Boron Potassium Nitrate (BPN) composition is a unique pyrotechnic igniter composition due to its high energy output and considerably long shelf life. However, ignition and combustion difficulty of boron particles due to its extremely high melting and vaporization temperature values limits its effective use in the systems where volume and mass are limited. Therefore increasing the ignition and combustion efficiency of boron by various means is highly significant. The effect of micron- and nano-sized boron particles on BPN ignition composition was investigated in this paper. As a starting point, thermochemical calculations were made to determine the most promising ignition compositions. Both stoichiometric and fuel-rich formulations of BPN were produced to observe the performance variation due to boron content. Particle morphology of boron particles and the surface structure of the ignition compositions were investigated by SEM. The influence of micron- and nano-sized boron particles on the calorific value, sensitivity properties, and pressure buildup of compositions were investigated. Sensitivity tests showed that all compositions were safe enough for handling. It was seen that although nano-sized boron particles enhanced calorific value and pressurization rate, they did not have a contribution on the maximum pressure level. The theoretical maximum adiabatic flame temperature was attained by the stoichiometric composition, but in practice, the stoichiometric composition resulted in much lower performance than the fuel rich composition. Possible reasons for these behaviors of the compositions were discussed in the paper.
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