Combustion of aluminum and boron in solid propellants.

A closed-type strand bomb was developed to trap all species participating in metalized solid propellant combustion. Combustion efficiencies (η) of aluminum (Al) and boron (B) were measured using titration techniques. Variations of ηAl and ηB with pressure and mutual effects of Al and B combustion were investigated. Al particles burn faster than B particles. However, it was found that burning of Al is hindered by B burning when Al coexists with B in propellants. On the other hand B burning is not affected by Al. These experimental results could be explained using a simplified analytical model describing agglomeration, ignition delay and burning processes of particles on the burning surface.