TiAl 合金以其低密度、高比刚度与高比强度，以及出色的高温力学性能在航空航天领域展现出重要的应用前景。 然而，该合金目前仍面临室温塑性较差、损伤容限有限及热加工难度较大等挑战，限制了其在实际工程中的广泛应用。 近年来的研究指出，通过调控合金组织，获得均匀且细小的片层结构，被认为是提升其室温塑性和改善加工性能的有效方法之一。本文以 Ti-42Al-6.5V-2Zr 合金为研究对象，在 β 单相区进行淬火处理，获得了以板条马氏体 α2 为主的显微组织，随后对马氏体组织进行保温及加载实验，实现了 TiAl 合金组织细化。 通过高能 X 射线衍射研究了中温保温及加载过程中的组织演化，结果表明，应力促进了 α2 相向 γ 相转变，α2 相和 γ 相力学各向异性导致 α2 相内弹性应变能和晶体缺陷的快速增加，显著促进了片层 γ 相形成。

TiAl alloys demonstrate significant application potential in the aerospace field because of their low density, high specific stiffness and strength, and excellent high temperature mechanical properties. However, challenges such as poor room-temperature plasticity, limited damage tolerance, and difficulties in hot working still hinder their widespread use in practical engineering. Research has suggested that obtaining a uniform and fine lamellar microstructure through microstructural control is an effective approach for enhancing room-temperature plasticity and improving workability. This study focused on a Ti-42Al-6.5V-2Zr alloy, which was subjected to quenching from the β single-phase region to obtain a microstructure dominated by lath martensite α2. Subsequent holding and loading experiments were performed on the martensitic structure to achieve microstructural refinement of the TiAl alloy. The subsequent microstructural evolution during intermediate-temperature holding and loading was studied by high-energy X-ray diffraction. The applied stress significantly promotes the phase transformation from α2 to γ.The mechanical anisotropy between the α2 and γ phases leads

to rapid accumulation of elastic strain energy and crystal defects within the α2 phase, which markedly accelerates the formation of the lamellar γ phase.