Electrostatic discharge sensitivity and electrical conductivity of composite energetic materials

Desensitizing nano powders to electrostatic discharge ignition

“…Fireworks are a class of pyrotechnics that are energetic materials and combine solid fuels and solid oxidizers together to form an energetic composite mixture. One of the first articles focusing on ESD ignition and energetic composites not only measured ESD ignition sensitivity but also related ESD sensitivity to a measurable property of the powder mixture: electrical conductivity [4]. Weir et al studied nine different energetic composites and showed aluminum combined with copper oxide (Al þ CuO) was the most electrically conductive and most ESD ignition sensitive [4].…”

“…One of the first articles focusing on ESD ignition and energetic composites not only measured ESD ignition sensitivity but also related ESD sensitivity to a measurable property of the powder mixture: electrical conductivity [4]. Weir et al studied nine different energetic composites and showed aluminum combined with copper oxide (Al þ CuO) was the most electrically conductive and most ESD ignition sensitive [4]. They defined ESD ignition sensitivity as ignition below the threshold energy of 100 mJ, a human body model threshold for ignition [5].…”

Electrostatic Discharge Sensitivity and Resistivity Measurements of Al Nanothermites and their Fuel and Oxidant Precursors

“…The data display a series of trends based on fuel and oxidant as follows: (i) a marked decrease in sensitivity of CuO or Fe 2 O 3 -based systems relative to those of MoO 3 . This trend is illustrated by the increase in the minimum ESD response energy down any and all of columns 1-6 in Table 1 [10] observed an oxidant sensitivity trend Bi > Mo >> Cu for L-Al and micrometric oxides, whilst Weir et al [17,18] observed the reverse trend for Mo and Cu with oxide passivated aluminium fuel. Although the literature data may appear contradictory, it is believed here to simply represent the complex relationship between particle properties and ESD sensitivity.…”

“…The extent to which nanothermites conduct spark-generated current may be central to the rationalisation of ESD sensitivity. The conductivity of thermite materials has been explored previously [17,18]. Low voltages were employed (typically 1 V) to avoid resistive heating and nanothermite ignition.…”

“…These were made using an in-house system capable of discharges of 5-25 kV and 0.006-0.156 J at 0.50 cm. The system design was similar to described instrumentation [17]. Measurements were made in a vented and electrically insulated box (ca.…”