针对新型航天飞行器热端部件对耐热钛合金薄板的迫切需求，系统研究了退火温度及冷却速率对 Ti65 合金冷轧薄板显微组织演变及室温拉伸性能的影响，并基于 SEM 和 EBSD 技术深入揭示了其微观变形机理。 结果表明，随退火温度升高(900~1 000 ℃)，合金组织由等轴状转变为片层状，900 ℃退火可获得良好的强塑性匹配；1 000 ℃退火形成片层组织呈现高强度-低塑性的特征。 在 900 ℃/30 min 退火条件下，随冷却速率提高，合金加工硬化能力显著提升，水冷试样实现了抗拉强度(1 142 MPa)与伸长率(12.3%)的协同优化。 经 900 ℃/30 min/WC 优选工艺热处理后，合金拉伸变形以柱面 <a> 滑移为主导，加工硬化阶段锥面 <a> 滑移协同参与。

In response to the critical demand for heat-resistant titanium alloy sheets in hot-end components of advancedaerospace vehicles, the effects of the annealing temperature and cooling rate on the microstructure evolution androom-temperature tensile properties of cold-rolled Ti65 alloy sheets were systematically investigated. Additionally, themicrodeformation mechanisms were elucidated via SEM and EBSD techniques. The results indicate that increasing theannealing temperature from 900 ℃ to 1 000 ℃ induces a microstructural transformation from an equiaxed morphology to alamellar morphology. Consequently, samples annealed at 900 ℃ exhibit excellent synergy in terms of strength and ductility,whereas the lamellar microstructure formed at 1 000 ℃ is characterized by high strength but significantly reduced ductility.After annealing at 900 ℃ for 30 min, an increase in the cooling rate significantly enhances the work-hardening capacity ofthe alloy. Notably, the ultimate tensile strength (1 142 MPa) and elongation (12.3%) of the water-cooled (WC) samples aresimultaneously optimized. For the alloy treated via the optimized process (900 ℃/30 min/WC), the tensile deformationbehavior is dominated primarily by prismatic <a> slip, whereas pyramidal <a> slip acts as a cooperative mechanism duringthe work-hardening stage.