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Reactive Armour Systems
Published in Paul J. Hazell, Armour, 2023
The use of low-sensitivity explosives in ERA is important in maximizing commercial gains that can be made in the armour business. Many countries, such as the United Kingdom, are only prepared to adopt insensitive munition-compliant products in service. Explosives that are very difficult to accidentally initiate are almost universally cast polymer bonded explosive (PBX)-based materials. These materials are very difficult, if not impossible, to initiate unless a very violent stimulant such as a shaped-charge jet penetrates them. Due to the very high-pressure region incurred in the explosive composition by the jet, it is relatively simple to guarantee initiation when desired whilst at the same time remaining safe at all other times. There are a number of tests that are done to check this. The most stringent of tests are done according to STANAG 4496 where a steel fragment-simulating projectile is fired at the armour at around 2500 m/s to test whether the explosive is shock initiated. This is the worst-case scenario for an impact from high-velocity fragment that has been propelled from a 155-mm HE shell.
Preparation and Thermal Stability of Nano-Sized HMX-Based Polymer Bonded Explosives
Published in Combustion Science and Technology, 2023
Zhimiao Zhang, Xinfu Cao, Jianbing Gao, Yong Chen, Deqi Wang, Yang Qin, Sensen Sun, Haomiao Yu, Jie Liu, Guodong Deng, Fengsheng Li
PBX (polymer-bonded explosive) is a kind of high-energy mixed explosive, which is composed of high-energy explosive (e.g., Hexahydro-1,3,5-trinitroperhydro-1,3,5-triazine (RDX), Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), et al.), adhesive, plasticizer and insensitive agent (He et al. 2021; Li et al 2019; Liu, Chen, Zhang 2020). It is widely used in conventional and sophisticated weapons such as anti-tank missiles and surface-to-air missiles (Kang, Ning, Chen 2020; Wang et al. 2021), and plays a vital role in killing and destruction (Liu et al. 2019). HMX is one of the most commonly used high-energy materials due to its excellent properties, for instance, high melting point, excellent explosion performance and chemical stability (Liu et al. 2012; Wang and Zhu 2020). Therefore, industrial micron-sized HMX (M-HMX) is nowadays widely used in HMX-based polymer bonded explosives (HMX-PBX) to improve its energy property (Liu, Chen, Zhang 2020). However, the high-temperature and high pressure molding process of HMX-PBX may lead to damage the M-HMX crystal (Drouet et al. 2020), reduce the original stability of M-HMX and thereby affect the comprehensive performances of HMX-PBX (Kaur et al. 2013).
High temperature and pressure regime soot: Physical, optical and chemical signatures from high explosive detonations
Published in Aerosol Science and Technology, 2022
Allison C. Aiken, Rachel C. Huber, Andrew M. Schmalzer, Mark Boggs, James E. Lee, Kyle J. Gorkowski, David W. Podlesak, Manvendra K. Dubey
Preparations of the HE composites and controlled atmosphere detonations were conducted at Los Alamos National Laboratory. Comp B-3 is composed of 40% trinitrotoluene (TNT) and 60% 1,3,5-trinitro-1,3,5-triazinane (RDX). The polymer-bonded explosive (PBX) 9501 is composed of 95% 1,3,5,7-tetranitro-1,3,5,7-tetrazoctane (HMX), 2.5% Estane and 2.5% of BDNPA/BDNPF. The detonation experimental details under steady conditions are described in Huber et al. (2018). In summary, HE composites were warm-pressed into ∼2.7 g pellets that were epoxied together with Aralhex B (a LANL urethane-based adhesive) to make ∼10.8 g detonation rate sticks. Detonations were initiated using an RP-1 detonator and conducted in a stainless-steel cylinder under air or argon as described in Huber et al. (2018). Argon was used to study reactions in an inert atmosphere to understand the role of the atmospheric gases in soot formation chemistry. Detonation soot was collected by vacuum onto an Ag filter (Huber et al. 2018). Fullerene soot was obtained from Alpha Aesar (stock lot #40971, lot #L18U002). Fullerene soot is a laboratory standard comprised of fractal-like aggregates of spherical primary particles with a diameter of ∼50 nm (Moteki et al. 2009; Gysel et al. 2011). According to the manufacturer, the composition is ≥90% amorphous carbon (carbon black) and ≤10% fullerenes (mostly C60). All samples were atomized (TSI Model 3079 A, TSI Inc., Shoreview, MN, USA) from aqueous and ethanol solutions and dried with a diffusion drier (TSI Model 3062).