About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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Mechanical Response of Materials Investigated Through Novel In-Situ Experiments and Modeling
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Presentation Title |
In-situ SEM Investigation of Thermally Induced Cracking in Shape Memory Ceramics |
Author(s) |
Isabel R. Crystal, Haoxue Yan, Christopher A. Schuh |
On-Site Speaker (Planned) |
Isabel R. Crystal |
Abstract Scope |
Transformation induced cracking is considered the main limitation in translating shape memory ceramics (SMCs) to bulk form. It is thought that micro-cracks nucleate at the tips of the martensitic plates. Here we employ a custom heating stage within an SEM to collect in-situ videos of bulk polycrystalline SMCs undergoing cyclic transformation. The videos show that cracks open and propagate on the cooling portion of the cycle, during the forward martensitic transformation from the austenite to martensite phase. Smaller grains are found to contain a single variant of martensite while larger grains have complex multi-variant structures that evolve with cycling. The above observations are in line with calorimetry experiments collected during cyclic martensitic transformations. An additional grain pop-out phenomenon is noted on the reverse transformation for which the closing of the crack causes grains along the crack to eject from the surface. |
Proceedings Inclusion? |
Planned: |
Keywords |
Other, Other, Other |