| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
|
| Presentation Title |
Transformation Induced Fatigue in Shape Memory Alloys |
| Author(s) |
Nicole Stoetzel, Jan Frenzel, Marcus Young, Tamas Ungar, Gunther Eggeler |
| On-Site Speaker (Planned) |
Nicole Stoetzel |
| Abstract Scope |
The present study investigates transformation induced structural fatigue (TISF) of NiTi shape memory alloys (SMAs). SMAs which are subjected to thermomechanical cycles can fail due to the formation and growth of cracks, even when stresses are constant. We refer this degradation process to as transformation induced structural fatigue (TISF), which is driven by irreversible processes accompanying a martensitic transformation. In the present work we provide results from experiments where NiTi SMAs were subjected to TISF using a special thermomechanical test rig. During the experiments, the evolution of resistivity is monitored as a direct measure for damage accumulation. Material states resulting from fatigue tests conducted at different stress levels were investigated in an advanced scanning electron microscope to analyze the formation and growth of cracks, and finally, failure mechanisms. We also present preliminary results from in-situ synchrotron diffraction experiments where X-ray line profile analysis was used to assess defects densities. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Characterization, Other |