Effect of reverse β-to-ω transformation on twinning and martensitic transformation in a metastable β titanium alloy

A metastable β titanium alloy, Ti–2Al-9.2Mo–2Fe (wt.%), with athermal ω phase after quenching has been subjected to high strain rate (∼3000 s−1) compression at ambient temperature by Spilt Hopkinson Pressure Bar arrangement. Reverse β-to-ω transformation was investigated by transmission electron microscopy during deformation. Furthermore, the novel distribution of athermal ω phase in {332} twinning and stress-induced martensitic was observed. We reveal that such novel distribution is attributed to the influence of ω phase on {332} twinning and stress-induced martensite transformation (SIMT) based on the viewpoint of the instability of the lattice structure of metastable β phase. Furthermore, a new process of twinning and SIMT in current alloy with ω phase was proposed.