturing methods or processes using a number of different reactive material compositions. For example, in one embodiment, the projectile 102 may be formed through vacuum or pressure casting wherein the projectile 102 is cast into a mold and the cast composition is cured to produce the monolithic projectile. The cast mold may be cured at ambient (e.g., approximately 70 F. (21 C.)) or it may be cured at an elevated temperature (e.g., greater than approximately 135 F. (57 C.)) to accelerate the cure rate. The cured projectile is then removed from the mold and ready for installation into an associated cartridge or assembled with a housing or casing such as shall be described hereinbelow.

(16) When forming the projectile 102 by casting, various reactive material compositions may be used. For example, the reactive material composition may include urethane binders such as hydroxyl terminated polybutadiene polymer cured with isocyanate curatives such as isophorone diisocynate (IPDI) and a cure catalyst such as dibutyltin diacetate, triphenylbismuth, or dibutyl tin dilaurate.

(17) In another example, an epoxy cure binder system may be used which, in one embodiment, may include a carboxyl terminated polyethyleneglycolsuccinate polymer (such as is known commercially as Witco 1780) cured with a BIS-phenyl A-trifunctional epoxy (ERL 0510) catalyzed with amines, or iron linoleate, or iron octoate. In another embodiment, such an epoxy cure binder system may include a liquid polysulfide polymer cured using one of a variety of epoxy curatives such as a Bis-A epoxy resin (commercially known as Epon 862) or a polyglycol epoxy resin (commercially known as GE 100) and an amine cure accelerator. Other epoxy compositions may also be used.

(18) In yet another example, an energetic polymer binder system may be used which, in one embodiment, may include glycidyl azide polymer (GAP polyol made by 3M) cured with IPDI or a similar curing agent and a cure catalyst such as dibutyltin diacetate, triphenylbismuth, or dibutyl tin dilaurate.

(19) A wide variety of organic polymers may be combined with oxidizers, fuels, reactive materials without oxidizers, intermetallic compositions, theremitic compositions, or combinations thereof.

(20) Examples of oxidizers include ammonium perchlorate, alkali metal perchloratessuch as sodium, barium, calcium, and potassium perchlorate, alkali and alkaline metal nitratessuch as lithium nitrate, sodium nitrate, potassium nitrate, rubidium nitrate, cesium nitrate, strontium nitrate, barium nitrate, barium and strontium peroxides.

(21) Examples of fuels include aluminum, zirconium, magnesium, iron, titanium, sulfur, tin, zinc, copper, indium, gallium, copper, nickel, boron, phosphorous, silicon, tungsten, tantalum, hafnium, and bismuth.

(22) Examples of intermetallic compositions include aluminum/boron, nickel aluminum, zirconium/nickel, titanium/aluminum, platinum/aluminum, palladium/aluminum, tungsten/silicon, nickel/titanium, titanium/silicon, titanium/boron, zirconium aluminum, hafnium/aluminum, cobalt/aluminum, molybdenum/aluminum, hafnium/boron, and zirconium/boron.

(23) Examples of thermitic compositions include iron oxide/aluminum, iron oxide/zirconium, iron oxide/titanium, copper oxide/aluminum, copper oxide/tungsten, aluminum/bismuth oxide, zirconium/bismuth oxide, titanium manganese oxide, titanium/copper oxide, zirconium/tungsten oxide, tantalum/copper oxide, hafnium/copper oxide, hafnium/bismuth oxide, magnesium/copper oxide, zirconium/silicon dioxide, aluminum/molybdenum trioxide, aluminum/silver oxide, aluminum/tin oxide, and aluminum/tungsten oxide.

