Molecular dynamics simulations of self-propagating reactions in Ni-Al multilayer nanofoils

The self-propagating high-temperature reaction that occurs in multilayer nanofoils is studied by means of molecular dynamics (MD) simulations, using an embedded-atom method type potential. The system is composed of two alloyable constituents stacked over a few hundred nanometers. The self-sustaining reaction, initiated locally by increasing the temperature, propagates along the foil, without any further supply of heat, due to the exothermic interdiffusion of the two metals. Beyond the simulation of a large length scale thermal process by MD, this work demonstrates the relation between the dynamics of front propagation and the underlying microscopic processes. Some specific properties are revealed, while well-established experimental characteristics of front velocity are observed.