About this Abstract |
Meeting |
2024 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 |
Cyclic Degradation of Superelasticity of Fe-Ni-Co-Al-Ti Shape Memory Alloy with Strong Texture Studied by In Situ Deformation |
Author(s) |
Robert Lehnert, Anja Weidner, Philipp Krooß, Thomas Niendorf, Horst Biermann |
On-Site Speaker (Planned) |
Anja Weidner |
Abstract Scope |
The superelasticity of iron-based shape memory alloys is determined by several microstructural features, e.g. precipitates and crystal orientation/texture. The interaction of martensite variants or dislocations pinning the austenite/martensite interface are known as reasons for functional degradation of the superelasticity. A Fe-Ni-Co-Al-Ti-B polycrystal with a strong 〈001〉 texture was studied under tensile loading in situ in a scanning electron microscope in combination with acoustic emission technique, electron channelling contrast imaging and transmission electron microscopy to study the functional degradation mechanisms. The acoustic emission data showed a decrease in intensity with increasing number of deformation cycles. In addition, the acoustic emission signals revealed an asymmetry of the forward and the reverse stress-induced martensitic phase transformation, which is related to the formation of dislocations. The pinning of the martensite interfaces by dislocations leads to reduction in the packet density of the reverse transforming martensite resulting in a lower amplitude of the AE signals. |
Proceedings Inclusion? |
Planned: |