Modelling of Al/MnO2 and Ti/MnO2 Thermite Mixtures

In previous work a model was developed and introduced to describe the conversion of pyrotechnic mixtures taking in consideration its particulate character and solving the heat and the mass transfer coupled with reaction kinetics [1]. In this work the model was applied to thermite mixtures with manganese(IV) oxide as oxidizer and aluminium or titanium as fuel. The modelling results of burning rate dependent of fuel-oxidizer ratio were compared with results from experiments. For the modelling process, the educts were characterized by determining particle size and distribution and chemical reaction kinetics parameters. Other parameters were taken from literature. The modelling results are in good agreement with the experimental ones. It seems that the made physical and chemical assumptions are the main factors to describe the shape of burning rate profile in thermite combustion and the negligence are not influential