Comparative analysis of the ESD sensitivity of B/KNO3 and B4C/KNO3 pyrotechnic compositions

Abstract

This study evaluates the electrostatic discharge (ESD) sensitivity of boron and potassium nitrate (BPN) and boron carbide with potassium nitrate (BCPN) compositions. Previous investigations for the BPN composition report limited ESD data, primarily in the undamped mode, showing insensitivity up to 5 J. However, prior work demonstrated a 50% initiation probability of 12 mJ in the damped mode, indicating higher sensitivity when measured under conditions more representative for pyrotechnic initiation by thermal decomposition. This study aims to compare the ESD sensitivity between BPN and BCPN compositions using different ratios of fuel and oxidizer to assess how different reactive components influence their sensitivity and safety profile. Results show that increasing fuel content generally enhances sensitivity, with boron-based compositions exhibiting lower minimum ignition energy (MIE) than their boron carbide counterparts. This difference is mainly attributed to boron's higher electrical resistivity and lower thermal conductivity, which favour localized charge accumulation and heat retention, increasing the likelihood of ignition. Purity content is also believed to play a significant role. The findings provide new insights into the electrostatic sensitivity of these compositions, contributing to safer formulation practices in pyrotechnic applications.