Universal Scaling Law for the Size Effect on Superelasticity at the Nanoscale Promotes the Use of Shape‐Memory Alloys in Stretchable Devices
Shape-memory alloys (SMAs) are the most stretchable metallic materials thanks to their superelastic behavior associated with the stress-induced martensitic transformation. This property makes SMAs of potential interest for flexible and wearable electronic technologies, provided that their properties...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/42582 |
| Acceso en línea: | http://hdl.handle.net/10810/42582 |
| Access Level: | acceso abierto |
| Palabra clave: | nanocompression shape-memory alloys size effects stretchable materials superelasticity CU-AL-BE induced martensitic transformations behavior strength pseudoelasticity anisotropy phase gold |
| Sumario: | Shape-memory alloys (SMAs) are the most stretchable metallic materials thanks to their superelastic behavior associated with the stress-induced martensitic transformation. This property makes SMAs of potential interest for flexible and wearable electronic technologies, provided that their properties will be retained at small scale. Nanocompression experiments on Cu-Al-Be SMA single crystals demonstrate that micro- and nanopillars, between 2 mu m and 260 nm in diameter, exhibit a reproducible superelastic behavior fully recoverable up to 8% strain, even at the nanoscale. Additionally, these micro-/nanopillars exhibit a size effect on the critical stress for superelasticity, which dramatically increases for pillars smaller than approximate to 1 mu m in diameter, scaling with a power law of exponent n = -2. The observed size effect agrees with a theoretical model of homogeneous nucleation of martensite at small scale and the universality of this scaling power law for Cu-based SMAs is proposed. These results open new directions for using SMAs as stretchable conductors and actuating devices in flexible and wearable technologies. |
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