About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Advanced Materials for Harsh Environments
|
| Presentation Title |
One-Dimensional Wormhole Corrosion in Metals |
| Author(s) |
Yang Yang, Weiyue Zhou, Sheng Yin, Mark D. Asta, Michael Philip Short, Andrew Minor |
| On-Site Speaker (Planned) |
Yang Yang |
| Abstract Scope |
Corrosion is a ubiquitous failure mode of materials. Often, the progression of localized corrosion is accompanied by the evolution of porosity in materials previously reported to be either three-dimensional or two-dimensional. However, using new tools and analysis techniques, we have realized that a more localized form of corrosion, which we call 1D wormhole corrosion, has previously been miscategorized in some situations. Using electron tomography, we show multiple examples of this 1D and percolating morphology. To understand the origin of this mechanism in a Ni-Cr alloy corroded by molten salt, we combined energy-filtered four-dimensional scanning transmission electron microscopy (4D-STEM) and ab initio density functional theory calculations to develop a vacancy mapping method with nanometer-resolution, identifying a remarkably high vacancy concentration in the diffusion-induced grain boundary migration zone, up to 100 times the equilibrium value at the melting point. Understanding the mechanisms behind 1D corrosion could help in designing structural materials that are more resistant to corrosion. |