| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Stability in Extreme Environments
|
| Presentation Title |
Taming the Pseudoelastic Response of Nitinol Using Ion Implantation |
| Author(s) |
Peter Martin Anderson, Alejandro Hinojos, Daniel Hong, Hariharan Sriram, Chao Yang, Janelle Wharry, Xuesong Gao, Khalid Hattar, Nan Li, Jeremy Schaffer, Yunzhi Wang, Michael Mills |
| On-Site Speaker (Planned) |
Peter Martin Anderson |
| Abstract Scope |
Implantation of Ni50.5Ti49.5 wire with 30 MeV Ni6+ ions at doses (< 0.1 DPA) typically smaller than employed in the literature is shown to systematically alter the pseudoelastic response, with extrema in Berkovich nanoindentation load (+50%), hysteresis (−60%), and recoverable displacement (−19%) occurring at ~ 3.6 μm below the implantation surface. These extraordinary values are attributed to ~ 10 to 20 nm amorphous clusters that constrain the stress-induced B2-B19′ phase transformation. This is substantiated by phase field simulations of crystalline-amorphous composites and molecular dynamics simulations of crystalline-vacancy cluster composites showing the spatial refinement of martensite created by nm-scale defects. The results suggest that ion implantation may potentially expand the processing and performance space for NiTi, by creating amorphous defects at smaller length scales than dislocation substructures produced by conventional deformation processing. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Computational Materials Science & Engineering, Mechanical Properties |