About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Defects and Interfaces: Modeling and Experiments
|
Presentation Title |
Nanoscale Vacancy Mapping in Metals by Four-dimensional Scanning Transmission Electron Microscopy (4D-STEM) |
Author(s) |
Yang Yang, Sheng Yin, Weiyue Zhou, Michael Short, Mark Asta, Andrew Minor |
On-Site Speaker (Planned) |
Yang Yang |
Abstract Scope |
Vacancies are ubiquitous in materials and can be supersaturated under extreme conditions like corrosion or irradiation. A detailed nanoscale understanding is vital for studying their interactions with other defects and the resultant degradation of materials. Our study unveils a highly localized corrosion form, "one-dimensional (1D) wormhole corrosion," causing rapid molten salt penetration into Ni-20Cr at 650˚C. Leveraging 4D-STEM and advanced simulations, we developed a nanometer-scale vacancy mapping method. This method identified the precursor of 1D wormholes as the diffusion-induced grain boundary migration (DIGM) zone, possessing a vacancy fraction nearly 100 times higher than metals near their melting points. Our research underscores the importance of nanoscale vacancy mapping for combating material degradation in extreme conditions. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, Environmental Effects, Nuclear Materials |