EPJ Web of Conferences
Volume 6, 2010ICEM 14 – 14th International Conference on Experimental Mechanics
|Number of page(s)||1|
|Section||Shape Memory Alloys|
|Published online||10 June 2010|
Magnetic field induced strain assisted by stress in Ni-Fe-GaCo single crystals
Dept. de Física, Univ. de les Illes Balears, Palma de Mallorca , Spain
* Institute of Metallurgy and Material Science of the Polish Academy of Sciences, Kraków, Poland
** Siberian Physical-Technical Institute, Tomsk, Russia
Ferromagnetic shape memory alloys (FSMA) have the possibility to induced a strain by applying a magnetic field. The main advantage of the FSMA is that the strain cycling frequency is two orders of magnitude higher than coventional shape memory alloys. The best alloy showing this effect is the Ni-Mn-Ga system, with a high mobility of its martensite variants and high magnetocrystalline anisotropy constant. Nevertheless, due to the high brittleness of this alloy, other systems (Ni-Fe-Ga, Co-Ni-Al, Co-Ni-Ga, ...) are being investigated as an alternative to Ni-Mn-Ga.
In the current work, Ni-Fe-Ga-Co single crystals have been studied. In spite of the formation of L10 martensite (low mobility of the variants), the  crystals exhibited magnetic-field-induced strains (in tension) larger than 2%, under an assisting tensile stress around 16 MPa and fields below 15 kOe. In martensitic samples previously compressed, application of a constant tensile stress along the same axis together with a perpendicular magnetic field produces the elongation of the sample by variant reorientation, as one of the variants rotates its c axis from the field direction to the stress-axis direction. An estimated magnetostress of ~0.8 MPa is in good agreement with the theoretical value given by the ratio of magnetocrystalline anisotropy constant and twinning shear.
Key words: Ferromagnetic shape memory alloys / magnetic-field-induced strain
© Owned by the authors, published by EDP Sciences, 2010
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.