Reaction pathway of Ni/Al clad particles under thermal loading: A molecular dynamics simulation

The reaction pathway of nanostructure Ni/Al clad particles with a atomic ratio Ni/Al = 3:1 under thermal loading on a local area is investigated by molecular dynamics simulations. We show a complete reaction pathway and confirm the NiAl compound is an intermediate product in the reaction of 3Ni + Al clad particles. The effect of particle size on the propagation of reaction is considered. For the system with larger particle size, part of the NiAl compound forms the phase of B2-NiAl by nucleation. The presence of NiAl precipitate retards the propagation of reaction. The formation of the NiAl phase is dependent on the temperature below a certain threshold. For longer time, the phase of B2-NiAl gradually transforms into Ni3Al compound that is the final product of 3Ni + Al clad particles.