The study of fatigue behavior in saltwater for TC17 titanium alloy has become a potential research issue in practical engineering and theoretical scientific research. In this study, it is found from the designed fatigue test that the corrosiveness of the test environment has a significant negative effect on the fatigue life of titanium alloy, and the distributions of fatigue life in 3.5%NaCl solution and 5%NaCl solution are similar. Typical surface failure characteristics and obvious corrosion traces are detected due to the coupling effect of corrosion and fatigue load. Then, electron back scatter diffraction (EBSD) is performed to figure out the change of micro grains from fine grains to coarse grains with the test environment changes from water to NaCl solution, and the strain concentration regions are detected at grain boundary and internal of coarse grains. Finally, the comparison of - curve with different models are carried out, Basquin model is proved to be suitable for the - curve estimation of TC17, and - models for different test environments are established. The micro test results provide a clear understanding of the corrosion fatigue failure behavior, and the newly established model considering the corrosiveness of test environment is novel and essential to the further fatigue study in theoretical research and engineering practice.

中文翻译：

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TC17钛合金在不同试验环境下的疲劳行为：盐水对疲劳失效特征和寿命估算的影响


TC17钛合金在盐水中的疲劳行为研究已成为实际工程和理论科学研究中潜在的研究课题。本研究从设计的疲劳试验发现，试验环境的腐蚀性对钛合金的疲劳寿命有显着的负面影响，且在3.5%NaCl溶液和5%NaCl溶液中的疲劳寿命分布相似。 。由于腐蚀与疲劳载荷的耦合作用，检测到典型的表面失效特征和明显的腐蚀痕迹。然后，通过电子背散射衍射（EBSD）来计算随着测试环境从水到NaCl溶液的变化，微观晶粒从细晶粒到粗晶粒的变化，并检测晶界和粗晶粒内部的应变集中区域。谷物。最后对不同模型的-曲线进行了比较，证明Basquin模型适用于TC17的-曲线估计，并建立了不同测试环境下的-曲线模型。微观试验结果为腐蚀疲劳失效行为提供了清晰的认识，新建立的考虑试验环境腐蚀性的模型具有新颖性，对进一步疲劳研究的理论研究和工程实践具有重要意义。