Investigation of early stage deformation mechanisms in a metastable β titanium alloy showing combined twinning-induced plasticity and transformation-induced plasticity effects

F. Sun (1) , J. Y. Zangh (1) , M. Marteleur (2) , Thierry Gloriant (3) , P. Vermaut (1) , Denis Laillé (3) , Philippe Castany (3) , C. Curfs (4) , P. J. Jacques (2) , F. Prima (1)

1 LPCS - Laboratoire de Physico-Chimie des Surfaces
2 IMMC - Institute of Mechanics, Materials and Civil Engineering [Louvain]
3 ISCR - Institut des Sciences Chimiques de Rennes
4 ESRF - European Synchrotron Radiation Facility

As expected from the alloy design procedure, combined Twinning Induced Plasticity (TWIP) and Transformation Induced Plasticity (TRIP) effects are activated in a metastable β Ti-12(wt.%)Mo alloy. In-situ Synchrotron X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) observations were carried out to investigate the deformation mechanisms and microstructure evolution sequence. In the early deformation stage, primary strain/stress induced phase transformations (β->ω and β->α'') and primary mechanical twinning ({332}<113> and {112}<111>) are simultaneously activated. Secondary martensitic phase transformation and secondary mechanical twinning are then triggered in the twinned β zones. The {332}<113> twinning and the subsequence secondary mechanisms dominate the early stage deformation process. The evolution of the deformation microstructure results in a high strain hardening rate (~2GPa) bringing about high tensile strength (~1GPa) and large uniform elongation (> 0.38).

Mots clés: In situ synchrotron XRD; Titanium alloy; Deformation twinning; Martensitic phase transformation; Deformation mechanism

Domaines: Matériaux

F. Sun, J. Y. Zangh, M. Marteleur, Thierry Gloriant, P. Vermaut, et al.. Investigation of early stage deformation mechanisms in a metastable β titanium alloy showing combined twinning-induced plasticity and transformation-induced plasticity effects. Acta Materialia, 2013, 61 (issue 17), pp.6406-6417. ⟨10.1016/j.actamat.2013.07.019⟩. ⟨hal-00865174⟩