ω-phase within α2+γ lamellar structure in Ti-45Al-10Nb alloy

ω-phase in α2+γ lamellar structure of Ti-45Al-10Nb alloy (atomic fraction, %) was investigated by high resolution electron microscopy (HREM). The orientation relationship between ω phase and α2+γ lamella was identified as [0001]ω // [Left Angle Bracket] 112 over-bar 0 [Right Angle Bracket] α2 // [Left Angle Bracket] 11 over-bar 0 [Right Angle Bracket] γ, {112 over-bar 0}ω // (0002)α2 // {111}γ. The ω phase with B82 structure further evolved to ω* phase with D88 structure in α2 lamella. It is possible that α2 -> ω direct transition occurred in lamellar structure.