METHOD FOR REPROCESSING A BASE COMPONENT AND COMPONENT WITH SUCH A REPROCESSED BASE COMPONENT

Description

[0001] The present invention relates to a method for post-processing a base component of a projectile, in particular a guided missile, a warhead or ammunition, as well as to a component of a projectile, in particular a guided missile, a warhead or ammunition, comprising such a post-processed base component.

[0002] For military applications, components made of reactive materials are increasingly being used in munitions, among other things, alongside components made of conventional inert materials. Reactive materials contain an oxidizer, such as a fluoropolymer, and a metal. These materials have been used to manufacture linings or fragments in warheads, for example. The use of reactive materials in such components can increase the energy available during warhead detonation.

[0003] For example, publication AU 2015 255003 A1 describes a reactive composite material for use in ammunition comprising a metal lattice structure with interstices and a powder in these interstices. The powder comprises at least one metal powder and / or at least one halogen-containing polymer powder.

[0004] However, the financial and technical effort involved in manufacturing such components from reactive material can be very high. Furthermore, certain components cannot be made from reactive material for strength reasons. In addition, the manufacture of new components from reactive material often entails redesigning the interfaces to other components of the warhead. This additional effort must be avoided. EP 3 736 524 A1, for example, describes a projectile whose tip is injection-molded onto the projectile shoe. The tip is a polymer composite material in which a metal powder is embedded. The material of this powder can be titanium, magnesium, aluminum, zirconium, or any mixtures thereof. EP 3 312 546 A1 describes a full metal jacket multi-purpose projectile in which a composite material consisting of a polymer matrix and metal powder is included as an incendiary device.The composite material was deposited layer by layer into the full jacket using a spraying technique to ensure a precise shape. Furthermore, US Pat. No. 5,096,507 A describes a method for applying an air-flammable cerium mixed metal coating to the surface of a fragmentation-active component. Depending on its base material, the fragmentation-active component contains various metals, including titanium, molybdenum, zirconium, or tungsten.

[0005] It is an object of the present invention to provide an alternative method for creating components with similar properties.

[0006] According to the invention, this object is achieved by the subject matter of the independent claims.

[0007] According to a first aspect of the invention according to claim 1, a method for post-processing a base component of a projectile, in particular a guided missile, a warhead, or munition, is provided. The method comprises the steps of providing a base component and applying a reactive material with a material property that can be activated by a predetermined stimulus to a predetermined processing area of ​​the base component such that the reactive material is firmly bonded to the base component.

[0008] According to a second aspect of the invention according to claim 11, a component of a projectile, in particular a guided missile, a warhead, or munition, is provided. The component comprises a base component with a predetermined processing area. Furthermore, the component comprises a reactive material having a material property that can be activated by a predetermined stimulus, wherein the reactive material is applied to the processing area and integrally bonded to the base component.

[0009] One idea underlying the present invention is to provide an existing component, hereinafter referred to as the base component, whose properties and / or product lifetime behavior are known or tested, with a reactive material in order to expand or modify the properties, for example the temperature resistance or the chemical reactivity, of this base component. In this case, the construction can be based on a proven component structure of the base component, in particular an interface such as a fastening thread. In this way, extensive redesigns, such as those that would be necessary for a newly manufactured component made of an alternative material, in particular of a reactive material, with properties comparable to the expanded properties of the base component provided with the reactive material, can be reduced.

[0010] Furthermore, the present invention simplifies the production of a specific component with the properties of a reactive material, which would otherwise be impossible or only possible with considerable effort from a purely reactive material. The post-processing according to the invention does not have to be performed directly after the production of the base component, but can be applied at any point in the product life cycle of the base component, for example, even on a base component that has already been worn out.

[0011] A projectile, as defined in the present invention, is a collective term for all types of projectiles / missiles / aircraft that can be fired using a long-range weapon. This includes, in particular, a guided missile, a warhead, a drop munition, and a projectile ammunition.

[0012] The processing area, as defined in the present invention, refers to the entirety of sections of the base component that are suitable for being provided with a reactive material. This includes, among other things, the surface, gaps, undercuts, and recesses of the base component.

[0013] Advantageous embodiments and further developments emerge from the subclaims which refer back to the independent claims and from the description with reference to the figures.

