Cooling rate-dependent phase evolution and mechanical properties in Ti-Mo-Cu alloys

The Ti-Mo-Cu alloy system's high strength-to-weight ratio and low elastic modulus make it a potential lightweight material for structural and biomedical applications. This work applies a thermodynamics-guided strategy to tailor phase stability and mechanical performance under conventional continuous cooling conditions. Phase evolution in Ti-10Mo-XCu (X = 0, 1, 3, and 5 wt%) was evaluated using computational thermodynamics over cooling rates from 0.01 to 10 °C s −1 . The results indicate that phase selection among α, β, Ti 2 Cu, and martensite is strongly governed by both cooling rate and Cu concentration. Martensitic transformation is promoted at higher cooling rates, whereas α, retained β, and Ti 2 Cu are favored under slower cooling conditions. Cu contributes to β stabilization through solid-solution effects and enhances strength via both solid-solution and precipitation strengthening, albeit at the expense of ductility.