Damping Capacities of Ni-Ga-Fe Ferromagnetic Shape Memory Alloy

The correlation between damping capacities of the Ni-Ga-Fe ferromagnetic shape memory alloys (FSMA), strain amplitude, frequency and temperature was investigated by using low frequency torsion pendulum on the basis of phase transition temperature and microstructure analysis. The results show that the martensite transformation of the Ni52Ga27Fe21 alloy was thermoelastic phase transition, there was lath martersite at room temperature. Its start temperatures of thermoelastic martensitic transformation and the reverse transformation were 69.3 and 93.6 ℃, and finish temperatures were 60.2 and 102.6 ℃, respectively. Damping properties of the Ni-Ga-Fe alloy at room temperature was determined by frequency. Damping of the Ni52Ga27Fe21 alloy was type of damping resonance, while that of Ni53Ga27Fe20 alloy and Ni50Ga27Fe23 alloy was anelasticity. The Ni52Ga27Fe21 alloy exhibited high damping capacities with a maximum damping value of 0.016 when martensitic and austenite phases coexisted.