High-velocity projectile impact induced 9R phase in ultrafine-grained aluminium

Authors

Sichuang Xue, Purdue University
Zhe Fan, Purdue University
Olawale B. Lawal, Rice University
Ramathasan Thevamaran, University of Wisconsin-Madison
Qiang Li, Purdue University
Yue Liu, Shanghai Jiao Tong Univeristy
K. Y. Yu, China University of Petroleum
Jian Wang, University of Nebraska-LincolnFollow
Edwin L. Thomas, Rice University
Haiyan Wang, Purdue University
Xinghang Zhang, Purdue UniversityFollow

Document Type

Article

Date of this Version

2017

Citation

NATURE COMMUNICATIONS 8: 1653, DOI: 10.1038/s41467-017-01729-4.

Comments

Copyright © The Author(s) 2017. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

Aluminium typically deforms via full dislocations due to its high stacking fault energy. Twinning in aluminium, although difficult, may occur at low temperature and high strain rate. However, the 9R phase rarely occurs in aluminium simply because of its giant stacking fault energy. Here, by using a laser-induced projectile impact testing technique, we discover a deformation-induced 9R phase with tens of nm in width in ultrafine-grained aluminium with an average grain size of 140 nm, as confirmed by extensive post-impact microscopy analyses. The stability of the 9R phase is related to the existence of sessile Frank loops. Molecular dynamics simulations reveal the formation mechanisms of the 9R phase in aluminium. This study sheds lights on a deformation mechanism in metals with high stacking fault energies.