Dynamic magnetomechanical properties of epoxy-bonded (Tb 0.3Dy 0.7) 1– xPr xFe 1.55 (0 ≤ x ≤ 0.4) pseudo-1–3 magnetostrictive composites

Abstract

Pseudo-1–3 magnetostrictive composites of 0.5 volume fraction are fabricated by embedding and aligning stabilizer (B, Co)-free, light rare earth (Pr)-contained magnetostrictive (Tb 0.3Dy 0.7) 1– x Pr x Fe 1.55 (0 ≤ x ≤ 0.4) particles with a size distribution of 10–300 μm in a passive epoxy matrix. The dynamic magnetomechanical properties of the composites with different Pr content x are investigated as a function of both bias field (=10–200 kA/m) and frequency (=25 Hz–70 kHz). The composites show similar qualitative trends in properties for all x with no frequency dispersion effect except for the resonance range. The dynamic relative permeability μ r 33 T demonstrates a decreasing trend with increasing x for the whole range of bias field due to the weakening of saturation magnetization with increasing Pr content. The two elastic moduli E 3 H and E 3 B , which result in negative-Δ E with maximum dynamic strain coefficient d 33 and dynamic magnetomechanical coupling coefficient k 33 near 140 kA/m bias in all composites, decrease with increasing x for all biases owing to the increasing compliance contribution from Pr. The (Tb 0.3Dy 0.7) 0.75Pr 0.25Fe 1.55 composite exhibits the largest d 33 and k 33 at 140 kA/m bias as a result of the compensation for magnetocrystalline anisotropy.