Visualization and validation of twin nucleation and early-stage growth in magnesium

Authors

Lin Jiang, University of California-Irvine, Thermo Fisher Scientific
Mingyu Gong, Shanghai Jiao Tong University
Jian Wang, University of Nebraska-LincolnFollow
Zhiliang Pan
Xin Wang, University of California, Irvine
Dalong Zhang, University of California, Irvine
Y. Morris Wang, University of Nebraska-Lincoln
Jim Ciston, Lawrence Berkeley National Laboratory
Andrew M. Minor, Lawrence Berkeley National Laboratory, University of California-Berkeley
Mingjie Xu, University of California, Irvine
Xiaoqing Pan, University of California, Irvine
Timothy J. Rupert, University of California, Irvine
Subhash Mahajan, University of California, Davis
Enrique J. Lavernia, National Academy of Engineering
Irene J. Beyerlein, University of California, Santa Barbara
Julie M. Schoenung, University of California, Irvine

Document Type

Article

Date of this Version

2022

Citation

NATURE COMMUNICATIONS | (2022) 13:20 | https://doi.org/10.1038/s41467-021-27591-z | www.nature.com/naturecommunications

Comments

Open access

Abstract

The abrupt occurrence of twinning when Mg is deformed leads to a highly anisotropic response, making it too unreliable for structural use and too unpredictable for observation. Here, we describe an in-situ transmission electron microscopy experiment on Mg crystals with strategically designed geometries for visualization of a long-proposed but unverified twinning mechanism. Combining with atomistic simulations and topological analysis, we conclude that twin nucleation occurs through a pure-shuffle mechanism that requires prismatic-basal transformations. Also, we verified a crystal geometry dependent twin growth mechanism, that is the early-stage growth associated with instability of plasticity flow, which can be dominated either by slower movement of prismatic-basal boundary steps, or by faster glide-shuffle along the twinning plane. The fundamental understanding of twinning provides a pathway to understand deformation from a scientific standpoint and the microstructure design principles to engineer metals with enhanced behavior from a technological standpoint.