Application of Ferromagnetic Shape-Memory Alloys in Power Generation Devices
Document Type
Conference Proceeding
Publication Date
2009
Abstract
By the inverse magnetoplastic (IMP) effect, twin boundaries in magnetic shape memory alloys (MSMA) can be reoriented by applying a mechanical stress. The result of this applied stress is a plastic deformation, as well as a change of magnetization. Used in conjunction with a coil, this changing magnetic field was harnessed in a power generation device to produce an electrical signal. With the application of a static bias magnetic field, as well as the removal of the applied stress, the twin boundaries reoriented themselves and restored the transducer’s initial geometry. This process was repeated via a periodic force applied with a variable speed motor, and was performed at room temperature and with compact permanent magnets. A Ni-Mn-Ga MSMA single crystal with approximate dimensions 5.4 x 3.9 x 3.1 mm3 served as magnetomechanical transducer. Actuation frequencies up to 2.25 Hz were applied resulting in an output voltage of up to 3.8 mV and a power output of up to 80 nW.
Publication Information
Carpenter, D.; Chmielus, Markus; Rothenbühler, A.; Schneider, R.; and Müllner, Peter. (2009). "Application of Ferromagnetic Shape-Memory Alloys in Power Generation Devices". Proceedings of the International Conference on Martensitic Transformations ‘ICOMAT’08’, Santa Fe, NM, June 29-July 5, 2008, 365-369.