高强韧Ti-3Al-5Mo-4Cr-2Zr-1Fe合金低周疲劳性能研究

Hang Zhang, Yangyang Sun, Igor V. Alexandrov, Zhigang Fang, Chengjie Yi, Yuecheng Dong, Hui Chang, Lian Zhou

科研成果: 期刊稿件文章同行评审

5 引用 (Scopus)

摘要

Low cycle fatigue (LCF) behavior of Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) alloy with bimodal microstructure consisting of lath α(αp) and βtrans was investigated by strain-controlled mode at room temperature. Results indicate that cyclic stress amplitudes of the Ti-35421 alloy with bimodal microstructure show cyclic softening at first, then reach to cyclic stability at high strain amplitude (Δεt/2=1.0%, 1.2%, 1.4%, 1.6%). However, the cyclic stress response characterizes cyclic saturation at low strain amplitudes (Δεt/2=0.6%, 0.8%). Only one fatigue crack source is found by fracture morphology observation when Δεt/2=0.6%, while a large number of small secondary cracks occur on the surface. On the contrary, multiple fatigue crack sources generate when the strain amplitude increases to 1.6%. The number of secondary cracks reduces, but the length and width of the secondary cracks increase significantly. TEM results indicate that a large number of dislocations generate at the αptrans interface at the low strain amplitude (Δεt/2=0.6%), which leads to micro-crack nucleation due to the stress concentration. Meanwhile, at high strain amplitude (Δεt/2=1.6%), deformation inhomogeneity phenomena occur in the αp phase, a large number of dislocation tangles and dislocation debris form in the αp phase, and some dislocation pile-ups form in the αs phase instead of β matrix. Due to the elongated αp phase, it can improve the compatibility of alloy α phase and β phase deformation, and delay crack nucleation and propagation. Therefore, Ti-35421 alloy has excellent low cycle fatigue performance.

投稿的翻译标题Study on Low Cycle Fatigue Behavior of Ti-3Al-5Mo-4Cr-2Zr-1Fe Alloy with High Strength and Toughness
源语言繁体中文
页(从-至)588-594
页数7
期刊Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering
50
2
出版状态已出版 - 2月 2021
已对外发布

关键词

  • Cyclic softening
  • Cyclic stability
  • Low cost titanium alloy
  • Low cycle fatigue

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