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 B 2-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 B 2-NiAl gradually transforms into Ni 3 Al compound that is the final product of 3Ni + Al clad particles.
