Delay Effect for Pulsed Excitation of Actuator Based on Rapidly Quenched Ti2NiCu Alloy with Thermoelastic Martensitic Transformation

Resumo

The pulse response of the actuator based on rapidly quenched Ti₂NiCu alloy with a thermoelastic martensitic transformation and the shape memory effect is studied experimentally. The mechanical response of the actuator cooled by running water is preserved when the duration of the excitation (activating) electric pulses decreases to 2 ms. High-speed activation is accompanied by a delay in the mechanical pulse in comparison with the excitation electric pulse. The minimum duration of the mechanical pulse, taking into account the delay, was 8 ms, which corresponds to a frequency of 125 Hz with periodic activation. Estimates show that the delay time includes both the time of mechanical inertia and the time of thermal inertia associated with heat transfer. The possible limitation of the rate of activation due to kinetic phenomena during the thermoelastic martensitic transition is evaluated.