Enhancing Mechanical Properties of TiZrAlV by Engineering a Multi-Modal-Laminated Structure†

In the present study, microstructure and mechanical properties of a new β-metastable TiZrAlV prepared via thermomechanical processing (TMP) treatments have been studied. An excellent combination of ultimate tensile strength (σb ≈ 1 630 MPa) and ductility (ϵf ≈ 6.6%) has been achieved in the alloy after cold rolling, thermal annealing (665 °C/1 h), and two-step aging (650 °C/0.5 h + 450 °C/2 h). This is attributed to the formation of a refined β microstructure with grain size of ≈10 µm and a multi-modal-laminated structure that consists of large primary ap grains (2 µm, 9.5 vol%) and coarse α precipitates (300 nm, 21 vol%) and fine α platelets (50 nm, 65 vol%). The fine α platelets contribute to high strength while the large primary αp grains and the refined β grain size provide ductility.