Comparison of the Response of Shape Memory Alloy Actuators Using Air-Cooling and Water-Cooling

摘要

Titanium-Nickel (Ti-Ni) alloy specimens with induced shape memory were subjected to various single step current inputs under water-cooled, natural convective air-cooling, and stagnant air-cooling conditions to determine cooling time constants and subsequent delay time for successive actuation. Power input, specimen recovery and reextension displacement with various loads applied to the coil shaped actuator, and temperature distributions along the coil were recorded as functions of time. Results suggested that liquid cooling was a viable method for increased actuator response time. A brief review of the phase transformations that give rise to the shape memory effect is included.