Abstract
The effect of oxygen on stability of isothermal omega precipitates in Ti-29Nb-13Ta-4.6Zr was examined using X-ray powder diffraction, transmission electron microscopy, and atom probe tomography. Two alloys with 0.1 and 0.4 mass% oxygen were subjected to single step, and two-step annealing heat-treatments to respectively promote omega and alpha formation. After second step annealing, large volume fraction of omega precipitates was retained in 0.4 mass% O alloy while mainly alpha phase was observed in TNTZ-0.1O. The enhanced stability of omega in the higher oxygen containing TNTZ alloys questions the conventionally accepted understanding that oxygen destabilizes the omega phase in titanium alloys.
| Original language | English |
|---|---|
| Pages (from-to) | 144-148 |
| Number of pages | 5 |
| Journal | Scripta Materialia |
| Volume | 123 |
| DOIs | |
| State | Published - Oct 1 2016 |
| Externally published | Yes |
Keywords
- Atom probe tomography
- Omega phase
- Oxygen
- Phase stability
- β-titanium alloy