Strength scaling law, deformation kinetics and mechanisms of nanostructured Ti.

Abstract: We investigate the tensile properties, strain rate sensitivity, and activation volume of nanostructured Ti prepared by equal channel angular pressing plus a series of thermal treatment. Simultaneous enhancement of strength and tensile ductility is achieved. The strain rate sensitivity is found to decrease with decreasing grain sizes (∼150–450nm). A new Hall–petch relationship is presented and discussed. The analyses on the internal friction peaks at around −70°C suggest that twins could play the primary role for the strain hardening of the annealed nanostructured Ti, consistent with the miniscule activation volumes. [Copyright &y& Elsevier]