(24) In accordance with another embodiment of the present invention, the projectile 102 may be formed using extrusion techniques. Using such techniques, the reactive material composition being used to form the projectile may be extruded into a near net shape of the desired projectile and then machined, or hot pressed in a mold, to obtain the desired final dimensions of the projectile 102. Examples of compositions that may be suitable for forming the projectile through extrusion techniques include a combination of a fluoropolymer such as terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidenefluoride (THV) with a metallic material. Such combinations may include THV and hafnium (Hf), THV and aluminum (Al), THV, nickel (Ni) and aluminum, or THV and tungsten (W). Examples of various polymers that may be used to form the projectile through extrusion techniques include the fluoropolymers set forth in TABLE 1 below. Examples of such compositions, as well as formation of structures by way of extrusion using such compositions, are set forth in U.S. patent application Ser. No. 10/386,617, now U.S. Pat. No. 6,962,634, issued Nov. 8, 2005, entitled LOW TEMPERATURE, EXTRUDABLE, HIGH-DENSITY REACTIVE MATERIALS, assigned to the assignee hereof, the disclosure of which is incorporated herein by reference in its entirety.

(25) TABLE-US-00001 TABLE 1 Fluoropolymers Properties Tensile Fluorine Strength (%) Elon- Melting Content (psi) at gation at Point (% by Polymer 23 C. 23 C. ( C.) Solubility weight) Polytetrafluoroethylene (PTFE) PTFE 4500 400 342 Insoluble 76 (TEFLON) Modified PTFE 5800 650 342 Insoluble 76 (TFM 1700) Fluoroelastomers (Gums) vinylidene 2000 350 260 Soluble in 65.9 fluoride ketones/ and esters hexafluoro- propylene (Viton A) FEX 5832X 2000 200 260 Soluble in 70.5 terpolymer ketones/ esters Fluorothermoplastic Terpolymer of Tetrafluoroethylene, Hexafluoroproplyene, and Vinylidenefluoride (THV) THV 220 2900 600 120 Soluble in 70.5 ketones/ Esters (100%) THV X 310 3480 500 140 Soluble in 71-72 ketones/ esters (partial) THV 415 4060 500 155 Soluble in 71-72 ketones/ esters (partial) THV 500 4060 500 165 Soluble in 72.4 ketones/ esters (partial) HTEX 1510 4800 500 165 Insoluble 67.0 Fluorothermoplastic Copolymer of Tetrafluoroethylene and Perfluorovinylether (PFA) PFA 4350 400 310 Insoluble 76 Fluorothermoplastic Copolymer of Tetrafluoroethylene and Hexafluoropropylene (FEP) FEP 2900-4300 350 260 Insoluble 76 Fluorothermoplastic Copolymer of Tetrafluoroethylene and Ethylene (ETFE) ETFE 6700 325 260 Practically 61.0 insoluble

(26) In certain examples, such polymers may be used together, or separately, while also being combined with a number of different fuels and oxidizers including metallic materials or intermetallic compositions such as described hereinabove.

(27) In another example of manufacturing the projectile 102, such may be formed using pressable compositions that are pressed to net shape projectile in a die at high pressures (e.g., above approximately 10,000 pounds per square inch (psi) (approximately 69 megapascals)). Generally, pressable compositions may be produced by decreasing the organic polymer binder and increasing the solid ingredients (e.g., oxidizer/fuel, fuel only, intermetallics, or thermites) of the reactive material composition being used. The various examples of oxidizers, metallics, intermetallics, thermitic compositions and other materials set forth hereinabove may be used.

(28) Additionally, pressable compositions may be formulated using an indium/tin/bismuth (INDALLOY) composition as a binder that is combined with oxidizers or fuels as set forth hereinabove to produce an energetic or reactive material composition. It is noted that increasing the amount of INDALLOY binder in the composition can result in the production of a liquid castable composition that may be poured into a hot mold and cooled to form a net shape of the projectile 102. More specific examples of such compositions and uses of such compositions are disclosed in U.S. patent application Ser. No. 10/801,948 entitled REACTIVE MATERIAL ENHANCED MUNITION COMPOSITIONS AND PROJECTILES CONTAINING SAME, U.S. patent application Ser. No. 10/801,946 entitled REACTIVE COMPOSITIONS INCLUDING METAL AND METHODS OF FORMING SAME, and U.S. patent application Ser. No. 11/512,058, now U.S. Pat. No. 7,614,348, issued Nov. 10, 2009, entitled WEAPONS AND WEAPON COMPONENTS INCORPORATING REACTIVE MATERIALS AND RELATED METHODS, each of which applications are assigned to the assignee hereof, the disclosures of each of which applications are incorporated by reference herein in their entireties.

