Examining correlations of electrostatic discharge sensitivity and electrical conductivity of composite energetic materials

Composite energetic material response to electrical stimuli was investigated and a correlation between the composite’s electrical conductivity and ignition sensitivity was examined. The composites consisted of micrometer particle aluminum combined with another metal, metal oxide, or fluoropolymer. Of the nine tested mixtures, aluminum and copper oxide was the only mixture to ignite by electrostatic discharge (ESD) with minimum ignition energy of 25 mJ and an electrical conductivity of 3.45 nS. In an ESD event, energy is delivered through the spark and through joule heating of the particles. For this reason, thermal ignition was also examined using a hot wire. This study showed a similar trend in minimum ignition energy for ignition triggered by a discharged spark compared with ignition triggered by a thermal hot wire source. However, a discharged spark concentrates energy locally supplying greater power for ignition. This study begins to explore critical parameters influencing electrostatic discharge ignition, specifically electrical resistivity and conductivity of particulate mixtures.