[0014] According to one embodiment of the invention, the base component is designed as a structural component. The structural component has, for example, a lattice structure, a honeycomb structure, or a comparable structure. Compared to so-called secondary components, structural components are distinguished by specific stiffness and / or strength requirements in order to absorb possible external loads and / or to support other components, usually secondary components. The base component is preferably designed as a housing or structural frame. In this way, a particularly relevant component of a guided missile, a warhead, or munition can be functionalized by the reactive material. A particularly relevant component is one that performs elementary functions and therefore cannot simply be omitted.In this respect, such a component can be provided with a reactive material in order to save a secondary component and consequently weight and / or installation space.

[0015] According to a further embodiment of the invention, the reactive material contains hafnium, copper oxide, molybdenum, molybdenum oxide, titanium, aluminum, magnesium, zirconium, tungsten, alloys thereof, or the like. An oxidizer-reducer combination, such as thermite or nanothermite, or another material mixture containing one of the aforementioned materials is also considered. Thus, the reactive material can form a controllable metastable material.

[0016] According to the invention, the reactive material comprises a metal component, wherein at least zirconium and / or tungsten are contained in the metal component. The metal component is an intermetallic compound. In a further preferred embodiment, the metal component is an intermetallic compound of zirconium and tungsten. An intermetallic compound (also called an intermetallic phase or intermediate phase) is a homogeneous chemical compound of at least two metals. In contrast to alloys, the intermetallic compound exhibits lattice structures that differ from those of the constituent metals. Its lattice is characterized by mixed bonding, consisting of a metallic bond component and smaller atomic or ionic bond components.

[0017] According to a further embodiment outside the claimed scope of protection, the metal component consists of a two-phase structure of the metals zirconium and tungsten. In certain embodiments, the reactive material consists of the metal component. The metal component allows the reactive material to exhibit greater hardness or strength and higher chemical resistance, particularly corrosion resistance, than commercially available materials.

[0018] According to a further development of the invention, the mass fraction of zirconium in the metal component is in a range from approximately 100 wt.% to approximately 50 wt.%, based on the total weight of the metal component. In particular, the mass fraction of zirconium in the metal component is in a range from approximately 95 wt.% to approximately 70 wt.%, based on the total weight of the metal component. In certain embodiments, the metal component consists of tungsten and zirconium, with the proportions of tungsten and zirconium in the metal component adding up to 100 wt.%. In this way, the reactive material can be bonded to most materials of the base component, with the combined properties varying only slightly depending on the material combination between the base component and the reactive material.

[0019] According to a further embodiment of the method, thermal spraying or pressing is used to apply the reactive material. Preferably, cold gas spraying is used to apply the reactive material, since cold gas spraying exhibits the lowest oxidation compared to other thermal spraying processes. Alternatively, hot isostatic pressing is preferably used to apply the reactive material. Thus, during hot isostatic pressing, the pressure acts on the component from all sides in such a way that the component can acquire isotropic properties.

[0020] According to a further development of the method, cold gas spraying is applied by a corresponding cold gas spraying device with a working pressure of approximately 20 bar to approximately 60 bar and with a working temperature in the range of approximately 400 °C to approximately 600 °C.

[0021] According to a further embodiment of the invention, the base component is made of steel, aluminum, titanium, magnesium, zirconium, tungsten, molybdenum, copper, alloys thereof, or the like. The base component is not limited to a pure or dominant material type, but can also form a material mixture with at least one of the aforementioned materials. Thus, all materials commonly used in the aerospace and defense technology sectors are contemplated. The base component can also be made of a reactive material, as listed above. According to some embodiments, the composition of the base component differs from the composition of the reactive material. For example, the base material can consist of the same components as the reactive material, but in a proportionally different composition.

[0022] According to a further embodiment of the invention, the predetermined stimulus is a thermal, mechanical, and / or electrical stimulus. For example, a predetermined temperature or a predetermined load can be set at a defined location on the reactive material; if exceeded, the reactive material undergoes a highly exothermic reaction, such as an explosion. In this way, the reactive material can be maintained in its metastable state until a defined event in the form of the stimulus releases the chemical energy of the reactive material.

[0023] According to one embodiment, the method further comprises the step of determining a mass of the reactive material to be applied and its distribution across the processing area. In order to obtain the desired properties, the mass of the reactive material required for this purpose can be determined, for example, using simulation / calculation programs or empirical test models. The distribution of the mass across the processing area also plays a role, since the distribution can, in principle, be unrestricted. This means that, for example, the layer thickness of the reactive material is thicker in one section of the processing area than in another section. However, this does not exclude a uniform distribution of the mass of the reactive material, but rather includes it.Thus, the base component can be provided with the reactive material according to individual requirements in such a way that, for example, the center of gravity is shifted or the chemical reaction is stronger or weaker in certain areas.

[0024] According to a further embodiment of the invention, the reactive material is formed as a coating in the processing area, at least in sections. In particular, the reactive material is formed as a multilayer coating in the processing area, at least in sections. Thus, the reactive material can be formed, in particular, as a corrosion protection layer, an electrically conductive / non-conductive layer, or a thermal protection layer until it is activated.

[0025] According to a further embodiment of the invention, the reactive material is formed as a filling in the processing area, at least in sections. Filling within the meaning of the present invention includes filled spaces, grooves, undercuts, recesses, holes, and the like. In this way, gaps can be closed and, for example, aerodynamics can be improved.

[0026] According to a further embodiment of the invention, the reactive material is applied in such a way that, upon activation, it first breaks down into individual components and then undergoes chemical conversion. This means that, after activation, the reactive material is initially in powder form and disperses in the environment like dust before oxidizing with a nearly maximum contact surface with the environment. Upon breaking down into individual components, the reactive material can also detach fragments of the base component. Thus, the reactive material is capable of enhancing the chemical conversion, as more oxygen is available for oxidation and / or additional fire mass is available due to the detached fragments.

[0027] According to a further embodiment of the invention, the reactive material is applied in such a way that, upon activation, the reactive material chemically reacts with a material of the base component. This is particularly advantageous when the base component also contains or consists of a reactive material. This means that, for example, the reactive material reacts chemically due to its activation, creating conditions on the base component that trigger a chemical reaction between the material of the base component and the activated reactive material. This can enhance the chemical reaction.

[0028] The above embodiments and further developments can be combined with one another as desired, where appropriate. Further possible embodiments, further developments, and implementations of the invention also include combinations of features of the invention not explicitly mentioned above or described below with regard to the exemplary embodiments. In particular, those skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.

[0029] The present invention will be explained in more detail below using exemplary embodiments with reference to the accompanying figures of the drawings. The figures show: Fig. 1 shows a flow diagram of a method for post-processing a base component according to an embodiment of the invention; Fig. 2 shows a schematic view of a component in section with a reactive material formed as a coating according to a further embodiment of the invention; and Fig. 3 shows an isometric view of a component with a reactive material formed partially as a coating and partially as a filling according to a further embodiment of the invention.

[0030] In the figures of the drawing, identical, functionally identical and acting elements, features and components are provided with the same reference symbols, unless otherwise stated.

[0031] The accompanying figures are intended to provide a further understanding of embodiments of the invention and, in conjunction with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the noted advantages will be apparent upon review of the drawings. The drawings are to be understood as schematic drawings only, and elements of the drawings are not necessarily drawn to scale. Directional terminology such as "top," "bottom," "left," "right," "above," "below," "horizontal," "vertical," "front," "rear," and similar terms are used for illustrative purposes only and are not intended to limit the generality to specific embodiments shown in the figures.

[0032] Fig. 1 shows a flowchart of a method for post-processing a base component 1. The base component 1 is a part of a projectile.

[0033] The method initially comprises a first step S1 of providing a base component 1. The base component 1 is embodied, for example, as a housing or a structural frame. The material for the base component 1 can be, in particular, steel, aluminum, titanium, magnesium, tungsten, molybdenum, copper, an alloy thereof, or a comparable material.

[0034] Furthermore, the method comprises a second step S2 of applying a reactive material 2 to a predefined processing area 3 of the base component 1. The reactive material 2 is applied in such a way that it is bonded to the base component 1. A sufficient bond quality of the bonded connection is achieved in particular when thermal spraying or pressing is used in the second step S2 of applying the reactive material 2. Preferably, according to the embodiment according to Fig. 1 a cold gas spraying is used, which is applied by an appropriate cold gas spraying device with a working pressure of about 20 bar to about 60 bar and with a working temperature in the range of about 400 °C to about 600 °C.

[0035] According to the invention, the reactive material 2 contains an activatable material property that can be activated by a predetermined stimulus. This predetermined stimulus is, for example, a thermal, mechanical, and / or electrical stimulus. A laser beam, which activates the reactive material 2 through its thermal energy input, is particularly suitable for the thermal stimulus. Alternatively or additionally, the deformation work performed on the reactive material 2 by the impact of the projectile is considered for the mechanical stimulus. Further alternatively or additionally, the predetermined stimulus is activated by an electrical pulse or an electrical current flow through the reactive material 2 by means of an electronic control element.

[0036] Furthermore, the method optionally comprises a third step S3 of determining a mass of the reactive material 2 to be applied and distributing it across the processing area 3. Preferably, the mass of the reactive material 2 to be applied corresponds at most to half the mass of the base component 1. Thus, the stability of a component comprising the base component 1 and the reactive material 2 can be ensured despite the increased dead weight on the basis of the stability design of the base component 1. For example, the mass of the reactive material 2 is distributed evenly across the entire processing area 3 of the base component 1 in order, for example, to maintain the center of gravity of the base component 1 for the component as well.

[0037] Fig. 2 shows a schematic view of a component 10 in section with a reactive material 2 formed as a coating.

[0038] Component 10 is a part of a projectile within the meaning of the present invention. This means that component 10 is, for example, a component of a guided missile, a warhead, or a piece of ammunition. Thus, component 10 can also serve as a carrier and / or source of fragments from the warhead.

[0039] The component 10 comprises a base component 1. This base component 1 contains a predefined processing area 3. For example, the processing area 3 corresponds to the outer surface of the base component 1. The base component 1 comprises mechanical interfaces, for example, fastening eyelets, threads, or the like (not shown), which can be individually excluded from the processing area 3. The base component 1 is optionally made of steel, aluminum, titanium, magnesium, tungsten, molybdenum, copper, alloys thereof, or similar materials.

[0040] Furthermore, the component 10 according to Fig. 2 a reactive material 2. According to the invention, the reactive material 2 contains, in accordance with the embodiment according to Fig. 1 an activatable material property that can be activated by a predetermined stimulus. The reactive material 2 is applied to the processing area 3 and bonded to the base component 1. For example, the reactive material 2 is formed as a coating on the outer surface of the base component 1. The reactive material 2 preferably contains a thermite made of copper oxide-aluminum (CuO / Al) or molybdenum oxide-aluminum (Mo2O3 / Al).

[0041] In the embodiment according to Fig. 2 The reactive material 2 is applied in such a way that the thermite 2, upon activation, chemically reacts with the material of the base component 1. This can, for example, increase the immediate blast of the projectile or achieve another chemical or thermal effect.

[0042] Fig. 3 shows an isometric view of a component 10 with a reactive material 2 partially formed as a coating 2a and partially formed as a filling 2b. The component 10 is a part of a projectile in the sense of the present invention.

[0043] The illustrated component 10 comprises a base component 1, wherein the base component 1 is designed as a hollow cylindrical structural component. The structural component is preferably made of steel, in particular of high-strength steel. For example, the hollow cylindrical structural component contains grooves, in particular crosswise grooves, on the outer side of the structural component. These grooves contain the reactive material 2 as a filling 2b.

[0044] Furthermore, the reactive material 2 is formed in sections as a coating 2a on the surface of the outer side of the structural component.

[0045] The reactive material 2 preferably comprises a metal component consisting of zirconium and tungsten. The mass fraction of zirconium in the metal component ranges from approximately 95 wt.% to approximately 70 wt.%, while the mass fraction of tungsten ranges from approximately 5 wt.% to approximately 30 wt.%.

[0046] Optionally, the metal component made of zirconium and tungsten is applied in such a way that this reactive material 2, upon activation, first disintegrates into individual fragments and then undergoes chemical conversion. In this way, the reactive material 2 can divide the hollow-cylindrical structural component 10, particularly along the grooves. This can result in numerous fragments being created from the component 10, which can serve, for example, as splinters. Consequently, the additional storage of prefabricated splinters in the projectile can be reduced, and the overall weight of the projectile can be reduced.

