Atomistic computer study on Mg segregation in the Ni 3 Al grain boundary

The embedded atom method (EAM) was applied to calculate the energy on Mg doping in polycrystalline Ni 3 Al. The EAM predicted the energy of Mg in Al site in grain boundary is lower than that of Mg in Ni site and much lower than that of Mg in Al or Ni site in bulk and in free surface. It means that Mg would segregate to grain boundary rather than bulk and free surface and Mg will favor to be the substitute of Al rather than of Ni in grain boundary. These results were consistent with the experiments that Mg segregated to grain boundaries with Al depletion and Ni enrichment.