Enhancing ductility and elevated-temperature strength of Ti ₂ AlNb-based alloys via tailored lamellar heterostructure

A heterogeneous lamellar structure (HLS) was engineered in a Ti2AlNb-based alloy via near-transus hot rolling to synergize room-temperature ductility and high-temperature strength. The alloy achieves a room-temperature yield strength of 939 MPa and a superior elongation of 13.3% (a 177% improvement over homogeneous counterparts) alongside an exceptional 650 °C tensile strength of 1106 MPa. This ductility is governed by interfacial strain partitioning and hetero-deformation-induced (HDI) hardening, driving synergistic co-deformation. At 650 °C, nanoscale O-phase precipitation provides potent obstacles to dislocation glide, securing high-temperature strength. This work demonstrates a hetero-interface engineering strategy to overcome the cross-temperature performance trade-off in Ti2AlNb-based alloys.