[0047] In the foregoing detailed description, various features have been combined into one or more examples for clarity of illustration. It should be understood, however, that the above description is merely illustrative and not restrictive in nature. It is intended to cover all alternatives, modifications, and equivalents of the various features and embodiments. Many other examples will be readily apparent to those skilled in the art based on their skill in the art in light of the above description.

[0048] The embodiments were chosen and described in order to best illustrate the principles underlying the invention and their possible practical applications. This will enable those skilled in the art to optimally modify and utilize the invention and its various embodiments with respect to the intended purpose. In the claims and the description, the terms "including" and "having" are used as neutral language terms for the corresponding term "comprising." Furthermore, the use of the terms "a," "an," and "an" is not intended to exclude a plurality of such described features and components. List of reference symbols

[0049] 1Base component 2Reactive material 2aCoating 2bFilling 3Processing area 10Component S1first step of provision S2second step of application S3third step of setting

Claims

1. Method for post-processing a base component (1) of a projectile, in particular of a guided missile, a warhead or a munition, comprising the steps of: providing (S1) a base component (1); and applying (S2) a reactive material (2) having a material property which can be activated by means of a predetermined stimulus to a predetermined processing region (3) of the base component (1) in such a manner that the reactive material (2) is bonded to the base component (1), characterised in that the reactive material (2) comprises an intermetallic compound, wherein at least zirconium and tungsten are contained in the intermetallic compound.

2. Method according to claim 1, wherein the base component (1) is designed as a structural component, in particular as a housing or structural frame.

3. Method according to claim 1 or 2, wherein the reactive material (2) contains hafnium, copper oxide, molybdenum, molybdenum oxide, titanium, aluminium, magnesium or alloys thereof.

4. Method according to at least one of the preceding claims, wherein the intermetallic compound consists of zirconium and tungsten.

5. Method according to at least one of the preceding claims, wherein the mass fraction of zirconium in the intermetallic compound is in a range from about 100 wt. % to about 50 wt.%, in particular in a range from about 95 wt.% to about 70 wt.%, in relation to the total weight of the intermetallic compound.

6. Method according to at least one of the preceding claims, wherein thermal spraying, in particular cold gas spraying, or pressing, in particular hot isostatic pressing, is used when applying (S2) the reactive material (2).

7. Method according to claim 6, wherein the cold gas spraying is applied by means of a corresponding cold gas spraying device with a working pressure of about 20 bar to about 60 bar and with a working temperature in the range from about 400 °C to about 600 °C.

8. Method according to at least one of the preceding claims, wherein the base component (1) is produced from steel, aluminium, titanium, magnesium, zirconium, tungsten, molybdenum, copper or alloys thereof.

9. Method according to at least one of the preceding claims, wherein the predetermined stimulus is a thermal, mechanical and / or electrical stimulus.

10. Method according to at least one of the preceding claims, further comprising the step of determining (S3) a mass of the reactive material (2) to be applied and its distribution over the processing area (3).

11. Component (10) of a projectile, in particular of a guided missile, a warhead or a munition, comprising: a base component (1) with a predetermined processing area (3); and a reactive material (2) which has a material property which can be activated by a predetermined stimulus, wherein the reactive material (2) is applied to the processing area (3) and is bonded to the base component (1), characterised in that the reactive material (2) has an intermetallic compound, wherein at least zirconium and tungsten are contained in the intermetallic compound.

12. Component according to claim 11, wherein the reactive material (2) in the processing region (3) is formed at least in sections as a coating (2a), in particular as a multilayer coating.

13. Component according to claim 11 or 12, wherein the reactive material (2) in the processing region (3) is formed at least in sections as a filling (2b).

14. Component according to at least one of claims 11 to 13, wherein the reactive material (2) is applied in such a manner that the reactive material (2) initially disintegrates into individual parts during its activation and is then chemically converted.

15. Component according to at least one of claims 11 to 14, wherein the reactive material (2) is applied in such a manner that the reactive material (2) chemically reacts with a material of the base component (1) during its activation.