Glassy features of crystal plasticity

TL;DR

This paper investigates the avalanche-like behavior of dislocation motion in crystal plasticity through extensive simulations, revealing power-law distributed avalanches and glassy, critical-like deformation features.

Contribution

It demonstrates that dislocation avalanches exhibit glassy features and extended critical-like behavior, challenging the notion of a non-equilibrium phase transition.

Findings

Avalanche sizes follow a power-law distribution.

Average avalanche size increases exponentially with stress.

Slip increases with system size, indicating size dependence.

Abstract

Crystal plasticity occurs by deformation bursts due to the avalanche-like motion of dislocations. Here we perform extensive numerical simulations of a three-dimensional dislocation dynamics model under quasistatic stress-controlled loading. Our results show that avalanches are power-law distributed, and display peculiar stress and sample size dependence: The average avalanche size grows exponentially with the applied stress, and the amount of slip increases with the system size. These results suggest that intermittent deformation processes in crystalline materials exhibit an extended critical-like phase in analogy to glassy systems, instead of originating from a non-equilibrium phase transition critical point.