MELABLE / CASTABLE EXPLOSIVE COMPOSITION AND ITS MANUFACTURING PROCESS

Description

[0001] The present invention lies in the field of fusible / castable explosive compositions. It can be applied to the field of explosive loading of munitions by the cast-melt process.

[0002] Existing fusible / castable matrix-based explosive compositions, implemented by melt-casting technology, are by nature heterogeneous because different granular, non-soluble species are randomly dispersed in this fusible media during the mixing phase. However, at the end of the implementation process, these charges must meet increasingly stringent requirements. On the one hand, fusible / castable explosive compositions must ensure homogeneity at all points of the charged object in order to ensure safety and functional performance (initiability, detonation, vulnerability - MURAT signature, abbreviation of Munitions à Risques Atténués). And on the other hand, they must meet the specific constraints of the approval of energetic defense materials.The good performance of the explosive composition must allow the munition to respond reliably during its operational use while reducing the risks of inadvertent triggering during a handling accident or deliberate attack; and if the accidental explosion occurs, to reduce collateral damage for personnel and the launch platform.

[0003] Thus, it is essential to ensure the best possible homogeneity of the explosive charge after solidification in the body of the munition in order to ensure the safety and performance of the munitions throughout their life profile (production, storage, transport, use and demilitarization). These formulations must also meet increasingly stringent requirements (low dispersion of physicochemical and mechanical properties and conservation of these properties after aging) described for France in the general instruction SCAT 17500 edition 6 dated December 2019 and for NATO members in STANAG.4170 edition 3 dated 2008. Complying with these regulatory requirements requires increased control of the uniformity of the munition loading.

[0004] Controlling the homogeneity of the explosive composition in the ammunition is therefore key to meeting all of these requirements. This control has so far been ensured by the use of a single component, or the addition of various additives to stabilize the mixture, such as surfactants, or by a mass percentage of granular species greater than 60%.

[0005] Historically, munitions were loaded with picric acid and then 2,4,6-trinitrotoluene (TNT) after the Second World War. These charges were single-component, so they naturally addressed this problem of homogeneity. For reasons related to terminal performance and the vulnerability of munitions, many formulations have been developed by adding additives to this TNT base. The first approach consisted of integrating granular explosives such as RDX (or cyclotrimethylene-trinitramine, also known as hexogen) and HMX (abbreviation for "High Melting Point Explosive": explosive with a high melting point, also called cyclotetramethylene-tetranitramine or octogen) into historical formulations in order to significantly increase detonation performance (an example is composition B 60 / 40 - RDX / TNT).In order to obtain the desired performance and to maintain homogeneity throughout the loading cycle, a rate of around 60% by mass of solid species, with different particle size distributions, is introduced. This rate makes it possible to significantly increase the viscosity of the liquid mixture to limit phase shifts and sedimentation but also makes it possible to influence the compactness of the species. The principle consists of determining as precisely as possible the particle size distribution that allows the introduction of the maximum number of granular species in a given space. This has the main effect of blocking the arrangement of the species relative to each other.

[0006] A first solution of the prior art developed to ensure the homogeneity and stability over time of the composition is the use of surfactant-type additives. These molecules have the capacity to possess a hydrophilic head and a hydrophobic tail, thus increasing the affinity between TNT and phlegmatizers, substances intended to make the explosive composition less sensitive to accidental impacts. We can cite the compositions mentioned in patents FR2750131 and FR2954308 using surfactants from the polyvinyl-pyrrolidones family.

[0007] The use of one or more surfactants to stabilize the liquid phase throughout the composition manufacturing process until solidification requires the use of specific industrial tools such as agitators and rotor / stator on the one hand. This type of agitator, usually used in the cosmetics industry to form emulsions, is difficult to transfer to mixtures containing explosives. Indeed, by definition, these blades generate very high shear stresses which could cause a pyrotechnic incident following heating or friction. On the other hand, the surfactants commonly used in this field were developed for the chemical, pharmaceutical, cosmetic and food industries. Their purpose is to interface between a "fatty" body (long, weakly functionalized alkyl chain) and an aqueous phase.For TNT-based explosive formulations, it is rather a question of stabilizing a heterogeneous or even immiscible mixture between two "fatty" substances of low chemical affinity, making most surfactants weakly effective or even ineffective. Such a solution is therefore not optimal.

