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X‐Ray Phase Contrast Imaging of the Impact of a Single HMX Particle in a Polymeric Matrix
Author(s) -
Kerschen Nicholas E.,
Sorensen Christian J.,
Guo Zherui,
Mares Jesus O.,
Fezzaa Kamel,
Sun Tao,
Son Steven F.,
Chen Weig W.
Publication year - 2019
Publication title -
propellants, explosives, pyrotechnics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.56
H-Index - 65
eISSN - 1521-4087
pISSN - 0721-3115
DOI - 10.1002/prep.201800002
Subject(s) - particle (ecology) , materials science , shock (circulatory) , ignition system , explosive material , particle size , matrix (chemical analysis) , phase (matter) , polymer , mechanics , particle velocity , composite material , thermodynamics , chemistry , physics , medicine , oceanography , organic chemistry , geology
A complete understanding of the mechanisms by which high explosives (HEs) are shock initiated, especially at the particle scale, is still in demand. One approach to explain shock initiation phenomenon is hot spot theory, which suggests that distributed energy in energetic material is localized due to shock or impact to generate the high temperatures for ignition. This study focuses on the impact response of a HE polycrystalline particle, specifically HMX, in a polymer matrix. This represents a simplified analog of a traditional polymer‐bonded explosive (PBX) formulation. A light gas gun, together with high‐speed x‐ray phase contrast imaging (PCI), was used to study the impact response of a single particle of production‐grade HMX in a Sylgard‐184® matrix. The high‐speed x‐ray PCI allows for real‐time visualization of HE particle behavior. The experiments revealed that, at impact velocities of ∼200 m s −1 , the energetic particle was cracked and crushed. When the impact velocity was increased to 445 m s −1 , a significant volume expansion of the particle was observed. This volume expansion is considered to be the result of chemical reaction within the HE particle.