Impact Factor:

9.5

DOI number:

10.1021/acs.nanolett.2c03852

Journal:

Nano Letters

Key Words:

5-fold twin; in situ nanomechanical testing; grain boundary; decomposition partial dislocation

Abstract:

A 5-fold twin is usually observed in nanostructured metals after mechanical tests and/or annealing treatment. However, the formation mechanism of a 5-fold twin has not been fully elaborated, due to the lack of direct time-resolved atomic-scale observation. Here, by using in situ nanomechanical testing combined with atomistic simulations, we show that sequential twinning slip in varying slip systems and decomposition of high-energy grain boundaries account for the 5-fold twin formation in a nanoscale gold single crystal under bending as well as the reversible formation and dissolution of a 5-fold twin in a nanocrystal with a preexisting twin under tension and shearing. Moreover, we find that the complex stress state in the neck area results in the breakdown of Schmid’s law, causing 5-fold twin formation in a gold nanocrystal with a twin boundary parallel to the loading direction. These findings enrich our understanding of the formation process of high-order twin structures in nanostructured metals.

Co-author:

Christopher R Weinberger

First Author:

Xiang Wang, SixueZheng

Indexed by:

Journal paper

Correspondence Author:

Chuang Deng,Guofeng Wang, Scott X Mao

Discipline:

Engineering

Document Type:

J

Volume:

23

Issue:

2

Page Number:

514−522

Translation or Not:

no

Date of Publication:

2023-01-12

Included Journals:

SCI

Links to published journals:

https://pubs.acs.org/doi/full/10.1021/acs.nanolett.2c03852