MAGNETOSTRICTION, ELASTIC-MODULI, AND COUPLING FACTORS OF COMPOSITE TERFENOL-D

Recently it was discovered that composites of Terfenol-D alloys with a n insulating binder produce very large magnetostrictions. Resistivitie s of these composites reach high values, making them attractive for hi gh-frequency applications which require small eddy current losses. In this paper the magnetostriction, magnetization, and Young's moduli mea surements made under constant magnetic field conditions and under cons tant flux conditions are reported. From these measurements, magnetomec hanical coupling factors are calculated. The properties are compared t o those of ordinary metallic Terfenol-D and nickel. Two different type s of composites were investigated. In the first type the composite has an isotropic structure and in the second type, anisotropic. It is sho wn that the anisotropic type is more desirable since it possesses both higher magnetostriction and higher coupling factors. It is also clear ly shown that the magnetization process for the anisotropic type can b e explained by a 180-degrees domain wall motion followed by a magnetiz ation rotation.