Performance of EAM and MEAM Potential for NiTi Alloys: A Comparative Study

Abstract

NiTi alloys is one of the unique materials exhibiting shape memory effect. The martensitic transformation is the main reason for their behaviour, which is very sensitive to the heat treatment and the ratio of Ni-Ti atoms. The study of the NiTi alloys behaviour at the atomic level is indispensable to elucidate the mechanism of the martensitic transformation under the specific conditions. Molecular dynamics simulation is widely used in this kind of study. The results of the molecular dynamics simulation depend on the selection of the interatomic potential. This study is aimed to evaluate the performances of the standard EAM potentials of Zhou et al. and the modified EAM of Ko et al. by means of obtaining the more accurate lattice constant in comparison with the experimental value. These interatomic potentials are also tested to reproduce the recrystallization behaviour below the melting temperature. We found that the high accuracy of the lattice constant for NiTi alloy system could be achieved by employing MEAM potential of Ko et el. However, the EAM potential by Zhou et al. gives the rapid recrystallization of NiTi alloys at 1100 K. These results indicate that the MEAM potential of Ko et. al. shows the better performance at low temperature simulation.