| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
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| Symposium
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Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments V
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| Presentation Title |
Influence of Defects Length-scale on Nuclear Graphite Properties |
| Author(s) |
Gongyuan Liu, Melonie Thomas, Jing Du, Khalid Hattar, William Windes, Aman Haque |
| On-Site Speaker (Planned) |
Gongyuan Liu |
| Abstract Scope |
Nuclear graphite has a complex microstructure comprising of high-purity crystallites and multi-scale defects, which demands structure-property characterization from nano to micron scales. We present macroscale fracture properties measured with x-ray computed tomography (XCT) for both pristine and neutron irradiated specimens. The experimental findings were computational modeled through finite element method using the XCT data. Nanoscale characterization was performed on electron transparent specimens inside the transmission electron microscope (TEM). We found that heavy ion irradiated specimens triggered ripplocation bands under compression to induce colossal plasticity. We also present a room temperature annealing technique for nuclear graphite that eliminated the nanocsale defects and thereby improves both hardness and elastic modulus. The technique takes only a few seconds, making it energy efficient. Creep experiments performed on these specimens showed remarkable differences in primary creep, suggesting the pronounced role of nanoscale defects.
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