Dislocation-mediated plasticity in the Al$_{2}$Cu {\theta}-phase

TL;DR

This study combines atomistic simulations and micropillar compression to explore dislocation-mediated plasticity in Al$_{2}$Cu, revealing unexpected slip systems and proposing a new order based on interplanar distances and Burgers vectors.

Contribution

It introduces a novel order for slip system activation in Al$_{2}$Cu based on effective interplanar distances and Burgers vectors, supported by experimental and simulation data.

Findings

Identification of unexpected slip planes {211} and {022} in Al$_{2}$Cu.

Proposed new order for slip system activation based on deff and beff.

Measured critical resolved shear stresses for multiple slip systems.

Abstract

The deformation behaviour of the intermetallic Al$_{2}$Cu-phase was investigated using atomistic simulations and micropillar compression, where slip on the unexpected {211} and {022} slip planes was revealed. Additionally, all possible slip systems for the intermetallic phases were further evaluated and a preference for the activation of slip systems based on their effective interplanar distances as well as the effective Burgers vector is proposed. The effective interplanar distance corresponds to the manually determined interplanar distance, whereas the effective Burgers vector takes a potential dislocation dissociation into account. This new order is: {211}1/2<111>, {022}1/2<111> and {022}<100>, {110}<001>, {310}<001>, {022}<011>, {110}1/2<111>, {112}<110> and {112}1/2<111> from high to low ratio of deff/beff. Also, data on the critical resolved shear stresses of several of these slip systems were measured.