About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
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Symposium
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Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
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Presentation Title |
A Multi-scale Characterization of the Effects of High Altitude Environments on the Damage Structure Evolution during Fatigue Loading of AA7075-T651 |
Author(s) |
Adam W. Thompson, Zachary D Harris, James T Burns |
On-Site Speaker (Planned) |
Adam W. Thompson |
Abstract Scope |
Aerospace aluminum alloys often operate at high altitude (typified by low temperatures and water vapor pressures [PH2O]); such environments retard the fatigue crack growth behavior. Incorporating these benefits into structural life management requires an understanding of the governing damage physics. The low temperature behavior retardation may be due to changes in dislocation structure evolution and/or on the hydrogen environment embrittlement (HEE) process. The HEE process would be influenced by temperature via a reduction in bulk PH2O, crack tip reaction kinetics producing/absorbing atomic H, H diffusion in the process zone, and/or changing the nature of the H-dislocation interactions. A novel multi-scale characterization (e.g. EBSD, HR-EBSD, GND calculation, FIB-TEM) of damage structure in the crack wake of different samples at a constant ΔK and constant PH2O but different temperature, is performed to provide insights into the governing mechanisms. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |