A hierarchical nanolamella-structured alloy with excellent combinations of tensile properties

Dual phase (α+β)-Ti alloys with a fully fine laminated microstructure usually exhibit a high strength but a limited ductility. In the present study, a hierarchical nanolaminated microstructure consisting of lamellae with nano- and submicrometer-sized widths has been produced in a TiZrAlV alloy by employing severe plastic deformation (SPD) combined with subsequent thermal annealing. The hierarchical nanolamella-structured Ti alloy exhibits excellent combinations of tensile properties, e.g., an ultimate tensile strength σUTS=1600 MPa and an elongation to failure εf=6.5%. The high strength can be attributed to the formation of a lot of nanoscale α lamellae in the alloy, and the enhanced ductility results mainly from both the coarse α lamellae that have a high strain hardening capability and the complex strain paths caused by a hierarchical nanolaminated structure.