(北京航空材料研究院 先进钛合金航空科技重点实验室，北京 100095)
摘 要: 研究双态组织和网篮组织对TC32钛合金高周疲劳(HCF)性能的影响，并与TC4钛合金等轴组织和TC21钛合金网篮组织的高周疲劳性能进行对比分析。结果表明：TC32钛合金双态组织与网篮组织的高周疲劳强度分别为535.7MPa与537.5MPa，明显高于TC4钛合金等轴组织的，也高于TC21钛合金网篮组织的。TC32钛合金双态组织因原始β晶粒细小，且初生α相与β转变基体强度匹配性良好，不存在异常的平均应力敏感性；TC32钛合金网篮组织因存在较多的二次裂纹，且主裂纹扩展路径曲折，疲劳裂纹扩展速率较双态组织更缓慢。
关键字: TC32钛合金；高周疲劳；疲劳断口；显微组织
（Aviation Key Laboratory of Science and Technology on Advanced Titanium Alloys,
Institute of Aeronautical Materials, Beijing 100095, China）
Abstract:The high cycle fatigue(HCF) properties were investigated on TC32 titanium alloy with the bimodal and basket microstructures, compared with the HCF properties of TC4 titanium alloy with the equiaxed microstructure and TC21 alloy with the basket microstructure. The results show that TC32 titanium alloy with bimodal and basket microstructures has a much higher HCF strength level compared to that of TC4 titanium alloy with the equiaxed microstructure and has a better HCF strength level than that of TC21 titanium alloy with the basket microstructure, which is 535.7MPa and 537.5MPa, respectively. TC32 alloy with the bimodal microstructure does not show anomalous mean stress sensitivity (AMSS) since its better matching strength between primary α and β phase, and its small grain size. TC32 alloy with the basket microstructure has a greater crack propagation resistance due to main crack deflection and more secondary cracks in propagation region.
Key words: TC32 titanium alloy; high cycle fatigue; fatigue fracture; microstructure
