α′ Martensite Ti–V–Sn alloys with low Young's modulus and high strength

Microstructures and mechanical properties of strength, ductility and Young's modulus were investigated using quenched and cold rolled Ti–V and Ti–V–Sn alloys consisting of α′ martensite. Young's modulus of both quenched and cold rolled (Ti–8 mass% V)–Sn alloys decreases with increasing Sn content, which is attributable to the lattice expansion by Sn addition. During cold rolling to a reduction of 86%, acicular α′ martensite structure in quenched Ti–8 mass% V and (Ti–8 mass% V)–4 mass% Sn changes into extremely fine dislocation cell-like structure with an average size of 60 nm, thereby increasing strength drastically. Sn addition to Ti–V alloys is effective for increasing ductility with keeping low Young's modulus and high strength. Thus, cold rolled α′ martensite Ti–V–Sn alloy is found to be attractive as a new type Ti alloy with low Young's modulus and high strength.