Strong and ductile nanoscale Ti-1Fe dual-phase alloy via deformation twinning

A nanoscale Ti-1Fe dual-phase alloy was fabricated by laser powder bed fusion. The microstructure, phase constituent, and tensile properties of this alloy were examined to understand the mechanisms of nanotwin formation and its deformation. The interfacial coherency between the α/α’-Ti and β-Ti phases, along with the abundance of dislocations at grain boundaries and the increased Schmid factor after deformation, effectively lowered the strain level needed to generate deformation twins. The resulting deformation twinning, grain refinement, and solid solution of Fe all contributed to the alloy's excellent room-temperature tensile strength of 1021.7±15.2 MPa and ductility of 13.4±0.8 %. This study provides a path towards the design of high-performance and economical titanium materials without using expensive alloying elements. [Display omitted]