Basal Slip in Laves Phases: the Synchroshear Dislocation

TL;DR

This study clarifies the mechanism of basal slip in Laves phases, demonstrating that synchroshear and undulating slip are identical and establishing synchroshear as the primary dislocation propagation mechanism.

Contribution

It provides a definitive comparison of slip mechanisms in Laves phases, confirming synchroshear as the key process through combined atomistic and ab initio simulations.

Findings

Synchroshear and undulating slip are identical mechanisms.

Synchroshear is the energetically favorable dislocation propagation mode.

The study resolves previous ambiguities about basal slip mechanisms.

Abstract

Two different mechanisms have been reported in previous ab initio studies to describe basal slip in complex intermetallic Laves phases: synchroshear and undulating slip. To date, no clear answer has been given on which is the energetically favourable mechanism and whether either of them could effectively propagate as a dislocation. Using classical atomistic simulations supported by ab initio calculations, the present work removes the ambiguity and shows that the two mechanisms are, in fact, identical. Furthermore, we establish synchroshear as the mechanism for propagating dislocations within the basal plane in Laves phases.