N. Kutsuzawa

Repeatable Shape Memory Effect and Mechanical Resonance of TiNiCu-Coated Magnetic Ribbons

This paper describes a new bimorph-type actuator composed of a shape-memory-alloy coated magnetic ribbon. A high magnetostrictive amorphous ribbon (Metglas 2605SC, 37 mm×6 mm×0.025 mm) coated with a 1.0 μm thick sputter-deposited Ti48.5Ni33.5Cu18 film exhibited a repeatable shape memory effect in the temperature range from 10 °C to 70 °C; reverse martensitic transformation upon heating bent the ribbon and martensitic transformation upon cooling flattened it. Simultaneous application of AC and DC magnetic fields excited the longitudinal mechanical vibration which can be monitored wirelessly with a pickup coil. The resonance frequency was proportional to the displacement of the ribbon within an accuracy of 0.76 %. Consequently, it is confirmed that a TiNiCu-coated magnetic ribbon actuator with high positioning resolution can be realized by monitoring its resonance frequency and feeding back it to the heating and/or cooling power control algorithms.