Formation of deformation-induced bimodal grain structure of a high strength Ti₉₃Co₇ alloy with enhancing plasticity

A minor Co addition to pure Ti can yield a ω-phase distributed along the large β-Ti grain boundaries in the as-cast Ti₉₃Co ₇ sample. During compression of the sample, a refinement of the ω-phase occurs yielding a unique bimodal grain structure comprising large β and nano-scale ω grains. A large plasticity of ∼30% combined with high strength of the Ti₉₃Co₇ sample (∼1.8 GPa) can be obtained through local shear dissipation during the refinement of the ω-phase.