Modeling the ignition of self-propagating combustion synthesis of transition metal aluminides

The ignition process in self-propagating high-temperature synthesis (SHS) reactions was modeled taking into account chemical and phase transformation processes. The model was applied to the synthesis of aluminides. The dependence of the ignition process on peak input energy density and peak temperature is demonstrated by ignition diagrams. The influence of the transition metal grain size and pellet porosity on the ignition conditions was demonstrated. With an increase in grain size, a significant increase in the input energy density is required and the region of SHS reactions in the ignition diagram is reduced. The experimentally observed difference in the ignition characteristics of the synthesis of different aluminides was attributed to differences in solubility limits and rate of dissolution. The effect of the ignition conditions on the velocity of the following self-sustaining reaction was analyzed.