AIP Advances (Feb 2021)

Superelastic behavior of single crystalline Ni48Fe20Co5Ga27 micro-pillars near austenite–martensite critical point

  • T.-F. M. Chang,
  • V. Chernenko,
  • H.-C. Tang,
  • C.-Y. Chen,
  • A. Umise,
  • M. Tahara,
  • H. Hosoda,
  • M. Sone

DOI
https://doi.org/10.1063/5.0036304
Journal volume & issue
Vol. 11, no. 2
pp. 025213 – 025213-4

Abstract

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Micro-pillars oriented in austenite along [100], [110], and [111] crystallographic directions were fabricated on the corresponding edges of a single crystalline plate of the Ni48Fe20Co5Ga27 magnetic shape memory alloy exhibiting martensitic transformation (MT) at 150 K. Superelastic behavior of pillars, due to micro-compression-induced MT, was investigated at different temperatures from 298 K to 373 K. At room temperature, Young’s moduli of the [100], [110], and [111] pillars in austenite are equal to 5.3 GPa, 7.9 GPa, and 9.9 GPa, respectively, resulting in the linear dependences of the elastic strain reaching up to the record-breaking value of 10%. On increasing temperature, the stress–strain dependencies exhibit changes that are interpreted in terms of the critical behavior on approaching to the end points on the martensite–austenite stress–temperature phase diagrams.