Dynamic magnetomechanical properties of Terfenol-D/epoxy pseudo 1-3 composites

Terfenol-D/epoxy pseudo 1-3 composites were fabricated by embedding and aligning Terfenol-D particles with a size distribution of 10-300 mu m in a passive epoxy matrix using six Terfenol-D volume fractions (v(f)) ranging from 0.22 to 0.72. The dependence of the dynamic relative permeability (mu(T)(r33)), elastic modulus (E-3(H)), and dynamic strain coefficient (d(33)) on v(f) was investigated as a function of magnetic bias field (H-Bias). The HBias response data showed that the built-in non-180 degrees domain states related to residual compressive stresses in the composites result in a significant decrease in mu(T)(r33) for H-Bias < 40 kA/m in addition to a minimization of E-3(H) and a maximization of d(33) near H-Bias=40 kA/m. The v(f) dependent data revealed that mu(T)(r33) is almost a linear function of v(f); E H increases gradually with increasing v(f); and d(33) increases initially, leveling 3 off for vf > 0.5. The present study provides a useful guide to optimize the composite properties for transducer design. (c) 2005 American Institute of Physics.