About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
Presentation Title |
Understanding the Effect of Applied Potential on Stress Corrosion Cracking of AA6111 Through In-Situ Measurements of Crack Tip pH |
Author(s) |
Katrina Catledge, Jenifer S. Locke |
On-Site Speaker (Planned) |
Jenifer S. Locke |
Abstract Scope |
While AA6xxx Al-Mg-Si alloys are typically regarded as resistant to stress corrosion cracking (SCC), particularly when compared to other age-hardenable Al alloys, research shows that anodic polarization results in a significant decrease in SCC resistance. Specifically, slow strain rate testing under full immersion in 0.6M NaCl solution show that the threshold for stress corrosion cracking (KTH) decreases ~18 MPa√m to below 6 MPa√m when polarized 100 mV above the freely corroding potential. Early results show that the crack tip pH when the stress intensity (K) is above KTH is acidic. Research is currently underway to utilize micro-pH electrodes to probe the crack tip pH when the crack is actively growing and transitioning into arrest or vice versa as either K or the applied potential is altered. The findings from this research will inform on the risk of galvanic coupling in automotive applications to induce SCC in automotive Al alloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Aluminum, Environmental Effects, Mechanical Properties |