About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Uncovering the Role of Nanoscale Precipitates on Martensitic Transformation and Superelasticity |
| Author(s) |
Shivam Tripathi, Karthik Guda Vishnu, Michael S Titus, Alejandro Strachan |
| On-Site Speaker (Planned) |
Shivam Tripathi |
| Abstract Scope |
We characterize the role of nanoscale spherical Ni50Al50 precipitates on temperature and stress-induced martensitic phase transformation in polycrystalline Ni63Al37 shape memory alloys using multi-million-atoms molecular dynamics simulations. We studied two types of precipitates: one where grain boundaries cut through precipitates (polycrystal precipitates) and a second case where precipitates are single crystals. The non-transforming precipitates result in a reduction of both thermal and stress-strain hysteresis, but the effect is more prominent in the case of single-crystal precipitates. Single crystal precipitates also result in lower remnant strain. A detailed analysis of the trajectories reveals that grain boundaries slide is the dominant mechanism over intra-grain plasticity and is mainly responsible for irrecoverable strain after loading-unloading cycles. We also characterize the role of grain orientation and size on martensitic transformation to provide detailed insight into the origins of experimentally reported characteristics of phase transformation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Modeling and Simulation, Other |