Projectile against structures made of aluminum alloys

Abstract

Projectile (1) against structures made of aluminium alloys, having the following characteristics: a) the projectile (1) is a ballistic projectile, b) the projectile (1) has a chamber (2), c) the chamber (2) contains gallium (25) to damage structures made of aluminium alloys. Suitable calibers range from 5 to 30 mm.

Description

[0001] The invention relates to a projectile against structures made of aluminum alloys.

[0002] Aluminum alloys are widely used in vehicle and aircraft construction. Attacking aluminum alloy structures is part of the normal target spectrum of introduced munitions. Improving the effectiveness of the missile on target is always the goal of product improvements.

[0003] The interaction between gallium and aluminum leads to an unusual property known as the "gallium-aluminum intermetallic compound." Gallium has the ability to infiltrate aluminum, forming a brittle intermetallic compound. When gallium comes into contact with aluminum, it diffuses into the aluminum structure, forming an intermetallic phase. This intermetallic compound has lower strength and hardness compared to pure aluminum. The result is that the aluminum loses strength and becomes more brittle. This effect can lead to structural problems, especially when aluminum components come into contact with gallium. It is important to note that the interaction between gallium and aluminum does not occur immediately but develops over time.The speed and effects of this process depend on various factors, including temperature, gallium concentration, and duration of contact. This property of gallium makes it a potential pollutant or contaminant for aluminum alloys.

[0004] A publication (Bonnet, Martin (2021): Non-violent destruction of an aluminum lock with gallium. In: Youtube channel Welt der Werkstoffe. Available online at: https: / / www.youtube.com / watch?app=desktop&v=XdqXJvuWG4o.) illustrates the effect of gallium on an aluminum alloy.

[0005] DE 10 2004 017 466 A1 shows a ballistic projectile with a chamber containing a colored powder to mark the point of impact.

[0006] DE 10 2010 044 001 B3 concerns the field of hailstorm investigations. Projectiles made of frozen water are used for this purpose.

[0007] US 2010 / 0 083 860 A1 concerns a ballistic, non-lethal projectile. The projectile is filled with a flowable payload, such as a liquid gallium alloy. At the moment of impact, an internal hydrodynamic structure forces the flowable charge to move radially from the center to the periphery and toward a weakened area. This facilitates rupture and reduces the projectile's pressure on a target surface, temporarily incapacitating an attacker.

[0008] DE 10 2012 002 687 A1 concerns a garnet with a tracer. The tracer may contain indium gallium arsenide (InGaAs). InGaAs is a photoluminescent substance.

[0009] DE 699 32 720 T2 relates to a metal projectile for shooting training. The metal projectile contains metal particles. A binding agent binds the metal particles together. One of several components of the binding agent can be gallium.

[0010] DE 10 2020 133 371 A1 concerns a full metal jacket bullet which can be provided with a substance that causes a chemical reaction when the full metal jacket bullet hits a target.

[0011] DE 295 03 118 U1 concerns a bomb that contains an adhesive instead of explosives to limit the mobility of people and military equipment.

[0012] The invention is based on the object of creating a projectile to damage structures of certain metal alloys.

[0013] This object is achieved according to the invention by the features of claim 1.

[0014] The advantages of the invention are based on the following features: the projectile against structures made of aluminum alloys is a ballistic projectile, • the bullet has a chamber, • the chamber contains gallium.

[0015] To combat protective structures made of aluminum alloys, it is proposed to use projectiles with an effective filling of elemental gallium. The impact of such a projectile on an aluminum alloy structure brings the gallium into direct contact with the aluminum alloy. Metallic gallium, due to its high wettability, has the property of penetrating deep into aluminum alloys and significantly weakening their intercrystalline cohesion. While this effect is not immediate, the damage is not visible to an enemy and, after a few hours, leads to significant damage to the structure, whose strength decreases significantly. The damage process is not readily detectable and is also irreversible. The protective effect of the structure being shot at is permanently reduced and progresses, imperceptibly from the outside.In aircraft, the loss of strength leads to failure of the device; in armored vehicles, ballistic protection drops significantly, even leading to structural disintegration under slight load. This process is not easily reversible; it can only be stopped by removing the affected areas. The gallium contained in the chamber is surrounded by a protective container. A protective container prevents a chemical reaction of the gallium. This simplifies the manufacture and storage of the ammunition. The protective container has a simple inert plastic layer. The bullet has a bullet core, and the chamber is embedded in the bullet core. To produce ammunition with gallium, it is merely necessary to modify an existing bullet core.

[0016] Building on the aforementioned design, the bullet core is an easily machined steel core. This allows for the simple manufacture of the chamber for the gallium.

[0017] According to a further advantageous embodiment of the invention, the projectile has the following features: • The projectile core has a receiving element, • the receiving element has a blind hole that accommodates the protective container with the gallium, • the plug is designed to close the blind hole.

[0018] Production is simplified because it can be based on existing cartridges or ammunition. Instead of the traditional bullet core, there is now an assembly comprising the receiver, the plug, and the protective container containing the gallium. This arrangement ensures that the gallium only reaches the bare surface of an aluminum alloy structure in the desired manner upon impact with the target.

[0019] According to a further advantageous embodiment of the invention, the caliber of the bullet is 5 to 30 mm. Smaller calibers contain too little gallium. Larger calibers offer such a high impact energy that the damaging effect of gallium is reduced.

[0020] Embodiments of the invention are explained in more detail below with reference to the drawing. Fig. 1, the only figure, • a nose section of a cartridge with a bullet chambered with gallium, as a schematic diagram and in longitudinal section with cut-outs to illustrate details.

[0021] The Fig. Figure 1 shows the nose of a cartridge with a bullet 1 designed to hit structures made of aluminum alloys. The bullet 1 is a ballistic bullet. The bullet 1 has a chamber 2. The chamber 2 contains gallium 25. The gallium 25 contained in the chamber 2 is surrounded by a protective container 20. The protective container 20 consists of an inert plastic layer made of polyethylene.

[0022] The bullet 1 has a bullet core 3. The chamber 2 is embedded in the bullet core 3. The bullet core 3 is a steel core. The bullet 1 is a bullet 1 of a modified 7.62 mm x 67 cartridge. Instead of the previous bullet core made of tungsten carbide, a two-part bullet core made of easily machined steel is now provided. The bullet core 3 has a receiving element 30 as its first part and a plug 35 as its second part. The receiving element 30 has a blind bore 31 that accommodates the protective container 20 containing the gallium. The plug 35 closes the blind bore 31. The lead filler 4, the bullet jacket 5, the propellant powder 8, and the propellant case 9 are retained.

[0023] The functional sequence is described below.

[0024] A cartridge is in the weapon's breech. Upon impact of the firing pin, the propellant powder 8 is ignited and burns. The projectile 1 is expelled from the propellant case 9 and accelerated in the weapon barrel. The projectile 1 hits the target. The target is a point on an aircraft skin. The aircraft skin is a sheet of aluminum alloy with an outer skin coating. Behind it are reinforcement elements made of an aluminum alloy. The sheet and reinforcement elements tear due to the impact. Bare surfaces of the aluminum alloy are formed. The projectile 1 is compressed. The protective container 20 breaks open. The gallium 25 escapes and wets bare areas of the sheet and the reinforcement elements. The gallium 25 damages the aluminum alloy structure as described above.

[0025] At least 5% by weight of the total weight of the projectile 1 is pure gallium to achieve effectiveness. An upper limit is 80% by weight to ensure mechanical stability so that the protective container 20 only ruptures upon impact, releasing the gallium 25.

[0026] The following deviations from the illustrated example are possible: - The projectile core 3 has a receiving element 30 and a plug 35. The receiving element 30 has a blind hole 31 that receives the protective container 20 with the gallium 25. The plug 35 closes the blind hole 31. Contrary to the illustration, the plug 35 can be at the front in the firing direction and the receiving element 30 can be behind it in the firing direction. - In the illustrated example, the caliber is 7.62 mm. Bullet 1 can also have other calibers in the range of 5 to 30 mm. - The protective container 20 according to Fig.1 consists of a single, inert plastic layer. The protective container may have additional layers in addition to the inert plastic layer. List of reference symbols 1 floor 2 chambers 3 storey core 4 packing elements 5 bullet jacket 8 propellant powder 9 Propellant case 20 protective containers 25 Gallium 30 receiving element 31 Blind hole drilling 35 plugs

Claims

[1] Projectile (1) against structures made of aluminium alloys, with the following characteristics: a) the projectile (1) is a ballistic projectile, b) the projectile (1) has a chamber (2), c) the chamber (2) contains gallium (25) to damage structures made of aluminium alloys, d) the gallium (25) contained in the chamber (2) is surrounded by a protective container (20), e) the protective container (20) has an inert plastic layer, f) the projectile (1) has a projectile core (3) and the chamber (2) is embedded in the projectile core (3). [2] Projectile (1) according to claim 1, wherein the projectile core (3) is a steel core. [3] Projectile (1) according to claim 1 or 2, having the features: • the projectile core (3) has a receiving element (30) and a plug (35), • the receiving element (30) has a blind hole (31) which receives the protective container (20) with the gallium, • the plug (35) closes the blind hole (31). [4] Projectile (1) according to one of claims 1 to 3, wherein the projectile (1) has a caliber of 5 to 30 mm.

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