MAGNETOMECHANICAL BEHAVIORS OF GIANT MAGNETOSTRICTIVE MATERIALS

The Laves phase alloy Tb-Dy-Fe,commercially known as Terfenol-D,exhibits the giant room-temperature magnetostriction at moderate fied strength of a few kOe due to its combination of high magnetostriction and low magnetocrystalline anisotropic energy.Thus,this pseudobinary rare earth iron compound has rolund quite a number of applications such as in mag-netomecnts of agnetostriction and magnetixation at various fixed conpressive pre-stresses applied in the axial direction for Tb0.3Dy0.7Fe1.95 samples are presented .The results show that the magnetostriction increases with increasing compressive stressuntil it reaches 1742×106 un-der 25 Mpa,so does the coercive magnetic field. And the hysteresis loop area for magnetication and magnetostriction increases with the incerment of applied aomperssive stresses.But the maximum magnetic susceptibility x(dM/dH)is obtained under zero stress field and the strain derivative dλ/bH increases to the highest amplitude of 0.039×10-6A-1m at a stress level of 5MPa.In the strain versus magnetixation intensity curve,the iniial flat stage mainly consisting of a 180° domain wall motion becomes shorter with increasing stress.It means more initial domains are driven to the transversal direction under the compressive stress before magnetixation, which is consistent with improvement of the magnetostriction.