(29) In another example of pressing reactive material compositions, materials such as, for example, fluoropolymers (e.g., PTFE) may be combined with reactive materials as set forth hereinabove and then pressed at a high temperature and sintered. One particular example of such suitable composition includes a composition of aluminum and PTFE. Pellets of such a composition may be pressed and sintered into a near net shape and then machined to produce the desired geometry of the projectile 102.

(30) Some more specific examples of compositions that may be used as pressable compositions include those shown in TABLES 2 and 3 wherein percentages are representative of a weight percent of the specified ingredient.

(31) TABLE-US-00002 TABLE 2 Common Name Ingredient 1 Ingredient 2 Ingredient 3 Ingredient 4 Al/PTFE 26% Aluminum 76% PTFE W/PTFE 71.58% Tungsten 28.42% PTFE Ta/PTFE 68.44% Tantalum 31.56% PTFE Al/THV220 31.6% Aluminum 68.4% THV220 Ta/THV220 74% Tantalum 26% THV220 Hf/THV220 69.5% Hafnium 30.% THV220 Zr/THV220 52.6% Zirconium 47.4% THV220 10% Al/PTFE 11.63% Aluminum 88.37% PTFE 25% Al/PTFE 28.3% Aluminum 71.7% PTFE 40% Al/PTFE 44.1% Aluminum 55.9% PTFE H95 Al/PTFE 28.3% Aluminum (H-95) 71.7% PTFE Al/Ti/THV500 22.6% Aluminum 11.93% Titanium 62.18% THV500 3.27% THV220 Ta/THV500 73.77% Tantalum 24.92% THV500 1.31% THV220 Hf/THV500 69.14% Hafnium 29.31% THV500 1.54% THV220 Zr/THV500 52.23% Zirconium 45.38% THV500 2.39% THV220 nano RM4 26% Aluminum (nano) 74% PTFE Ta/WO3/THV500 Tantalum WO3 THV500 THV220 Al coated Hf/PTFE-Stoic 8.8% Aluminum 42.9% Hafnium 48.3% PTFE Al coated Hf/PTFE-25% 9.151% Aluminum 44.679% Hafnium 46.17% PTFE Ni/Al/PTFE-IM 34.255% Nickel 28.745% Aluminum 37% PTFE Ni/Al/PTFE-FR 34.25% Nickel 23.2% Aluminum 42.55% PTFE Ni/Al/PTFE-Stoic 25.22% Nickel 13.78% Aluminum 61% PTFE Zr/(35%)THV 63.85% Zirconium 34.34% THV500 1.81% THV220

(32) TABLE-US-00003 TABLE 3 Common Name Ingredient 1 Ingredient 2 Ingredient 3 Ingredient 4 Ingredient 5 Ingredient 6 Ingredient 7 CRM 70% 10% 10% 2.5% 5.81% 1.69% W/Kp/Zr-high Tungsten KP Zirconium Permapol Epon 862 Epicure energy 88-2 5534 3200 CRM 69.33% 9.9% 9.9% 8.15% 2.61% 0.11% W/Kp/Zr-high Tungsten KP Zirconium LP33 Epon 862 Epicure energy 88-4 3200 CRM W/Kp/Zr 84.25% 4.21% 4.41% 5.49% 1.76% 0.07% 88-7 Tungsten KP Zirconium LP33 Epon 862 Epicure 3200 CRM W/Kp/Zr 34.83% 34.83% 9.95% 9.95% 7.83% 2.51% 0.1% 88-4A Tungsten Tungsten KP Zirconium LP33 Epon 862 Epicure (90 mic) (6-8 mic) 3200 CRM W/Kp/Zr 52.5% 17.5% 9.9% 9.9% 8.15% 2.61% 0.11% 88-4B Tungsten Tungsten KP Zirconium LP33 Epon 862 Epicure (90 mic) (6-8 mic) 3200 CRM Ni/Al 57.5% 26.5% 4% 9.3% 2.7% epoxy Nickel Aluminum Permapol Epon 862 Epicure (3-5 mic) (H-5) 5534 3200

