Fabrication of Tb0.3Dy0.7Fe2/epoxy composites: Enhanced uniform magnetostrictive and mechanical properties using a dryprocess

To improve the uniformity of the magnetostrictive properties of Terfenol-D composites along the field direction, a dry method is developed in the present study. We examined the compaction pressure, particle volume fraction, particle size and composite configuration as factors that affected the magnetostrictive properties of the composites. The experimental results indicated that the magnetostrictive properties were improved with the increase of compaction pressure and particle volume fraction. In addition, larger average particle size was shown to result in more pronounced magnetostrictive properties. The particle alignment due to the orientation field is beneficial for the promotion of the magnetostrictive properties. The largest saturation magnetostriction and the maximum piezo-magnetic coefficient in the absence of a mechanical preload was obtained at 1005 ppm and 4.08 nm/A, respectively, for the aligned composite including a particle volume fraction of 77% and an average particle size of 210 μm.

Research Highlights
► Magnetostrictive composites were usually fabricated using a wet process. Since the settlement of the particles in the liquid polymers frequently occurred, the properties of the composites were inhomogeneous.
► The dry process developed in the present study was proved effective to fabricate magnetostrictive composites with uniform properties.
► The largest saturation magnetostriction and the maximum piezo-magnetic coefficient in the absence of a mechanical preload was obtained at 1005 ppm and 4.08 nm/A.