| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Mitigation of Intergranular Stress Corrosion Cracking in Al-Mg Alloys Through the Electrochemical and Chemical Effects of Metal Rich Primer Coatings Near Stationary and Propagating Cracks |
| Author(s) |
Matthew McMahon, John R. Scully, James T. Burns |
| On-Site Speaker (Planned) |
John R. Scully |
| Abstract Scope |
This talk will demonstrate galvanic and chemical protection phenomena achieved by metal-rich primer coatings on, as well as new mechanistic understanding of stress corrosion cracking in Al-Mg alloys. Mildly elevated temperatures can lead to intergranular precipitation of the β phase (Al3Mg2) in Al-Mg alloys. The β phase is highly anodic to the matrix and in the presence of corrosive environments can lead to intergranular stress corrosion cracking [4]. This behavior is governed by a coupled anodic dissolution process (of the β phase and under certain conditions the Al matrix), which by the hydrolytic acidification mechanism catalyzes an aggressive local crack tip chemistry. In order to systematically discuss the mitigation and newfound insights into this mechanism, four main topics will be sequentially covered concerning stationary as well as propagating cracks: (1) mild cathodic polarization via potentiostat, (2) galvanic effects of metal-rich primer coatings, and (3) chemical protection effects provided by Zn2+. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |