Molecular dynamics simulations of the phase transformation from bodycentered-\ncubic (bcc) to face-centered-cubic (fcc) structures were performed.\nA Morse-type function was applied, and the parameters were determined so\nthat both fcc and bcc structures were stable for the perfectcrystal model.\nWhen the fcc structure was superior to the bcc structure, the bcc model\ntransformed to fcc. Two mechanisms, based on the Bain and Nishiyama-\nWasserman (NW) relationships, were considered. Then, point or linear lattice\ndefects, i.e. , randomly scattered or regularly aligned vacancies, were introduced.\nConsequently, bcc models tended to transform to an fcc structure,\nwhereas fcc models remained stable. The transformation process was also\ninvestigated in detail. BCC-to-FCC transformation is often considered as a\nhomogeneous process based on changes in the axis lengths, and such a\nprocess was observed for the perfectcrystal model. Conversely, for the defect\nmodels, local heterogeneous deformation patterns, including cylindrical\ndomain and planar interface formation, were observed. These behaviors are\nconsidered to be related to plastic deformation during phase transformation,\nand the validity of the presented model for further investigation was confirmed.
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