[0008] Another prior art solution consists of using only single-component explosive charges such as TNT or DNAN (dinitroanisole). Such a charge becomes by nature perfectly homogeneous, since it is single-component. However, the intrinsic properties of these components do not allow them to meet the performance requirements required for new generation munitions (MURAT signature, increased terminal ballistic performance (e.g.: shaped charge for armor piercing, etc.)).

[0009] Another solution of the prior art consists of very significantly increasing the percentage of solid constituents (above 60% by mass) and modulating the particle size distribution of each of the solid additives in order to achieve maximum compactness. Indeed, once this compactness is achieved, the different granular species are mechanically constrained not to sediment or dephase once loaded into the ammunition. However, upon reaching this compactness, the mixture becomes extremely viscous and results in a limitation of the flowability of the composition obtained. It is then often necessary to increase the temperature of the mixture, or even to generate a depression in the ammunition bodies (vacuum of the order of 50 mbar).The increase in temperature leading to a significant increase in energy expenditure to produce ammunition and the vacuum loading operation is not compatible with the standard tools used by those skilled in the art in this technical field.

[0010] GB574879 discloses a desensitized meltable / castable explosive composition comprising 47% TNT, 1.1% tannic acid and 42% PETN. The tannic acid is added to the molten TNT.

[0011] The invention aims to overcome all or part of the problems mentioned above by proposing a fusible / castable explosive composition capable of meeting the increasingly stringent requirements imposed, both in terms of operational performance and safety for MURAT signature, with a small number of components. The invention also has the advantage of not requiring any change in manufacturing tools compared to the usual tools in the technical field. The composition of the invention also allows for the desired performance to be controlled, for the loading obtained after solidification of the composition, by simply adapting the proportion of its components, without impacting the manufacturing process of the composition.

[0012] To this end, the invention relates to a fusible / castable explosive composition comprising at least two components: a fusible explosive, the fusible explosive preferably being a nitro aromatic cycle, and more preferably 2,4,6-trinitrotoluene; a phlegmatizer soluble at the melting temperature of the fusible explosive, the phlegmatizer being present in a non-zero mass proportion and less than or equal to 10% of the total mass of the fusible / flowable explosive composition, preferably between 2 and 6% of the total mass of the fusible / flowable explosive composition, and more preferably between 3 and 5% of the total mass of the fusible / flowable explosive composition;the fusible explosive being present in a mass proportion greater than 20% and less than 100% of the total mass of the fusible / flowable explosive composition, preferably greater than 30% and less than 100% of the total mass of the fusible / flowable explosive composition, and preferably greater than 40% and less than 100% of the total mass of the fusible / flowable explosive composition, and even more preferably greater than 50% and less than 100% of the total mass of the fusible / flowable explosive composition, the sum of the mass proportions of the components of the fusible / flowable explosive composition being equal to 100%. ;

[0013] Advantageously, the phlegmatizer has a melting temperature higher than that of the fusible explosive.

[0014] Advantageously, the phlegmatizer has a density greater than 1.0, preferably greater than 1.2.

[0015] In one embodiment of the invention, the phlegmatizer may be a derivative of one of benzene, naphthalene, or anthracene.

[0016] In another embodiment of the invention, the phlegmatizer may be a benzene derivative of one of benzene, naphthalene, or anthracene, functionalized by one or more groups of hydroxyl, carboxyl, or sulphonyl groups.

[0017] Advantageously, the phlegmatizer is naphthol, preferably napht-2-ol.

[0018] In another embodiment of the invention, the fusible / castable explosive composition according to the invention further comprises at least one component from an inert granular species and / or at least one energetic granular species, present in a mass proportion less than or equal to 60% of the total mass of the fusible / castable explosive composition, preferably less than or equal to 50% of the total mass of the fusible / castable explosive composition.

[0019] The invention also relates to a munition delimited by a hollow body, the hollow body being at least partially filled with such a fusible / castable explosive composition.

[0020] The invention also relates to a method of manufacturing such a fusible / castable explosive composition, comprising the following steps: melting the fusible explosive; adding the phlegmatizer to the melted fusible explosive; mixing the phlegmatizer into the melted fusible explosive to obtain a homogenized mixture.