(33) Referring now to FIG. 3, a projectile 102 in accordance with another embodiment of the invention is shown. The projectile 102 may include a main body portion 113 formed of a reactive material such as has been described hereinabove. Additionally, a jacket 114 or casing may be partially formed about the main body portion 113 to lend additional strength or structural integrity to the projectile 102. Such added strength or structural enhancement may be desired, for example, depending on the composition of the reactive material used, the size of the projectile 102, or other variables associated with the firing of the projectile 102 and its intended target. Such a jacket 114 may be formed, for example, of a material such as copper or steel.

(34) It is noted that the projectile 102 still includes a portion, most notably the intended leading tip 116, wherein the reactive material 111 is unbuffered or exposed to both the barrel of a weapon from which it will be launched and to the target that it is intended to impact. Thus, the projectile 102 retains its rapid reactivity and suitability for thin-skinned targets such as has been discussed hereinabove.

(35) Referring now to FIG. 4, yet another projectile 102 is shown in accordance with another embodiment of the present invention. The projectile 102 is configured substantially similar to the projectile 102 described in association with FIG. 3, including a main body portion 113 formed of a reactive material 111 and a jacket 114 partially formed thereabout. In addition, the projectile 102 includes a core member 118 disposed substantially within the reactive material 111 of the body portion 112. The core member 118 may be formed as a penetrating member or it may be formed as a second reactive material composition. For example, in one embodiment, the core member 118 may be formed from tungsten or from a material that is denser than that of the reactive material 111 that forms the body portion 113 of the projectile 102. The use of a core member 118 enables the projectile 102 to be tailored to specific applications and for impact with specifically identified targets.

(36) Referring now to FIG. 5, another projectile 102 in accordance with yet a further embodiment of the present invention is shown. The projectile 102 includes a main body portion 113 formed of a reactive material 111 of a desired composition. A second reactive material 120 is disposed and the intended leading end of the projectile 102 that is more sensitive than the reactive material 111 of the main body portion 113. A jacket 114 is disposed about and substantially covers the main body portion 113 and the second reactive material 120 and lends structural integrity to the projectile 102. A closure disc 122 may be formed at an intended trailing end of the projectile 102 and placed in a hermetically sealing relationship with the jacket 114 after the reactive material 111 and the second reactive material 120 are disposed therein.

(37) As noted above, the second reactive material 120 may include a material that is more sensitive to initiation (such as upon impact with a target) than the reactive material 111 of the main body portion 113. Thus, the initiation threshold of the projectile 102 may be tailored in accordance with an intended use or, more particularly, in anticipation of impact with an intended target type and consideration of the desired damage that is to be inflicted thereon by the projectile 102, by altering the volume or the composition of the second reactive material 120. In one specific example, the second reactive material may include a copper material.

(38) Of course, in other embodiments, multiple types of reactive material compositions, such as with different levels of sensitivity, may be used without an accompanying jacket, or only with a partial jacket such as has been described herein with respect to FIGS. 3 and 4.

(39) It is further noted that other munitions and components of other munitions, including structural components, may be formed in accordance with various embodiments of the present invention such that, for example, such components typically formed of relatively inert materials may be formed of reactive materials and tailored for a desired reaction depending on the intended use of such components.

(40) While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.