Crystal plasticity as a mean field depinning transition: results from a phase field crystal model

TL;DR

This study uses phase field crystal simulations at finite temperature to analyze avalanche statistics in crystal plasticity, confirming its universality class as a mean field elastic depinning transition.

Contribution

It introduces a phase field crystal simulation approach to study crystal plasticity, extending beyond previous force-controlled, zero-temperature models.

Findings

Avalanche size and energy distributions follow mean field elastic depinning universality.

Avalanche duration distributions and power spectra are consistent with mean field predictions.

Results confirm the universality class of crystal plasticity as a mean field elastic depinning transition.

Abstract

Until now, most of our knowledge about the universality class of crystal plasticity has come from simulations using discrete dislocation dynamics. These are force-controlled, typically at zero temperature, and deal with the creation and annihilation of dislocations phenomenologically. In this work, we go beyond these limitations by using phase field crystal simulations in two dimensions at finite temperature to extract the avalanche statistics of a simulated crystal under constant shear velocity. In addition to the avalanche size and energy distributions we extract the avalanche duration distributions and power spectra. All exponents and scaling functions extracted here for the statics and dynamics of crystal plasticity, belong to the mean field elastic depinning universality class, confirming earlier findings based on discrete dislocation dynamics.