Microstructure analysis of magnetostrictive composites

To understand the mechanism and the dependency between magnetostrictive composite performance and the orientation of the magnetic field, composites with 30% particles by volume were fabricated by distributing Terfenol-D particles in an unsaturated polyester resin matrix under various orientation fields. Their static and dynamic magnetostriction was tested without pre-stress at room temperature. The results indicate there is a positive correlation between magnetostrictive property and the orientation field. This study used scanning electron microscopy to observe the material longitudinal microstructures followed by a statistical analysis to evaluate the angle distribution between the major axis of the particles and the orientation field in different composites. In summary, this method can be used to elucidate the microstructure of the composites directly: the higher the orientation field, the closer the microstructure to 1-3 structure. As a result, the static and dynamic magnetostriction is increased as the orientation field increases.