|About this Abstract
||MS&T22: Materials Science & Technology
||Processing-Microstructure-Property Relationships of Titanium and Titanium Alloys
||Role of Oxygen on Phase Stability, Precipitation, and Deformation in Beta Titanium Alloys
||Kathleen Chou, Emmanuelle Marquis
|On-Site Speaker (Planned)
Titanium’s reactivity with oxygen presents significant challenges to mechanical performance, including embrittlement caused by oxygen in solid solution. Oxygen modifies the phase formation and precipitation sequences in metastable β titanium alloys, which results in novel mechanical behavior suggestive of potential new application spaces. Compositionally-graded microstructures were created using oxidation followed by ageing to understand oxygen’s influence on ω and α phase precipitation kinetics and morphologies in β Ti-Nb, Ti-15-333, and Ti-15Mo alloys. Elevated oxygen levels induced morphology, number density, and size changes for the ω phase and accelerated α nucleation rate. Notably, oxygen partitioning to ω during ageing resulted in increased resistance of ω to precipitate shearing and suppression of catastrophic failure during micropillar compression. Furthermore, oxygen-induced α refinement provides a pathway to obtain fine α laths for accelerated precipitation strengthening of β Ti alloys. These findings provide design strategies to mitigate detrimental effects from interstitial oxygen and ω precipitation.