Title: Characteristic boundaries associated with three-dimensional twins in hexagonal metals

Abstract

Twinning is a critically important deformation mode in hexagonal close-packed metals. Twins are three-dimensional (3D) domains, whose growth is mediated by the motion of facets bounding the 3D twin domains and influences work hardening in metals. An understanding of twin transformations therefore necessitates that the atomic-scale structure and intrinsic mobilities of facets be known and characterized. The present work addresses the former point by systematically characterizing the boundary structures of 3D $$\overline{\{1}$$012} twins in magnesium using high-resolution transmission electron microscopy (HRTEM). Eight characteristic facets associated with twin boundaries are reported, five of which have never been experimentally observed before. Further, molecular dynamics simulations suggest that the formation and motion of these facets is associated with the accumulation of twinning dislocations. This work provides insights into understanding the structural character of 3D twins and serves to develop strategies for modulating twin kinetics by modifying twin boundaries, such as solute segregation.

Authors:

Wang, Shujuan  ^[1];

• Search DOE PAGES for author "Wang, Shujuan"
• Search DOE PAGES for ORCID "0000-0001-5650-8370"

Gong, Mingyu ^[2]; McCabe, Rodney J.  ^[1];

• Search DOE PAGES for author "McCabe, Rodney J."
• Search DOE PAGES for ORCID "0000-0002-6684-7410"

Capolungo, Laurent ^[1]; Wang, Jian  ^[3];

• Search DOE PAGES for author "Wang, Jian"
• Search DOE PAGES for ORCID "0000-0001-5130-300X"

Tomé, Carlos N. ^[1]

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+ Show Author Affiliations

1. Material Science and Technology Division, Los Alamos National Lab, Los Alamos, NM 87545, USA.
2. Material Science and Technology Division, Los Alamos National Lab, Los Alamos, NM 87545, USA., Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA.
3. Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA.

Publication Date:

Fri Jul 10 00:00:00 EDT 2020

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1637978

Alternate Identifier(s):

OSTI ID: 1815598

Grant/Contract Number:  

W-7405-ENG-36

Resource Type:

Published Article

Journal Name:

Science Advances

Additional Journal Information:

Journal Name: Science Advances Journal Volume: 6 Journal Issue: 28; Journal ID: ISSN 2375-2548

Publisher:

American Association for the Advancement of Science (AAAS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 42 ENGINEERING