Interface Facilitated Reorientation of Mg Nanolayers in Mg-Nb Nanolaminates

Authors

Y. CHen, University of Minnesota, MinneapolisFollow
Mingyu Gong, University of Nebraska–LincolnFollow
N. A. Mara, University of Minnesota, Minneapolis
Jian Wang, University of Nebraska-LincolnFollow

Date of this Version

2019

Citation

Published in JOM: The Journal of The Minerals, Metals & Materials Society 71:4 (April 2019), pp 1215–1220.

https://doi.org/10.1007/s11837-019-03360-8

Comments

Copyright © 2019 The Minerals, Metals & Materials Society. Published by Springer Nature. Used by permission.

Abstract

Mg/Nb nanolaminates synthesized through vapor deposition techniques exhibit high flow strength without conventional twinning in Mg. In this work, we investigated the influence of laminated microstructures on deformation mechanisms of Mg nanolayers. Using molecular dynamics simulations, we explored that (0001)-oriented Mg layers transform or re-orient to {10¯10}-oriented Mg layers through nucleation and growth of {10¯12} twins by atomic shuffling, instead of conventional {10¯12} twinning shear. Such a reorientation accommodates in-plane compressive strain and out-of-plane tensile strain when Mg/Nb laminates are subjected to compression parallel to the Mg/Nb interfaces. The nucleation of {10¯12} twins is promoted at the Mg/Nb interface due to the structural change associated with the glide of interface dislocations. The growth of {10¯12} twins is accomplished through migration of basal–prismatic boundaries via nucleation and glide of one-layer and two-layer disconnections associated with atomic shuffling. The results shed light on improving mechanical properties of hexagonal close-packed metals employing laminated structures.