Study of the Mechanical Deformation of Transforming Nanowires Constrained in Metal Matrix

We report the results of a simulation study of the mechanical deformation of NiAl nanowires constrained in Al metal matrix. The constrained nanowires showed high elastic yield stress and nonelastic stretching via a transition from the B2 to BCT phase. The phase transformation mechanism was that of atomic shuffling, via the appearance, spreading, and aggregation of isolated defect atoms, instead of dislocation movement. Because of geometry constraints, the interphase energy between the new and parent phases is not readily released, which results in strain hardening.