Vibration Damping in Ni-Mn-Ga/PU Polymer Composites

Abstract

Ni-Mn-Ga ferromagnetic shape memory alloy is mainly focused from the class of active materials be- cause of their large field induced strain. They exhibit strains up to 10% with respect to the applied magnetic field through twin boundary motion in the martensite phase. This is the main advantage of this material which could over- come the frequency bound of the conventional shape memory alloys. Ni-Mn-Ga FSMAs show much large field-induced strain at low frequencies than do other active materials such as piezoelectrics or magentostrictors. When the twin boundaries are moving back and forth, the hysteresis connected to this motion provides vibration damping part of the damping bases on the magnetoelastic properties of the materials. The excellent damping properties of Ni-Mn-Ga alloys are bonded with the correct polymer matrix makes possible to develop new damping materials which are effective, less expensive and easier to form than bulk Ni-Mn-Ga. They can suit well to be used in the correct site for effective damp- ing in special engineering applications. In this article, we have prepared the composite materials and reported its basic characterization and the damping behavior of composite materials.