Interdiffusion of Ni-Al multilayers: A continuum and molecular dynamics study

Abstract

Molecular dynamics simulation of Al/Ni multilayer foils reveals a range of different reaction pathways depending on the temperature of the reaction. At the highest temperatures, Fickian interdiffusion is the rate-limiting step in the intermixing process. At intermediate temperatures, Ni dissolution into the Al liquid becomes the rate-limiting mechanism for intermixing prior to formation of the B2 intermetallic phase. At lower temperatures, the B2 intermetallic forms early in the reaction process precluding both of these mechanisms. Interdiffusion and dissolution activation energies as well as diffusion prefactors are extracted from the simulations.