A molecular dynamics study of the fcc→bccfcc→bcc transformation at fault intersections

Molecular dynamics simulations have been used to investigate the role of fault band intersections on the nucleation of α′α′ martensite from austenite. The results show that nucleation and growth of body-centered cubic (bcc) α′α′ occurs, despite the non-bcc stacking in the fault band intersection, following the model proposed by Olson and Cohen. The processes of nucleation and growth are interpreted based on the crystallography of the phases (orientation relationship), together with the deformation required to achieve the transformation and crystallographic orientation relationship. These features of the transformation have subsequently been compared against experiments and the macroscopic theory of martensite formation.