About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Understanding Metal Corrosion by Four-Dimensional Scanning Transmission Electron Microscopy (4D-STEM) |
| Author(s) |
Yang Yang |
| On-Site Speaker (Planned) |
Yang Yang |
| Abstract Scope |
Metal corrosion critically impacts the longevity of structural materials. This talk presents our recent applications of four-dimensional scanning transmission electron microscopy (4D-STEM) to uncover nanoscale corrosion mechanisms. In Ni-Cr alloys corroded by FLiNaK salt at 650 °C, we identified a localized one-dimensional wormhole corrosion mode with percolating void-channels along grain boundaries. Combining energy-filtered 4D-STEM, energy-dispersive X-ray spectroscopy, and density functional theory, we mapped excess vacancies up to 100 times the equilibrium concentration. For zirconium alloy oxidation, an in-situ strain mapping method integrating precession-assisted 4D-STEM and a gas-cell holder captured strain evolution under oxidizing conditions, illuminating chemo-mechanical effects. Lastly, in 316L stainless steel exposed to lead-bismuth eutectic, 4D-STEM facilitates the understanding of LBE penetration along twin boundaries and later ferritization of the FCC matrix. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Nuclear Materials, Environmental Effects |