[0021] The invention also relates to a method for explosively loading a munition delimited by a hollow body, comprising: the steps of the manufacturing process of a fusible / castable explosive composition; casting the homogenized mixture into the hollow body of the munition.

[0022] The invention will be better understood and other advantages will appear on reading the detailed description of an embodiment given by way of example, a description illustrated by the attached drawing in which: there [ Fig.1 ] schematically represents the principle of the emulsion of a fusible / flowable explosive composition according to the prior art; the [ Fig.2 ] schematically represents the principle of the solubilization of a fusible / flowable explosive composition according to the invention; the [ Fig.3 ] schematically represents a munition comprising a fusible / castable explosive composition according to the invention; the [ Fig.4 ] represents a flowchart of the steps of a method for manufacturing a fusible / castable explosive composition according to the invention.

[0023] For the sake of clarity, the same elements will have the same references in the different figures. For better visibility and to enhance understanding, the elements are not always represented to scale.

[0024] The object of the invention lies in ensuring the homogeneity of the composition, with a simple and reproducible process for all types of concentrations, based on the solubility of the added component(s). Furthermore, the invention makes it possible to limit the number of components in the fusible / castable explosive composition. Unlike the compositions of the known prior art which tend to add more and more components, such as surfactants, the invention makes it possible to guarantee excellent homogeneity of the fusible / castable explosive composition in solid phase, while ensuring a good level of insensitivity to accidental shocks and good detonating performance in the operational phase.

[0025] There figure 1 schematically represents the principle of the emulsion of a fusible / flowable explosive composition according to the prior art. A fusible / flowable explosive composition conventionally comprises a fusible explosive, for example 2,4,6-trinitrotoluene (commonly TNT). A phlegmatizer must be added to make the explosive composition less sensitive to accidental impacts. In addition, in existing compositions, and as explained previously, surfactants or emulsifiers are necessary to ensure a certain level of mixing between the molecules.

[0026] The phlegmatizers in use are mainly mixtures of long linear or weakly branched alkane chains, not having a high degree of functionalization. These molecules have only weak Van der Waals interactions and have very little chemical affinity with TNT. For temperatures above the melting temperature of TNT (around 80.4 °C depending on the purity of TNT), they form two-phase media. The use of a surfactant is then essential to improve the chemical affinity between TNT and the usual phlegmatizers (paraffin-type waxes). This surfactant is selected through a hydrophobic tail having a strong chemical affinity with waxes and a rather hydrophilic head having a certain affinity with TNT. For given ratios and operating conditions, it is then possible to form an emulsion that is more or less stable over time.

[0027] Such a composition of the prior art, in addition to including many components, has the disadvantage of having to produce an emulsion. An emulsion is a heterogeneous mixture of two immiscible liquid substances, one (the phlegmatizer and the surfactant) being dispersed in the form of small droplets in the other (liquid TNT). These two liquids do not mix spontaneously. A macroscopically homogeneous appearance can only be obtained with specific operations of stirring, mixing, and possible addition of active ingredients. However, the emulsion remains microscopically heterogeneous.

[0028] This problem is schematized on the figure 1 . Reference A represents liquid TNT 12. Reference B represents the addition of phlegmatizer 13 and surfactant 14 to liquid TNT 12. Reference C represents the combination of liquid TNT 12, phlegmatizer 14 and surfactant 14, with a homogeneous appearance, after a few minutes, for example 10 minutes, with suitable stirring. As explained previously, this stirring is very specific and requires the adaptation of existing manufacturing tools and an increase in staff skills in this type of emulsion technology. In addition, it can present a risk due to the high shear generated by the type of stirring required and cause a pyrotechnic incident. Finally, as can be seen very schematically in reference D, several minutes or even hours after stirring has stopped, the combination of liquid TNT 12, phlegmatizer 14 and surfactant 14 is not completely homogeneous.

[0029] There figure 2 schematically represents the principle of solubilization of a fusible / flowable explosive composition 10 according to the invention. Reference A' represents liquid TNT 12. Reference B' represents the addition of phlegmatizer 23 in the liquid TNT 12 according to the invention. Reference C' represents the liquid TNT 12 and phlegmatizer 23 assembly after a few minutes, for example 10, under standard stirring. Finally, several minutes after stopping stirring, the liquid TNT 12 and phlegmatizer 23 assembly according to the invention is completely homogeneous. It should be emphasized that in addition to ensuring homogeneity at the microscopic level, the mixing of the phlegmatizer in the liquid TNT is carried out by existing mixing means, without additional difficulty.

