Granular shape memory ceramic packings
Author(s)
Yu, Hang
Hassani Gangaraj, Seyyed Mostafa
Du, Zehui
Gan, Chee Lip
Schuh, Christopher A
Date Issued
June 2017
Journal
Acta Materialia
Publisher
Elsevier BV
Citation
Yu, Hang Z. et al. "Granular shape memory ceramic packings." Acta Materialia 132 (June 2017): 455-466 © 2017 Acta Materialia Inc
Version
Author's final manuscript
Abstract
Although bulk shape memory ceramics (SMCs) are brittle, in particulate form they exhibit large recoverable strains in both shape memory and superelastic modes. Here, we investigate the fundamentals of mechanically- and thermally-triggered martensitic transformation of granular SMC packings. Specifically, (ZrO2)1-x-(CeO2)x is studied in three different composition regimes. In the shape memory regime (below the martensite finish temperature), confined uniaxial compression leads to martensite re-orientation in the granular SMC packing, with the peak intensity of preferred crystallographic orientation increasing with external loading. In the intermediate regime (between austenite start and martensite start temperatures), confined uniaxial compression leads to irreversible martensitic transformation with the transformed volume increasing with external loading. This provides direct evidence of stress-induced martensitic transformation in granular SMCs. In the superelastic regime (above the austenite finish temperature), confined uniaxial compression leads to forward (during loading) and reverse (during unloading) martensitic transformation, manifesting in a large hysteresis loop in each load-unload cycle with remarkably high energy dissipation density. Based on finite element modeling of SMC particles in contact, we explore the martensitic transformation under non-uniform Hertzian stresses, which in turn provides insight on the experimental results. Keywords: Shape memory; Granular materials; Zirconia; Martensitic transformation; Superelasticity
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.actamat.2017.04.057
