采用等温热压缩实验，在变形温度 820~970 ℃、应变速率 0.001~1.000 s-1 范围内，系统研究了 TA15 钛合金的热变形行为及微观组织演变规律。 真应力-应变曲线呈现典型的流动软化特征，流动应力随变形温度升高而降低，随应变速率升高而增大。建立了考虑应变补偿效应的 Arrhenius 型本构模型，预测值与实验值的相关系数 R=0.990，平均相对误差绝对值 AARE=8.26%， 在 0.001~1.000 s-1 应变速率范围内具有良好预测能力。 基于动态材料模型构建了热加工图，明确了 820~860 ℃、0.1~1.0 s-1 为失稳区，该区域对应高应变速率下再结晶受抑、核平均取向差值异常升高的微观组织特征。 EBSD 分析表明，820 ℃时以不连续动态再结晶为主导，形成“项链状”等轴细晶；随温度升高至 960~970 ℃，演变为全片层组织；在近相变点高温侧，降低应变速率至 0.001~0.010 s-1 有利于获得均匀粗大的全片层组织，而提高应变速率至 0.1~1.0 s-1 则能保留更多等轴 α 相并细化 β 晶粒(由＞100 μm 细化至 ~15 μm)。

The hot deformation behavior and microstructure evolution of TA15 titanium alloy were systematicallyinvestigated via isothermal hot compression tests conducted at deformation temperatures ranging from 820 to 970 ℃ andstrain rates ranging from 0.001 to 1.000 s-1. The true stress-strain curves exhibit typical flow softening characteristics, withflow stress decreasing with increasing temperature and increasing strain rate. A strain-compensated Arrhenius-typeconstitutive model is established, with a good predictive ability, a correlation coefficient (R) of 0.990 and an averageabsolute relative error (AARE) of 8.26% over the strain rate range of 0.001~1.000 s-1. On the basis of the dynamicmaterials model (DMM), heat-processing maps were constructed, identifying the instability domain at 820~860 ℃/0.1~1.0 s-1, which corresponds to the microstructural features of suppressed recrystallization and abnormally elevated KAMvalues at high strain rates. EBSD analysis reveals that discontinuous dynamic recrystallization (DDRX) dominates at 820 ℃,resulting in the formation of a necklace-like equiaxed fine-grained structure. As the temperature increases to 960~970 ℃,the microstructure evolves into a fully lamellar structure. At temperatures near the β-transus, decreasing the strain rate to0.001~0.010 s-1 favours the formation of a uniform and coarse fully lamellar structure, whereas increasing the strain rate to0.1~1.0 s-1 results in the retention of more equiaxed α phase and refined β grains (from >100 μm to ~15 μm).