[0030] As will become clear from the description below, the invention relates to a fusible / castable explosive composition comprising a fusible explosive and a phlegmatizer whose chemical structure has very strong chemical affinities with the fusible explosive. The TNT molecule exhibits strong Van der Waals interactions due to the benzene ring and the Nitro groups in positions 2, 4 and 6. TNT is also a strong Lewis base due to the non-bonding pairs present on the oxygens of the Nitro groups. To ensure miscibility and therefore maximum homogeneity of the solution, the structure of the phlegmatizer according to the invention exhibits strong Van der Waals interactions and Lewis acid functions.

[0031] The invention relates to a fusible / castable explosive composition 10, which comprises at least two components which are a fusible explosive 12 and a phlegmatizer 23: the fusible explosive 12 being preferably a nitro aromatic, and even more preferably trinitrotoluene; the phlegmatizer 23 being soluble at the melting temperature of the fusible explosive.

[0032] According to the invention, the phlegmatizer 23 is present in a non-zero mass proportion and less than or equal to 10% of the total mass of the fusible / flowable explosive composition 10.

[0033] According to the invention, the fusible explosive is present in a mass proportion greater than 20% and less than 100% of the total mass of the fusible / flowable explosive composition, preferably greater than 30% and less than 100% of the total mass of the fusible / flowable explosive composition, still more preferably greater than 40% and less than 100% of the total mass of the fusible / flowable explosive composition, and still more preferably greater than 50% and less than 100% of the total mass of the fusible / flowable explosive composition. The sum of the mass proportions of the components of the fusible / flowable explosive composition 10 is equal to 100%. It should be noted that for a mass proportion of the fusible explosive less than 30%, it is preferable for the phlegmatizer to be present in a mass proportion between 5 and 10% of the total mass of the fusible / flowable explosive composition 10.This allows the composition to maintain a proportion of liquid phase (before solidification of the composition) sufficient to ensure good flowability of the composition before its final solidification.

[0034] In other words, the composition according to the invention is composed of the fusible explosive and up to 10% by mass of a phlegmatizer with the characteristics mentioned above. In this case, the mass proportion of the fusible explosive is adapted so that the sum of the mass proportions of the fusible explosive and the phlegmatizer reaches 100%. In a variant of the invention, the composition may also comprise granular species. In this case, the proportions are adapted so that the sum of the mass proportions of the fusible explosive, the phlegmatizer and the granular species reaches 100%. It should once again be emphasized that the composition according to the invention does not comprise any surfactant or emulsifier. Indeed, the judicious choice of the phlegmatizer allows the phlegmatizer to dissolve in the fusible explosive in liquid form, and a traditional mixture ensures the homogeneity of the composition.Once dissolved, the phlegmatizer is perfectly dispersed in the liquid fusible explosive and this dispersion is maintained until the material solidifies, which generally takes place in the body of the munition.

[0035] The composition according to the invention makes it possible to intrinsically meet the requirements of homogeneity after solidification of the explosive charge in the body of the munition.

[0036] The fusible / castable explosive composition consists of a fusible explosive, which is first melted. Then, the phlegmatizer is incorporated into the liquid fusible explosive where it is mixed to form a perfectly homogeneous liquid assembly. This liquid assembly is then intended to be cast into a munition where it will solidify.

[0037] The fusible explosive is preferably a nitro aromatic cycle, and even more preferably TNT (2,4,6-trinitrotoluene). TNT has good detonating properties and relatively low shock sensitivity. TNT has the particularity of melting at temperatures close to 80°C, thus allowing the loading in the liquid state of a metal casing (body of the munition) by the sole action of gravity. As the phlegmatizer of the invention is soluble at the melting temperature of the fusible explosive (for example approximately 80.4°C for TNT), the problems of inhomogeneity in the tank and in the projectile after the cooling phases are greatly limited. Once solubilized, the phlegmatizer is perfectly dispersed in the liquid TNT and this dispersion will be preserved until the solidification of the material.In addition to the mixture of the fusible explosive and the phlegmatizer, both in liquid form, the chemical affinity between the phlegmatizer and the fusible explosive ensured by their chemical structure guarantees a coherent mixture at the molecular level of the mixture obtained. After solidification of the composition according to the invention, the phlegmatizer is thus perfectly distributed in the medium formed by the fusible explosive.

[0038] Nitro aromatic explosives have a basic structure consisting of at least one aromatic nucleus and one NO 2 function. An example of a nitro aromatic explosive may have a basic structure consisting of at least one benzene nucleus comprising at least three NO 2 groups and three other radicals designated for example R, R' and R". Such a molecule can be schematized by the following structure:

[0039] There are many nitro aromatic explosives which are not structured by a benzene ring but rather tetrazoles, triazines, triazoles, pyrazoles and may have only one NO 2 group. These nitro aromatic explosives can be the fusible explosive 12 of the composition according to the invention.

[0040] For 2,4,6-trinitrotoluene, of empirical formula C 7 H 5 N 3 O 6 , or C 6 H 2 (NO 2 ) 3 CH 3 , R is a -CH3 radical, and R' and R" are -H radicals. Note that there are also three trinitrotoluene isomers of TNT (2,4,6-trinitrotoluene): 2,3,4-, 2,3,5- and 2,3,6-trinitrotoluene. Although less used because they are obtained as by-products of reactions and have slightly less interesting properties than TNT, these trinitrotoluene isomers of TNT can also be used as a fusible explosive component in the composition that is the subject of the invention.

[0041] In the composition according to the invention, the fusible explosive is preferably TNT, but other fusible explosives are suitable, for example 2,4-Dinitroanisole (DNAN), or N-MeTNP (for N-methyltrinitropyrazoles). The radicals R, R' and R" may be chosen from the radicals: -H, -CH 3 , -NHCH 3 , -OH, -NH 2 and their combinations. In any event, the nature of the miscible molecule is adapted according to the fusible explosive chosen.

[0042] In variants of the invention, the phlegmatizer is present in a mass proportion preferably between 2 and 6% of the total mass of the fusible / castable explosive composition, and even more preferably between 3 and 5% of the total mass of the fusible / castable explosive composition. An increased proportion of phlegmatizer increases the insensitivity of the composition to accidental impacts, and an increased proportion of fusible explosive ensures a good level of terminal performance of the munition in terms of explosive. It is therefore wise to choose the right ratio between these two components. A mass proportion of 2 to 6% of phlegmatizer in the total mass of the composition makes it possible to obtain a good level of insensitivity while retaining good detonating characteristics.A mass proportion of 3 to 5% of phlegmatizer in the total mass of the composition guarantees better detonating characteristics while ensuring a good level of insensitivity to shocks such as fire, friction, bullet impact.

[0043] The composition according to the invention therefore offers great flexibility in the development of new formulations in relation to the targeted terminal performances by simply adapting the mass percentage of its components without impacting the industrial means required or the skills necessary for the production of such a composition.

[0044] It thus appears clearly that the explosive composition according to the invention does not require the use of additives such as surfactants, as is necessarily the case for TNT and wax compositions as phlegmatizers. The invention makes it possible to achieve the expected final performances (terminal efficiency and MURAT signature) by eliminating the use of additives, stabilizers, and by limiting the number of constituents in the formulation. The invention makes it possible to respond microscopically to the homogeneity requirements arising from the general instruction and the STANAG.

[0045] Other variants of the explosive composition according to the invention are described below with optional characteristics, which can be combined with each other.

[0046] Advantageously, the phlegmatizer has a higher melting point than the fusible explosive. A high melting point of the phlegmatizer makes it possible to significantly limit problems of exudation of the explosive charge during the life cycle of the munition.

[0047] Advantageously, the phlegmatizer has a density greater than 1.0, and preferably greater than 1.2. The density of the explosive charge is directly linked to certain performances of the ammunition such as the projection speed of the fragments, it is thus sought to obtain the highest possible density of explosive charge.

[0048] In a variant of the invention, the phlegmatizer may be a benzene derivative from among benzene, naphthalene, or anthracene. The structure of the phlegmatizer has strong Van der Waals interactions and Lewis acid functions. This structure ensures miscibility and therefore maximum homogeneity of the solution.

[0049] In another variant of the invention, the phlegmatizer may be a derivative of one of benzene, naphthalene, or anthracene, functionalized by one or more groups among the hydroxyl, carboxyl, or sulphonyl groups. These families of molecules make it possible to solubilize up to at least 10% by mass of the phlegmatizer in the liquid medium, the fusible explosive, preferably TNT, which makes it possible to cover all of the current requirements expected in terms of performance and safety.

[0050] Thanks to the judicious choice of the properties of the phlegmatizer, the strong chemical affinity at the molecular level between the fusible explosive and the phlegmatizer ensures the homogeneity of the mixture in the liquid phase.

[0051] In one embodiment of the invention, the phlegmatizer is naphthol, preferably napht-2-ol. This phlegmatizer makes it possible to address the issue of homogeneity of the explosive charge and compatibility with the ReaCH regulation (European environmental regulation). In addition, its long-term supply is secure. The napht-2-ol phlegmatizer has a melting point significantly higher than that of TNT, namely 120 °C, and has a density of 1.2 much higher than the values ​​of non-soluble waxes commonly used for the same type of phlegmatization functionality (melting point of 30 to 79 °C and density of 0.6 to 0.9). This phlegmatizer ensures the limitation of exudation problems of the explosive charge during the life cycle of the munition and guarantees the final performance.

[0052] It may be noted that its isomer, naphth-1-ol, is also suitable as a phlegmatizer for the composition according to the invention.

[0053] As already mentioned, the fusible / castable explosive composition according to the invention may further comprise at least one component from an inert granular species and / or at least one energetic granular species, present in a mass proportion less than or equal to 60% of the total mass of the fusible / castable explosive composition, preferably less than or equal to 50% of the total mass of the fusible / castable explosive composition. The inert granular species may comprise an oxidizing product, such as perchlorate salts, and / or a reducing product, such as aluminum or tungsten, at different mass percentages. The energetic granular species may comprise “High Energy Materials” (HEM) such as ONTA (3-nitro-1,2,4-triazol-5-one, or oxynitrotriazol), RDX, HMX as well as “High Energy Density Materials” (HEDM) but also pyrotechnic compositions such as titanium carbon and nickel carbon.The addition of these energetic granular species to the composition increases the detonating performance of the composition. Depending on the mass proportion of the granular species, the mass proportion of the fusible explosive and the phlegmatizer is adapted, so that the sum of the mass proportions of the components of the fusible / castable explosive composition 10 is equal to 100%.

[0054] It can therefore be seen that the explosive composition of the invention differs from the composition disclosed in document FR2954308 by the fact that it does not contain an emulsifier or other additive whose role would be to contribute to the cohesion of the mixture. In the invention, homogeneity is ensured by a simple mixture of two species: the liquid fusible explosive and the phlegmatizer having the appropriate properties.

[0055] There figure 3 schematically represents a munition 50 comprising a fusible / castable explosive composition 10 according to the invention. The munition 50 is delimited by a hollow body 51, the hollow body 51 being at least partially filled with the fusible / castable explosive composition 10 according to the invention.

[0056] There figure 4 represents a flowchart of the steps of a method for manufacturing a fusible / castable explosive composition 10 according to the invention. The method for manufacturing a fusible / castable explosive composition 10 according to the invention comprises the following steps: melting (step 100) the fusible explosive 12; adding (step 101) the phlegmatizer 23 into the melted fusible explosive 12; mixing (step 102) the phlegmatizer 23 into the melted fusible explosive 12 to obtain a homogenized mixture.

[0057] Step 101 of adding the phlegmatizer 23 to the molten fusible explosive 12 is preferably done directly, i.e. the phlegmatizer 23 in solid form at room temperature is added to the liquid fusible explosive 12. However, it is also possible to add the phlegmatizer 23 already in liquid form to the molten (liquid) fusible explosive 12. In this case, the phlegmatizer is melted in a step prior to step 101.

[0058] The invention also relates to a method for explosively loading a munition 50 delimited by a hollow body 51, comprising: the steps of the method for manufacturing a fusible / castable explosive composition described previously; casting (step 103) into the hollow body 51 of the munition 50 of the homogenized mixture.

[0059] This method concerned by the invention is the method of explosive loading of munitions by casting-melting. In the munitions activity, the invention is applicable in the field of artillery, naval, airborne munitions, bombs, mines, grenades, and warheads.

