| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Microstructural and Compositional Effects on The Fracture Toughness and Fatigue Response of NiTiHf High-Temperature Shape Memory Alloys |
| Author(s) |
Roberto Orrostieta, Benjamin Young, Ibrahim Karaman |
| On-Site Speaker (Planned) |
Roberto Orrostieta |
| Abstract Scope |
Shape memory alloys (SMAs) undergo reversible martensitic transformation upon stress and temperature cycling, which can be utilized as solid-state actuators with high energy density. Their large recoverable strain makes them attractive in a wide range of applications. Particularly, high-temperature SMAs (HTSMAs), with transformation temperatures above 100°C, are envisioned as practical components under extreme environments for aerospace, defense, and energy conversion applications. Unfortunately, insufficient understanding of the effect of cyclic martensitic transformation on their structural degradation has hindered their adoption. The current study seeks to elucidate the effects of processing, microstructure, and composition on fracture toughness and thermomechanical fatigue of NiTiHf HTSMAs across martensitic transformation. Toughening mechanisms are proposed for the increased resistance to crack growth across martensitic transformation. Moreover, a unified Paris-Erdogan curve is demonstrated using both mechanical and actuation fatigue crack growth experiments, alluding to the prediction of actuation crack growth rates with cost-efficient mechanical fatigue crack growth experiments. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Phase Transformations, Mechanical Properties |