Effect of Magnetic Field on the Damping Capability of Ni52.5Mn23.7Ga23.8/Polymer Composites

The effect of the orientation magnetic field (Hori) and the magnetic field during the damping test (Htest) on the damping capability of 30 vol%Ni52.5Mn23.7Ga23.8/epoxy resin (EP) composites was investigated. Hori did not affect the phase temperatures of Ni52.5Mn23.7Ga23.8/EP composites, but these single-crystal Ni52.5Mn23.7Ga23.8 powders were oriented along their easy magnetization axis (c axis) due to Hori. Damping properties of all Ni52.5Mn23.7Ga23.8/EP composites were much better than that of pure EP when the testing temperature was below the glass transition temperature of EP. Compared with the sample without magnetic field, the internal friction peak of Ni52.5Mn23.7Ga23.8/EP composite was increased about 23, 14, 0% to that with Hori and Htest, with Htest or with Hori, respectively. Htest significantly enhanced the damping capability of Ni52.5Mn23.7Ga23.8/EP because the severe twin-boundary motion was generated from the synergistic effect between the magnetic field and oscillation force. Hori combined with Htest will improve the damping capability of Ni52.5Mn23.7Ga23.8/EP composite, while showing little effect without Htest.