Gao, J., Huang, Y., Guan, D. orcid.org/0000-0002-3953-2878 et al. (4 more authors) (2018) Deformation mechanisms in a metastable beta titanium twinning induced plasticity alloy with high yield strength and high strain hardening rate. Acta Materialia, 152. pp. 301-314. ISSN 1359-6454
Abstract
Metastable β titanium alloys with both twinning (TWIP) and martensite transformation (TRIP) usually exhibit a low yield strength of between 200 and 500 MPa, but high strain hardening rate and large uniform elongation. Alloys that exhibit twinning on a single system provide a higher yield strength, but a lower strain hardening rate. Here, for the first time, we report a new alloy (Ti-7Mo-3Cr wt%) with both high yield strength (695 MPa) and high work hardening rate (∼1900 MPa) and a substantial 33.3% uniform elongation. The deformation mechanisms were systematically investigated using EBSD and TEM for samples strained to 1.3%, 5% and 16%. The high yield strength was achieved through initial deformation mechanisms of two twin systems, namely both {332}<113> and {112}<111> twinning. Importantly, the martensite transformation was suppressed at this stage of deformation. The combination of two twin systems, with approximately the same intensity, resulted in a high strain hardening rate (1600 MPa–1900 MPa), much greater compared to alloys that exhibit a single twin system. Moreover, the TRIP effect was observed at strains greater than 5%, which also contributed to the high strain hardening rate large uniform elongation.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 Acta Materialia Inc. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Dates: |
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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: | 09 Aug 2018 10:33 |
Last Modified: | 09 Aug 2018 10:33 |
Published Version: | https://doi.org/10.1016/j.actamat.2018.04.035 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.actamat.2018.04.035 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:133645 |