On the temperature and chemical dependency of prismatic stacking faults in C14 Laves phases

TL;DR

This study uses atomistic simulations to explore how temperature and chemical composition influence prismatic stacking faults and non-basal slip mechanisms in C14 Laves phases, enhancing understanding of their deformation behavior.

Contribution

It provides new insights into the temperature and chemical dependence of prismatic stacking faults in C14 Laves phases through atomistic simulation analysis.

Findings

Multiple prismatic stacking fault states identified at various conditions.

Prismatic slip is thermally activated involving short-range diffusion.

Results extend understanding of slip mechanisms in complex intermetallics.

Abstract

Activation of non-basal slip is essential in improving the deformability of hexagonal crystals. However, the mechanism of non-basal slip remains largely unknown, especially for complex intermetallics such as Laves phases. In this work, the prismatic slip systems of C14 Laves crystals and possible metastable states along the slip paths are assessed using atomistic simulations. Multiple prismatic stacking fault states with the same lattice pattern but different site occupancies and chemical distributions are identified at different inter-atomic layers, temperatures and chemical compositions. The formation of energetically favorable prismatic stacking faults involves short-range diffusion which implies the thermally activated nature of prismatic slip. The outcomes of this work advance the understanding of temperature and chemical-dependent non-basal slip in Laves phases and can be extended to other topologically close-packed phases.