About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
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Tackling Structural Materials Challenges for Advanced Nuclear Reactors
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Presentation Title |
Investigation of Fracture Behavior of Nuclear Graphite NBG-18 Using In-situ Mechanical Testing Coupled with Micro-CT |
Author(s) |
Gongyuan Liu, Yichun Tang, Jing Du, Aman Haque |
On-Site Speaker (Planned) |
Gongyuan Liu |
Abstract Scope |
This paper presents the results of an experimental investigation on fracture behaviors of NBG-18 nuclear graphite through three-point bend tests. Four single-edge notched beam (SENB) specimens were prepared according to the suggested dimensions in ASTM D7779-20. Three-point bending tests on three SENB specimens were performed using a mechanical tester. The fracture toughness was measured to be 1.186 - 1.240. An incremental three-point bending test was conducted on the remaining specimen using a mechanical tester coupled with micro-CT. Oriented lenticular thermal cracks and round gas entrapment pores in the reconstructed tomographic cross-sectional images are used to identify the filler and binder phases. racks were observed to originate primarily from larger open pore structures on the edge of the notch. Then, the cracks propagated along the paths of the larger open pores. Crack bridging by uncracked ligament, crack deflection, and crack blunting were observed as toughening mechanisms. |