|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Environmentally Assisted Cracking: Theory and Practice
||Investigating the Effect of Polarization on SCC Resistance of AA6111 and the Role of Crack Tip pH
||Katrina E. Catledge, Gabriella C. Montiel, Saba N. Esmaeely, Jenifer S. Locke
|On-Site Speaker (Planned)
||Jenifer S. Locke
AA6xxx Al-Mg-Si alloys are age-hardenable and resistant to stress corrosion cracking (SCC) compared to other age-hardened aluminum alloys. Their high strength-to-weight ratio makes them attractive for automotive applications in conjunction with steels and carbon fiber reinforced polymer (CFRP). In fracture mechanics-based experiments in 0.6 M NaCl, applied anodic polarization to simulate galvanic coupling with CFRP has been shown to severely reduce SCC resistance of AA6111-T8. When anodically polarized 100 mV<sub>SCE</sub> above the freely corroding potential (OCP), threshold stress intensity decreases to less than half that at OCP and Stage II crack growth rate increases. Testing under cathodic polarizations down to -1300 mV<sub>SCE</sub> does not appear to deleteriously affect SCC resistance. Efforts are ongoing to measure crack-tip pH in-situ and correlate effects of applied potential to SCC resistance.
Part of this work is supported by the Department of Energy under award number DE-EE0007760 through a sub-award under PPG Industries, Inc.
||Environmental Effects, Aluminum, Mechanical Properties