Work hardening and softening behavior driven by α′′-β interactions in a metastable β titanium alloy
In this study, a metastable β Ti–7Mo–3Al–3Cr–3Nb alloy with αs+β microstructure shows both TRIP and TWIP effects. Although the alloy has a low yield strength of 433 MPa, it shows a high work hardening rate of approximately 8.3 GPa. Besides, it has a total elongation of nearly 20 %. The deformation m...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-05-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785425013729 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | In this study, a metastable β Ti–7Mo–3Al–3Cr–3Nb alloy with αs+β microstructure shows both TRIP and TWIP effects. Although the alloy has a low yield strength of 433 MPa, it shows a high work hardening rate of approximately 8.3 GPa. Besides, it has a total elongation of nearly 20 %. The deformation mechanism was systematically investigated by combining EBSD and TEM analysis on specimens with tensile strains of 1.7 %, 3.5 %, 8.3 %, until failure. The primary deformation mechanisms during tensile deformation are stress-induced α′′ martensitic transformation and dislocation slip. At strain initiation stage stress-induced lath martensite forms, accompanied by its growth, widening, and merging. At medium strain levels, martensitic domains form, accompanied by the appearance of a small number of martensitic twins. At high strain levels, a significant increase in martensitic twins is observed. The high work hardening rate is attributed to the continuous cutting of the β phase by martensitic variants that growing in different directions under low strain levels, which leads to a dynamic Hall-Petch effect. In the later stages of deformation, various types of martensitic twins form within the martensite domain until the matrix β phase is exhausted, playing a crucial role in achieving significant uniform elongation. |
|---|---|
| ISSN: | 2238-7854 |