[0060] The implementation of this solution in explosive charges makes it possible to retain all the current tools and industrial resources specific to the cast-melt process and does not require the use of skills not mastered by the professional.

[0061] This solution is then compatible and easily transferable to standard tools of the cast-melt process by professionals because it does not require skills specific to emulsion chemistry and / or specific production tools.

[0062] It appears that the fusible / pourable explosive composition according to the invention has numerous advantages. The phlegmatizer soluble in the liquid fusible explosive responds by its nature to the problem of inhomogeneity due to its chemical affinity with the fusible explosive. The dispersion of the product is optimal and is preserved over time. The solution provided by the invention makes it possible to significantly reduce the observed range of inhomogeneity in the concentration of the charge. Conventional compositions have an inhomogeneity range of ± 2%, whereas the composition according to the invention has an inhomogeneity range of ± 0.5%. In addition, the solution proposed by the invention is directly transferable to existing implementation processes and does not require any increase in skills in the complex field of emulsions.The composition according to the invention does not require the addition of additives such as surfactants, which until now were necessarily combined for a composition based on fusible explosive (TNT) and phlegmatizer (wax). The invention allows control of the performance of the ammunition by adapting the percentage of phlegmatizer in the composition without requiring any change to the manufacturing process used.

Claims

1. A meltable / castable explosive composition (10), characterised in that it comprises at least two components: - a meltable explosive (12), the meltable explosive being preferably a nitrated aromatic ring, and more preferably 2,4,6-trinitrotoluene; - a desensitiser (23) soluble at the melting temperature of the meltable explosive (12), and in that - the desensitiser (23) is present in a non-zero proportion by mass less than or equal to 10% of the total mass of the meltable / castable explosive composition (10), preferably between 2 to 6% of the total mass of the meltable / castable explosive composition (10), and more preferably between 3 to 5% of the total mass of the meltable / castable explosive composition (10); - the meltable explosive (12) is present in a proportion by mass of more than 20% and less than 100% of the total mass of the meltable / castable explosive composition (10), preferably more than 30% and less than 100% of the total mass of the meltable / castable explosive composition (10), and preferably more than 40% and less than 100% of the total mass of the meltable / castable explosive composition (10), and more preferably more than 50% and less than 100% of the total mass of the meltable / castable explosive composition (10), the sum of the proportions by mass of the components of the meltable / castable explosive composition (10) being 100%.

2. The meltable / castable explosive composition (10) according to claim 1, wherein the desensitiser (23) has a melting temperature greater than that of the meltable explosive (12).

3. The meltable / castable explosive composition (10) according to any one of claim 1 or 2, wherein the desensitiser (23) has a density greater than 1.0, preferably greater than 1.2.

4. The meltable / castable explosive composition (10) according to any one of claims 1 to 3, wherein the desensitiser (23) is a derivative of one of benzene, naphthalene or anthracene.

5. The meltable / castable explosive composition (10) according to any one of claims 1 to 4, wherein the desensitiser (23) is a benzenic derivative of one of benzene, naphthalene and anthracene which is functionalised with one or more groups from hydroxyl, carboxyl or sulfonyl groups.

6. The meltable / castable explosive composition (10) according to any one of claims 1 to 5, wherein the desensitiser (23) is naphthol, preferably naphth-2-ol.

7. The meltable / castable explosive composition (10) according to any one of claims 1 to 6, further comprising at least one component from an inert granular species and / or at least one energetic granular species, present in a proportion by mass of 60% or less of the total mass of the meltable / castable explosive composition, preferably of 50% or less of the total mass of the meltable / castable explosive composition.

8. An ammunition (50) delimited by a hollow body (51), characterised in that the hollow body (51) is at least partially filled with the meltable / castable explosive composition (10) according to any one of claims 1 to 7.

9. A method for manufacturing a meltable / castable explosive composition according to any one of claims 1 to 7, comprising the following steps - melting (100) the meltable explosive (12); - adding (101) the desensitiser (23) to the molten meltable explosive (12); - mixing (102) the desensitiser (23) into the molten meltable explosive (12) to obtain a homogenised mixture.

10. A method for explosively charging an ammunition (50) delimited by a hollow body (51) comprising: - the steps of the method for manufacturing a meltable / castable explosive composition according to claim 9; - casting (103) the homogenised mixture into the hollow body (51) of the ammunition (50).