Abstract
Microstructures of α precipitation from a deformed β matrix by thermomechanical processing were studied in a representative β titanium alloy, i.e. Ti-15V-3Cr-3Sn-3Al alloy. In the aged specimens, after solution treatment, the grain boundary is the most preferential nucleation site in the α precipitation. Localized slip occurs in the β matrix by cold rolling after solution treatment whereas {332}<113> deformation twins are formed by subzero rolling at 77 K. After subsequent aging of the rolled specimens, the α phase preferentially forms on those defects in the β matrix with a low energy orientation relationship (Burgers relationship). There is strong variant restriction in heterogeneous nucleation on such defects. Controlled short time annealing above the β transus (β recovery treatment) after cold rolling produces the fine β subgrain. By subsequent aging, α precipitates form preferentially on β subgrain boundaries and also within β subgrains. A great number of α variants are observed locally in the recovered and aged specimens than those in the cold rolled and aged specimens. β recovery treatment prior to aging improves the strength-ductility balance mostly because of the increase of local elongation.
Original language | English |
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Pages (from-to) | 221-224 |
Number of pages | 4 |
Journal | Metals and Materials International |
Volume | 6 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2000 Jun |
Externally published | Yes |
Keywords
- Crystallography
- Microstructure
- Precipitation
- Strength
- Titanium alloy
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry