(1. 中南大学 材料科学与工程学院，长沙 410083;
2. 中南大学 有色金属材料科学与工程教育部重点实验室，长沙 410012;
3. 中航商用航空发动机有限责任公司，上海 200241;
4. 北京航空材料研究院 钛合金研究室，北京 100095;
5. 华南理工大学 机械工程学院，广州 510640)
摘 要: 采用金相、扫描电镜和电子背散射衍射(EBSD)研究两相区退火温度和时间对热压缩态TC11(Ti- 6.5Al-3.5Mo-1.5Zr-0.3Si)双相钛合金组织和微观取向的影响。结果表明：初始魏氏组织在850 ℃热压缩后被破坏，形成较为细小、扭折的片层组织，晶粒取向呈非均匀分布；在后续700和900 ℃退火过程中，α相变形组织和亚结构发生静态再结晶而转变为等轴状晶粒，晶粒尺寸较退火前的更为细小，再结晶程度和等轴组织比例随保温时间的延长而增加，片层组织的球化程度、晶粒取向和形貌的均匀性与合金的再结晶程度相关。在900 ℃退火时，α相的再结晶程度较700 ℃退火时的更为明显；经过120 min退火后，合金发生完全再结晶，得到较为均匀、细小的等轴状组织。
关键字: 钛合金；再结晶；退火；微观组织；微观织构
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering,
Ministry of Education, Central South University, Changsha 410012, China;
3. AVIC Commercial Aircraft Engine Co., Ltd., Shanghai 200241, China;
4. Titanium Alloy Laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, China;
5. School of Mechanical Engineering, South China University of Technology, Guangzhou 510640, China）
Abstract:The effects of annealing temperature and time on the microstructure and microtexture of TC11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) titanium alloy pre-deformed by hot working were investigated using optical microscopy, scanning electron microscopy and electron back-scattered diffraction (EBSD). The results show that the initial Widmanstätten structure is destroyed after hot compression at 850 °C, leading to fine and distorted lamellar structures with non-uniform grain orientation distributions. Upon subsequent annealing at 700 and 900 ℃, the deformed and substructured α phase evolve into refined equiaxed grains due to static recrystallization, while the extent of recrystallization and the proportion of equiaxed grains increase with the annealing time increasing. The globularization of lamellar structures and the heterogeneity of grain morphology and orientations depend on the extent of recrystallization. Compared with that of 700 ℃, annealing at 900 ℃ leads to more extensive recrystallization, and a reasonably homogeneous fully recrystallized microstructure with equiaxed fine grains is achieved after 120 min.
Key words: titanium alloy; recrystallization; annealing; microstructure; microtexture
