| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Metastable Phases and Phase Equilibria: Towards Designing the Next Generation of Alloys
|
| Presentation Title |
Precipitation Kinetics and Mechanical Behavior of Oxygen-stabilized Metastable Beta Ti-Nb Alloys |
| Author(s) |
Kathleen Chou, Emmanuelle Marquis |
| On-Site Speaker (Planned) |
Kathleen Chou |
| Abstract Scope |
Phase stability in metastable beta titanium has been actively investigated to develop alloys with controllable deformation behavior including superelasticity and TRIP/TWIP mechanisms. Oxygen has shown substantial influence through martensite suppression and stability changes in beta Ti that significantly affect deformation. In this work, a model Ti-20Nb (at. %) alloy was oxidized to obtain a dissolved oxygen gradient in the beta matrix, and subsequently aged to understand oxygen effects on metastable omega and stable alpha phase formation. During ageing, oxygen induced an increase in the omega number density and a change in the omega morphology from ellipsoid to rod-like. Elevated oxygen content expanded the omega phase stability region up to above 600 °C. Micropillar compression testing suggests enhanced work-hardening for oxygen-stabilized microstructures compared to oxygen-free specimens. These insights on oxygen as both an alpha and omega stabilizer open new avenues of microstructural control and design of beta Ti alloys. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |