利用高分辨电镜（ＨＲＥＭ）观察了Ｔｉ－４５Ａｌ－１０Ｎｂ（原子分数，％）合金α２＋γ层状结构中的ω相。发现ω相与α２和γ片层存在着取向关系［０００１］ω／／＜１１２０＞α２／／＜１１０＞γ，｛１１３０｝ω／／（０００２）α２／／｛１１１｝γ．同时，观察到在片层中具有Ｂ８２结构的ω相进一步转变为Ｂ８８结构的ω相．片层中可能存在着α２→ω的直接转变 The phase of α2 + γ phase in Ti-45Al-10Nb (atomic fraction,%) alloy was observed by high resolution electron microscopy (HREM). It is found that the ω phase has an orientation relationship with the α2 and γ sheets [0001] ω // <1120> α2 // <110> γ, {1130} ω // (0002) α2 // {111} γ. In the meantime, it is observed that the ω phase having the B82 structure in the sheet layer is further transformed into the ω phase of the B88 structure. There may be a direct transition of α2 → ω in the slice