TiAl 合金因具有低密度、高温抗氧化能力以及综合优异的高温力学性能，成为航空航天领域备受关注的轻质高温结构材料。然而，TiAl 合金室温本征脆性的缺点，严重限制了其在工程应用中的潜力。因此，改善组织均匀性和晶粒细 化 ，是 TiAl 合金的研究 热点 。 本文以铸造Ti-48Al-2Cr-2Nb 合金 为 研 究 对 象 ，结合 低 温 预 形 变 和 后 续 热 处 理 ，探究了形变热处理参数对 TiAl 合金组织演变的影响规律，同时采用高温激光共聚焦手段，原位分析了低温变形组织的再结晶、晶粒生长、片层析出等现象。 结果表明，基于铸态合金片层团尺寸为 400 μm 的初始粗大组织，通过科学控制高于韧脆转变温度的低温预形变和 α+γ 两相区后续热处理参数，可以获得片层团和 γ 晶粒分别为 21 和 12 μm 的细晶双态组织。

TiAl alloys possess advantages such as low density, excellent high-temperature oxidation resistance, and comprehensive high-temperature mechanical properties, making them highly regarded as lightweight high-temperature structural materials in the aerospace industry. However, the inherent brittleness of TiAl alloys at room temperature severely imits their potential for engineering applications. Consequently, improving the microstructural uniformity and grain refinement has become a research focus for TiAl alloys. The influence of deformation heat treatment parameters on microstructural evolution in cast Ti-48Al-2Cr-2Nb alloys was investigated by employing a combination of low-temperature pre-deformation and subsequent heat treatment. Additionally, in situ observations using high-temperature laser scanning confocal microscopy were employed to analyse phenomena such as recrystallization, grain growth, and lamellar precipitation in the low-temperature deformed microstructure. Starting from an initial coarse microstructure of the as-cast alloy with lamellar colonies of approximately 400 μm, fine-grained duplex microstructures with lamellar colonies and γ grain sizes of 21 and 12 μmcan be obtained through scientifically controlled low-temperature pre-deformation above the ductile-to-brittle transition temperature and subsequent heat treatment in the α+γ phase region.