Novel magnetostrictive bimetal actuator using permendur

In this research permendur (49Fe-49Co-2V) and nickel were used to make a novel bimetal actuator. The actuator consists of a main body and core with energizing coil. The main body of actuator is made of annealed permendur with two magnetostrictive bimetal arms. The magnetostrictive bimetal technique is used to enhance the small displacement of permendur. Static and dynamic behaviors of the actuator are investigated at both, room temperature (RT) and 77 K. The actuator magnified the small displacement of permendur strip (1.8 μm) and large displacement of 9 and 5 μm are achieved at RT and 77 K, respectively when the coil was energized by ± 5 A current. Additionally, it is found that resonance frequency of actuator is 1240 Hz at 77 K and 1125 Hz at RT. Since the stiffness of actuator increases at 77 K, the displacement of actuator is reduced 33-50% when the coil is energized with different amplitudes at cryogenic environments.