Gao, J., Sharp, J., Guan, D. et al. (2 more authors) (2015) New compositional design for creating tough metallic glass composites with excellent work hardening. Acta Materialia, 86. 208 - 215. ISSN 1359-6454
Abstract
The extrinsic size of both crystalline alloys and amorphous metallic alloys strongly affects their mechanical properties at the submicron scale or nanometre scale. For example, Zr-based metallic glass nanopillars exhibit ceramic-like strengths (2.25 GPa) and metal-like ductility (25%) simultaneously when the pillar dimension is reduced to <100 nm. Here, we report a new compositional design approach to create tough metallic glass composites consisting of micrometre-scale dendrites and nanometre-scale amorphous matrices that exhibit high strength and ductility in the normally brittle MgZnCa metallic glass system. When the thickness of the amorphous matrix is reduced to the nanometre scale, a low density (ρ ≈ 1.99 g cm−3) Mg91.5Zn7.5Ca1 alloy exhibits room temperature tensile ductility exceeding 15.6%, a yield strength of 215 MPa and a fracture strength of 478 MPa. Transmission electron microscopy analysis demonstrates that the alloy consists of micrometre-scale α-Mg solid solution dendrites and nanometre-scale amorphous matrix (80–530 nm in thickness). The homogeneous deformation of nanometre scale amorphous matrices is believed to be responsible for the high toughness and excellent work-hardening behaviour.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
Keywords: | Mg-based metallic glass composite; Composition design; Work hardening; Homogeneous deformation |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 13 Jul 2015 14:23 |
Last Modified: | 09 Dec 2015 04:49 |
Published Version: | http://dx.doi.org/10.1016/j.actamat.2014.11.055 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.actamat.2014.11.055 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:87918 |