Magnetomechanical properties of terfenol-D 2-2 composites with internal field biasing

Two self-biased Terfenol-D 2-2 composites have been produced with laminations perpendicular to (112) and an internal magnetic field along [112]. The characteristic frequency of a sample of dimensions 2.5 x 7.0 x 10.0 mm has been increased to 53 kHz compared to 0.2 kHz for the bulk material by increasing the resistivity to 1 x 10(-5) Omega m. The static strain along [(11) over bar1] was found to be 752 and 647 ppm for the two samples when [(11) over bar1] was parallel to the externally applied field H-appl.When [(11) over bar (\)1] was perpendicular to H-appl the internal field H-int must be added to H-appl thereby giving an asymmetrical strain versus H-appl curve. Eddy currents have been reduced by the introduction of a thin insulating layer, the mechanical properties of which critically control the magnetoelastic performance of the composite.