Dynamic Magnetoelastic Properties of Epoxy-Bonded Terfenol-D Particulate Composite With a Preferred [112] Crystallographic Orientation.

The dynamic magnetoelastic properties of a [1121-oriented magnetostrictive composite comprising 0.49 volume fraction of needle- shaped, [112]-oriented Terfenol-D particles and Spurr epoxy were investigated as a function of magnetic bias field. These properties included elastic moduli (E3H and E3B), dynamic strain coefficient (d33), and magnetoelastic coupling coefficient (k33). A randomly oriented composite with 0.51 volume fraction of irregular-shaped, hall-milled Terfenol-D particles was also prepared and characterized for comparison. It was found that the [112] preferential particulate orientation increases non-180° domain-wall motion in the [112]. oriented composite, resulting in maximum negative-ΔE, d33, and k33 values of about 10%, 5.5 nm/A, and 0.34, respectively. These are the largest property values reported as yet for magnetostrictive particulate composites, being up to 67% larger than the randomly oriented composite and approach to 65% of the monolithic Terfenol-D. [ABSTRACT FROM AUTHOR]