Dany Frem

IMX‐101 and IMX‐104 are novel insensitive melt‐pour explosives developed and produced by BAE Systems at the Holston Army Ammunition Plant (HSAAP). The U.S. Army has selected these two explosives as common low‐cost replacements for legacy explosives TNT and Composition‐B used in indirect fire weapons such as artillery and mortar munition systems. This paper will review the literature related to the properties and manufacturing processes of IMX‐101 and IMX‐104, including their physicochemical, thermal, explosive, and sensitivity properties as well as their behavior in Insensitive Munition (IM) tests specifically designed to simulate real threats and hazards faced by a munition on the battlefield. IMX‐101 has been qualified and is currently fielded in the 155 mm M795 and the 105 mm M1 rounds. IMX‐104 has been integrated into various mortar projectiles including the 60 and 81 mm rounds and is being evaluated as a main explosive charge in the next‐generation 155 mm family of ammunition, which includes the XM1128 Extended Range High Explosive round and the XM1113 Rocket Assisted Projectile (RAP).

The simplicity and versatility of the Gurney model has led to its widespread adoption for the calculation of peak fragment velocity of explosively-driven munitions such as fragmentation warheads and artillery projectiles. The Chemical Equilibrium with Applications (CEA) thermochemical code provides several relevant parameters that were found to be important for the construction of a mathematical model for estimating the Gurney velocity of pure and mixed chemical high explosives. Compared to other methods, the proposed model demonstrated its accuracy in predicting the Gurney velocity of sensitive and insensitive explosive compositions. Models based on detonation velocity were found to be particularly inadequate to predict the Gurney velocity of insensitive explosives, which is strong proof that the detonation velocity does not necessarily correlate with the Gurney velocity for all types of high explosives. Results from the cylinder expansion test provide some evidence that the low to moderate metal acceleration ability of insensitive explosives is due to their unique and steep expansion isentropes rather than charge diameter effects or non-ideal detonation behavior. Graphical abstract

The plate dent test is one of the simplest tools for fast determination of the detonation pressure. The test is based on the observation that the detonation pressure correlates with the depth of the...

The plate dent test is one of the most useful tools used by experimenters for the determination of explosive performance. However, performing the test for every new composition is certainly tedious and time consuming. Hence, the aim of the present study was to introduce a model from which the plate dent performance output could be predicted. Using three set of variables namely, the loading density ρ, oxygen balance Ω and the specific impulse I_sp (calculated according to the [H₂O‐CO₂] arbitrary decomposition assumption), a correlation was derived, which is capable of reliable prediction of the dent depth δ produced on 1018 cold‐rolled steel by a detonating explosive cylinder. Furthermore, the calculated δ values and the well‐known Kamlet‐Jacobs and Keshavarz‐Pouretedal methods were used to estimate the detonation pressure P of CHNOClF‐containing explosives, and the results of each were then compared to experimental/thermochemical code data. The root‐mean square deviation (RMSD) analysis clearly shows that the proposed model is more reliable to predict P than the Kamlet‐Jacobs method especially for fluorine and chlorine‐containing compositions.

In the present study, a relationship is proposed that is capable of predicting the output of the plate dent test. It is shown that the initial density ; condensed phase heat of formation ; the number of carbon (C), nitrogen (N), oxygen (O); and the composition molecular weight (MW) are the most important parameters needed in order to accurately predict the absolute dent depth produced on 1018 cold-rolled steel by a detonating organic explosive. The estimated values can be used to predict the detonation pressure (P) of high explosives; furthermore, we show that a correlation exists between and the Gurney velocity parameter. The new correlation is used to accurately estimate for several C-H-N-O explosive compositions.

Simple relationships are presented for the calculation of both prompt and terminal Gurney velocity of chemical high explosives. By considering that a given explosive behaves like a propellant, its specific impulse was calculated using Mader’s ISPBKW code; it was found that the density impulse ( where is the explosive density and is an empirically optimized variable) performance factor correlates well with the terminal Gurney velocity of both ideal and nonideal explosives. Furthermore, the cylinder wall energy can be computed from ( from which the prompt Gurney velocity can be obtained through the application of the Gurney’s cylinder equation. It was concluded that ( is a powerful factor for the prediction of the Gurney velocities, especially for nonideal compositions.

Four types of nitrogen-rich heterocycles substituted with -NO2, -NHNO2 and -C(NO2)3 explosophoric groups were explored as potential explosives and propellants materials. The calculated crystal density (?0)and the condensed phase heat of formation (?H?0f)for each of the twelve structures investigated shows that all these derivatives possess high (1.834-1.980 g cm-3)(?H?0f) and (605-2130 kJ kg-1) values. Interesting properties such as detonation velocity (D), pressure (P) and specific impulse (Isp) were calculated using the Kamlet-Jacobs method and ISPBKW thermochemical code. Detonation velocity and pressure in excess of 8.44 km s-1 and 32.87 GPa was obtained in all cases. Furthermore, trinitromethyl substituted derivatives shows performance exceeding that of HMX with an estimated D = 9.32-9.72 km s-1 and P = 40.61-43.82 GPa. Some -NO2 and -NHNO2 substituted derivatives were shown to be impact insensitive while retaining good detonation performance and thus are regarded as potential replacement for current RDX -based explosives. Finally, the calculated specific impulse (Isp between 248 and 270 s) of all investigated derivatives indicate that these energetic materials can be considered as possible ingredient in future rocket propellant compositions.