About this Abstract |
Meeting |
2021 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 |
Giant Superelasticity in SrNi<sub>2</sub>P<sub>2</sub> Micropillars via Lattice Collapse and Expansion |
Author(s) |
Shuyang Xiao, Vladislav Borisov, Guilherme Gorgen-Lesseux, Gyuho Song, Roser Valentí, Paul Canfield, Seok-Woo Lee |
On-Site Speaker (Planned) |
Shuyang Xiao |
Abstract Scope |
An elastic strain limit of most crystalline solids is less than one percent because the permanent shape change usually occurs at a very small strain. In order to obtain a large elastic strain limit, crystalline solids need to undergo a reversible structural transition. In this work, we show that a SrNi<sub>2</sub>P<sub>2</sub> single crystal micropillar exhibits the ultrahigh compressive elastic strain limit over 17% via double lattice collapse and expansion. High-resolution transmission electron microscopy revealed the co-existence of two different crystal structures, and density functional theory shows that each structure is collapsed at a different stress state. This superelastic deformation process is repeatable over 10<sup>4</sup> cycles. In comparison to other superelastic crystalline solids, the elastic strain limit of SrNi<sub>2</sub>P<sub>2</sub> is nearly the largest ever, and this result suggests that a new group of superelastic materials could be potentially discovered in ThCr<sub>2</sub>Si<sub>2</sub>-structured intermetallic compounds that can exhibit the similar structural transition. |
Proceedings Inclusion? |
Planned: |