Integrated preparation of Al-based energetic micro-unit fuel toward combustion performance

Abstract

An Al-based energetic micro-unit Al@PFPE@AP fuel powder with the oxidant AP coated on the surface of fluoride-modified Al powder was designed and prepared by the component composite technique to address the two major problems of incomplete combustion and component polarization of Al powder in solid propellants. The morphology, particle size, combustion properties and combustion products of the micro-unit powder were analyzed by scanning electron microscopy, laser particle size measurement, oxygen bomb calorimetry, inductively coupled plasma emission spectrometry and X-ray diffraction. The results show that the energetic microunits Al@PFPE@AP present a more obvious core-shell structure with uniform particle size, and when the addition amount of PFPE is 5%, the combustion heat value of Al@5%PFPE@AP is increased by 63.86%, the particle size of combustion products is decreased by 61.83%, and the active aluminum content of combustion products is decreased by more than 57% compared with the mechanically mixed AP+Al samples. Combustion mechanism analysis shows that PFPE can occur with Al powder pre-ignition reaction, increase the reaction activity of Al powder, and the surface of Al powder has a catalytic effect on the decomposition of AP, which reduces AP high temperature decomposition temperature and low temperature decomposition temperature were reduced by 12 ℃ and 10 ℃ respectively. The micro-unit structure has a significant contribution to the improvement of the combustion performance of the system and can substantially increase the energy performance of the important propellant components during combustion.

Keywords

• al powder
• energetic microunit
• combustion performance