| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Fatigue Crack Propagation in AA7085-T7451 Exposed to Complex Atmospheric Environments |
| Author(s) |
Brandon T. Free, Sarah Galyon Dorman, Jason Niebuhr, Jenifer Locke |
| On-Site Speaker (Planned) |
Brandon T. Free |
| Abstract Scope |
AA7085-T7451 is used in complex aerospace environments of varied temperature, humidity, and ozone level while also being exposed to surface salt deposits that can form electrolyte droplets. The effect of these atmospheric environments on corrosion fatigue (CF) is not well understood. The objective of this work is to quantify the effect of these environments on CF crack growth rates (da/dN) when surface salt deposits are present and to compare against traditional environments. Testing to date has shown similar da/dN over a range of fatigue loading frequencies when comparing full immersion in 0.06M NaCl to 80% RH with 300 μg/cm2 of deposited NaCl. During a wet-dry cycling, testing shows a sudden increase in da/dN when RH is increased past the deliquescent point. This acceleration persists unless dried to an RH well below the deliquescent point. Overall, this work will lead to a better quantitative understanding of corrosion fatigue in atmospheric environments.
This material is based on research sponsored by the USAFA and The Ohio State University under agreement number FA7000-18-2-0001. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon. The opinions, findings, views, conclusions or recommendations contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied of the USAFA and the U.S. Government. |
| Proceedings Inclusion? |
Planned: |