On the nucleation mechanism of {112}〈111〉mechanical twins in as-quenched β metastable Ti-12 wt.% Mo alloy
(2019) Materialia — Vol. 7, p. 100418 (2019)
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- Authors
Marteleur, Matthieu 
- Abstract
- Recently developed 𝛽-metastable Ti grades take advantage of the simultaneous activation of TRIP and TWIP effects for enhancing their work hardening rate. However, the role of each plasticity mechanism on the macroscopic mechanical response is still unclear. In this work, the nucleation mechanism of the first activated plasticity mechanism, namely { 112 } ⟨111 ⟩ twinning, was investigated. Firstly, post-mortem TEM analysis showed that twins nucleate on pre-existing microstructural defects such as thermal jogs with the zonal dislocation mechanism. The precipitation of the 𝜔 phase on twin boundaries has been observed, as well as the emission of numerous dislocations from super-jogs present in these twin boundaries. It is also shown that { 112 } ⟨111 ⟩twins act as effective dislocation sources for the subsequent plasticity mechanisms such as 𝛽→𝛼′′martensitic transformation and { 332 } ⟨113 ⟩twinning. Secondly, in situ TEM tensile testing of the investigated Ti grade highlighted the primary role of the initial defect configuration present in the microstructure. It is shown that twins cannot nucleate without the presence of specific defects allowing the triggering of the dislocation decomposition needed for the twinning mechanism highlighted in investigated bulk samples.
- Affiliations
University of Antwerp EMAT, Department of Physics Colorado School of Mines Department of Mechanical Engineering PSL Research University Chimie ParisTech, Institut de Recherche de Chimie Paris
Citations
Marteleur, M., Idrissi, H., Amin-Ahmadi, B., Prima, F., Schryvers, D., & Jacques, P. (2019). On the nucleation mechanism of {112}〈111〉mechanical twins in as-quenched β metastable Ti-12 wt.% Mo alloy. Materialia, 7, 100418. https://doi.org/10.1016/j.mtla.2019.100418 (Original work published 2019)