Dynamic magneto-mechanical properties of epoxy-bonded Terfenol-D composites

The dependence of the dynamic magneto-mechanical properties of epoxy-bonded Terfenol on the composition parameters of particle size (P-s) and volume fraction of Terfenol (V-f) is investigated as functions of bias field (H) and high frequency (f), Samples were prepared with powder in five? size ranges between 106 and 710 mu m using three volume fractions. The dynamic strain coefficient (d) and magneto-mechanical coupling coefficient (k) were found to be independent of P-s and V-f while the dynamic relative permeability (mu(r)) was proportional to V-f. d showed less variation with H up to 100 kA m(-1), than for bulk Terfenol with d also exhibiting a flat response with frequency, up to 20 kHz. The frequency dependence of mu(r), up to 200 kMz, was also flat apart from the occurrence, at similar to 15 KHz, of a fundamental shape resonance which was also experienced by d, Classical eddy current theory was used to Model the behaviour of mu(r) with f and it was found that experiment and theory were qualitatively similar, (C) 2000 Elsevier Science S.A. All rights reserved.