Role of oxygen in stress-induced ω phase transformation and {3 3 2}〈1 1 3〉 mechanical twinning in βTi–20V alloy

The Ti–20V wt.% alloy containing a low level of oxygen plastically deforms via stress-induced ω phase transformation, while the same alloy with a high level of oxygen deforms via {3 3 2}〈1 1 3〉 twinning. The high level of oxygen suppresses stress-induced ω phase transformation. The high-oxygen Ti–20V wt.% alloy has a much lower Young’s modulus and high yield strength compared with the low-oxygen alloy. Oxygen plays a significant role in stress-induced ω phase transformation and {3 3 2}〈1 1 3〉 mechanical twinning, which governs the mechanical properties of βTi–20V wt.% alloys.