Conditions for combustion synthesis in nanosized Ni/Al films on a substrate

The conditions for self-sustaining combustion synthesis in nanosized multilayer Ni/Al films deposited on a substrate are studied based on a 2D model. The model considers two conjugate processes, i.e. propagation of the synthesis wave in a multi-layer Ni/Al system and propagation of the accompanying thermal wave into the substrate. It is shown that the boundary between the regimes of self-sustaining reaction and annealing is determined by the number of binary layers of reactants (at a given heater temperature, stoichiometric ratio of the reactants and ration of film and substrate thermal diffusivities), but it does not depend on the bilayer thickness. The distinctive features of synthesis in the thermal explosion mode and in the annealing regime are studied as well.