Effect of Ageing on Damping Capacities of Ni₅₃Ga₂₇Fe₁₅Co₅ Ferromagnetic Shape Memory Alloy

The effect of ageing on damping capacities of the Ni53Ga27Fe15Co5 ferromagnetic shape memory alloy (FSMA) was investigated by using low frequency torsion pendulum.The results show that when the strain amplitude was less than 4.0×10-5,the damping capacities of the Ni53Ga27Fe15Co5 alloy were determined by frequency,when the strain amplitude was more than 4.0×10-5 those were controlled by strain amplitude before and after ageing.Martensitic transformation temperature decreased,the converse transformation temperature increased and latent heat of phase transition was reduced of the Ni53Ga27Fe15Co5 alloy after ageing at 700 ℃ for 4 h,the damping capacities of the ageing alloy were twice larger than those of the as-cast alloy.The maximum damping capacities reached 0.139.