Title :
NiMnGa polycrystalline magnetically activated shape memory alloys
Author :
Pasquale, M. ; Sasso, C. ; Besseghimi, S. ; Passaretti, F. ; Villa, E. ; Sciacca, A.
Author_Institution :
IEN Galileo Ferraris, Torino, Italy
fDate :
9/1/2000 12:00:00 AM
Abstract :
We report on the structural characteristics, magnetic properties and magnetically induced deformations obtained on as produced and annealed samples of bulk polycrystalline NiMnGa alloys. Extensive structural, magnetic and magnetomechanical characteristic are presented. A peak cyclic strain of the order of 1.2 10-4, connected to the presence of martensite twins, is found when a magnetic field is applied. Annealing produces positive effects on the austenite to martensite transition, on the overall magnetic properties but does not produce a larger strain. These results are discussed with reference to previously published data
Keywords :
annealing; ferromagnetic materials; gallium alloys; magnetomechanical effects; manganese alloys; martensitic transformations; nickel alloys; shape memory effects; twinning; NiMnGa; NiMnGa polycrystalline shape memory alloy; annealing; austenite to martensite transition; cyclic strain; ferromagnetic magneto-strained material; magnetic activation; magnetic properties; magnetically induced deformation; magnetomechanical characteristics; martensite twin; structural characteristics; Annealing; Cooling; Grain size; Magnetic field induced strain; Magnetic materials; Magnetic properties; Magnetostriction; Optical microscopy; Shape memory alloys; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
