The magnetostriction and dynamic magnetomechanical coupling properties of the epoxy-filled composites that were manufactured by replacing the eutectic phase with the epoxy were investigated as a function of the bias field and the RFe2 volume fraction. The composites were prepared with RFe2 volume fractions from 0.34 to 0.88 and were compared with as-grown crystals. The filled composites exhibit a greater maximum strain than do as-grown crystals, strongly dependent on the RFe2 volume fraction. Furthermore, the dynamic magnetomechanical coupling coefficient of the filled composite, which was measured by resonance analysis, shows a maximum value of 0.45 at 47.2 kA/m, the highest known value for [1-3] composite Terfenol-D and strongly dependent on the volume fraction of RFe2. (C) 2005 American Institute of Physics.