About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
Presentation Title |
On the Applied Potential Dependence of Environment-assisted Cracking Behavior of 7xxx-series Al Alloys in Marine Environments: Towards Informing Metal-rich Primer-based Mitigation Strategies |
Author(s) |
James Burns, Zach Harris, Alen Korjenic, John Scully |
On-Site Speaker (Planned) |
James Burns |
Abstract Scope |
Metal-rich primers (MRPs) have been shown to effectively attenuate the environment-assisted cracking (EAC) susceptibility of 5xxx-series Al alloys exposed to marine environments, suggesting that such galvanic protection schemes may be suitable for use on 7xxx-series Al alloys. A detailed understanding of the relationship between EAC susceptibility and the applied electrochemical potential is needed to design effective MRPs, but such relationships are not well-understood in 7xxx-series Al alloys. Fracture mechanics experiments were performed on AA7075-T651 and AA7050-T7451 in 0.6 M NaCl at applied potentials ranging from -1300 to -750 mVSCE (vs. saturated calomel electrode) and fixed loading rates (dK/dt) ranging from 0 to 2.0 MPa√m/hr. A small potential ‘window’ of reduced susceptibility is observed in AA7075, but crack growth kinetics remain sufficiently severe that MRPs are unlikely to prevent EAC. Conversely, AA7050 exhibits a potential ‘window’ with sufficiently suppressed crack growth kinetics that MRPs could potentially be used to mitigate EAC. |
Proceedings Inclusion? |
Planned: |
Keywords |
Aluminum, Mechanical Properties, Environmental Effects |