About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
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Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
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Presentation Title |
Impact of Temperature and Microstructure on Dwell Fatigue in Near-alpha Titanium Alloys |
Author(s) |
Michelle E. Harr, Samantha Daly, Adam Pilchak |
On-Site Speaker (Planned) |
Michelle E. Harr |
Abstract Scope |
Near-alpha titanium alloys, such as Ti-6242, experience a reduction in fatigue lifetime when the peak stress is held for each loading cycle. This type of sustained peak loading, also known as dwell fatigue, mimics the long periods of high mean stress experienced by titanium fan and compressor components during takeoff and cruise. The significant lifetime reduction is attributed to the phenomenon of load shedding, where the relaxation of a soft grain requires a neighboring hard grain to carry a higher load, thereby creating a favorable location for early crack nucleation. Both local microstructure and temperature are known to impact load shedding, but the underlying mechanisms are still under active investigation. This work utilizes Digital Image Correlation (DIC) and Electron Backscatter Diffraction (EBSD) at multiple length scales to experimentally investigate and statistically quantify the effect of temperature and local microstructure on the distribution of stain and damage accumulation during dwell fatigue. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |