The microstructure, preferred orientation and magnetostriction of Y doped Fe-Ga magnetostrictive composite materials

Abstract This paper presents the production process and the results of investigations into the microstructure and magnetic properties of (Fe 83 Ga 17 ) 100−x Y x (x = 0, 3) composite materials. The manufactured composite materials consist of powdered (Fe 83 Ga 17 ) 100−x Y x (x = 0, 3) alloy particles of two different size distributions (50 and 75 μm), bonded in an epoxy-binder with a weight ratio of 3:1, then oriented under a constant applied magnetic field with 1.0 T. The microstructure and magnetic properties of as-cast alloys, unoriented and oriented composite materials were examined by X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), vibrating sample magnetometer (VSM) and strain gauge method. The powder particle shape of composite material was observed by optical microscopy (OM). The highest value of magnetostriction (~120 ppm) has been found in the oriented (Fe 83 Ga 17 ) 97 Y 3 composite materials with 75 μm particle size, more than 4 times that of unoriented Fe 83 Ga 17 composite materials. The enhancement of magnetostriction is source from the preferred orientation of direction induced by grain slip and rotation during orientation under applied magnetic field, the rotation and arrangement of domains by magnetization and the decrease of Young’s modulus caused by grain refinement.