Cu-enabled lamellar architecture for enhanced mechanical properties in Ti-Mo alloys

Despite growing interest in Cu-containing titanium alloys, how Cu regulates microstructures in Ti alloys remains unclear. Here, we demonstrate that Cu converts the basket-weave-like structure into a lamellar architecture in cast Ti-Mo alloy. Hot rolling at 780°C refines and aligns this framework, yielding a α/β hierarchical structure with a strength-ductility synergy of 1154 MPa ultimate tensile strength (UTS) and 12.6% elongation. Rolling at 850 °C induces a heterogeneous structure of blocky αp, nanoscale αs, retained β, and precipitated Ti2Cu, which delivers ultrahigh UTS of 1364 MPa with 6.3% elongation. This work establishes a Cu-regulated microstructure strategy for titanium alloys.