Maria Semenova

The electroplasticity effect involves reduced yield stress in deformed metals under pulsed electric currents, unexplained by Joule heating alone. In coarse-grained metals, plastic deformation primarily occurs via dislocation slip, modeled here using Frenkel –Kontorova kinks. This numerical study explores how electric pulses affect dislocation mobility, comparing two mechanisms: Joule heating localized at dislocations and electron wind transferring momentum. Key findings show that, at lower temperatures, Joule heating enhances dislocation mobility more significantly, while higher temperatures favor electron wind dominance. Within an intermediate temperature range, both mechanisms contribute nearly equally to increased plasticity. These insights clarify the interplay of thermal and electronic effects in electroplasticity, addressing long-standing debates on its fundamental mechanisms. The results emphasize context-dependent dominance of Joule heating versus electron wind, advancing theoretical models for electrically assisted metal forming processes.

The biatomic crystal with CsCl structure is considered with the interatomic interactions described by the $\beta$-Fermi-Pasta-Ulam-Tsingou potential. The case of a large difference in the atomic masses of the components is analyzed when there is a gap in the phonon spectrum of the crystal. A spatially localized large-amplitude vibrational mode, called the discrete breather (DB), is found by applying a localization function to the delocalized nonlinear vibrational mode (DNVM). The DNVM and consequently the DB have frequencies in the gap of the phonon spectrum. It is shown that the DB can be set in motion using a physically motivated ansatz.