A hierarchical and multiphase nanolaminated alloy with an excellent combination of tensile properties

Ti alloys that possess a fine fully lamellar structure generally exhibit high strength but limited ductility. In this study, a hierarchical and multiphase nanolaminated structure that consists of large microscale primary αp grains (~1.5 μm), sub-microscale α plates (~200 nm) and nanoscale acicular isothermal (orthorhombic) α″ martensites (~15 nm) is produced in a TiZrAlV alloy with a fine (~12 μm) β grain size through the use of severe plastic deformation (SPD) combined with subsequent recrystallisation annealing and aging treatments. This specific structure results in an excellent combination of tensile properties, e.g., an ultimate tensile strength of σb~1545 MPa and an elongation to failure of εf~7.9%. The present study demonstrates an alternative route for enhancing the mechanical properties of titanium alloys with laminated structures.