On the temperature and density dependence of dislocation drag from phonon wind

TL;DR

This paper investigates how temperature and density affect dislocation drag in metals like aluminum and copper, focusing on phonon wind effects at high strain rates, and analyzes the influence of elastic constants on this behavior.

Contribution

It provides detailed calculations of dislocation drag coefficients considering temperature and density variations, highlighting the role of anharmonic phonon scattering.

Findings

Dislocation drag coefficients vary significantly with temperature and density.

Anharmonic phonon scattering is a key factor in dislocation drag at high strain rates.

Elastic constants influence the sensitivity of drag coefficients to environmental changes.

Abstract

At extreme strain rates, where fast moving dislocations govern plastic deformation, anharmonic phonon scattering imparts a drag force on the dislocations. In this paper, we present calculations of the dislocation drag coefficients of aluminum and copper as functions of temperature and density. We discuss the sensitivity of the drag coefficients to changes in the third-order elastic constants with temperature and density.