| Numéro |
J. Phys. IV France
Volume 112, October 2003
|
|
|---|---|---|
| Page(s) | 1017 - 1020 | |
| DOI | https://doi.org/10.1051/jp4:20031054 | |
J. Phys. IV France 112 (2003) 1017
DOI: 10.1051/jp4:20031054
Development of the Co-Ni-AI ferromagnetic shape memory alloys
K. Oikawa1, T. Omori2, Y. Sutou2, R. Kainumal1 and K. Ishidal11 National Institute of Advanced Industrial Science and Technology, 4-2-1 Nigatake, Miyagino-ku, Sendai 983-8551, Japan
2 Department of Materials Science, Graduate School of Engineering, Tohoku University, Aoba-yama 02, Sendai 980-8579, Japan
Abstract
Ferromagnetic shape memory alloys have been developed in the Co-Ni-AI temary system with
two-phase structure. The
(B2) phase of the Co-33Ni-27Al and Co-34Ni-28Al alloys exhibits both
paramagneticlferromagnetic transition and a thermoelastic martensitic transformation from
to
(L1
0). The microstructure of both alloys shows the primary
phase surrounded by the
(A1) phase which brings about the drastic effect in the
improvement of the hot workability. By annealng in the two-phase region after solution treatment,
the
phase precipitates along grain boundaries in the
phase, besides in the
grain. The alloys
annealed at 1273 K showed a good cold workability and a thermal activated shape memory effect. These
ferromagnetic and ductile shape memory alloys are very promising for one of the new smart matenals.
© EDP Sciences 2003