Martensitic transformation induced dislocation walls in Fe42Mn38Co10Cr10 high-entropy alloy

Two types of hitherto unreported dislocation walls in a cold-deformed Fe42Mn38Co10Cr10 (at.%) high-entropy alloy are characterized using aberration-corrected scanning transmission electron microscopy at the atomic-scale. Both walls are located at the interface between two parallel and juxtaposed marten-site lamellae, although they are respectively constituted by all-30 degrees mixed or all-90 degrees edge Shockley partial dislocations. Within each of these two walls, two different sets of Shockley partials that have Burgers vectors of the same magnitude but opposite signs are arranged alternately on successive basal planes of the hexagonal lattice. The interfaces containing such compact dislocation walls are expected to contribute to strain hardening and plastic accommodation via various dislocation-interface interactions. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study characterized two types of previously unreported dislocation walls in a high-entropy alloy, showing the importance of these structures in strain hardening and plastic accommodation. The walls are constituted by specific types of partial dislocations and play a significant role in dislocation-interface interactions.