Combustion thermodynamical metal-complex oxidizer mixtures

Previous chemical equilibrium calculations of metal-oxygen:and metal-nitrog en reacting systems revealed that, due to the large enthalpies of vaporizat ion-dissociation of the condensed phase formed, the flame temperature is li mited to the boiling point or, more appropriately, vaporization-dissociatio n temperature of the products. Though it has been commonly accepted that th e flame temperature of metals reacting with oxygen is indeed the vaporizati on-dissociation (designated the volatilization temperature) temperature of the metal oxide, the dame temperature reacting with air never achieves this volatilization temperature. Analysis of the different Ti-N-2 reacting syst ems provided the clue that, when a metal reacts with oxygen in the presence of an inert or combustion gases that do not substantially interact with th e species volatilized from the condensed phase product, the enthalpy of vol atilization-dissociation of the metal oxide still controls the dame tempera ture. Further, it has been shown that the flame temperature of a metal burn ing in oxygen-inert or other complex oxidizer mixtures corresponds to the v olatilization temperature of the oxide evaluated at a pressure that corresp onds to the partial pressure of the volatilized gases and not to the total pressure of the reacting system, This realization has important consequence s in evaluating the radiative power of burning aluminum particles in solid propellants, understanding flammability limits of metal dusts in air, and a pplying Glassman's criterion for the vapor phase combustion of metals (Glas sman, I., "Metal Combustion Processes," American Rocket Society, Preprint N o. 938-59, New York, 1959), as well as in combustion synthesis.