Thermally induced martensitic transformations in Cu-based shape memory alloy microwires
Prior studies on shape memory alloys have identified size effects on the superelastic, i.e., stress-induced, hysteresis of martensitic transformations. However, literature on thermally induced transformations and size effects upon stored elastic energy is rather limited. In this work, a complementar...
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| Format: | Article |
| Language: | English |
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Springer US
2016
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| Online Access: | http://hdl.handle.net/1721.1/103382 https://orcid.org/0000-0001-7660-7210 https://orcid.org/0000-0001-9856-2682 https://orcid.org/0000-0001-6339-2708 |
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| author | Tuncer, Nihan Qiao, Lei Radovitzky, Raul A. Schuh, Christopher A. |
| author2 | Massachusetts Institute of Technology. Department of Aeronautics and Astronautics |
| author_facet | Massachusetts Institute of Technology. Department of Aeronautics and Astronautics Tuncer, Nihan Qiao, Lei Radovitzky, Raul A. Schuh, Christopher A. |
| author_sort | Tuncer, Nihan |
| collection | MIT |
| description | Prior studies on shape memory alloys have identified size effects on the superelastic, i.e., stress-induced, hysteresis of martensitic transformations. However, literature on thermally induced transformations and size effects upon stored elastic energy is rather limited. In this work, a complementary sample size effect on the stored elastic energy of the transformation, and its effect on variant selection, is elaborated. Shape memory alloy microwires of a CuAlMnNi alloy are drawn with diameters varying between 45 and 255 μm and processed to obtain bamboo grain structures, where the grain boundaries lay almost perpendicular to the wire axis. Calorimetric and thermomechanical analyses of the microwires establish a decreasing contribution of stored elastic energy to the free energy of martensitic transformation as the wire diameter is reduced. This in turn affects the transformation ranges and macroscopic strain generated in constrained thermal cycling. The effect is shown to be associated with a decrease in number of interacting martensite variants as well as relaxation on free surfaces. The presented results indicate that thermal actuation of lightly biased SMA wires is enhanced in finer wires. |
| first_indexed | 2024-09-23T13:17:11Z |
| format | Article |
| id | mit-1721.1/103382 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T13:17:11Z |
| publishDate | 2016 |
| publisher | Springer US |
| record_format | dspace |
| spelling | mit-1721.1/1033822022-10-01T14:18:13Z Thermally induced martensitic transformations in Cu-based shape memory alloy microwires Tuncer, Nihan Qiao, Lei Radovitzky, Raul A. Schuh, Christopher A. Massachusetts Institute of Technology. Department of Aeronautics and Astronautics Massachusetts Institute of Technology. Department of Materials Science and Engineering Tuncer, Nihan Qiao, Lei Radovitzky, Raul A. Schuh, Christopher A. Prior studies on shape memory alloys have identified size effects on the superelastic, i.e., stress-induced, hysteresis of martensitic transformations. However, literature on thermally induced transformations and size effects upon stored elastic energy is rather limited. In this work, a complementary sample size effect on the stored elastic energy of the transformation, and its effect on variant selection, is elaborated. Shape memory alloy microwires of a CuAlMnNi alloy are drawn with diameters varying between 45 and 255 μm and processed to obtain bamboo grain structures, where the grain boundaries lay almost perpendicular to the wire axis. Calorimetric and thermomechanical analyses of the microwires establish a decreasing contribution of stored elastic energy to the free energy of martensitic transformation as the wire diameter is reduced. This in turn affects the transformation ranges and macroscopic strain generated in constrained thermal cycling. The effect is shown to be associated with a decrease in number of interacting martensite variants as well as relaxation on free surfaces. The presented results indicate that thermal actuation of lightly biased SMA wires is enhanced in finer wires. United States. Army Research Office. Institute for Soldier Nanotechnologies (contract number W911NF-13-D-0001) 2016-06-30T14:42:23Z 2016-06-30T14:42:23Z 2015-08 2015-05 2016-05-23T12:15:29Z Article http://purl.org/eprint/type/JournalArticle 0022-2461 1573-4803 http://hdl.handle.net/1721.1/103382 Tuncer, Nihan, Lei Qiao, Raul Radovitzky, and Christopher A. Schuh. “Thermally Induced Martensitic Transformations in Cu-Based Shape Memory Alloy Microwires.” Journal of Materials Science 50, no. 22 (August 5, 2015): 7473–7487. https://orcid.org/0000-0001-7660-7210 https://orcid.org/0000-0001-9856-2682 https://orcid.org/0000-0001-6339-2708 en http://dx.doi.org/10.1007/s10853-015-9306-4 Journal of Materials Science Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ Springer Science+Business Media New York application/pdf Springer US Springer US |
| spellingShingle | Tuncer, Nihan Qiao, Lei Radovitzky, Raul A. Schuh, Christopher A. Thermally induced martensitic transformations in Cu-based shape memory alloy microwires |
| title | Thermally induced martensitic transformations in Cu-based shape memory alloy microwires |
| title_full | Thermally induced martensitic transformations in Cu-based shape memory alloy microwires |
| title_fullStr | Thermally induced martensitic transformations in Cu-based shape memory alloy microwires |
| title_full_unstemmed | Thermally induced martensitic transformations in Cu-based shape memory alloy microwires |
| title_short | Thermally induced martensitic transformations in Cu-based shape memory alloy microwires |
| title_sort | thermally induced martensitic transformations in cu based shape memory alloy microwires |
| url | http://hdl.handle.net/1721.1/103382 https://orcid.org/0000-0001-7660-7210 https://orcid.org/0000-0001-9856-2682 https://orcid.org/0000-0001-6339-2708 |
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