About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Deformation Mechanisms, Microstructure Evolution, and Mechanical Properties of Nanoscale Materials
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Presentation Title |
Multi-stage Superelasticity in SrNi<sub>2</sub>P<sub>2</sub> Intermetallic Compound via Lattice Collapse and Expansion and the Influence of Cryogenic Temperature |
Author(s) |
Shuyang Xiao, Vladislav Borisov, Adrian Valadani, Guilherme Gorgen-Lesseux, Roser Valentí, Paul Canfield, Seok-Woo Lee |
On-Site Speaker (Planned) |
Shuyang Xiao |
Abstract Scope |
Mechanical behavior of SrNi<sub>2</sub>P<sub>2</sub> , one of ThCr<sub>2</sub>Si<sub>2</sub>-structured intermetallic compounds, has been investigated using in-situ micro-compression and micro-tension along [001] direction at room temperature, 200K and 100K. Room temperature mechanical testing revealed the giant superelasticity with an elastic strain limit near 20% if both compression and tension are considered. This is nearly the highest elastic strain limit ever reported for crystalline solids. Density Functional Theory calculation and High-Resolution Transmission Electron Microscopy show that this excellent superelastic performance is achieved by multiple-stage lattice collapse and expansion, which result from forming and breaking P-P bonds in two co-existing crystal structures. Our state-of-the-art in-situ cryogenic nanomechanical testing shows that at lower temperature, phase transition requires the lower transition stress under compression but the higher transition stress under tension due to the temperature-dependent P-P distance. Our results provide an insight into fundamental understanding of the superelasticity mechanism of SrNi<sub>2</sub>P<sub>2</sub> at different temperatures. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, Phase Transformations, Environmental Effects |