Abstract In this work, stress-controlled high-cycle fatigue tests were performed on Ti-7Mo-3Nb-3Cr-3Al alloy with β-cubic texture to investigate fatigue crack-initiation mechanisms and microstructurally small fatigue crack growth behaviors. The S-N curve shows a general feature of monotonic increase in the mean lifetime with decreasing stress level. Fatigue crack-initiation sites revealed the contiguous β facets. The fracture surface observations and the slip trace analysis show that most faceting occurred in {1 1 0} 〈1 1 1〉 slip system with the highest Schmid factor. Besides, a higher Kernel average misorientation (KAM) was found in fatigued microstructure. This strain localization would contribute to the fatigue crack-initiation process.

中文翻译：

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立方织构对高周疲劳亚稳态β钛合金疲劳裂纹的影响

摘要 在这项工作中，对具有 β 立方织构的 Ti-7Mo-3Nb-3Cr-3Al 合金进行了应力控制高周疲劳试验，以研究疲劳裂纹萌生机制和微观结构小疲劳裂纹扩展行为。SN 曲线显示了平均寿命随着应力水平的降低而单调增加的一般特征。疲劳裂纹起始位点显示了连续的 β 面。断口观察和滑移迹分析表明，大多数刻面发生在{1 1 0} 〈1 1 1〉滑移系统中，Schmid 因子最高。此外，在疲劳微观结构中发现了更高的核平均取向差（KAM）。这种应变局部化将有助于疲劳裂纹萌生过程。