Elena Korznikova

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 dynamics of a triangular lattice consisting of active particles is studied. Particles with nonlinear friction interact via nonlinear forces of Morse potential. Nonlinear friction slows down fast particles and accelerates slow ones. Each particle interacts mainly with the nearest neighbors due to the choice of the cut-off radius.
Stationary modes (attractors) and metastable states of the lattice are studied by methods of numerical simulation.
It is shown that the main attractor of the system under consideration is the so-called translational mode — the state with equal and unidirectional velocities of all particles. For some parameter values translational modes with defects in the form of vacancies and interstitial particles are possible.
Metastable localized states are presented by the plane soliton-like waves (M-solitons) with inherent velocity and density maxima. The lifetime of such states depends on the lattice parameters and the wavefront width. All metastable states transform into the translational mode after a transient process.