Non-diffusional growth mechanism of I-1 basal stacking-faults inside twins in hcp metals

A Ostapovets and A Serra and RC Pond, SCRIPTA MATERIALIA, 172, 149-153 (2019).

DOI: 10.1016/j.scriptamat.2019.07.024

Deformation twins in magnesium exhibit considerable densities of I-1 basal-plane stacking-faults. Since these faults generally transect their host twin, they presumably lengthen concommitantly with boundary migration during twin growth. We investigate this process using atomic- scale simulation for 10 (1) over bar2 and 10 (1) over bar1 twinning. It is demonstrated first that the intersection of a stacking-fault with a stationary twin boundary is delineated by a sessile imperfect disconnection. Subsequently, by applying a shear strain, we stimulate twin growth by the passage of twinning disconnections along twin boundaries, and show that these are able to propagate through such pre- existing imperfect disconnections in a conservative manner. (C) 2019 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved.

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