Abstract
The tensile deformation mode at ambient temperature and the crevice corrosion resistance at a high temperature of 373 K were investigated in Ti-15Mo and Ti-15Mo-1Fe (mass%) alloys. The β phase stability increased, and the formation of an athermal ω phase was suppressed by the Fe addition. EBSD and TEM observations showed that the deformation mode in the Ti-15Mo alloy changed from a {3 3 2}〈1 1 3〉 twinning to a slip by the Fe addition, which coincided with the predictions from the electron/atom (e/a) ratio and the Mo equivalency. EPMA examinations indicated that the existence of twins in a few regions in the Ti-15Mo-1Fe alloy was caused by the solidification segregation of Mo and Fe atoms. The yield strength of the Ti-15Mo-1Fe alloy of 837 MPa was much higher than that of the Ti-15Mo alloy of 439 MPa due to the change in the deformation mode. The Ti-15Mo-1Fe alloy maintained an extremely high crevice corrosion resistance in a 10% NaCl water solution with a pH value of 0.5 at 373 K since there was no significant decrease in the average value of the bond order (Bo). A good combination of tensile properties, crevice corrosion resistance and cost is thought to be obtainable through further optimization of the chemical compositions by the e/a ratio, the Mo equivalency and the Bo.
| Original language | English |
|---|---|
| Pages (from-to) | 2693-2701 |
| Number of pages | 9 |
| Journal | Materials Science and Engineering A |
| Volume | 527 |
| Issue number | 10-11 |
| DOIs | |
| Publication status | Published - 2010 Apr 25 |
| Externally published | Yes |
Keywords
- Beta titanium alloys
- Crevice corrosion
- Deformation mode
- Phase stability
- Solidification segregation
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering