Combustion of aluminum particles in the flames of condensed systems

Abstract

1. When a ballistite containing aluminum particles burns, the metal particles adhere to the heat-resistant decomposition products of nitrocellulose on the surface of the charge and subsequently coalesce near the surface. In the case of model composite systems the aluminum particles coalesce on the surface of the charge. An increase in the percentage metal content of the fuel leads to an increase in particle size. Aluminum particles accumulate and agglomerate on the combustion surface. 2. In the initial stage of combustion of model composite systems containing aluminum, i.e., in the reaction zone, exothermic metal oxidation reactions begin to take place at the surface of the metal particles, 4–6% of the total heat produced by combustion of the metal in the flame being released in the reaction zone. In the case of ballistites the metal particles begin to react in the fizz zone near the surface of the charge. 3. The combustion of the aluminum particles in the flame proceeds via intermediate products with the formation of lower oxides. 4. The temperature of the aluminum particle combustion zone exceeds the flame temperature by 400–600°C.