Lattice Dynamics of Martensitic Transformations Examined by Atomistic Simulations

TL;DR

This paper uses atomistic simulations to study the lattice dynamics and phase transition mechanisms in Fe-Ni alloys, revealing nanoscale shear development and phonon anomalies near the martensitic transition.

Contribution

It introduces molecular dynamics simulations with an EAM potential to analyze martensitic transformations and phonon behavior in Fe-Ni alloys.

Findings

Nanoscale inhomogeneous shear system develops during transition

Phonon dispersion shows anomalies near transition temperature

Microstructure formation linked to phonon anomalies

Abstract

We have performaed molecular dynamics simulations of Fe(80)Ni(20) alloys using an inter-atomic potential of the EAM-type which allows the simulation of the martensite-austenite transition. We present results, showing the development of an inhomogeneous shear system on a nanoscale during the thermally induced austenitic transition. In addition to this we obtained the phonon dispersion relations of the martensite phase by calculating the dynamical structure factor from our simulation results. On approaching the transition temperature the phonon dispersion shows anomalies which might be connected with the formation of the microstructure during the austenitic transition.