Ductile ultrafine-grained Ti-based alloys with high yield strength

The authors report on ductile ultrafine-grained (Ti0.72Fe0.28)100−xTax (0 ⩽ x ⩽ 4) alloys with not only high fracture strength but simultaneously high yield strength exceeding 2000 MPa along with distinct plasticity, which are superior to high-strength Ti-based bulk metallic glasses and bimodal composites. All alloys mainly consist of β-Ti and FeTi solid solutions but display different microstructures. The alloys exhibit a high fracture strength >2500 MPa and a high yield strength >2000 MPa as well as large plasticity of ∼ 5%–7.5%. The microstructure-property correlation of these ultrafine-grained alloys is discussed.