Editors: | F. Kongoli, A. G. Mamalis, K. Hokamoto |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2018 |
Pages: | 352 pages |
ISBN: | 978-1-987820-88-1 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Phase transforming materials exhibiting significant recoverable inelastic deformations due to reversible solid-to-solid phase transformations have both existing and potential applications in a wide variety of fields. This presentation focuses on Shape Memory Alloys (SMA), which undergo a reversible austenitic to martensitic phase transformation, and covers recent research efforts to characterize and model their behavior to enhance the applicability of these materials in multiple engineering capacities and requirements. We first discuss the recent development of several new SMA beyond NiTi alloys, especially high temperature NiTiHf alloys and their key characteristics and potential for applications. We then review the micromechanical modeling of SMA, modeling of fatigue and fracture of SMA, and modeling of SMA structural components and morphing structures. Since precipitation can adjust their thermomechanical cyclic stability, phase transformation temperatures, and transformation strains, micromechanical modeling of SMAs focuses on the prediction of precipitation hardened SMA's behavior to capture their thermomechanical response. Using SMAs in applications requires understanding their durability and especially their actuation fatigue life and fracture properties, so we investigate the phase transformation induced fatigue under load (actuation fatigue) and fracture under thermal actuation. Finally, we present some applications inspired by origami based designs of foldable morphing structures.