| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Characterization Techniques for Quantifying and Modeling Deformation
|
| Presentation Title |
Understanding Functional Fatigue with 3D In-situ Grain Map Reconstructions Using High-energy Diffraction Microscopy |
| Author(s) |
Ashley N. Bucsek, Lee Casalena, Darren Pagan, Michael Mills, Aaron Stebner |
| On-Site Speaker (Planned) |
Ashley N. Bucsek |
| Abstract Scope |
Solid-state shape memory alloy (SMA) actuators are compact, scalable, and capable of generating large mechanical loads while weighing a fraction of traditional actuators, making SMAs an enabling technology for biomedical and aerospace applications. SMA actuators are limited, however, by the fact that the vast majority of SMAs do not exhibit perfectly reversible responses: an inherent cyclic instability known as functional fatigue originates from microstructure changes induced by the underlying phase transformation. Using near-field and far-field high-energy diffraction microscopy and microcomputed tomography, we investigate changes to the microstructure generated under actuation conditions. We present 3D grain map reconstructions of single-crystal and polycrystalline nickel-titanium sample volumes under load and at high temperatures after different numbers of cycles. The results show the incremental development of small-angle grain boundaries and the emergence of high-angle Σ boundaries. Finally, we discuss the various techniques for 3D grain map reconstructions using high-energy diffraction microscopy. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |