Investigations of the role of SIM α’’ phase in the plasticity of β- metastable Ti alloys exhibiting TRIP and TWIP effects

Marteleur, Matthieu [UCL] Jacques, Pascal [UCL] et al.

β titanium alloys are becoming more and more used in several application fields thanks to their unique combination of properties. However, they still suffer from a lack of work hardening resulting in a rapid strain localization and low ductility levels, which can be a serious drawback in applications requiring plasticity. In previous studies, a design strategy had been developped to predict compositions allowing the activation of multiple plastic deformation mechanisms [1]. Various characterization methods confirmed the activation of TWIP (Twinning Induced Plasticity) and TRIP (Transformation Induced Plasticity) effects [2]. Understanding the role of each mechanisms is thus a key issue for their optimization. In-situ tensile tests with synchrotron X-ray diffraction (SXRD) have been performed to investigate the role of the β to α’’ stress-induced martensitic transformation.