Investigation on martensitic transformation and field-induced two-way shape memory effect of Ni-Mn-Ga alloy

Citation
Zh. Liu et al., Investigation on martensitic transformation and field-induced two-way shape memory effect of Ni-Mn-Ga alloy, ACT PHY C E, 50(2), 2001, pp. 233-238
Citations number
10
Language
CHINESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
ACTA PHYSICA SINICA
ISSN journal
1000-3290 → ACNP
Volume
50
Issue
2
Year of publication
2001
Pages
233 - 238
Database
ISI
SICI code
1000-3290(200102)50:2<233:IOMTAF>2.0.ZU;2-Q
Abstract
The martensitic phase transformation temperature, T-m and the Curie tempera ture, T-C, of polycrystalline samples Ni2+xMn1-xGa(x = -0.1,0,0.08,0.13,0.1 8,0.2) and Ni2-xMn1+x/2Ga1+x/2(x = -0.1,0,0.04,0.06,0.1) have been investig ated by measuring the temperature dependence of alternating-current suscept ibility. It was found that, with the increase of Ni content, T-C decreases and T-m increases for Ni2+xMn1-xGa, and both T-C and T-m increase first and decrease afterwards for Ni2-xMn1+x/2Ga1+x/2 Stress-free and two-way thermo elastic shape memory, with 1.2% strain, has been found in single crystal Ni 52Mn24Ga24 The deformation can be enhanced more than three times, up to 4.0 % shrinkage with a bias field 1.2T applied along the measurement direction. The origin of large recoverable strain should be attributed to the low lev el of internal stress and the field-induced rearrangement of martensitic va riants through twin boundary motion rather than the phase boundary motion.