Molecular Dyanmics simulationo of Martensitic Transformatinos in Alloys System
Details
The martensitic tarnsformations in alloys were studied using molecular dynamics (MD) simulations. The modified embedded atom method was used with the pseudo monoatomic potentials in which the angular dependence was taken into consideration. The thermally induced martensitic B2→3R tarsformations and the reverse 3R→B2 transformations have been obtained in the present MD simulations for NiAl alloy. The transformation is accompanied by a twin in the 3R phase which leads to a lattice-invariant deformation so as to minimize the transformation strain energy. The crystallographic orientation relationship, (001)_<B2>‖(001)_<3R> and [110]_<B2>‖[100]_<3R> was found, which agrees with experiments. The concentration dependence of the transformation temperature for Ni_xAl_<1-x>(0.58<x<0.69) alloys has been observed. The present MD simulation was carried with a medium-size of computational cell. The MEAM potentials are useful since they involve many-body effects through the electron density.
