Actuation Frequency Dependent Power Generation Via Inverse Magnetoplasticity
Dr. Peter Mullner
Inverse magnetoplasticity is the variation of the macroscopic magnetization of a magnetic shape-memory alloy induced by plastic deformation. This effect was utilized to induce a voltage in a coil, which was placed around a single crystalline Ni-Mn-Ga transducer. The transducer was cyclically deformed within a static magnetic bias field of 0.91 T and the time-dependent magnetization was recorded. The actuation frequency was varied between 0.5 and 40 Hz. The induced voltage depends linearly on the actuation rate. At the frequency of 20 Hz, an output voltage of (unknown, will calculate soon) V was recorded, corresponding to a power output of (unknown also) W. The efficiency of the transducer depends on the mechanical hysteresis and may, thus, be drastically improved by a reduction of the twinning stress. At low frequency, eddy currents and self-induction are insignificant and the efficiency to convert mechanical to electrical power increases linearly with frequency.