Combustion features of boron-based composite solid propellants

Abstract

This paper describes a technique for the sampling of condensed combustion products (CCPs) of metalized propellants. Experiments were carried out with model propellants containing 15.7% of a metallic fuels, ammonium perchlorate, and an inert binder under pressure levels of about 2, 4, and 8 MPa. We used microsized powders of aluminum, boron, aluminum diboride and aluminum dodecaboride as metallic fuels. For the initial fuels, we defined the granulometric composition and determined the content of the active (non-oxidized) metal by the cerimetric method. The quenching of the dispersed phase particles was performed near the burning surface by a co-current argon flow. The paper provides the burning rate of the propellants and CCPs characteristics – the particle size and morphological composition, and the combustion incompleteness of the metal fuels. We have identified the morphology features of the agglomerated particles of aluminum and boron. The paper also contains calculated data on the heat release efficiency of the tested propellants. The obtained experimental data provide a basis for the development and verification of theoretical models on the combustion of metalized propellants. For the studied propellant formulations, we have not identified the increase in the boron combustion completeness due to the adding of aluminum into the propellant composition.