Initiation of Nanothermites by Electric Spark
A. Yu. Dolgoborodov1,2,3, B. D. Yankovskii1, P. A. Arsenov1, S. Yu. Anan'ev1, L. I. Grishin1,4, G. E. Val'yano1, T. I. Borodina1, G. S. Vakorina1
1Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow, Russia
2Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences
3MEPhI National Research Nuclear University
4MEPhI National Research Nuclear University,, Moscow, Russia
Keywords: thermite compositions, nanothermites, electrospark initiation, combustion, energy density
Abstract
Electrospark initiation of thermite mixtures based on nanosized powders of aluminum and copper oxide has been studied. Data on the effect of the energy of an electric spark discharge on the ignition delay have been obtained. When initiating long cylindrical samples of mixtures with a low-current spark, two types of unsteady combustion were observed. The first type is characterized by an exponential nature of the establishment of a constant burning rate. The second type is characterized by regions with incomplete reaction along the main direction of propagation. To obtain stationary modes of a thermite mixture with a minimum ignition delay time, it is necessary to use a discharge with energy of more than 5 mJ per 1 mm2 mixture surface.
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