MAGNETOMECHANICAL DAMPING IN GIANT MAGNETOSTRICTION ALLOYS

Magnetomechanical damping in the giant magnetostriction material Terfe nol-D has been investigated by quasi-static stress-strain measurements and modeled theoretically. The damping capacity is a strong function of applied stress amplitude, increasing to a maximum at some finite st ress and then decreasing slowly at still larger applied stresses. Maxi mum damping capacities greater than 1.0 were observed for the lowest m agnetic bias fields and prestresses at applied stress amplitudes of 4 MPa. Both the qualitative behavior of the damping and its magnitude ar e successfully described by a model of abrupt magnetization jumps with in individual domains driven by the applied stress.